1998 Fall Meeting Special Sessions
UNION Section
ATMOSPHERIC SCIENCES Section
GEODESY Section
GEOMAGNETISM AND PALEOMAGNETISM Section
HYDROLOGY Section
OCEAN SCIENCES Section
PLANETOLOGY Section
SEISMOLOGY Section
SPACE PHYSICS AND AERONOMY Section
SPA - AERONOMY Subsection
SPA - HELIOSPHERIC PHYSICS Subsection
SPA - MAGNETOSPHERIC PHYSICS Subsection
TECTONOPHYSICS Section
VOLCANOLOGY, GEOCHEMISTRY, AND PETROLOGY Section
Union (U)
If you are submitting an abstract to a special session, you must also
send a copy of your abstract to the primary special session convener
(first listed or marked with a *). Sending a copy of your abstract to
a convener, however, does not constitute sending it to AGU. Abstracts
MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
U01 Frontiers of Nonlinear Geophysics -- 1998 (Joint with SM)
This session will focus on recent advances in understanding of nonlinear dynamical geophysical systems. Many of the most important space-time features of these systems are emergent and cannot be understood from a purely reductionist viewpoint. Topics of interest will include: fractals and scaling, chaos, nonlinear waves, solitons, critical phenomena and nucleation, time series prediction, and numerical simulations of nonlinear phenomena.
Sponsored by the AGU Technical Committee on Nonlinear Geophysics and the AGU Technical Committee on Mineral Physics.
Conveners: John Rundle, Colorado Center for Chaos and Complexity, CIRES CB 216, University of Colorado, Boulder, CO 80309 USA, Tel: +1-303-492-5642, Fax: +1-303-492-5070 E-mail: rundle@fractal.colorado.edu; and Raymond Jeanloz, Department of Geology and Geophysics, 301 McCone Hall, University of California, Berkeley, CA 94720-4767 USA, Tel: +1-510-642-3993, Fax: +1-510-642-9980, E-mail: jeanloz@uclink.berkeley.edu
U02 Research Opportunities in the Solid Earth Sciences: A 10-Year Vision
This session is designed to assist the National Science Foundation (NSF) and the National Research Council (NRC) in developing a long-term vision for basic research in the solid earth sciences, which will form the basis of a new long-range plan for the NSF's Earth Sciences Division.
Conveners: J. Freeman Gilbert, Board on Earth Sciences and Resources, National Research Council, National Academy of Sciences, 2101 Constitution Ave., NW, HA 372, Washington, DC 20418 USA, Tel: +1-202-334-2744, Fax: +1-202-334-1377, E-mail: fgilbert@ucsd.edu; Ian MacGregor, Earth Sciences Division, National Science Foundation, 4201 Wilson Blvd., Rm. 785, Arlington, VA 22230 USA, Tel: +1-703-306-1550, Fax: +1-703-306-0382, E-mail: imacgreg@nsf.gov; and Anthony R. de Souza, Board on Earth Sciences and Resources, National Research Council, National Academy of Sciences, 2101 Constitution Ave., NW, HA 372, Washington, DC 20418 USA, Tel: +1-202-334-2744, Fax: +1-202-334-1377, E-mail: adesouza@nas.edu
U03 Accretion of Extraterrestrial Matter Throughout Earth's History
Accretion of extraterrestrial (ET) matter has influenced the biological, chemical, and physical evolution of Earth. Recent studies indicate that records of the terrestrial accretion history can be obtained from ice cores and marine sediments, complementing existing long-term cratering records. Contributions to the terrestrial accretion record based on chemical tracers in ice and sediments, collection of ET particles, detection of ET matter in space, as well as cratering records are welcomed.
Conveners: Birger Schmitz, Deparment of Marine Geology, Earth Sciences Center, Box 460, University of Göteborg, S-405 30 Göteborg, Sweden, Tel: +46-31-773-4902, Fax: +46-31-773-4903, E-mail: birger@gvc.gu.se; and Bernhard Peucker-Ehrenbrink, Department of Marine Chemistry and Geochemistry, MS 25, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1541 USA, Tel: +1-508-289-2518, Fax: +1-508-457-2193, E-mail: behrenbrink@whoi.edu
U04 Plate Tectonics After 30 Years
Thirty years have passed since plate tectonics became generally accepted in the scientific community. This session hopes to frame a serious inquiry into the origins, development, and long-range impact of the theory. Participants include scientists involved in the seminal discoveries that led to the plate tectonics revolution and historians who have studied its historical context and development.
Co-sponsored by the AGU History of Geophysics Committee and the History of Earth Science Society.
Conveners: Homer Le Grand, Faculty of Arts, University of Melbourne, Parkville, Victoria 3052, Australia, Tel: +61-3-344-7570, Fax: +61-3-344-7959, E-mail: homer@ariel.ucs.unimelb.edu.au; Kenneth Taylor, Department of the History of Science, Physical Sciences Building 623, University of Oklahoma, Norman, OK 73019-0315 USA, Tel: +1-405-325-5416, Fax: +1-405-325-2363, E-mail: ktaylor@uoknor.edu; Naomi Oreskes, Department of History 0104, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0104 USA, Tel: +1-619-534-1996, Fax: +1-619-534-7283, E-mail: noreskes@ucsd.edu; and Edward Cliver, Phillips Laboratory GPSG, 29 Randolph Road, Hanscom AFB, MA 01731-3010 USA, Tel: +1-781-377-3975, Fax: +1-781-377-3160, E-mail: cliver@plh.af.mil
U05 Imaging Geodesy
Geodetic imaging, using such techniques as interferometric radar, dense GPS arrays, and laser altimetry, identifies crustal deformation with specific locations, structures, and processes both geographically and at depth as well as in time. Spatially dense, two-dimensional images of deformation quantify strain accumulations with time and can address silent or slow seismic activity. Recent work using imaging geodetic techniques has analyzed subsurface fluid flow, volcanic dike intrusion, and local tectonic creep.
Conveners: Howard A. Zebker, Department of Geophysics, 360 Mitchell, Stanford University, Stanford, CA 94305-2215 USA, Tel: +1-650-723-8067, Fax: +1-650-725-7344, E-mail: zebker@stanford.edu; Jean-Bernard Minster, Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0225 USA, Tel: +1-619-534-5650, Fax: +1-619-534-2902, E-mail: jbminster@ucsd.edu; and Paul Rosen, Radar Science and Engineering Section 334, MS 300-235, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA, E-mail: par@parsar.jpl.nasa.gov
U06 Life in Extreme Environments
Research on life in extreme environments provides knowledge fundamental to understanding the processes that led to the formation and adaptation of life on Earth and whether and how life may thrive on other planets. Recent discoveries in diverse disciplines provide spectacular opportunities for research progress in this area that combines elements of volcanology, microbiology, chemistry, paleobiology, polar sciences, biotechnology, oceanography, planetary sciences, and astrobiology.
Conveners: G. M. Purdy, Division of Ocean Sciences, National Science Foundation, 4201 Wilson Blvd, Arlington, VA 22230 USA, Tel: +1-703-306-1580, Fax: +1-703-306-0390, E-mail: mpurdy@nsf.gov; and M. A. Meyer, Code SR, NASA Headquarters, Washington, DC 20546 USA, Tel: +1-202-358-0307, Fax: +1-202-358-3097, E-mail: mmeyer@mail.hq.nasa.gov
U07 RIDGE, Approaching a Decade of Multidisciplinary Science
For almost a decade, the RIDGE program has fostered inter-disciplinary studies of the global mid-ocean ridge system, from the Earth's deep mantle, through the oceanic crust to the volcanic, hydrothermal and biological systems above and beneath the seafloor. An oral session (mostly invited) will review a decade of progress in mid-ocean ridge science, highlighting the major achievements in mid-ocean ridge science, and briefly discussing future directions. Posters highlighting any aspect of mid-ocean ridge research are especially requested.
Conveners: David M. Christie, College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331-5503 USA, Tel: +1-541-737-5205, Fax: +1-541-737-2064, E-mail: dchristie@oce.orst.edu; Robert S. Detrick, Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA, Tel: +1-508-289-3335, Fax: +1-508-457-2150, E-mail: bobd@copper.whoi.edu or rdetrick@whoi.edu; and Lauren S. Mullineaux, Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA, Tel: +1-508-289-2898, Fax: +1-508-457-2134, E-mail: lmullineaux@whoi.edu
U08 Deep Earth Observations From the Seafloor
Major new advances in our understanding of the structure, composition, and state of the mantle; lithospheric deformation, fluid flow, and chemical budgets; dynamo and core dynamics; plate tectonics processes; the mechanisms by which life is supported without sunlight; and the ocean's role in climate change require observations on the seafloor for durations spanning years to decades. Seafloor fiber-optic cables, and cellular communications satellite networks, provide a new capability to implement and interact with a global network of multidisciplinary real-time submarine observatories. This session focuses on the scientific challenges, opportunities, and facilities involved in launching this new era of inquiry on and beneath the largely uninstrumented part of our planet -- the seafloor. What groundbreaking science could you do if you had access to real-time data from your deep-sea instruments, external power, and
intervention capability near the seafloor?
Sponsored by the AGU Committee on the Study of the Earth's Interior (SEDI)
Conveners: Adam Schultz, Institute of Theoretical Geophysics, University of Cambridge, Downing Street, Cambridge CB2 3EQ, United Kingdom, Tel: +44-1223-330-270, Fax: +44-1223-333-450, E-mail: adam@esc.cam.ac.uk; John Orcutt, IGPP (0225), Scripps Institution of Oceanography, La Jolla, CA 92093 USA, Tel: +1-619-534-2887, Fax: +1-619-534-2902, E-mail: jorcutt@igpp.ucsd.edu; Alan Chave, Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050 USA, Tel: +1-508-457-2000, Fax: +1-508-457-2150, E-mail: achave@whoi.edu; John Delaney, School of Oceangraphy, Box 357940, University of Washington, Seattle, WA 98195-7940 USA, Tel: +1-206-543-4830, Fax: +1-206-543-0275, E-mail: jdelaney@u.washington.edu; Barbara Romanowicz, Department of Geology and Geophysics, University of California, Berkeley, 301 McCone, Berkeley, CA 94720-4767 USA, Tel: +1-510-643-5690, Fax: +1-510-643-5811, E-mail: barbara@seismo.berkeley.edu; and Keir Becker, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149-1098 USA, Tel: +1-305-361-4661, Fax: +1-305-361-4711, E-mail: kbecker@rsmas.miami.edu
U09 Oceanic Islands and Global Environmental Change
Oceanic islands provide unique insights into several aspects of global environmental change by virtue of their isolation and on the basis of their sensitive landscapes. Indeed, Darwin and Russell in the nineteenth century made use of oceanic islands to develop their theories of biogeography. This session seeks to bring together a diverse suite of scientists interested in oceanic island environments. Topics for discussion could include paleoclimate, sea level fluctuations, biodiversity patterns, ice cover variability, episodic volcanism, and atoll sensitivity to extreme weather patterns. The aim is to promote new perspectives on global environmental change using oceanic island observations.
Sponsored by the AGU Committee on Global Environmental Change
Conveners: Jim Garvin, NASA Goddard Space Flight Center, Geodynamics, Mail Code 921, Building 22, Room 132, Greenbelt, MD 20771 USA, Tel: +1-301-286-6565, Fax: +1-301-286-1616; E-mail: garvin@denali.gsfc.nasa.gov
U10 New Evidence for Rapid Climate Change From Ocean Drilling
Abundant evidence for rapid and dramatic climatic changes in the geologic past has challenged our understanding of the Earth's climate system and has motivated research into the causes and effects of rapid climate fluctuations. Marking the thirtieth anniversary of scientific ocean drilling, this session will focus on recent contributions of the Ocean Drilling Program to understanding natural climate variability and the causes of rapid climate change. Papers will include studies of high-resolution climate records recovered from anoxic marine basins, sediment drifts, and continental margins and their relations to ice core records, studies of abrupt climatic events (e.g., changes following the K/T boundary; warming at the Paleocene/Eocene boundary), and studies of the consequences of the opening and closing of ocean gateways. The session will highlight the significant advances made possible by ocean drilling in understanding climate and environmental change and will look to new research directions in the future.
Conveners: Larry C. Peterson, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 USA, Tel: +1-305-361-4692, Fax: +1-305-361-4632; E-mail: lpeterson@rsmas.miami.edu; and Eystein Jansen, Department of Geology, University of Bergen, Allegaten 41, N-5007 Bergen, Norway, Tel: +47-55-583-491, Fax: +47-55-589-416 x17, E-mail: eystein.jansen@geol.uib.no
U11 Climatic Effects of a Changing Sun
Two decades of measurements of both electromagnetic and particle fluxes from the Sun have established conclusively that it exhibits changes on timescales from minutes to decades. Since solar energy is one of the major natural driving forces of the terrestrial atmospheric and climate system, the effect of solar variability on climate change is critical for a wider understanding of the climate response to other influences including increasing greenhouse gas concentrations.
Conveners: Linton Floyd, Code 7660, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 USA, Tel: +1-202-767-2258, Fax: +1-202-767-5636, E-mail: floyd@susim.nrl.navy.mil; Judit Pap, Department of Physics and Astronomy, University of California, Los Angeles, Box 951562, 405 Hilgard Avenue, Los Angeles, CA 90096-1562 USA, Tel: +1-310-825-1289, Fax: +1-310-206-2096, E-mail: pap@astro.ucla.edu; Claus Frohlich, Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, PMOD/WRC, Dorfstrasse 33, CH-7260 Davos Dorf, Switzerland, Tel: (general) +41-81-417-5111 (direct) +41-81-417-5136; Fax: +41-81-417-5100; E-mail: cfrohlich@pmodwrc.ch; and Gerald North, Department of Meteorology, Texas A&M University, College Station, TX 77843 USA, Tel: +1-409-845-7679, Fax: +1-409-862-4466, E-mail: northead@ariel.met.tamu.edu
U12 1997-98 El Niño-La Niña Effects on the Earth System as Seen by SeaWiFS
This session will focus on applications of measurements from the Sea Wide-Field-of-Viewing Sensor (SeaWiFS) for studying marine, terrestrial, and atmospheric systems with particular emphasis on phenomena associated with the 1997-1998 El Niño/La Niña. SeaWiFS began operational global data collection in mid-September 1997 and captured the final phase of the 1997 El Niño and the transition to La Niña in 1998. Papers that illustrate the use of SeaWiFS observations to study changes in clouds, dust, smoke, and ice, as well as marine primary production that resulted from 1997 to 1998 El Niño-La Niña event are encouraged. The session will highlight multidisciplinary applications of SeaWiFS observations and to provide a framework for using satellite-derived observations for studying global effects of coupled ocean-atmosphere processes.
Conveners: Richard Barber, NSOE Marine Laboratory, Duke University, 135 Duke Marine Lab Road, Beaufort, NC 28516-9721 USA, Tel: +1-919-504-7578, Fax: +1-919-504-7648, E-mail: rbarber@duke.edu; and Compton (Jim) Tucker, NASA Goddard Space Flight Center, Mail Code 923, Greenbelt, MD 30771 USA, Tel: +1-301-286-7122, Fax: +1-301-286-1775, E-mail: compton@kratmos.gsfc.nasa.gov
U13 The 1997-1998 El Niño: Observations and Predictions
The 1997-1998 El Niño was a truly important meteorological event that had significant consequences for the global environment. Advances in observational and modeling capability have allowed this El Niño event to become more clearly characterized than any previous one, and the new predictive capability allowed for improved estimates of its effects throughout its evolution. This session will review the major atmospheric and oceanic impacts that the El Niño event had on the global environment, the role that new observing and modeling capability played in its description, and the status of predictions developed for use by the meteorological community.
Conveners: Ants Leetmaa, NOAA/NCEP, Washington, DC 20233 USA, Tel: +1-301-763-8396, Fax: +1-301-763-8125, E-mail: ants.leetmaa@noaa.gov; and Tony Busalacchi, NASA Goddard Space Flight Center, Mail Code 970, Greenbelt, MD 20771 USA, Tel: +1-301-286-6171 Fax: +1-301-286-1761, E-mail: antonio.j.busalacchi.1@gsfc.nasa.gov
U14 Putting Science to Work: Economic and Policy Value of El Niño Prediction
The El Niño of 1997-1998 was predicted months in advance. This session will investigate how those predictions were put to use by policy makers, what the economic and policy consequences were, and how economic value can be calculated for El Niño predictions. We invite abstracts from scientists who worked with policy makers to formulate strategies; from policy makers who executed such policies; and from economists and policy scientists who have studied value of information related to El Niño, the economy, and decision theory.
Sponsored by the AGU Committee on Public Affairs (COPA)
Conveners: Margaret Goud Collins, WHOI Marine Policy Center and American Academy of Arts and Sciences, MS 41, Woods Hole, MA 02543 USA, Tel: +1-508-289-2373, Fax: +1-508-457-2184, E-mail: mcollins@whoi.edu; Greg van der Vink, IRIS, 1200 New York Ave, NW, Suite 800, Washington, DC 20005 USA, Tel: +1-202-682-2220, Fax: +1-202-682-2444, E-mail: gvdv@iris.edu; and Margo Kingston, U.S. Geological Survey, MS 910, Reston, VA 20192 USA, Tel: +1-703-648-6369, Fax: +1-703-648-6683, E-mail: mkingsto@usgs.gov
U15 Dealing With Natural Disasters
Through a forum, this session will debate such questions as: What constitutes a natural hazard? What impact do natural hazards have on the development of the United States and other countries? How will changes in sea level, global warming trends, and El Nino cycles affect the frequency and severity of natural hazards? To what extent are zoning laws, building codes, insurance programs, and disaster assistance programs encouraging responsible land use? How can we reduce our vulnerability to natural hazards?
Sponsored by the AGU Committee on Public Affairs (COPA)
Conveners: Greg van der Vink, IRIS, 1200 New York Ave, NW, Suite 800, Washington, D.C. 20005 USA, Tel: +1-202-682-2220, Fax: +1-202-682-2444, E-mail: gvdv@iris.edu; Margaret Goud Collins, WHOI Marine Policy Center and American Academy of Arts and Sciences, MS 41, Woods Hole, MA 02543 USA, Tel: +1-508-289-2373, Fax: +1-508-457-2184, E-mail: mcollins@whoi.edu; and Margo Kingston, US Geological Survey, MS 910, Reston, VA 20192 USA, Tel: +1-703-648-6369, Fax: +1-703-648-6683, E-mail: mkingsto@usgs.gov
U16 20 Year Anniversary of Nimbus 7
The Nimbus 7 satellite, launched in October 1978, was an important event in the history of Earth science because it facilitated multiyear global observations in several areas of Earth science. Nine instruments constituted the Nimbus 7 payload; collectively, these made major contributions in several areas of atmospheric and ocean science. In addition to providing in many cases the first global space-based measurements of environmental parameters and critical long-term (› 10 years) observations in some areas, Nimbus 7 provided a demonstration of space-based measurement techniques that served as the basis for more recent observations. This session will review the contributions of Nimbus 7 to different areas of Earth Science and as a progenitor of more modern
instruments, as well as the scientific lessons gained from comparing observations made from the Nimbus 7 time period to those made today.
Conveners: Jack A. Kaye, NASA Headquarters, Mail Code YS, Washington, DC 20546 USA, Tel: +1-202-358-0757, Fax: +1-202-358-2770, E-mail: jack.kaye@hq.nasa.gov; and Richard D. McPeters, NASA Goddard Space Flight Center, Mail Code 916, Greenbelt, MD 20771 USA, Tel: +1-301-286-3832, Fax: +1-301-286-1662, E-mail: cpeters@qhearts.gsfc.nasa.gov
U17 Structure and Dynamics of the Inner Core
Recent observational and theoretical breakthroughs reveal considerable new insights into the structure of the inner core and the dynamics at the center of the Earth. This Union/SEDI session will highlight new results on inner core shear waves, fine structure of anisotropy, deformation and crystal alignment, interactions with the geodynamo and the mantle, and constraints on inner core rotation. Papers from across disciplines are invited on these problems aimed at understanding the role of the inner core in various Earth processes, including the generation of the geomagnetic field, the transfer of angular momentum in the interior, and the thermal evolution of the Earth.
Sponsored by the AGU Committee on the Study of the Earth's Deep Interior (SEDI)
Conveners: Xiadong Song, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964 USA, Tel: +1-914-365-8828, Fax: +1-914-365-8150, E-mail: xsong@ldeo.columbia.edu; and Lars Stixrude, Department of Geological Sciences, University of Michigan, 425 E. University Avenue, Ann Arbor, MI 48109-1063 USA, Tel: +1-734-647-9071, Fax: +1-734-763-4690, E-mail: stixrude@umich.edu
U18 Science Data and Information Systems
Posters in this session describe science data and information systems. This session is intended to inform science data producers and science data users, planner, and managers of available data system services and tools. Services include those that will help scientists process, archive, and access data and information for research, applications, planning, and management. Posters should describe system services, functionality, access requirements, and procedures, and intended user community.
Conveners: Robin Pfister, NASA Goddard Space Flight Center, Mail Code 423, Greenbelt, MD 20771 USA, Tel: +1-301-614-5171, Fax: +1-301-614-5267, E-mail: robin.pfister@gsfc.nasa.gov; and Kenneth McDonald, NASA Goddard Space Flight Center, Greenbelt, MD 20771 USA, Tel: +1-301-614-5331, Fax: +1-301-614-5267, E-mail: ken.mcdonald@gsfc.nasa.gov
U19 Innovations in Undergraduate Geoscience Education and K-12 Earth Science Teacher Preparation, Parts 1 and 2
Over the past several years, there have been a number of initiatives aimed at restructuring undergraduate geoscience education and K-12 Earth science teacher preparation. These projects take a variety of approaches to integrating advances in science education with reform efforts in undergraduate geoscience curriculum. This session will highlight some of the efforts that are underway with an emphasis on models for success, potential roadblocks, and lessons learned. The conveners welcome papers on a wide range of issues pertaining to Earth science teacher preparation and undergraduate geoscience curriculum reform. Presentations on specific courses, teaching approaches, and assessment strategies are of interest as well as descriptions of institutional strategies that may involve partnerships among colleges and universities, K-12 systems, government laboratories, and professional societies.
Sponsored by the AGU Committee on Education and Human Resources.
Conveners: Part 1, M. Frank Ireton, Pre-College Education Programs, American Geophysical Union, 2000 Florida Ave., NW, Washington, DC 20009-1277 USA, Tel: +1-202-462-6910, ext. 243, Fax: +1-202-328-0566, E-mail: fireton@agu.org; Randy Richardson, Gould-Simpson Building, University of Arizona, Tucson, AZ 85721 USA, Tel: +1-520-621-3374, Fax: +1-520-621-8389, E-mail: rmr@u.arizona.edu; and Stephanie Stockman, Science Systems and Applications, Inc., NASA Goddard Space Flight Center, Mail Code 920, Greenbelt, MD 20771 USA, Tel: +1-301-286-3181, Fax: +1-301-286-1616; E-mail: tockman@core2.gsfc.nasa.gov; Part II, Elizabeth L. Ambos, College of Natural Sciences and Mathematics, California State University at Long Beach, 1250 Bellflower Boulevard, Long Beach, CA 90840 USA, Tel: +1-562-985-4931, Fax: +1-562-985-2315, E-mail: bambos@csulb.edu; and Ellen P. Metzger, Department of Geology, San Jose State University, One Washington Square, San Jose, CA 95192-0099 USA, Tel: +1-408-924-5048, Fax: +1-408-924-5053, E-mail: metzger@geosun1.sjsu.edu
Atmospheric Sciences (A) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
A01 Polar Tropospheric Chemistry and Dynamics
Since the first studies of the phenomenon of "Arctic Haze," there has been increasing interest in polar tropospheric chemistry. The past decade has seen intense interest in the phenomenon of Arctic marine boundary layer ozone depletion, supported by measurements at Barrow, Alert, and Ny-Alesund. Recent field and laboratory measurements have indicated the likelihood that rapid ozone depletion occurs at sunrise as a result of a chain reaction involving Br and Cl atom chemistry. Furthermore, there are indications that this process occurs to some extent in the Antarctic region as well. The ozone depletion is likely mediated by heterogeneous processes, either on the surface of aerosols or at the snow/ice/air interface. At the same time, understanding the relationships between atmospheric and ice phase trace gas concentrations is required for the interpretation of the Greenland and Antarctic ice core samples. In 1998, several major field studies were conducted, including the FIRE-3 campaign in the Beaufort Sea, the Polar Sunrise Experiment, conducted at Alert, and a campaign at Summit, Greenland. This session will cover recent research results, both from these and other field studies, as well as laboratory studies of the relevant processes.
Conveners: Paul Shepson, Purdue University, Department of Chemistry and Earth and Atmospheric Sciences, 1393 Brown Building, West Lafayette, IN 47907-1393 USA, Tel: +1-765-494-7441, Fax: +1-765-494-0239, E-mail: pshepson@purdue.edu and Dr. Jan W. Bottenheim, Atmospheric Environment Service ARQM, 4905 Dufferin St., Downsview ON M3H 5T4, CANADA; Tel: +1-416-739-4838; Fax: +1-416-739-5704; E-mail: jbottenheim@dow.on.doe.ca
A02 Middle Atmospheric Influences on Climate
This session will examine the dynamical and physical effects that the middle atmosphere may exert on climate, including year to year variability of the tropospheric circulation. Particular emphasis will be placed on 1) observational evidence of links between the stratosphere and troposphere in high latitudes and the tropics; 2) model studies of such links and their causality; 3) examination of the effects of resolving the middle atmosphere in climate models; and 4) studies of the effects of stratospheric perturbations and change on climate. This session should provide opportunities for detailed discussion of the physical causes of such connections, as well as technical aspects related to climate modeling.
Convener: Steven Pawson, USRA, NASA Goddard Space Flight Center, Mail Code 916, Greenbelt, MD, 20771 USA, Tel: +1-301-286-2985, Fax: +1-301-286-1754, E-mail: pawson@polska.gsfc.nasa.gov
A03 Isotopically Substituted Species as Probes of Atmospheric Chemistry and Transport
The measurement of the concentrations of isotopically substituted species has long been used to provide information on the sources and sinks for trace constituents in the Earth's atmosphere. More recently, increasing availability of measurements on the isotopic distribution of trace constituents in the atmosphere has been used to help understand the chemical pathways by which such molecules are produced and destroyed and also the balance between transport and chemistry. This has been particularly true in recent years for species such as ozone, carbon dioxide, nitrous oxide, carbon monoxide, water vapor, and methane due to the development of in situ mass spectrometric measurement techniques as well as high-resolution remote sensing spectral measurements. In this session, papers addressing new measurements of isotopically substituted molecules in the atmosphere (especially the middle and upper troposphere as well as the stratosphere), models for the isotope-specific composition of compounds in the atmosphere, and laboratory and theoretical methods for the detailed understanding of isotope-specific aspects of chemistry are all desired.
Conveners: Manvendra Dubey, Los Alamos National Laboratory, Los Alamos, NM, 87545 USA, Tel: +1-505-665-6969, Fax: +1-505-665-4817, E-mail: dubey@lanl.gov; and David Keith, Harvard University, Atmospheric Research Project, 12 Oxford Street, Cambridge, MA, 02138 USA, Tel: +1-617-495-5922, Fax: +1-617-495-4092, E-mail: keith@huarp.harvard.edu
A04 Long-Range Transport of Pollutants and Dust Across the Pacific and Atlantic Oceans
Recent ground-based, airborne and satellite observations indicate that dust and pollutants emitted from one continent can be transported long distances across the oceans and impact a downwind continent. This is based on observations of pollutant and dust transport from Asia to North America, as well as similar observations of transport across the Atlantic to Europe. This session welcomes papers presenting observational data, as well as modeling and process-oriented studies focused on understanding how the surface emissions from one continental region are processed and transported to a downwind continental region. In addition, papers which consider the implications of this transport on the downwind regions are also welcome.
Conveners: Dan Jaffe, University of Washington-Bothell, 22011 26th Avenue SE, Bothell, WA 98021, Phone: +1-425-352-5357, Fax: +1-425-352-5335, E-mail: djaffe@u.washington.edu; and Douglas A. Schaefer, Institute for Tropical Ecosystem Studies, Box 363682, San Juan, PR 00936, Phone: +1-787-767-0371, Fax: +1-787-758-0815, E-mail: d_schaefer@uprl.clu.edu
A05 Measurements and Models for UV Radiation at the Earth's Surface
The recent well-documented decrease in midlatitude stratospheric ozone as well as the larger ozone decline in polar regions have spurred the development of significant ground-based measurement programs to provide long-term data of UV reaching the Earth's surface. In addition, satellite platforms such as the Total Ozone Mapping Spectrometer (TOMS) combine measurements of backscattered UV irradiances from space with models to infer the UV at the Earth's surface. Finally, there is continued development of radiative transfer models, including new three-dimensional models, which predict UV surface irradiances under a wide range of physical input parameters. This session invites presentations related to surface fluxes of ultraviolet radiation from the ground-based, satellite-based, and radiative transfer communities. Possible topics include the effects of aerosols (including smoke from biomass burning, mineral dust, and urban and continental aerosols) and broken water and ice clouds on UV irradiances, biases that arise when comparing the different footprints from the ground and from space, advances in instrumentation and calibration, and UV trends and climatology.
Conveners: Jim Slusser, U.S. Department of Agriculture/Colorado State University, Fort Collins, CO 80523, Phone: +1-970-491-3623, Fax: +1-970-491-3601, E-mail: sluss@NREL.ColoState.EDU; and Jay Herman, NASA Goddard Space Flight Center, Mail Code 916, Greenbelt, MD 20771, Phone: +1-301-286-7821, Fax: +1-301-286-1662, E-mail: herman@tparty.gsfc.nasa.gov
A06 Atmospheric Effects of Large Fires
The last year has seen a significant number of major fires around the world, most notably in Indonesia and Mexico, although important fires have been seen in other places as well. There is now unprecedented ability to characterize the distribution of these fires using space-based measurements, and there have been increased efforts to provide information on the chemical and particle impacts on surrounding regions of the atmosphere using in situ and remote sensing techniques. In this session, papers in which information on the distribution, characteristics, and atmospheric impact (both chemical and radiative) of large fires occurring during the 1997-1998 time frame are desired. Space-, airborne-, and surface-based measurements are all relevant for this session, as are model calculations of the effects of fires on the surrounding atmosphere.
Conveners: Sundar Christopher, University of Alabama in Huntsville, Huntsville, AL 35899, Phone: +1-205-922-5872, Fax: +1-205-922-5755, E-mail: sundar@atmos.uah.edu; and Gregory Carmichael, Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52240, Phone: +1-319-335-1399, Fax: +1-319-335-3337, E-mail: gcarmich@icaen.uiowa.edu
A07 Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS)
The Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) mission utilized the ER-2 and the balloons in the spring and summer of 1997 to study the chemical composition of the mid-high-latitude northern hemisphere. The primary aircraft base for this mission was in Alaska, although aircraft flights from Hawaii and California were carried out to provide a broader geophysical context for the mid-high-latitude observations. A particular goal of the mission was to understand the reasons for which high latitude ozone concentrations decrease over the spring-summer period. Papers involving presentation of both observational and modeling results obtained during the POLARIS mission, as well as those presenting information on the state of the atmosphere during the POLARIS mission through analysis of meteorological data, are desired for this session.
Conveners: Bill Brune, Department of Meteorology, Pennsylvania State University, University Park, PA 16802, Phone: +1-814-865-3286, Fax: +1-814-865-3663, E-mail: brune@essc.psu.edu; Paul Newman, NASA/GSFC, Mail Code 916, Greenbelt, MD 20771, Phone: +1-301-286-3806, Fax: +1-301-286-1754, E-mail newman@notus.gsfc.nasa.gov; and David Fahey, NOAA Aeronomy Laboratory (R/E/Al6), 325 Broadway, Boulder, CO, 80303-3328, Phone: +1-303-497-5277, Fax: +1-303-497-5373, E-mail: fahey@al.noaa.gov
A08 Laboratory Measurements of Phase Transitions and Heterogeneous Chemistry
Papers are invited on laboratory measurements in the field of atmospheric chemistry. Papers are also encouraged on the detailed use of laboratory information in models or in the analysis and interpretation of field data. Although this is a general session, oral presentations this year will emphasize topics related to particle surface chemistry and phase transitions. These chemical processes play important roles in numerous topical areas of current interest, including cirrus cloud formation, radiative forcing, ozone depletion, air visibility, sea-salt chemistry, and other heterogeneous chemical cycles.
Convener: Scot Martin, Department of Environmental Sciences and Engineering, University of North, Carolina at Chapel Hill, Chapel Hill, NC 27599-7400, Phone: +1-919-966-9698, Fax: 1+919-966-7911, E-mail: scot_martin@unc.edu
A09 El Niño Signatures in Physical and Biogeochemical Systems
Oceanic and atmospheric circulation changes that are associated with El Niño conditions are often also responsible for quantifiable changes in other chemical and physical properties of the Earth system. This session seeks contributions that document the effects of El Niño on the physical climate system and quantify the resulting perturbations to chemical and biological variables. In particular, comparisons of the 1997-1998 El Niño with previous events are encouraged. In addition to the atmospheric and oceanic physical signatures of El Niño, signatures of El Niño in observed ozone, water vapor, and/or other trace chemical species in the atmosphere, as well as ocean color, are of interest. Other observational or modeling results that may link the spatial and temporal patterns of tracer distributions in the Earth system to the dynamics of El Niño circulation are also sought after. Studies that explicitly link the physical climate system with biogeochemical tracer distributions, and possible feedbacks between these systems (i.e., DMS), are especially encouraged.
Conveners: David Erickson, National Center for Atmospheric Research, Boulder, CO 80307-3000, Phone: +1-303-497-1424, Fax: +1-303-497-1400, E-mail: erickson@acd.ucar.edu; and Ken Bergman, NASA Headquarters, Mail Code YS, Washington, DC 20546, Phone: +1-202-358-0765, Fax +1-202-358-2771, E-mail: kbergman@hq.nasa.gov
A10 The WB57F Aerosol Mission (WAM)
The WB57F Aerosol Mission (WAM) was a series of seven flights of the WB57F aircraft from Ellington Field, Texas in April-May 1998. The mission was primarily designed to help understand the chemical composition of aerosol particles in the upper troposphere and lower stratosphere. The payload included an instrument to measure the chemical composition of aerosol particles, as well as several other instruments to measure the physical properties of aerosol particles, in situ chemical composition, and meteorological information in the vicinity of the aircraft. A total of seven flights of over a 6-hour duration covering the latitude range from 9 degrees to 47 degrees N were carried out. Among the results was the demonstration of the chemical richness of the particles sampled, including contributions of sulfate, organics, soot, meteoritic material, and other elements (e.g., Hg, I). Papers in which the results obtained during WAM are presented, as well as those providing information on the underlying atmospheric conditions during WAM through analysis of meteorological and or satellite data, are desired for this session.
Convener: Adrian Tuck, NOAA Aeronomy Laboratory (R/E/AL6), 325 Broadway, Boulder, CO 80303-3328, Phone: +1-303-497-5485, Fax: +1-303-497-5373, E-mail: tuck@al.noaa.gov
A11 The Vostok Ice Core: Paleoclimate Through Four Climatic Cycles (Joint with H and OS)
The international effort by the Russians, Americans, and French to drill an ice core at Vostok Station was completed early this year and achieved both technical and scientific success by reaching a depth of 3623 m below the surface at the Russian Vostok Station in East Antarctica (78oS, 106oE; elevation, 3488 m; mean temperature, -55oC). In addition to being the deepest ice core ever drilled, the Vostok core is now believed to cover the past four glacial-interglacial cycles (over 400,000 years) and to contain a wealth of information that will be a gold mine for paleoclimatologists from many years to come. This session will focus on recent results obtained from this ice core, including measurements of stable isotopes, major anions and cations, dust, gases, ice fabric, and their interpretation in the context of the paleoclimate story they have to tell. Papers which use other proxy records (marine sediments, land-based records, corals, etc.) for comparison with the results of the Vostok core will be encouraged. This session should attract a diverse group of scientists from a number of AGU sections, including atmospheric sciences, hydrology, ocean sciences, volcanology, geochemistry, petrology, and perhaps others.
Conveners: Julie Palais, National Science Foundation, Office of Polar Programs, 4201 Wilson Blvd., Arlington, VA 22230, Phone: +1-703-306-1033, Fax: +1-703-306-0139, E-mail: jpalais@nsf.gov; Claude Lorius, Lab Glaciologie and Geophysique, BP96, St. Martin d'Heres, 38402, France, E-mail: lorius@glaciog.ujf-grenoble.fr; and Vladimir Kotlyakov, Institute for Geography, Russian Academy of Sciences, Staromoetny St 29, Moscow 109017, Russia, E-mail: geography@glas.apc.org
A12 The Effects of Lightning on the Middle and Upper Atmospheres (Joint with SA)
Papers are invited for this special session devoted to all aspects of electrodynamic, electrochemical, and radio effects of thunderstorm activity on the middle and upper atmospheres. Contributors are invited to present their latest results on "red sprites," "blue jets," "elves," airglow enhancements, and other, more recently discovered, optical and infrared transient events, associated radio and electromagnetic (ULF-VHF)effects, energetic particle and Xray/gamma ray effects, and the thunderstorm and meteorological correlates of these phenomena. Papers reporting new results from the various summer 1998 field campaigns are of special interest.
Conveners: D. D. Sentman, Geophysical Institute, University of Alaska, Fairbanks, AK 99775-7320, Phone: +1-907-474-6442, Fax: +1-907-474-7290, E-mail: dsentman@gi.alaska.edu; and J.S. Morril, Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC 20375-5352, Phone.: +1-202-404-7826, Fax: +1-202-767-5636, E-mail: morrill@shogun.nrl.navy.mil
A13 Analysis and Synthesis of CH4, NOx, and N2O Flux Data
To continue furthering our understanding of trace gas exchange between terrestrial ecosystems and the atmosphere, we want to encourage researchers conducting trace gas flux studies and modeling analysis of trace gas fluxes to submit abstracts for papers to be included within a half day oral or half day poster special session. The focal point of the session will be papers developed through the culmination of an effort by the U.S. Trace Gas Network (TRAGNET) to develop an accessible database of multiyear trace gas flux (CH4, NOx, N2O, sulfur-containing gases, nonmethane hydrocarbons) data from a variety of ecosystems ranging from tropical to subarctic and to use the data to further the understanding of trace gas exchange. The general goals of the session are (1) to further a generalized understanding of environmental factors controlling trace gas fluxes in order to develop methods for spatial and temporal interpolation and regional extrapolation; (2) to bring together data to test and validate trace gas models across different spatial, temporal, and process scales; and (3) to bring together information needed to determine regional trace gas fluxes from measured fluxes. Contributions from persons conducting flux studies and/or modeling analysis of CH4, NOx, N2O, sulfur-containing gases, and nonmethane hydrocarbon trace gas fluxes are welcomed.
Conveners: Arvin Mosier, USDA/ARS, Fort Collins, CO, Phone: +1-970-490-8250, Fax: +1-970-490-8213, E-mail: amosier@lamar.colostate.edu; and Dennis Ojima, Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, Phone: +1-970-491-1976, Fax: +1-970-491-1965, E-mail: dennis@nrel.colostate.edu
A14 Climatic Processes at High Elevation Sites
There has been an awareness, in recent years, that climatic processes in mountain regions exhibit some surprising characteristics which make these environments particularly sensitive to climate fluctuations. Recent studies suggest that in certain mountainous regions, climate records from mountain observatories and other high elevation sites could be used as a means of early detection of climatic change. Furthermore, global and regional climate models are today providing sharper information on regional climatic sensitivity to global forcings ; use of appropriate data from high elevation sites will therefore become of increasing importance for model initialization, verification, and intercomparison purposes. The necessity of accurate projections of climate change is paramount to assessing the likely impacts of climate change on mountain biodiversity, hydrology and cryosphere, and on the numerous economic activities which take place in these regions. We are looking for contributions dealing with paleoclimatic and current climate observations in mountain regions of the world. Another focus of the session will be the simulation of current climate processes at high elevations, and the sensitivity of regional climates to global climatic change, using high resolution climate models.
Conveners: Prof. Martin Beniston, Department of Geography, University of Fribourg, Perolles, CH-1700 Fribourg, Switzerland, Phone: +41 26 300 90 10, Fax: +41 26 300 97 46, E-mail: Martin.Beniston@unifr.ch; Dr. Henry F. Diaz, NOAA/ERL/CDC, 325 Broadway, Boulder, CO, 80303 - 3328, Phone: +1-303- 497 6649, Fax. +1-303- 497 7013, E-mail: hfd@cdc.noaa.gov
A15 The Cooperative LBA Airborne Regional Experiment (LBA-CLAIRE)
The Cooperative LBA Airborne Regional Experiment (LBA-CLAIRE) is dedicated
to an investigation of the fluxes and chemical transformations of trace gases and aerosols over the Amazon forest, including the effects of deep convection on the chemistry of the tropical troposphere. The first campaign, CLAIRE-98, took place from March 1 to April 20, 1998, and included two aircraft and four ground stations. A large body of data was obtained on biological emissions of trace gases (especially VOC), on atmospheric transformations of trace gases, on aerosol properties over the rain forest, and on long-range transport of biomass smoke and mineral dust. In addition to presentations based on the LBA-CLAIRE-98 campaign results, contributions on related research are encouraged. In particular, abstracts dealing with biosphere/atmosphere interactions in the humid tropics, chemical processes in the tropical boundary layer, and effects of deep convection on the chemistry of the tropical troposphere would be welcome.
Conveners: Meinrat O. Andreae, Biogeochemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, D-55020 Mainz, Germany, (for FedEx, etc., street address is J.J. Becherweg 27, D-55128 Mainz, Germany), Phone: +49-6131-305-420, Fax: +49-6131-305-487, E-mail: moa@mpch-mainz.mpg.de or moa@cco.caltech.edu; and Paulo Artaxo, Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05315-970, Sao Paulo, SP, Brazil, phone: +55-11-818-7016, fax +55-11-818-6749, e-mail: artaxo@if.usp.br
Geodesy (G) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
G01 Space Geodesy and Global Plate Motions (Joint with T)
Space geodetic techniques provide measurements that can be used to infer crustal
deformation over global scales and can be compared with predictions from
conventional global plate motion models, which average motion over millions of
years. In the past 5 years the scope and accuracy of space geodetic techniques
have expanded greatly. In some regions, geodetic measurements are probably more
accurate than conventional global plate motion models. In this session we focus
on space geodetic techniques and their contribution to understanding plate
motion and intraplate deformation. For example, are there any decisive
differences between angular velocities inferred from geodetic data and those of
NUVEL-1A, which is mainly based on data averaged over 3 million years? What
part of these differences is caused by inaccuracies in global plate motion
models and what part is due to nonsteady plate motions? What bounds can be
placed on intraplate deformation? How is relative plate motion accommodated
within diffuse plate boundaries? Do velocities for island and nonisland sites
agree equally well with plate predictions? We welcome studies using GPS, VLBI,
SLR, DORIS, Doppler, "conventional" plate motion approaches, or any combination
of these techniques.
Conveners: Kristine Larson, Hawaii Volcano Observatory, P. O. Box 51, Hawaii National Park, HI 96718 USA; E-mail: kristine.larson@colorado.edu; and Richard Gordon, Rice University, Geological and Geophysicals, MS 126, 6100 South Main Street, Houston, TX 77005-1892 USA; Tel: +1-713-285-5279; Fax: +1-713-285-5214; E-mail: rgg@geophysics.rice.edu
G02 GPS Site-Specific Errors
This session will focus on the identification, characterization, quantification, and minimization of errors in GPS products which are a function of the station location. As the use of GPS for positioning, time keeping, atmospheric monitoring, and ionospheric monitoring continues to expand, site-specific noise continues to be an area whose importance must be evaluated. An understanding of such errors can provide room for improvement in the products derived from the GPS data. Examples of contributions to this session might include theoretical and practical examples of assessments of the size of multipath, tropospheric, geographically correlated, or other related errors; algorithms for identifying location-specific errors in GPS data or products; or methods and examples of reducing the size of site-specific errors, either using analysis software or station hardware.
Conveners: Kenneth Hurst, JPL, 4800 Oak Grove Drive, MS 238-600, Pasadena, CA 91109, Phone: +1-818-354-6637, Fax: +1-818-393-4965, E-mail: hurst@cobra.jpl.nasa.gov; and Pedro Elosegui, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138, Phone: +1-617-496-7645, Fax: +1-617-495-7345, E-mail: pelosegui@cfa.harvard.edu
G03 Regional Deformation (Joint with T)
Advances in GPS and other geodetic techniques have greatly reduced the time needed to resolve localized and regional deformation in areas that traditionally have low strain rates. These advances have decreased the time needed to observe regional deformation patterns from many decades to several years. This session will focus on, but is not limited to 1) recent measurements of crustal deformation in modern geodetic networks; 2) geodetic arrays with low strain rates which exhibit significant signals, such as rift zones, intracontinental extensional regions, and broad plate boundaries; and 3) the varied deformation styles associated with volcanic complexes. Investigations that describe geodetic observations (continuous GPS, campaign style GPS, InSAR, leveling, EDM) and provide models of the processes associated with measured deformation are welcome.
Conveners: Gerald Bawden, U.S. Geological Survey, MS 977, 345 Middlefield Road, Menlo Park, CA 94025-3591, Phone: +1-650-329-5729, Fax: +1-650-329-5163, E-mail: gbawden@omega7.wr.usgs.gov; and Paul Segall, Stanford University, Department of Geophysics, Stanford, CA 94305, Phone: +1-415-725-7241, Fax: +1-415-725-7344, E-mail: segall@pangea.stanford.edu
G04 Crustal and Lithospheric Dynamics in Antarctica: Models and Observations
The goal of this special session is to discuss the measurement and modeling of crustal motions in the Antarctica. A host of ice, land, sea, airborne, and space-based data are relevant to this question. Because the solid Earth is capable of both elastic and viscous deformations, we have come to understand that the question of ice sheet motion and stability is intimately connected to regional crustal motion and time-dependent gravity. Considering that the Antarctic ice sheet today has a volume equivalent to 73 m of eustatic sea level (whereas the Fennoscandian and Laurentide ice sheets contained a combined 60-65 m at Last Glacial Maximum), changes in mass, or in mass distribution, integrated over the last 10 millennia, may drive a substantial postglacial rebound at present-day. Current efforts to measure glacial rebound and crustal motions involve land-based GPS and gravimetry. Of particular importance to these data is the uniquely harsh environment in which they must be recovered and special consideration of error sources. The trade-off of rebound versus tectonic crustal motion is unknown, and any information related to active faulting is especially important. Future space missions, such as CHAMP, GRACE, and GOCE, will provide higher-resolution gravity anomaly and geoid data.
Crustal profiling and seismic tomography may provide crucial data that help tie down models of Neogene tectonic evolution. Papers addressing these data types and their interpretation are especially encouraged. Contributions that emphasize geomorphologic constraints on Pleistocene ice sheet thickness and regional paleoshoreline reconstructions are also strongly encouraged.
Conveners: Erik Ivins, Jet Propulsion Lab, MS 183-501, 4800 Oak Grove Drive, Pasadena, CA 91109-8099, Phone: +1-818-354-4785, Fax: +1-818-354-0966, E-mail: eri@scnl.jpl.nasa.gov; and Reinhard Dietrich, Technische Universitat Dresden, Institut Planetare Geodasie, Dresden D-01062, Germany, Phone: +49-351-4634652, Fax: +49-351-4637106; E-mail: dietrich@kpgrs1.geo.tu-dresden.de
G05 Active Geologic Structure Growth and Mountain Building (Joint with S and T)
We invite contributions based on research of the active growth of geologic structures as mountains are rising and geodetic estimates of the motion presently creating such structures. Of interest are folding, reverse faulting, and mountain building in response to contraction, as well as normal faulting environments. Analyses of fault scarps and isotope dating to estimate rates of uplift are welcome, as are quantitative analyses of digital elevation data to identify recent tectonic activity. We are particularly interested in how deformation over geologic time scales relates to crustal deformation measurements using geodetic techniques. Efforts to understand the buoyancy and flexural forces driving mountain building are wanted, as are studies of the interaction between mountain building and tectonics on one hand and mountain collapse and erosion on the other.
Conveners: Donald Argus, Jet Propulsion Laboratory, 4800 Oak Grove Dr., MS 238-600, Pasadena, CA 91109, Phone: +1-818-354-3380, Fax: +1-818-393-4965, E-mail: argus@tecton.jpl.nasa.gov; and Roland Burgmann, University of California, Davis, Department of Geology, Davis, CA 95616, Phone: +1-916-752-6808, Fax: +1-916-752-0951, E-mail: burgmann@geology.ucdavis.edu
G06 Permanent GPS Arrays in Western North America
GPS instrumentation and infrastructure is playing an increasingly important role in the Earth sciences. Large concentrations of continuous GPS sites are being installed to monitor active plate boundaries and seismic hazards, in particular in Japan (~1000 stations) and in western North America (~120 active and ~225 planned stations). Western North American efforts include the Southern California Integrated GPS Network (SCIGN), the Bay Area Regional Deformation Array (BARD), the Northern Basin and Range (NBAR), the Eastern Basin and Range (EBAR), the Pacific Northwest GPS Geodetic Array (PANGA), and GPS arrays being developed in Mexico by CICESE, INEGI, and UNAM. This session will provide a forum to overview the technical, scientific, and programmatic aspects of continuous GPS arrays, with a particular focus on western North America. Coordination of these efforts will provide a complete circuit from the stable North American plate to the extending regime of the Basin and Range and tied to the San Andreas fault system and will allow the geophysical/geodetic community to realize a long hoped for data set: a relatively detailed picture of western U.S. kinematics at a subcontinent scale. Arrays in the Pacific Northwest will add crustal deformation data associated with subduction between the Juan de Fuca and North America plates and back arc deformation related to Pacific-North America motion. Arrays in Mexico will provide the main deformation farther south along the North American plate boundary from the transcurrent motion along the San Andreas fault system to the extensional regime of the Gulf of California and to compressional motion along the Middle America trench. The long-term goal is to achieve a fundamental physical understanding of the earthquake and to develop advanced models of seismic hazard analysis. Focusing on achieving broad-scale spatial coverage with dense temporal resolution will provide insight into such processes as stress evolution, fault mechanics, fault zone structure, and stress triggering. The colocation of many of the new GPS instruments at seismic stations will enhance the multidisciplinary study of tectonic motion, plate boundary deformation, earthquake physics, and seismic hazards.
Conveners: Yehuda Bock,IGPP 0225, 9500 Gilman Drive, La Jolla, CA 92093-0225, Phone: +1-619-534-5292, Fax: +1-619-534-9873, E-mail: ybock@ucsd.edu; and Brian Wernicke, Division of Geological and Planetary Sciences, California Institute of Technology, MC 100-23, Pasadena, CA 91125, Phone: +1-818-395-6192, Fax: +1-818-568-0935, E-mail: brian@legs.gps.caltech.edu
G07 Tectonics of Western North America Inferred From Geodetic Data (Joint with T)
The main goal of this session is to bring together research in the broad fields
of geodesy and tectonophysics to understand the kinematics of present-day
western North America deformation from Alaska to Mexico. Western North America
is largely understood as a diffuse continental plate boundary zone driven by
interactions between the Pacific, North America, Juan de Fuca, and other plates
expressed in rich variety of tectonically active strike-slip, subduction zone,
extensional, and volcanic regions. A growing body of evidence, including
physical models of such deformation, suggests that intraplate forces, including
buoyancy forces and perhaps tractions along the base of the plate, may also
play an important role. Continuously operating GPS networks installed over the
last few years now span much of this vast region. Data from these networks,
combined with campaign-mode GPS, trilateration, and other geodetic data, allow
the pattern of present-day deformation to be determined at an unprecedented
range of spatial and temporal scales. This session will present results of
these recent deformation measurements and how they constrain tectonic models of
deformation and strain accumulation in western North America.
Conveners: Mark Murray, Stanford University, Department of Geophysics, Mitchell Building, Stanford, CA 94305-2215 USA; Tel: +1-415-723-9594; Fax: +1-415-725-7344; E-mail: mmurray@pangea.stanford.edu; and Rick Bennett, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138 USA; Tel: +1-617-495-7453; Fax: +1-617-495-7345; E-mail: rbennett@cfa.harvard.edu
G08 Polar Motions From Hours to Decades
Both the accuracy of polar motion measurement series and the analysis of the geophysical excitation of the polar motion continue to improve dramatically. Global Positioning System (GPS) observations now provide a continuous daily series of highly accurate polar motion estimates. The polar motion series from very long baseline interferometry (VLBI) and satellite laser ranging (SLR) are now long enough to unambiguously separate the Chandler and annual wobbles, and the space geodetic data should therefore now be able to directly address the excitation of the Chandler wobble. On the longest timescales, the HIPARCOS satellite celestial reference frame has been used to redetermine the polar motion using the historical optical astrometric data, and "decadal" polar motions may now be observable. Meteorological estimates of the polar motion excitation are now available in decades-long homogeneous "reanalysis" series, while oceanic angular momentum estimates are finally demonstrating coherence with the observed polar motion. Contributions that address improvements in the observations and analysis of the polar motion are welcome, including: (1) results from the new GPS series and from comparisons between GPS, SLR,
and VLBI series; (2) results from the HIPARCOS reanalysis of the century-long optical data set; (3) studies of the optimal combination of results from these diverse techniques; and (4) studies of the new excitation estimates from satellite altimetry, numerical ocean modeling, hydrological cycle modeling, etc.
Conveners: Marshall Eubanks, 7243 Archlaw Drive, Clifton, VA 20124, Phone: +1-202-762-1464, E-mail: tme@usno01.usno.navy.mil; and Rui Ponte, AER, Inc., 840 Memorial Drive, Cambridge, MA 02139, Phone: +1-617-547-6207, Fax: +1-617-661-6479, E-mail: ponte@aer.com
G09 Geodetic VLBI in the Next Millennium
The accuracy of geodetic measurements by very long baseline interferometry has improved by about an order of magnitude per decade in the 30 years since the first successful observations. This has been achieved through a combination of better instrumentation, advances in the physical models, changes in observing technique, and improvement in analysis tools. Tremendous advances in geodynamics have resulted from the application of VLBI and other space techniques, especially GPS and satellite laser ranging, in order to better define the shape and deformation of the Earth. As we move into the next millennium, it is valuable to anticipate what further advances can be made in VLBI. This is also a time to assess both the actual level of accuracy we have achieved and the limitations to the technique. Contributions that address these topics are invited. In particular, What science results show where improvements are needed in either accuracy or temporal coverage? What factors limit the current accuracy (and precision) of geodetic VLBI results, and how can they be improved? What is the best use of VLBI? What new technology can improve the quality, quantity, ease of use, or economics of VLBI?
Conveners: Arthur Niell, MIT Haystack Observatory, Westford, MA 01886 USA; Tel: +1-978-692-4764; Fax: +1-781-981-0590; E-mail: aniell@haystack.mit.edu; and Leonid Petrov, University of Bonn, Bonn, Germany; E-mail: petrov@kuestner.geod.uni-bonn.de
G10 Absolute Versus Relative GPS Determinations Using the IGS Network
While GPS applications are becoming increasingly widespread, it remains a challenge to understand and to realize the full potential of GPS in an "absolute" sense, rather than differential or relative modes. This session seeks papers to examine the "absolute" accuracy of GPS determinations in a variety of applications. Examples include comparisons of IGS orbits with laser tracking data; assessments of IGS polar motion values and their attachment to the ITRF; sources of bias in GPS station coordinates, especially the heights; accuracy of tropospheric path delay estimates; effects on estimates of clock differences; and potential for determinations of unbiased Universal Time and nutation angles.
Conveners: J. Kouba, Geomatics Canada NRCAN, Geodetic Survey Division, 615 Booth Street, Ottawa, Ontario K1A 0E9, Canada, Phone: +1-613-995-5302; J. Ray, 1829 S Street, NW, #4, Washington, DC 20009-6196, Phone: +1-301-713-2850, Fax: +1-301-713-4475, E-mail: jimr@maia.usno.navy.mil; and T. Springer, Sidlerstrasse 5, Bern 3006, Switzerland
G11 Global Systematic Errors in the GPS System
The Global Positioning System (GPS) has demonstrated outstanding capabilities for relative positioning on the Earth's surface at the millimeter level. However, certain systematic errors, for example, in the scale (and origin) of the terrestrial system, still exist at observable levels. Causes identified so far include media effects, orbit mismodeling, and transmitter and receiver phase center location uncertainties. This session is intended to raise the geodetic community's awareness of the existence and treatment of these global effects (as opposed to local, site specific errors) and to begin discussing possible solutions. We welcome contributions discussing any errors in the GPS system which affect many sites, including systematic differences between the Block IIR and IIA satellites, large-scale errors due to ionosphere and troposphere, orbit modeling, and others.
Conveners: Michael Watkins, Jet Propulsion Laboratory, MS 238 600, 4800 Oak Grove Drive, Pasadena, CA 91109-8099, Phone: +1-818-354-7514, Fax: +1-818-393-4965, E-mail: mmw@cobra.jpl.nasa.gov; and Yoaz Bar-Sever, Jet Propulsion Lab, MS 238-600, Pasadena, CA 91109, Phone: +1-818-354-2665, Fax: +1-818-393-4965, E-mail: yeb@cobra.jpl.nasa.gov
G12 Advances in Gravity Field Modeling
Gravity field determination will enter a new paradigm in the next decade as several dedicated satellite missions are planned. This session is intended to cover all aspects of the determination and modeling of the gravity field, but with special emphasis on the following topics: 1) spatial-temporal descriptions of the variability of the gravity field due to redistribution of mass in the oceans, atmosphere, continental water, ice, etc., and their accuracy assessment; 2) the development of future gravity missions (e.g., CHAMP, GRACE, GOCE) and data analysis techniques to process measurements from these missions; 3) innovative applications of data from future gravity missions; and 4) improvements in current gravity field models and their temporal variation using new measurements and/or analysis techniques.
Conveners: R. Steven Nerem, Center for Space Research, 3925 West Braker Lane Suite 200, Austin, TX 78759-5321, Phone: +1-512-471-7599, Fax: +1-512-471-3570, E-mail: nerem@csr.utexas.edu; and Benjamin F. Chao, NASA Goddard Space Flight Center, Mail Code 926, Greenbelt, MD 20771, Phone: +1-301-286-6120, Fax: +1-301-286-1760, E-mail: chao@denali.gsfc.nasa.gov
G13 Applications of Airborne and Spaceborne Laser Altimetry
Laser altimetry from airborne and spaceborne platforms is providing a tool for investigation of geophysical phenomena, such as monitoring of volcanoes, ice sheets, and beach erosion. This session will focus on results obtained with existing systems and summarize the systems expected to be available in the next 2-3 years. The synergy between airborne and spaceborne applications and the geodetic requirements will be discussed.
Conveners: Bob Schutz, Center for Space Research, 3925 West Braker Lane, Suite 200, Austin, TX 78759, Phone: +1-512-471-4267, Fax: +1-512-471-3570, E-mail: schutz@csr.utexas.edu; and Bill Carter, University of Florida, Department of Civil Engineering, 345 Weil Hall, Gainesville, FL 32611-6589, E-mail: bcarter@ce.ufl.edu
G14 Satellite Radar Altimetry: Past, Present, and Future
Since 1985, there has been at least one radar altimeter in Earth orbit nearly continuously, except for a gap between the end of the Geosat mission in 1989 and the start of the ERS-1 mission in 1991. Future missions are planned to begin before current missions end to ensure continuous coverage into the next century. The data from radar altimeter missions have improved our knowledge of ocean tides, the ocean geoid, and other geophysical properties. For this session, we seek contributions discussing research utilizing data from current and past missions, including Geosat, ERS-1, ERS-2, TOPEX/Poseidon, and Geosat Follow-On, as well as overviews of future missions such as Jason-1 and ENVISAT. Studies linking data from different missions is especially encouraged, particularly studies of long-period ocean variability and mean sea surface and ocean geoid modeling.
Conveners: Don Chambers, Center for Space Research, 3925 West Braker Lane, Suite 200, Austin, TX 78759-5316 USA, Tel: +1-512-471-7483; Fax: +1-512-471-3570; E-mail: chambers@csr.utexas.edu; and Gregg Jacobs, NOARL, Stennis Space Center, Mail Code 321, Stennis Space Center, MS 39529-5004 USA; E-mail: jacobs@proteus.nrlssc.navy.mil
G15 Observing Tectonic Strain in Boreholes: New Results and Instrumentation (Joint with T)
Borehole strainmeters provide critical documentation of aseismic crustal movements near active faults and volcanoes because they are uniquely capable of measuring localized strain changes smaller than 10-8 over periods of hours to days. For this reason, they are an important complement to continuous GPS and seismic networks. Recent instrumentation advances extend the depth and temperature ranges at which borehole strainmeters can operate and under some circumstances permit the instruments to be retrievable after installation. This special session solicits abstracts presenting instrumentation developments as well as observations of crustal deformation from borehole strainmeters and other downhole geophysical instruments.
Conveners: Evelyn Roeloffs, U.S. Geological Survey, 5400 MacArthur Blvd., Vancouver, WA 98661, Phone: +1-360-696-7912, Fax: +1-360-696-7866, E-mail: evelynr@usgs.gov; and Michael T. Gladwin, P.O. Box 62, St Lucia, Queensland 4067, Australia, Phone: +61-7-32124562, Fax: +61-7-3715896, E-mail: gladwin@brolga.cc.uq.oz.au
Geomagnetism and Paleomagnetism (GP) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
GP01 Paleomagnetism and Tectonics of Active Margins (Joint with T)
In honor of the recent retirement of Myrl Beck Jr., presentations on the various
aspects of paleomagnetism and tectonics of active margins studied over the
course of his career are solicited. Examples might include paleomagnetic
results from the North American Cordillera relating to the tectonic evolution
of Baja California, studies evaluating magnetic inclinations (and possible
tilts) in plutonic rocks, paleomagnetism and rotation of elements in the Andean
margin, and more general studies of tectonic processes of convergent margins.
Conveners: Bernie Housen, Geology Department (ES 236), Western Washington University, Bellingham, WA 98225-9080 USA; Tel: +1-360-650-6573; Fax: +1-360-650-7302; E-mail: bernieh@cc.wwu.edu; and Jimmy Diehl, Michigan Technological University Department, Geological Engineering and Science, 1400 Townsend Drive, Houghton, MI 49931 USA; Tel: +1-906-487-2665; Fax: +1-906-487-3371; E-mail: diehl@mtu.edu
GP02 Resolving Different Components of the Earth's Magnetic Field (Joint with SA)
The geomagnetic field has primary sources in the core, lithosphere, oceans, ionosphere, and magnetosphere, as well as secondary induced sources in the mantle, crust, and oceans. Increasingly, progress in modeling one part of the field depends on taking account of the other components, through physical modeling, filtering, data selection, removal of standard models, or simultaneous inversion for parameters representing different sources. The forthcoming launch of several satellites with geomagnetic sensors offers the opportunity to make major advances in understanding the various sources, provided the contributions from each source are properly considered. This session solicits papers that address the modeling, resolution, and separation of different parts of the field.
Conveners: Stephen Zatman, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, Phone: +1-301-286-6603, E-mail: zatman@denali.gsfc.nasa.gov; and Art Richmond, High Altitude Observatory, NCAR, Boulder, CO, 80307, Phone: +1-303-497-1570; E-mail: richmond@ucar.edu
GP03 Contributions by Electromagnetic Methods to Multidisciplinary Studies (Joint with T)
This session concentrates on the role electrical and electromagnetic methods play in furthering our understanding of geological and tectonic processes, particularly when combined with other geophysical and geological information. We encourage contributions that review the background geology and supporting geophysical data followed by descriptions of how integrated electromagnetic experiments produce solutions. Where appropriate, these functions could be spread across pairs of talks presented by different authors.
Conveners: Steven Constable, Scripps Institution of Oceanography, MC 0225, La Jolla, CA 92093-0225, Phone: +1-619-534-2409; E-mail: sconstable@ucsd.edu; and Alan G. Jones, Geological Survey of Canada, 1 Observatory Crescent, Ottawa, Ontario K1A 0Y3, Canada, Phone: +1-613-992-4968, Fax: +1-613-992-8836, E-mail: jones@cg.NRCan.gc.ca
GP04 Hotspots: Gone With the Wind? (Joint with T)
Paleogeographic reconstructions have been an integral part of global tectonic research since the advent of the plate tectonic paradigm. Hotspots offer a unique contribution to constrain reconstructions since they provide paleolongitudinal control on plate positions (absolute reference scheme) in contrast to reconstructions based on paleomagnetic data alone (unknown paleolongitude). A fundamental assumption, however, is that hotspots are stationary or move at insignificant speeds relative to plate tectonic speeds. Discrepancies between hotspot and paleomagnetic reference frames have traditionally been explained by true polar wander or simply the fact that hotspots may not be as stationary as often taken for granted. In this session we invite any contribution on hotspots but with emphasis on hotspot migration patterns and rates (theoretical and/or observational data), mantle circulation modeling, and observational constraints offered by precise palaeomagnetic and geochronological data.
Convener: Trond H. Torsvik, NGU, Box 3006 Lade, N-7040 Trondheim, Norway, Phone: +47-73-904411, Fax:+47-73-921620, E-mail: trond.torsvik@ngu.no
GP05 Low-Temperature Magnetic Properties of Iron Oxides, Hydroxides, and Sulphides
There is growing interest in using low-temperature magnetic measurements to identify the magnetic minerals in rocks, sediments, and soils. Precise and sensitive laboratory measurements can now be made of the temperature dependences of susceptibility, remanence, and magnetic hysteresis properties at low temperatures. These can pinpoint crystallographic phase transitions, remanence transitions, and magnetic isotropic points. This session will present our state-of-the-art knowledge of low-temperature magnetic characteristics of magnetite, titanomagnetite, hematite, pyrrhotite, and iron oxyhydroxides and will assess their utilities as analytical tools. In addition, such studies yield information on the nature of remanence acquisition in these magnetic minerals, for example, on the respective roles of magnetocrystalline, shape, and stress anisotropies. Special attention will be given to experimental and theoretical studies on the physical mechanism of magnetic memory, low-temperature demagnetization, and the Verwey and Morin transitions in magnetite and hematite. Other topics of interest include low-temperature characteristics of TRM, CRM, ARM, and SIRM; effect of impurities and other crystal defects on the transitions and magnetic memory; and use of phase and remanence transitions in determining domain states and magnetic domain obsevations at low temperatures.
Convener: Ozden Ozdemir, Department of Physics, University of Toronto at Mississauga, 3359 Mississauga Road North, Ontario L5L 1C6, Canada, Phone: +1-905-828-3829, Fax: +1-905-828-3717, E-mail: ozdemir@physics.utoronto.ca
GP06 Paleomagnetic Objectives for Post 2003 Ocean Drilling
Although important geomagnetic and paleomagnetic problems can still be addressed
by individual investigators, there are many forefront problems of geomagnetism
and paleomagnetism which are best addressed by programs and sampling strategies
beyond the abilities of individual investigators. Consequently, in these
situations paleomagnetists must work together towards common goals using a large
scale approach. One such approach is offered by the Ocean Drilling Program.
ODP is due to end on October 1, 2003 and plans are that it will be replaced by a
two-ship drilling program in which one ship will be equipped with a riser and
will be drilling in continental margins where well head control is necessary.
Riser drilling will not offer much to paleomagnetists because of the rotary
drilling. The other drill ship will be of roughly equivalent size to the JOIDES
RESOLUTION but will hopefully have a much better drilling capability. In order
to proceed along this path it is necessary to identify the major scientific
problems which can be tackled by each vessel. Riser drilling was the topic of
the CONCORD meeting in Japan (report available at
http://mstip1.jamstec.go.jp/jamstec/OD21/CONCORD/result.html). It is the purpose
of an international conference to be held at the University of British Columbia
May 26-29, 1999 to address the scientific questions to be studied by non-riser
drilling post 2003. We think it highly desirable to have forums for discussion
of the major problems in geomagnetism and paleomagnetism which should be
addressed by a successor to ODP.
For many years paleomagnetists have been satisfied to glean data from locations
determined by other scientific interests. Has this strategy worked? Need it be
modified? Should there be a geomagnetic or paleomagnetic research program
proposed for future ocean drilling?
Research Focus Areas
1. Paleofield Behavior. Hydraulic piston coring used by the Ocean Drilling
Program has allowed records of unparalleled time resolution to be obtained.
Four aspects of the geomagnetic field can potentially be addressed: (1)
paleosecular variation, including both direction and intensity results, (2) paleofield geometry, (3) the geomagnetic field reversal time scale, and (4)
field reversal geometry. The last of these has probably been carried the
farthest. To date the first has been approached piecemeal and the second has been limited mainly to historical records or very simple models spanning millions of years. Can we take existing or proposed cores and generate sets of paleomagnetic directions that could be used to define paleofield geometries in the past several million years? For example, one could obtain high time resolution by having oxygen isotope curves for each core site and by referencing
paleomagnetic data to isotope stages. But how many sites are needed? How
should the measurements be made. If existing DSDP/ODP cores are insufficient,
can we envision 1-2 ODP legs that would provide the needed sites? If not,
should we consider a program to obtain a global network of oriented, giant
piston cores?
2. Vine-Matthews Hypothesis. Despite several decades of research, our knowledge
of the magnetization structure of the ocean crust and upper mantle is still
rudimentary. Models of oceanic crustal magnetization still frequently imply
that the intrusive portion of the crust (layer 3) is non-magnetic, despite the
results from hole 735b showing strong magnetizations which may contribute to the
lineated anomalies. But we do not know when the lower crust acquired its
magnetization, and we do not know the nature of the boundary between different
polarities within the lower crust. Can ODP provide the data to put some of our
questions to rest? Has the past approach of gleaning paleomagnetic results from
cores drilled to investigate the lithosphere been successful? Is the strategy
for investigating crustal magnetization any different from that to investigate
crustal structure and composition (i. e., do we need our own program) Can we
propose 1-2 ODP legs that would address the problem? We certainly need better
penetration into the coeanic crust and a higher recovery rate. Solution of some
of the problems of oceanic crustal magnetization will also help to solve the
questions asked of the petrologic structure of the crust as well.
3. Hot Spot Fixity. The past decade has seen little progress in measuring the
drift of the hot spots relative to the paleomagnetic axis. Indeed, recent
results imply that some of our treasured assumptions, such as meaning of the
Hawaiian-Emperor bend, may be erroneous. This problem of sorting out global
reference frames clearly needs a global approach. How might we go about using
ODP to answer our questions about true polar wander, hot spots, and hot spot
relative motions? Would it suffice to drill several sites on the
Hawaiian-Emperor chain, Louisville chain, and Ninetyeast ridge?
We propose a special session at the fall AGU meeting 1998 at which these and
other problems may be discussed in terms of the drilling capabilities needed to
solve them. We will set aside some time for informal discussion after the formal
session has been completed. Depending on the response to this call, some of the
papers will be highlighted and given extra time for presentation.
If you are interested, please submit an abstract to AGU in the usual way and
send a copy to one of us. Abstracts are due August 26 for postal, and September
2 for Interactive Web Site submissions.See June 30 EOS for instructions.
Conveners: Will Sager, Texas A&M University, Department of Oceanography, College Station, TX 77843 USA; Tel: +1-409-845-9828; Fax: +1-409-845-6331; E-mail: wsager@ocean.tamu.edu; and Chris Harrison, RSMAS, University of Miami, 4600 Rickenbacker Causeway, Miami FL 33149 USA; Tel: +1-305-361-4610; Fax: +1-305-361-4632; E-mail: charrison@rsmas.miami.edu
Hydrology (H) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
H01 Geomorphic Processes and Riverine Habitat
Geomorphic processes in many riverine landscapes control the volumes and quality of available habitat and determine the magnitude/frequency/sequencing of habitat disturbance. This special session will focus on new research linking geomorphic processes with riverine habitats, including the channel, groundwater, and the aquatic-terrestrial transition. We encourage presentations that emphasize quantitative evaluations of habitat formation, disturbance, maintenance, or metamorphosis.
Conveners: Robert B. Jacobson, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO 65201, Phone: +1-573-876-1844, Fax: +1-573-876-1896, E-mail: jacobson@usgs.gov; and Joseph M. Dorava, U.S. Geological Survey, 4230 University Drive, Suite 201, Anchorage, AK 99508-4664, Phone: +1-907-786-7104, Fax: +1-907-786-7150, E-mail: jmdorava@usgs.gov
H02 Hillslope and Fluvial Processes
Studies of hillslope or fluvial processes and their interactions are solicited for this long-running session. We encourage submission of both field and theoretical studies that will hopefully range from detailed studies of individual field sites to continental-scale modeling of sediment yields. Submission concerning tropical, polar, and temperate landscapes is equally encouraged. The session will only include poster presentations.
Conveners: David R. Montgomery, Department of Geological Sciences, Box 351310, University of Washington, Seattle, WA 98195-1310, Phone: +1-206-685-2560, Fax: +1-206-543-3836, E-mail: dave@bigdirt.geology.washington.edu; and Jim Pizzuto, Department of Geology, University of Delaware, Newark, DE 19716, Phone: +1-302-831-2710, or +1-302-368-3826, Fax: +1-302-831-4158, E-mail: pizzuto@udel.edu
H03 Floodplain Processes, Evolution, and Restoration
Advances in remote sensing as well as surveying and monitoring tools and recent theoretical developments have led to new insights about the hydrology, sedimentology, and geomorphic evolution of floodplains. New thinking regarding floodplain restoration and management is emerging. Here, we call for empirical and theoretical papers on floodplain processes, evolution, restoration, and management.
Conveners: Leal A.K. Mertes, Department of Geography, University of California, Santa Barbara, CA, 93106-4060, Phone: +1-805-893-7017, Fax: +1-805-893-7782, E-mail: eal@geog.ucsb.edu; and William E. Dietrich, Department of Geology and Geophysics, University of California, Berkeley, CA 94720, Phone: +1-510-642-2633, Fax: +1-510-643-9980
H04 Geomorphology of Mountainous Regions
Mountain ranges are shaped by uplift and erosion, and they influence regional and possibly global climate. The orographic distribution of precipitation probably affects the spatial pattern of erosion, which may in turn alter the rock uplift pattern. These feedbacks are transmitted through processes such as bedrock river incision, glacial erosion, landsliding, and chemical weathering. Tectonic, climatic, and internal controls on the rates and patterns of erosion are therefore inherently of cross-disciplinary interest. We invite contributions on all aspects of geomorphology, meteorology, and tectonic feedbacks in mountains. This session is co-sponsored by Snow, Ice and Permafrost Committee.
Convener: Suzanne P. Anderson, Department of Earth Sciences, UCSC, Santa Cruz, CA 95064 USA, Phone: +1-831-459-5827, Fax: +1-831-459-3074, E-mail: spa@es.ucsc.edu and Kelin X Whipple, Department of Earth Sciences, MIT, Cambridge, MA 02139, Phone: +1-617-253-2578, Fax: +1-617-252-1800, E-mail: kxw@mit.edu
H05 Surface Chemistry and Multiphase Flow in Porous and Fractured Media
Surface chemistry plays a major role governing multiphase flow in porous and fractured media. Research and models generally treat surface chemistry as static, ignoring dynamic aspects or local nonuniformities. These assumptions are true only for single-component fluids, constant temperature, and spatially uniform mineralogy. These conditions are highly unlikely due to generally complex NAPL composition, geologic heterogeneity, and enhanced remediation effects. We seek contributions which examine dynamic fluid compositional effects, compositional changes during fluid flow, matrix surface mineralogy, enhanced remediation technology effects on surface chemistry of multiphase flow systems, and how dynamic changes influence multiphase flow and subsurface distribution.
Conveners: David M. Tuck, WSRC, Bldg. 773-42A, Aiken, SC 29808, Phone: +1-803-725-2927, Fax: +1-803-725-4129, E-mail: david.tuck@srs.gov; Andrew F. B. Tompson, Earth Sciences Department, Lawrence Livermore National Laboratory, University of California, Livermore, CA 94551, Phone: +1-510-422-6348, Fax: +1-510-422-3118, E-Mail: afbt@llnl.gov; and Wendy E. Soll, EES-5, Geoanalysis, Mail Stop F665, Los Alamos National Laboratory, Los Alamos, NM 87545, Phone: +1-505-665-6930, Fax: +1-505-665-8737, E-mail: wes@vega.lanl.gov
H06 Fluid Flow in the Earth's Crust (Joint with V)
Understanding how fluids move and transport mass and energy in geologic environments is critical to a better understanding of many geochemical and geophysical processes that occur within the Earth's crust. For this session, presentations on large-scale fluid flow that address how this flow affects the geochemical evolution of the crust are solicited. Also, contributions of studies in a variety of geologic settings, including basin evolution, burial metamorphism, regional or tectonically induced metamorphism, plutonic regions and hydrothermal systems are solicited. Presentations on coupled thermal-hydrological-geochemical processes (e.g., the feedback between mineral precipitation/dissolution and porosity/permeability changes) and studies that include both reactive transport modeling and field observations are especially encouraged.
Conveners: Nina D. Rosenberg, Earth and Environmental Sciences, LLNL, Livermore CA 94550 USA, Phone: +1-510-424-5212, Fax: +1-510-422-3118, E-mail: rosenberg4@llnl.gov; and Barb Dutrow, Department of Geology and Geophysics, Louisiana State University, Baton Rouge LA 70803, Phone: +1-504-388-2525, Fax: +1-504-388-2302, E-mail: dutrow@hermes.geol.lsu.edu
H07 Transport of Particles at the Microscale
There is an explosion of research exploring the transport of viruses, bacteria, colloids, and particle-facilitated contaminant transport in porous and fractured media. Most of this work is at a scale that is orders of magnitude greater than typical particle sizes; there is much less work at the microscopic scale. Research contributions that explore how particle characteristics, variations in mineral surface properties, void space geometry, and their interactions affect the particle transport in geologic media are sought. We envision talks on novel surface characterization techniques, small-scale transport experiments, flow visualization studies, and theoretical analyses.
Conveners: Carlo Montemagno, Department of Agricultural Engineering, Cornell University, Ithaca, NY, Phone: +1-607-255-2280, Fax: +1-607-255-4080, E-mail: cdm11@cornell.edu; and James E. Saiers, Department of Geology, Florida International University, Miami, FL 33199, Phone: +1-305-348-3117, Fax: +1-305-348-3977, E-mail: saiers@fiu.edu
H08 Impact of Physical and Chemical Heterogeneity on Reactive Transport in Geological Media
Understanding reactive solute transport in geological media is relevant to many important environmental problems. Spatial variability in physical and chemical properties of geologic media significantly impacts reactive transport at the field scale. Theoretical developments and computational studies have addressed a variety of reactive transport problems. However, characterizing heterogeneity of the reactive properties of aquifer material and fracture surfaces remains a challenge. Contributions are solicited on approaches to characterizing chemical heterogeneity, including direct measurements and correlations to hydraulic properties or texture. This session will bring together contributions on field observations of chemical heterogeneity and reactive transport, computational studies, and theoretical predictions.
Conveners: Hari Rajaram, Department of Civil Engineering, University of Colorado, Boulder, CO 80309-0428, Phone: +1-303-492-6604, Fax: +1-303-492-7317; E-mail: hari@spot.colorado.edu; and Richelle M. Allen-King, Department of Geology, Washington State University, Pullman, WA 99164-2812, Phone: +1-509-335-1180, Fax: +1-509-335-7816, E-mail: allenkng@wsuvml.csc.wsu.edu
H09 The Influence of Landscape and Land Use on Climate Variability and Change on the Regional and Global Scales
Land use change and heterogeneity have been hypothesized to have impacts on climate that are at least as large as doubling of greenhouse gas concentrations. This session highlights papers that support or refute the hypothesis, with a goal of establishing whether land use change and heterogeneity and biophysical, biogeochemical and biogeographic processes are important climatic influences on regional and global scales and must be included in climate change assessments.
Conveners: Roger A. Pielke Sr., Department of Atmospheric Sciences, Colorado State University, Fort Collins, CO 80523, Phone: +1-970 491-8293, Fax: +1-970 491-8293, E-mail: dallas@hercules.atmos.colostate.edu; and Roni Avissar, Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901-8551, Phone: +1-732 932-9520, Fax: +1-732 932-1038, E-mail: avissar@gaia.rutgers.edu
H10 Land-Atmosphere Exchange: From Experiments to Theory and Models
The land-atmosphere processes linking vegetated surfaces to the atmosphere coexist over a wide range of space and timescales. Physical and physiological measurement and modeling of these processes are progressing with little exchange between these two disciplines. This session highlights recent developments in experiments and process-oriented physical and biophysical modeling of these processes. Abstracts are solicited that concern relevant contributions from (1) turbulence modeling, (2) measurements of land-atmosphere exchange at different scales, (3) scaling from leaf to canopy, and (4) parameterization of land surface process for numerical models.
Convener: Gabriel Katul, School of the Environment, Duke University, Durham, NC 27708-0328, Phone: +1-919-613-8033, Fax: +1-919-684-8741, E-mail: gaby@duke.edu, and John Albertson, Department of Environmental Science, University of Virginia, Charlottesville, VA 22903, Phone: +l-804-924-7241, Fax: +1-804-982-2137, E-mail: jdalbertson@virginia.edu
H11 Mechanistic Controls of Soil Moisture Dynamics
Presentations are invited on theoretical and experimental aspects of soil moisture transport in the vadose zone near the land-atmosphere interface including aspects dealing with (1) infiltration and water movement in soils; (2) soil-plant-atmosphere continuum; (3) mechanics of coupled heat and water movement in soils; and (4) evaporation into the atmosphere. In addition, papers are requested which focus on measurement techniques and their application in both the lab and field. New numerical, analytical or stochastic approaches which lead to improved understanding of soil moisture dynamics and the measurement of soil hydraulic properties are most welcome.
Conveners: Marc B. Parlange, Johns Hopkins University, Baltimore MD 21218, Phone: +1-410-516-6042, Fax: +1-410-516-8996, E-mail: mbparlange@jhu.edu; and Jan W. Hopmans, Department of Land, Air, and Water Resources, University of California, Davis, CA 95616, Phone: +1-530-752-3060, Fax: +1-530-752-5262, E-mail: jwhopmans@ucdavis.edu
H12 Scaling, Multifractals, and Nonlinear Variability in Precipitation and Hydrology (Joint with U)
Fractals, multifractals, and other scaling techniques have already shown their great potential for modeling the variability and intermittency with the help of various scale invariant properties and exponents. This session will be devoted to the most recent theoretical and operational developments and applications of scaling approaches to characterize hydrological porous media and to model precipitation, surface, and groundwater processes. This session seeks to confront data and theories in areas which include raingauge, radar (and other remotely sensed) rainfall measurements and analyses; run-off and river flows (including extreme events, floods); river networks (including the relationship between the networks, topography, and other geophysical fields); and subsurface hydrology including groundwater pollution, hydraulic conductivity, and transport through scaling media.
Conveners: Shaun Lovejoy, Physics Department, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8, Canada, Phone: +1-514-398-6537, Fax: +1-514-398-8434, E-mail: lovejoy@physics.mcgill.ca; and D. Schertzer, Laboratoire de Modelisation en Mechanique, B.P. 162, Universite Pierre et Marie Curie, 4 Place Jussieu, Paris, 75005, France, Phone: +33-1-44274963, Fax: +33-1-44276272, E-mail: schertze@allegro.lmd.jussieu.fr
H13 Regional Hydrologic Variations and the 1997-1998 El Niño
The tremendous impact of the 1997-1998 El Niño on global water resources has sparked an increased awareness of El Niño-Southern Oscillation (ENSO) relationships. This session will provide a forum for the discussion of ENSO impacts on regional hydrology and the implications of climate/hydrologic forecasts. Papers are invited that report on the hydrologic anomalies present during El Niño events, that develop methodologies for making long-range climate/hydrologic forecasts, and that demonstrate the use and limitations of such forecasts for better management of water resource systems.
Conveners: T. Piechota, UCLA, Department of Civil and Environmental Engineering, Los Angeles, CA 90095-1593, Phone: +1-310-206-8612, Fax: +1-310-206-7245, E-mail: piechota@ucla.edu; and D. Cayan, Scripps Institution of Oceanography and USGS, La Jolla, CA 92093-0224, Phone: +1-619-534-4507, Fax: +1-619-534-8561, E-mail: dcayan@ucsd.edu
H14 Relations and Interactions Between Water, Energy, and Carbon Exchange at Varied Spatial and Temporal Scales
Total evaporation couples water and energy balance equations, while transpiration, which is a major component of total evaporation, is coupled to carbon exchange by the terrestrial plant communities. Interactions and relations among these processes have been proposed in various forms, including water and radiation use efficiencies and evaporative fraction. Papers are solicited which will review these relations and interactions at varied spatial and temporal scales and address issues related to spatial and temporal scaling. Models, surface observations, and satellite data in pursuit of these relations and scaling characteristics are of interest. Also of interest are papers identifying current limitations in models and data and approaches to rectify these limitations for regional and global studies and to assess seasonal and interannual variabilities.
Conveners: Bhaskar J. Choudhury, Code 974, NASA Goddard Space Flight Center, Greenbelt, MD 20771, Phone: +1-301-286-5155, Phone: +1-301-286-5155, Fax: +1-301-286-1758, E-mail: bchoudhury@hydro4.gsfc.nasa.gov; and Randal Koster, Code 974, NASA Goddard Space Flight Center, Greenbelt, MD 20771, Phone: +1-301-286-7061, Fax: +1-301-286-1758, E-mail: koster@janus.gsfc.nasa.gov
H15 Observations and Modeling of Land Surface Hydrological Processes
There have been numerous studies in recent years on land surface hydrological processes. These include approaches such as the use of observations from field experiments to study the dynamics of land surface behavior, numerical modeling of the evolution of land surface response to solar heating and precipitation, the comparison of simulations to observed quantities from field experiments, and the use of satellite remote sensing data to both drive and validate hydrological models. It is widely believed that the combination of field observations and satellite data with hydrological models will produce improved estimates of hydrologic fluxes and energy budgets. This session will explore this concept through examination of a broad range of topics: water and energy budgets; soil moisture; runoff; streamflow; surface temperature; latent; sensible; ground heat; and net radiation fluxes. Papers dealing with any one or a combination of the above topics are invited for this special session.
Conveners: Venkataraman Lakshmi, NASA Goddard Space Flight Center, Mail Code 910.4, Greenbelt MD 20771, Phone: +1-301-286-9040, Fax: +1-301-286-1757, E-mail: venkat@spectra.gsfc.nasa.gov; and John D. Albertson, Department of Environmental Sciences, Clark Hall, University of Virginia, Charlottesville, VA 22903, Phone: +1-804-924-7241, Fax: +1-804-982-2137, E-mail: jdalbertson@virginia.edu
H16 Impact of Global Environmental Change on the Hydrological Cycle
One of the most tangible aspects of global environmental change may be its impact on the hydrological cycle at regional and global scales. The goal of this session is to summarize the current understanding of such changes. Papers are solicited on documented or anticipated changes in all components of the hydrological cycle (water vapor, clouds, precipitation, sea surface fluxes and land surface processes) in response to observed or predicted rates of global warming. Of particular interest are analyses of long-term, ground-based, and satellite observational data sets, and results of long-term simulations using regional and global climate models. Papers dealing with the potential of EOS-era satellites to document long-term variations in the global water cycle are also welcome.
Conveners: Jay Famigletti, Department of Geological Sciences, University of Texas, Austin, TX 78712, Phone: +1-512-471-3824, Fax: +1-512-471-9425, E-mail: jfamiglt@maestro.geo.utexas.edu; and Eric Barron, Earth System Science Center, Pennsylvania State University, University Park, PA 16802-2711, Phone: +1-814-865-1619, Fax: +1-814-865-3191, E-mail: eric@essc.psu.edu
H17 Relationships Between the Composition of the Atmosphere and Snow
The processes by which atmospheric impurities are incorporated into snow and those which control the redistribution of water vapor and many chemicals between air and snow and within the snowpack after deposition are complex. Limited understanding of these processes has made quantitative inversion of glaciochemical records to past atmospheric composition records a major challenge. This session is intended to provide an update on the status of recent field campaigns in Greenland and Antarctica with emphasis on first year-round sampling program at Summit, Greenland (June 1997 to April 1998). We invite contributions about sites in Antarctica, Greenland, alpine glaciers, laboratory tests, as well as models of air/snow exchange and inverse models producing paleoatmosphere reconstructions.
Conveners: Jack Dibb, GRG/CCRC/EOS, Morse Hall, University of New Hampshire Durham, NH 03824, Phone: +1-603-862-3063, Fax: +1-603-862-2124, E-mail: jack.dibb@unh.edu; and Andrew G. Fountain, Geology, Portland State University, Portland, OR 97207-0751, Phone: +1-503-725-3386, E-mail: fountaina@pdx.edu
H18 Snow Hydrology
The storage and modulated release of water from seasonal snowpacks are major components of hydrologic systems in many parts of the world, particularly in the western portions of the United States and Canada. This session will address a broad range of topics that are important to understanding this important resource. We are soliciting poster presentations on all aspects of snow hydrology in general, with emphasis on the following specific topics: snow measurement and monitoring techniques and instruments; investigations into physical properties of snow linking microscale properties to macroscale processes; snow stability and avalanches; snowcover modeling in vegetated and complex terrain; and remote sensing of snow cover properties and extent.
Conveners: Danny Marks, USDA-ARS, Northwest Watershed Research Center, 800 Park Blvd, Suite 105, Boise, ID 83712, Phone: +1-208-422-0721, Fax: +1-208-334-1502, E-mail: danny@quercus.ars.pn.usbr.gov; Janet Hardy, US Army CRREL, 72 Lyme Road, Hanover, NH 03755, Phone: +1-603-646-4306, Fax: +1-603-646-4278, E-mail: jhardy@crrel41.usace.army.mil; and Robert Davis, US Army CRREL, CECRL RG, 72 Lyme Road, Hanover, NH 03755-1290, Phone: +1-603-646-4278, Fax: +1-603-646-4278, E-mail: bert@hanover-crrel.army.mil
H19 Glaciers and Ice Sheets
The complexity of glacier systems (mechanical, constitutive, thermal, chemical) probably precludes ever obtaining a fully deterministic understanding. Although concentration of efforts on selected aspects of glacier dynamics is essential to progress, it is often unclear what aspects should be selected. What problems in glacier dynamics promise to yield the greatest scientific benefit once solved? Which tools presently in use, or in development, can add significantly to our broad understanding of glacier processes? How can related fields, such as glacial geology, be better integrated into glacier dynamics research? Submissions of papers concerning all aspects of glaciers and ice sheets and particularly those dealing with the theme of this year's session are encouraged.
Conveners: W. Tad Pfeffer, Institute of Arctic and Alpine Research, CB-450, University of Colorado, Boulder CO 80309-0450, Phone: +1-303-492-3480, Fax: +1-303-492-3480, E-mail: pfeffer@tintin.colorado.edu; and Andrew G. Fountain, Geology, Portland State University, Portland, OR 97207-0751, Phone: +1-503-725-3386, Fax: +1-503-725-3025, E-mail: fountaina@pdx.edu
H20 Hydrologic and Sedimentation Effects of Forest Roads
Research has shown that the sediment budget and hydrologic response of forested basins are affected by the presence of roads. Recent modeling studies have sought to improve our understanding of linkages between plot scale processes and watershed scale effects. The session will cover examinations of the effects of forest roads and encourage discussion about scaling road effects, improving road design, and road closure.
Conveners: Charlie Luce, U.S. Forest Service, 316 East Myrtle, Boise, ID 83702, Phone: +1-208-373-4382, Fax: +1-208-373-4391, E-mail: cluce@rmci.net; and Beverley Wemple, Forest Science, Oregon State University, Corvallis, OR 97331, Phone: +1-541-737-6592, E-mail: wempleb@ccmail.orst.edu
H21 Statistical Methodology in Hydrology
New statistical methodology is currently being developed and applied to a variety of different hydrologic problems to gain a better understanding of the hydrologic phenomena and/or to help improve water resource management schemes. These techniques often involve interdisciplinary approaches, crossing traditional boundaries of deterministic and stochastic hydrology. In this session, researchers applying new statistical methodology can present their current research and obtain feedback from others working on similar issues. Research topics may include, but are not limited to, regionalization techniques in hydrology, prediction of extreme hydrologic events, management techniques for water allocation, forecasting hydrologic change due to potential global climate fluctuations, and associated issues of uncertainty quantification and risk assessments in hydrology.
Conveners: Chuck Kroll, Environmental Resources Engineering, SUNY ESF, Syracuse, NY 13210, Phone: +1-315-470-6699, E-mail: cnkroll@mailbox.syr.edu; and Richard Vogel, Civil and Environmental Engineering, Tufts University, Medford, MA, 02155, Phone: +1-617-628-5000 x4260, Fax: +1-617-627-3994, E-mail: rvogel@emerald.tufts.edu
H22 The Role of Digital Terrain Modeling and Analysis in Hydrological Modeling
The use of digital terrain models (DTMs) within hydrological models is now common. The representation of topographic structure, gradients, and apparent flow paths has become a key component of both runoff generation and routing algorithms. Most research papers and presentations focusing on this area now have a terrain analysis section. However, the issues of DTM quality, resolution, and the assumptions behind the hydrological models are often not fully discussed. This session seeks to redress this anomaly with a set of presentations that lift the terrain analysis component from within their modeling projects and lay them open for scrutiny.
Conveners: Paul Quinn, Water Resources Engineering, Department of Civil Engineering, University of Newcastle Upon Tyne, Newcastle NE1 7RU, United Kingdom, Phone: +44-191-222-5773, Fax: +44-191-222-6669, E-mail: P.F.Quinn@newcastle.ac.uk; and Larry Band, University of North Carolina, Chapel Hill, NC 27599, Phone: +1-919-962-3921, Fax: +1-919-962-1537, E-mail:lband@geog.unc.edu
H23 The Links Between Soil Properties, Terrain Features, and Runoff Processes in Catchments
The current geomorphic attributes of a landscape including soil catena, drainage density and channel and valley morphology strongly influence the modern hydrologic processes found there. Over long time periods there is feedback between the dominant hydrologic processes and geomorphic evolution of a landscape. Poster and oral contributions are invited that report on experimental or theoretical investigations into relationships between catchment geomorphology and hydrologic process. The session aims to provide a framework for improving models of catchment hydrology and landscape evolution.
Conveners: Riccardo Rigon, Dipartimento di Ingegneria Civile e Ambientale, Universita di Trento, I-38050 Mesiano di Povo (TN), Italy, Phone: +39-0461-882610, Fax: +39-461-882672, E-mail: riccardo@itnca1.ing.unitn.it; and Cathy Wilson, CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia, Phone: +61-26-246-5816, Fax: +61-26-246-5800, E-mail: cathy.wilson@cbr.clw.csiro.au
H24 Parameter Estimation and Data Assimilation Issues in Hydrologic Modeling
The purpose of this session is to summarize recent investigations involving the incorporation of diverse digital hydrometeorological data (e.g. from point sources, radars, atmospheric models, and remote sensing) in hydrological modeling and forecasting. Contributions on the following topics are encouraged: (1) the development of objective parameter estimation techniques, (2) appropriate methods of distributing data for use in distributed-parameter models, (3) data assimilation strategies for hydrometeorological data, (4) evaluation of the accuracy and robustness of various digital data sets, (5) effects of scale, process complexity, and uncertainty on parameter estimation and data assimilation, and (6) implications of interdependence, feedback, and error propagation in the integration of diverse hydrometeorological data sets.
Conveners: Don Cline, NWS, 1735 Lake Drive West, Chanhassen, MN 55317, Phone: +1-612-361-6610 x252, Fax: +1-612-361-6634, E-mail: cline@nohrsc.nws.gov; and George Leavesley, USGS, MS 412, Denver, CO 80225, Phone: +1-303-236-5026, Fax: +1-303-236-5034, E-mail: george@usgs.gov
H25 See Session H15
H26 Monitoring and Modeling of the Performance of Engineered Covers for Waste Isolation
Engineered covers, including simple monolithic covers and complex layered systems, are being used widely to minimize net infiltration into contaminated areas and into newly developed waste disposal facilities. This session will evaluate the performance of different designs, optimal monitoring schemes, and numerical modeling of engineered covers. Papers dealing with any of these topics are invited for this session.
Conveners: Bridget Scanlon, Bureau of Economic Geology, University of Texas at Austin, University Station, Box X, Austin, TX 78713, Phone: +1-512-471-8241, Fax: +1-512-471-0140, E-mail: scanlonb@begv.beg.utexas.edu; and Glendon Gee, Pacific Northwest National Laboratory, Phone: +1-509-372-6096, Fax: +1-509-372-6089, E-mail: glendon.gee@pnl.gov
H27 Interphase Mass Transfer in NAPL-Contaminated Goundwater Systems
Mass exchanges between NAPL, aqueous, gas, and solid phases are important processes with regard to the ultimate fate of NAPLs in the subsurface. However, our ability to quantify rates of interphase mass exchange at the field scale is still insufficient. Multiphase mass exchange processes have been investigated intensely in other disciplines, notably chemical engineering. The intent of this session is to bring together researchers and practitioners from the hydrology and chemical engineering communities. The session will include results from theoretical, mathematical modeling, laboratory, and field
studies.
Conveners: Alex Mayer, Department of Geological Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, Phone: +1-906-487-3372, Fax: +1-906-487-3372, E-mail: asmayer@mtu.edu; Tissa Illangasekare, Division Environmental Sciences and Engineering, Colorado School of Mines, Golden, CO 80401, Phone: +1-303-492-6644, Fax: +1-303-492-7317, E-mail: tillanga@mines.edu; and Danny Reible, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803, Phone: +1-504-388-1426, Fax: +1-504-388-1476, E-mail: cmreib@lsuvm.sncc.lsu.edu
H28 Scaling Issues in Vadose Zone
Vadose zone measurements are used to manage water and chemicals in agricultural and waste management, and to quantify near-surface, soil moisture changes. Using measurements collected at a variety of spatial scales, data are used to solve basic and applied problems ranging from point scale to basin scale. The need to scale point measurements to field- and basin-scale processes is consistent with the need to downscale volume-averaged measurements to small-scale processes. The goal of this session is to seek relationships and their uncertainties between local-scale measurements and basin-scale vadose zone processes (upscaling, aggregation) and vice versa (downscaling, disaggregation).
Conveners: Jan W. Hopmans, Hydrology Program, Department of Land, Air and Water Resources, 123 Veihmeyer Hall, University of California, Davis, CA, 95616, Phone: +1-530-752-3060, Fax: +1-530-752-5262, E-mail: jwhopmans@ucdavis.edu; and Michael H. Young, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0512, Phone: +1-404-894-5009, Fax: +1-404-894-8266, E-mail: youngmh@ce.gatech.edu
H29 Preferential Flow in Unsaturated and Multiphase Systems: Connecting Simulations to Field and Laboratory Observations
In unsaturated or multiphase systems, preferential flow paths may develop as a
result of abrupt changes in material properties, spatial variation in phase
saturation, or physical processes of fluid-fluid displacement. Failure to
properly consider such phenomena may result in the misinterpretation of field
observations or the underestimation of transport velocities. Numerical
simulation of preferential flow is hindered by the requisite sharp changes in
material properties (spatial) and/or phase saturation (spatial and temporal).
This session will consider innovative numerical and analytic techniques for
simulating preferential flow in unsaturated and multiphase systems. Field and
laboratory investigations that are designed to elucidate processes or provide
validation for numerical simulations are also encouraged.
Conveners: Michael Nicholl, School of Geology, Oklahoma State University, Stillwater, OK 74078, Phone: +1-405-744-6358, Fax: +1-405-744-7841, E-mail: nicholl@okway.okstate.edu; and Jiamin Wan, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 90-1116, Berkeley, CA 94720; Phone: +1-510-486-6004, Fax: +1-510-486-7797, E-mail: jwan@lbl.gov
H30 Mixing Analysis in Hydrology: Reassessing Assumptions, Evaluating Tracers, and Scaling Up
Mixing models have turned into the tool of choice in deducing runoff sources at the small catchment scale, despite the potential for violating assumptions necessary for their use. What constitutes an adequate data set for their application? Contributions are solicited that explore the assumptions of temporal invariance in concentration, geographic extent of runoff source, conservative behavior of tracers, and application of mixing analysis to larger river basins.
Conveners: Helmut Elsenbeer, University of Bern, Institute of Geography, Hallerstr. 12, CH-3012 Bern, Switzerland, Phone: +41-316313855, Fax: +41-316318511, E-mail: elsenbeer@giub.unibe.ch; and Richard P. Hooper, U.S. Geological Survey, 3039 Amwiler Road, Suite 130, Atlanta, GA 30360, Phone: +1-770-903-9146, Fax: +1-770-903-9199, E-mail: rphooper@usgs.gov
H31 Hydrophobic Organic Compounds in Rivers
Understanding the transport and fate of hydrophobic organic compounds in rivers has been hampered by their low solubilities, the complexity of partitioning processes, and the large number of compounds to be considered. This session invites contributions on innovative field technologies, such as semipermeable membrane devices; quantitative techniques for investigating in situ partitioning of these compounds among water, biota, and sediment; and creative applications of methods for interpreting multi-dimensional data sets.
Conveners: Valerie Kelly and Kathy McCarthy, Both at: U.S. Geological Survey, 10615 SE Cherry Blossom Drive, Portland, OR 97216; Phone: +1-503-251-3244, Fax: +1-503-251-3470, E-mails: (Valerie Kelly) vjkelly@usgs.gov, (Kathry McCarthy) mccarthy@usgs.gov
H32 Water Quality of Hydrologic Systems
Submissions for poster presentations are invited on all aspects of water quality and tracers in hydrology, including field, laboratory, or theoretical work, directed at groundwater or surface water, at any spatial scale. Presentations may range from the use of solutes purely as tracers of water movement to investigations focused mainly or solely on geochemical processes/reactions. Both contaminants and naturally occurring chemicals species are appropriate for this session.
Conveners: David Genereux, Geology Department and Southeast Environmental Research Program, Florida International University, Miami, FL 33199, Phone: +1-305-348-3119, Fax: +1-305-348-3877, E-mail: genereux@fiu.edu; and James A. Smith, Department of Civil Engineering, University of Virginia, Charlottesville, VA 22903-2442 USA, Phone: +1-804-924-7991, E-mail: jsmith@virginia.edu
H33 Biogeochemistry of Forested Ecosystems (Posters)
The watershed unit is particularly well-suited for integrated studies of forested ecosystems because the integrated system response can be observed. Posters are solicited on biological and hydrogeochemical processes in forested ecosystems, watershed ion budgets, storm and snowmelt events, selection of representative catchments for study, experimental manipulation of catchments, biogeochemical modeling of forested catchments, and long-term monitoring of catchment response to environmental perturbations.
Conveners: Robbins Church, U.S. EPA, 200 SW 35th Street, Corvallis, OR 97333, Phone: +1-541-754-4424, Fax: +1-541-754-4716, E-mail: church@mail.cor.epa.gov; and Rick Hooper, U.S. Geological Survey, 28 Lord Road, Suite 280, Marlborough, MA 01752, Phone: +1-508-490-5069, Fax: +1-508-490-5068, E-mail: rphooper@fs1dgadrv.er.usgs.gov
H34 Geothermal Effects on Water Quality (Joint with VGP)
Volcanic and associated geothermal activity often elevate concentrations of major ions, trace metals, and silica. Influences on ecosystems include eutrophication of receiving waters and impairing the suitability of water for various uses. This session will focus on recent insights into how geothermal processes influence water quality. Presentations on field, laboratory, or theoretical work are welcome.
Conveners: David Genereux, Geology Department and Southeast Environmental Research Program, Florida International University, Miami, FL 33199, Phone: +1-305-348-3119, Fax: +1-305-348-3877, E-mail: genereux@fiu.edu; and Johan C. Varekamp, Department of Earth and Environmental Sciences, 265 Church Street, Wesleyan University, Middletown, CT 06459-0139, Phone: +1-860-685 2248, Fax: +1-860-685-3651, E-mail: jvarekamp@wesleyan.edu
H35 Physical and Chemical Remediation of Contaminated Aquifers
This session examines recent innovative techniques for the removal and/or stabilization of contaminants in the subsurface. Suggested topics include, but are not limited to, air sparging (including physical and chemical techniques to increase mass transfer or to enhance bioremediation), electrokinetic treatment for the removal of metals, in situ vitrification for the stabilization of inorganic contaminants, and surfactant enhanced remediation of organics. Both experimental data and model interpretations are welcome; however, studies that include both aspects are especially encouraged.
Conveners: Susan E. Burns, Department of Civil Engineering, University of Virginia, Charlottesville, VA 22903-2442, Phone: +1-804-924-6370, Fax: +1-804-982-2951, E-mail: sburns@virginia.edu; and James A. Smith, Department of Civil Engineering, University of Virginia, Charlottesville, VA 22903-2442, Phone: +1-804-924- 7991, E-mail: jsmith@virginia.edu
H36 Dynamics of Sediment-Laden Flows
New insight into the dynamics of sediment transport by riverine and coastal waters and the complex interactions between fluid, sediment, and bottom topography is critical for assessing erosion and sedimentation problems, for developing watershed and oceanic models, and for analyzing two-phase flows. Topics to be addressed in this session include the mechanics of sediment suspension and transport, turbulence modulation, linking sediment flux with coherent turbulent flow structures, flow energetics, processes of sediment dispersion, temporal and spatial variability of suspended sediment transport, and improved techniques such as laser anemometry, particle image velocimetry, and acoustics.
Conveners: Sean J. Bennett, USDA-ARS, National Sedimentation Laboratory, P.O. Box 1157, Oxford, MS 38655, Phone: +1-601-232-2926, Fax: +1-601-232-2915, E-mail: bennett@sedlab.olemiss.edu; and Marian Muste, Iowa Institute of Hydraulic Research, University of Iowa, Iowa City, IA 52242-1585, Phone: +1-319-384-0622, Fax: +1-319-335-5238, E-mail: marian-muste@uiowa.edu
H37 El Niño, Landslides, and Coastal Retreat
What lessons have we learned from the past El Niño season about landslide and coastal erosion processes? With rainfall accumulations of roughly 200% of normal, ancient deep-seated landslides are becoming reactivated, while the occurrences of catastrophic debris flows were fewer than expected. Coastal erosion was exacerbated by high sea levels reflecting the elevated sea surface temperatures, regional low-pressure conditions, south to north prevailing winds, and periodic storm surges. Will the events of last year help with future land use planning decisions? What research is needed? Is landslide insurance a practical solution or is litigation the only reasonable redress?
Conveners: David G. Howell, U.S. Geological Survey, MS 975, 345 Middlefield Road, Menlo Park, CA 94025, Phone: +1-650-329-5430, Fax: +1-650-329-4936, E-mail: dhowell@octopus.wr.usgs.gov; and William Z. Savage, U.S.Geological Survey, P.O. Box 25046, MS 966, Lakewood, CO 80225, Phone: +1-303-273-8635, E-mail: savage@usgs.gov or savage@gldvxa.cr.usgs.gov
H38 From Chemical Mechanisms to Field-Scale Transport
The understanding of field-scale pollutant transport based on mechanistic
chemical information from laboratory-scale experiments remains a challenging
research area. The purpose of this session is to present recent advances in
this area. The papers presented in this session will focus on the following
areas: (1) laboratory studies of sorption, dissolution, and precipitation
reactions relevant to pollutant transport; and (2) field scale observations and
modeling of pollutant transport and weathering based on chemical mechanisms
from laboratory experiments.
Convener: Stephan Kraemer and Sing-Foong Cheah, Division of Ecosystem Sciences-ESPM, 151 Hilgard Hall, University of California-Berkeley, Berkeley, CA 94720-3110, Phone: +1-510-643-9951, Fax: +1-510-643-5098, E-mail: (Stephan Kraemer) skraemer@uclink4.berkeley.edu or (Sing-Foong Cheah) sfcheah@nature.berkeley.edu, and Janet Hering, California Institute of Technology, 1200 E. California Blvd., Environmental Engineering Science, MC 138-78, Pasadena, CA 91125, Phone: +1-626-395-3644, Fax: +1-626-395-2940, E-mail: jhering@cco.caltech.edu
H39 Dilution and Mixing in Intrinsic and Enhanced Bioremediation
Chemical transformations in the context of natural and enhanced in-situ bioremediation are controlled by the interaction of multiple species. When the transformation rate laws are nonlinearly dependent on the reactant concentrations, small-scale mixing of reactants controls transformation rates and macroscopic chemical kinetics. While considerable work has been done on nonreactive transport in aquifers, sensitivities of multispecies reactions are less explored. It remains to be shown whether/how it is possible to incorporate such reactions in models to make predictions at scales of practical interest. Papers on applications, laboratory and field experiments, numerical simulation, and analysis that reveal the nature of dilution, mixing, and chemical/biological transformations are welcome.
Conveners: Vivek Kapoor, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0355, Phone: +1-404-894-2216, Fax: +1-404-894-2677, E-mail: vkapoor@ce.gatech.edu; and Peter K. Kitanidis, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, Phone: +1-650-723-8321, Fax: +1-650-725-9720, E-mail: kitanidis@cive.stanford.edu
H40 Studies on Issues of Subgrid Spatial Variabilities (Joint with A)
Recent field experiments, remote sensing analyses, and numerical modeling studies have all indicated the importance of representing spatial variabilities that arise from subgrid heterogeneity in land surface cover, surface topography, soil properties, and cloud/precipitation processes in land surface and climate models. This session aims to provide a forum for reporting recent findings in this area. A broad range of topics from data analysis, numerical
modeling, and development of subgrid parameterizations to methods for aggregation and disaggregation of data and model parameters are welcome on studies of subgrid spatial variabilities related to clouds, precipitation, surface fluxes, soil moisture, and runoff processes.
Conveners: L. Ruby Leung, Pacific Northwest National Laboratory, Richland, WA 99352, Phone: +1-509-372-6182, Fax: +1-509-372-6168, E-mail: ruby.leung@pnl.gov; and Xu Liang, Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710, E-mail: liang@ce.berkeley.edu
Ocean Sciences (OS) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
OS01 Salinity Remote Sensing From Aircraft and Satellite
The session will address recent developments and concepts toward present-day airborne and future satellite measurements of sea surface salinity (SSS) within next decade, and will focus on the scientific and technical merits of such programs. Airborne systems are evolving from engineering and development to scientific instruments for regional process studies. Various satellite systems are in design and proposal phases. Retrieval errors from satellite are expected to be in the range of ~0.1 to ~1 psu for ~7-30 day and ~40-100 km averages, depending on the specifics of the instrument and environmental variables. A Salinity Sea Ice Working Group (SSIWG) has recently proposed three broad primary scientific objectives for satellite measurement: (1) Improving seasonal to interannual (ENSO) climate predictions, (2) improving ocean rainfall estimates and global hydrologic budgets, and (3) monitoring large scale salinity events, including interannual SSS variability in the Nordic seas. Keynote invited papers will describe the measurement principles, various mission designs and their prospective SSS accuracy, and the potential scientific impact of the data. Contributed papers are solicited addressing the need and application of such measurements for diagnostic and regional process studies, model assimilation, flux corrections, climate prediction, hydrological cycle, synergy with in situ observations (CLIVAR, GOOS), marginal seas, sea ice and ice melt, runoff, etc.
Conveners: Gary S.E. Lagerloef, Earth and Space Research, 1910 Fairview Ave E, Suite 102, Seattle, WA 98102 USA; Tel: +1-206-726-0501 ext 11, Fax: +1-206-726-0524, E-mail: lagerloef@esr.org; Web-page: http://www.esr.org; and Jerry L. Miller, Naval Research Laboratory, Code 7332, Stennis Space Center, MS 39529 USA; Tel: +1-228-688-4169, Fax: +1-228-688-5997, E-mail: jmiller@nrlssc.navy.mil
OS02 Formation of Sedimentary Strata on Continental Margins
Sedimentary strata accumulating on continental margins preserve a
high-resolution record of environmental processes occurring on land (e.g.,
floods) and in the ocean (e.g., sea level change). The ability to
investigate the record of environmental events requires that the character
of ancient strata be documented well (through seismic profiling and
coring/drilling) and that studies of modern processes and strata provide
keys for interpreting the formative conditions for ancient strata. A
number of ongoing studies are investigating the formation of strata on
margins, and this is an ideal time to disseminate and exchange insights.
Papers are invited that present observational, experimental, and modeling
results related to the mechanisms forming margin strata and to better
interpretation of strata.
Convener: Charles A. Nittrouer, School of Oceanography, University of Washington, Seattle, WA 98195-7940, Phone: +1-516-632-8652, E-mail: cnittrouer@ocean.washington.edu
OS03 From Intergrating Observations on Individuals to Predicting Changes in Planktonic Ecosystems
Most research on planktonic life forms as individuals is done in the
laboratory. These observations, sometimes in minute details and at small
temporal and spatial scales, form the basis of our knowledge about the
evolutionary and ecological roles individuals may play in the much larger
ecosystems of the water column. However, to infer with accuracy from
results gained by in vitro experimentation to the behavior of larger water
bodies as ecosystems is a step not yet fully mastered in biological
oceanography. This special session will address the different approaches,
such as fractal geometry and artificial intelligence, which could bridge
the gap between the laboratories and the seas. Speakers from different
backgrounds and with experiences on different aspects of the problem will
analyze the approaches and help to synthesize the solutions.
Conveners: J. Rudi Strickler, WATER Institute, UWM, 600 E Greenfield Ave, Milwaukee WI 53204, Phone: +1-414-382-1700, Fax: +1-414-382-1705, E-mail: jrs@uwm.edu; and Lynda Shapiro, Oregon Institute of Marine Biology, P.O. Box 5389, Charleston, OR 97420, Phone: +1-541-888-2581, Fax: +1-541-888-3250, E-mail: lshapiro@oimb.uoregon.edu
OS04 Nearshore Processes
This special session concerns the dynamics and interactions of wind, waves, currents, sediment transport, and seabed morphology in nearshore waters. While papers on all aspects of nearshore research are solicited, topics of particular interest include (1) wave propagation and nonlinear wave interaction from the shelf to the shoreline; (2) wave breaking, dissipation, and nearshore circulation; (3) swash processes and beach face evolution; (4) sediment transport, bedforms, and beach morphology; and (5) bottom boundary layer turbulence and small-scale sediment processes. Abstracts may describe work of a theoretical, numerical, or experimental nature.
Conveners: Nicholas Dodd, Coastal Group, HR Wallingford, Howbery Park, Wallingford, OX10 8BA, United Kingdom, Phone: +44-1491-835381, Fax: +44-1491-825539, E-mail: Nick.Dodd@hrwallingford.co.uk; and H. Tuba Ozkan-Haller, Naval Architecture and Marine Engineering, University of Michigan, 2600 Draper Road, Ann Arbor MI 48109-2145 USA, Tel: +1-734-936-2804, Fax: +1-734-936-8820, E-mail: ozkan@engin.umich.edu; Web-page: http://www-personal.engin.umich.edu/~ozkan/
OS05 Application of SeaWiFS Measurements for Understanding Marine and Terrestrial Ecosystems
With over a year of SeaWiFS data available by the time of the Fall AGU
meeting, it is possible to examine the distribution of marine and
terrestrial vegetation over an annual cycle and examine the transition of
the 1997 El Nino to La Nina. The session will focus on the applications of
SeaWiFS data for understanding ecosystem dynamics, physical-biological
interactions, and biogeochemical cycles on all spatial scales. Also,
papers dealing with biooptical algorithms and the validation of standard
and developmental land and ocean SeaWiFS products are solicited for a
poster session.
Conveners: Janet Campbell, MTPE/Code YS, NASA Headquarters, 300 E St., SW, Washington, DC 20546, E-mail: jcampbe1@mail.hq.nasa.gov; and Charles R. McClain, Code 970.2, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, Phone: +1-301-286-5377, Fax: +1-301-286-1775, E-mail: mcclain@calval.gsfc.nasa.gov
OS06 Sedimentation and Tectonics Along a Rift Basin Margin: The Gulf of California
From both tectonic and sedimentologic perspectives, the Gulf of California represents hybrids of existing models. Tectonically, it is a prime example of an oblique-divergent plate boundary which differs significantly from better understood and strictly orthogonal plate boundaries. Sedimentologically, the western margin of the Gulf exhibits mixed carbonate-siliciclastic depositional systems which have been influenced by a complex interplay between tectonics, climate, and sea level since Miocene time. These latter sediments in fact represent a regime transitional in character between extensively studied tropical carbonate settings and less well understood cool-water carbonate environments.
New and exciting research has been undertaken in recent years focusing on (1) analysis of uplifted Neogene sections exposed along the margins of the Gulf of California and (2) oceanographic, tectonic, and biologic patterns and processes controlling Pleistocene-Holocene nearshore, shelf, and slope sedimentation along the western side of the gulf. The goal of this session is to compare and integrate analyses and records of both modern and Neogene sedimentation and tectonics in order to form a more complete and detailed picture of this young rift basin margin and erect more appropriate models for the transitional setting represented by the Gulf of California and similar settings elsewhere in time and space.
Conveners: Jochen Halfar, Stanford University, E-mail: jochen@pangea.stanford.edu; and Enrique Nava, E-mail: enava@vmredipn.ipn.mx
OS07 Broadband Seismology in the Oceans (Joint with S)
This session will focus on marine seismology in the frequency band 0.001-10.0 Hz and the issues involved in extending the global seismic network to the seafloor. These issues include observations and theory of the ambient noise field, earthquake signal detection, comparison of results with land stations, borehole versus seafloor stations, seismometer design and coupling, and the engineering challenges of providing power to and recovering data from long-term seafloor seismic observatories. The relevance of ocean floor seismic data to imaging the earth at regional and global scales and the effects of oceanic processes on the broadband ambient noise field will also be addressed.
Conveners: Ralph Stephen, WHOI, Department of Geology and Geophysics, Woods Hole, MA 02543, Phone: +1-617-548-1400 x2538, Fax: +1-508-457-2150, E-mail: rstephen@whoi.edu; and Fred Duennebier, University of Hawaii, Department of Geology and Geophysics, Honolulu, HI 96822, Phone: +1-808-956-4779, Fax: +1-808-956-4780, E-mail: fred@akule.soest.hawaii.edu
OS08 Recent Advances in Understanding the Arctic System
Climate model studies indicate that potential effects of greenhouse gas emmisions might be amplified in the polar regions. These predictions together with the recent observations of changes in the hydrographic structure of upper waters and the sea ice in the Arctic Ocean have focused our attention on the need for more complete understanding of the Arctic region. The resulting multidisciplinary research involves studies of its climate, oceanography, biology, chemistry, and geophysics. Major research programs initiated during the past years include the Arctic '91 Expedition, the AOS '94 Section, SHEBA, JOIS, and SCICEX, to name just a few. Most of these recent experiments are linked to satellite observations and major modeling studies, which ignificantly contribute to our understading of this region. This session invites contributions on observational, theoretical, and modeling work advancing our knowledge of the coupled ocean - sea ice - atmosphere system in the Arctic. Synthesis and integration of cross-disciplinary field, laboratory, and numerical results are especially welcome. The session encourages broad international participation.
Conveners: Wieslaw Maslowski, Department of Oceanography, Naval Postgraduate School, 833 Dyer Rd. RM 331, Monterey, CA 93943-5122, Phone: +1-408-656-3162, Fax: +1-408-656-2712, E-mail: maslowsk@ucar.edu; and Peter Schlosser, Lamont-Doherty Earth Observatory, Columbia University, P.O. Box 1000, Palisades, NY 10964-8000, Phone: +1-914-365-8707, Fax: +1-914-365-8155, E-mail: peters@ldeo.columbia.edu
OS09 The 1997-1998 El Niño in the World's Oceans (Joint with H)
The 1997-1998 El Niño was the most anticipated, most hyped, and most studied climate event in history. But headlines aside, what were the effects of this El Niño on the world's oceans? We seek presentations that describe the development, progress, and decline of this event. We would like to hear about this event from all angles: model and observations, forecast and reality, large-scale and local, in the extratropical, tropical, and equatorial oceans, coastal oceans, embayments and estuaries. How did this event start? How did its signal reach the extratropics? How does the 1997-1998 event stack up against previous major El Niños? We believe there will be considerable interest in this topic, sufficient to run several sessions.
Themes for El Niño sessions, which will depend on the response to the call for abstracts, could include 1) development of El Niño in the tropics, 2) El Niño teleconnections between the tropics and extratropics, 3) regional effects of El Niño in the North Pacific, 4) local effects of El Niño in the coastal ocean and adjacent embayments, 5) El Niño modeling, and 6) comparison of El Niño forecasts to observations.
Conveners: Marlene Noble, U.S. Geological Survey, 345 Middlefield Road, MS 999, Menlo Park, CA, 94025, Phone: +1-650-329-5411, E-mail: marlene@octopus.wr.usgs.gov; and Franklin B. Scwing, NOAA/NMFS, PFEL, 1532 Lighthouse Avenue, Pacific Grove, CA 93950, Phone: +1-408-648-9034, Fax: +1-408-648-8440, E-mail: fschwing@pfeg.noaa.gov
OS10 Strong-Current Dynamics at Midlatitudes and High Latitudes
The focus will be on the dynamics and fluxes associated with strong currents in midlatitudes and high latitudes, such as the ACC, Kuroshio, Gulf Stream, NAC, and so on. As models have become more sophisticated, and as observational programs have become more detailed, we are now seeing fascinating descriptions of the higher-order dynamics and indirect fluxes (including cross-frontal exchanges) associated with the most energetic midlatitude and high-latitude currents.
Analytical and numerical model submissions are encouraged. In addition, this session is appropriate for researchers describing preliminary results from recently fielded experiments in, for example, the ACC (e.g., the U.S.-Australia Sub-Antarctic Flux and Dynamics Experiment, SAFDE) and the North Atlantic Current (deployed under WOCE/ACCE auspices), as well as from experiments that were completed a few years back and are now turning out polished results (e.g., the Kuroshio Extension Regional Experiment, KERE).
Conveners: Douglas S. Luther, Department of Oceanography, MSB 205, University of Hawaii at Manoa, 1000 Pope Road, Honolulu, HI 96822, Phone: +1-808-956-5875, Fax: +1-808-956-9165, E-mail: dluther@soest.hawaii.edu; and D. Randolph Watts, Graduate School of Oceanography, University of Rhode Island, Kingston, RI 02881, Phone: +1-401-874-6507 E-mail: randy@drw.gso.uri.edu
OS11 Changes in Major and Trace Element Chemistry of the Oceans Over the Plio-Pleistocene
Material is supplied to the oceans in dissolved form via rivers, hydrothermal fluids, and dissolution of atmospheric (and micrometeoritic) dust, while removal is predominantly by burial in marine sediments and alteration of basalt at spreading centers. On the one hand, variations in ocean chemistry over time can be used to monitor changes in input and output fluxes (and thus potentially to identify the controls on the processes that govern these fluxes). On the other, the development of elemental and isotopic tracers as reliable paleoceanographic proxies demands that the time history of their oceanic concentrations be reasonably well constrained. Thus it is desirable to develop as complete a picture as possible of how the chemistry and chemical budget of the oceans have evolved over timescales of thousands to millions of years. The aim of this session is to assemble papers that address variations in the elemental and isotopic budgets of seawater over the Plio-Pleistocene.
Papers are invited that (1) address variations in riverine, hydrothermal, sediment burial, and other fluxes of dissolved material to and from the oceans and (2) evaluate the time variation of concentrations of elements and isotopes used as paleoenvironmental proxies.
Conveners: Rachel Oxburgh, Department of Geology and Geophysics, Edinburgh University, West Mains Road, Edinburgh EH9 3JW, United Kingdom, Phone: ++0131-650-4912, Fax: ++0131-668-3184, E-mail: rachel.oxburgh@glg.ed.ac.uk; and Philip N. Froelich, School of Earth and Atmospheric Sciences, 221 Bobby Dodd Way, Georgia Institute of Technology, Atlanta, GA 30332-0340, Phone: +1-404-894-3944, Fax: +1-404-894-5638, E-mail: philip.froelich@eas.gatech.edu
OS12 Reconstructing Past Tropical Cyclone Frequency During the Last 1000 to 5000 Years
Intense tropical cyclones (hurricanes and typhoons) that reach landfall cause more deaths, damage, and financial loss than any other natural disaster. Estimating the landfall probability of an intense tropical cyclone, or the recurrence interval for other extreme weather phenomena, is difficult because historical records for a given location typically contain few, if any, of these rare events. Estimates of the probability of intense hurricane landfall and extreme weather events are important for global change studies, emergency management planning, and pricing wind and flood insurance. An intense storm can leave a variety of environmental records ranging from sandy overwash deposits in coastal lakes to changes in tree ring records to isotopic signals in carbonate deposits. These types of environmental changes can be used as proxies to extend the historical record and to improve probability estimates for intense landfalling tropical cyclones and other extreme weather events. This session will explore the development and use of different proxies to reconstruct extreme weather events.
Conveners: Richard J. Murnane, Science Program Manager, Risk Prediction Initiative, Bermuda Biological Station for Research, Inc., Ferry Reach, St. George's GEO1 Bermuda, Phone: +441-297-1880 ext. 246, Fax: +441-297-2890, E-mail: rmurnane@bbsr.edu; and David L. Malmquist, Bermuda Biological Station for Research, Ferry Reach, GE01, Bermuda, Phone: +441-297-1880 x255, Fax: +441-297-2890, E-mail: malmquist@bbsr.edu
OS13 Ocean Drilling in Laminated Sediments for High-Resolution Paleoenvironmental Records
This session will focus on diverse studies of terrestrial and oceanic conditions through the Holocene and latest Pleistocene as recorded in
sediments of Saanich Inlet, a fjord on southern Vancouver Island, and Palmer Deep, an Antarctic shelf basin. The results presented are from the Ocean Drilling Program's (ODP) coring during Leg 169S in the Saanich Inlet in August 1996. For much of the Holocene, Saanich Inlet was an anoxic basin resulting in the accumulation of varved sediments which provide an ultra-high-resolution record (seasonal) of environmental change in the region. Results of investigations into past seismic activity, glaciomarine sedimentary processes, geochemistry, magnetic properties, physical properties, fish and plankton communities,terrestrial vegetation, climate variability, and the role of bacteria and viruses in sediment diagenesis will be presented. The Palmer Deep is a neotectonic inner shelf basin influenced by glacial activity on the Pacific side of the Antarctic Peninsula. The Palmer Deep was drilled with two sites during ODP Leg 178 in March of this year. The record has provided an unprecedented resolution of the Holocene for the Southern Ocean (45 m at site 1098) and has recovered pre-glacial maximum succesions (site 1099). The Holocene record has continuously laminated intervals and, on the basis of prior study, contains elements of solar-forced climate variability and productivity changes. Similarity of the Palmer Deep record and the Greenland Ice Sheet Project 2 (GISP2) ice core has already been established for the last 3500 years. The more continuous record will address this correlation in a more rigorous manner. Linkages between the tropical Pacific and the Atlantic might reasonably take place through the Drake Passage, and hence the Palmer Deep may be the best site to evaluate the connection of these two oceanic realms over timescales appropriate to understanding rapid change.
Conveners: Brian D. Bornhold, University of Victoria, Victoria, British Columbia V8W 3H5, Canada, Phone: +1-250-655-4035, E-mail: bornhold@uvic.ca; Alan E.S. Kemp, University of Southampton, Southampton, England, U.K., E-mail: Alan.E.S.Kemp@soc.soton.ac.uk; and Eugene Domack, Hamilton College, E-mail: edomack@hamilton.edu
OS14 Large Lake Records and New Perspectives for Continental Paleoclimate Archives
One approach to determine the role of potential global climate forcing factors is to correlate high-resolution proxy archives. Ice cores and deep-sea records are traditional sources of paleoclimate information with long temporal and spatial resolution. Continental records from non polar regions, however, yield information on environmental responses to climate changes that are most pertinent to human activities. By developing and integrating an interhemispheric network of long continental records, evidence will emerge on the character, rate, and spatial extent of global climate change and its forcing mechanisms.
Modern limnogeology studies large lake basins in the same fashion as paleoceanography studies marine basins, applying similar methods and techniques. Today, there is a growing interest within the paleoclimate community in linking marine and terrestrial records to obtain better regional and global paleoclimatic reconstructions. Recovery of long paleoclimate records from large lakes that cover in some cases several glacial-interglacial cycles provides ideal archives to accomplish this link. Furthermore, these lake studies have recently become a major focus of the International Geosphere-Biosphere Past Global Change Program (IGBP-PAGES). Papers covering a wide range of aspects such as seismic surveys of lacustrine basins and neolimnology as well as paleolimnology of the recovered sediments are invited from presently
ongoing research projects in large lakes all over the world.
Conveners: Daniel Ariztegui, Laboratory of Limnogeology, Geological Institute, Swiss Federal Institute of Technology (ETH), Sonneggstrasse 5, ETH-Zentrum, 8092 Zuerich, Switzerland, Phone: +41-1-632-3673, Fax: +41-1-632-1030, E-mail: daniel@erdw.ethz.ch; Vera Markgraf, Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309-0450, Phone: +1-303-492-5117, Fax: +1-303-492-6388, E-mail: markgraf@spot.colorado.edu; and Paul Baker, Duke University, Division of Earth and Ocean Sciences, 103 Old Chemistry Building, Durham, NC 27708-0227, Phone: +1-919-684-6450, Fax: +1-919-684-5833, E-mail: pbaker@geo.duke.edu
OS15 Innovations in Ocean Science Education and Outreach
In response to calls on the science community to take a broader role in meeting the economic, strategic, and educational needs of society the interface between the ocean research community and the public has been rapidly expanding in the past few years. Exploitation of new multimedia technologies, such as CD-ROM, WWW, and videoconferencing, has greatly increased both the quality and cost-effectiveness of providing timely information on the marine environment to the public and innovative resources to K-12 schools, colleges, and universities.
The designation of 1998 as the Year of the Ocean provides new opportunities for partnerships among business, research, education, government, and private enterprises to share expertise and resources for broad-based access to new curricula, displays, and products. This session will highlight the use of new ways of delivering formal K-16 education as well as informal public education.
Conveners: Paula G. Coble, Department of Marine Science, University of South Florida, 140 Seventh Avenue South, St. Petersburg, FL 33701, Phone: +1-727-553-1631, Fax: +1-727-553-1189, E-mail: pcoble@marine.usf.edu; and Don Reed, Department of Geology, San Jose State University, San Jose, CA 95192-0102, Phone: +1-408-924-5036, Fax: +1-408-924-5053, E-mail: dreed@geosun1.sjsu.edu
OS16 Paleoenvironmental Changes Along the Northern Siberian Margin Since the Last Glacial Maximum
It has become clear in recent years that the circum-Arctic region is very sensitive to changes in climate and capable of influencing climate at a global scale. Because of new opportunities for international scientific cooperations in the Russian Arctic, access is now available to the vast areas of the shallow Arctic Siberian shelves and the large land masses adjacent to these marginal seas that are particularly important for understanding the Arctic's role in past global climate change. Despite considerable progress made in studying the paleoclimate changes of this area by programs such as PALE, PACT, QUEEN, and RAISE a number of fundamental issues are still incompletely resolved. For instance, controversy remains regarding the existence and extent of Weichselian ice-sheets in northern Siberia; the fate of Siberian river runoff into the Arctic Ocean during the Weichselian and its impact for Holocene climate change in the Arctic, the rate of post-Weichselian sea level rise, and the exact timing of postglacial climatic and biotic changes.
For this session, papers providing new information and preliminary syntheses regarding the paleoenvironmental change in Arctic Siberia since 20 ka using marine and terrestrial proxy records as well as appropriate modeling and modern process studies needed to interpret the paleoenvironmental record are invited.
Conveners: Henning A. Bauch, GEOMAR, Research Center for Marine Geosciences, Department of Paleoceanology, Wischhofstrasse 1-3, 24148 Kiel, Germany, Phone: +49-431-600-2856, Fax: +49-431-600-2941, E-mail: hbauch@geomar.de; and Glen M. MacDonald, Department of Geography and Department of Biology, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1524, Phone: +1-310-825-2568, Fax: +1-310-206-5976, E-mail: macdonal@geog.ucla.edu
OS17 Shallow Intergyre Exchange Between the Tropics and Subtropics
Several studies have suggested that the shallow circulation in the tropical and subtropical oceans, particularly the intergyre exchange of thermocline waters, can influence climate variability over interannual and decadal timescales. Critical issues include identifying the sources of water that upwells in the tropics, establishing what processes control the rate of ventilation of the tropical thermocline, and determining how climatic variability can influence those pathways. Observations from the TOGA/TAO current meter arrays, WOCE (and JGOFS) hydrographic and tracer surveys, and coral records, as well as advances in ocean modeling, allow for new insights into these issues. Abstracts that address the exchange and circulation of thermocline waters between the subtropics and tropics, and across the equator, using any of a wide variety of approaches including observations from chemical tracers, instrumental data, and modeling are welcome.
Conveners: Dan Schrag, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, Phone: +1-617-495-7676, E-mail: schrag@eps.harvard.edu; Bill Jenkins, School of Ocean and Earth Science, Southampton Oceanography Centre, Southampton, SO14 3ZH, United Kingdom, Phone: +44-1703-596261, E-mail: W.Jenkins@soc.soton.ac.uk; and Mark Cane, Lamont Doherty Earth Observatory, Columbia University, Palisades, NY, 10964, Phone: +1-914-365-8344, E-mail: mcane@lamont.ldgo.columbia.edu
OS18 Status and Requirements for Interdisciplinary Activity and Support for Ocean Data Assimilation
The present, unsatisfactory state of ocean modeling, especially with regard to coupled ocean modeling and assimilation of ocean data, has the focused attention of a number of people who have joined efforts to bring effective change. The primary focus is on requirements for substantial enhancement of modeling and data assimilation capabilities in all subdisciplines of the ocean sciences, with emphasis on the importance of the linkages between subdisciplines to effectively meet their joint needs for data, technological support, and computing power.
This special session will have two parts: an invited paper session with overview presentations of the status and requirements of ocean data assimilation in various modeling areas including biological, chemical, physical, and coupled ocean modeling and a complementary contributed poster session. It is anticipated that the latter will primarily offer reports of work in which data are assimilated in the initialization of nowcast or forecast fields.
Convener: H. Jean Thiebaux, NOAA, World Weather Building, 5200 Auth Road, Room 206, Camp Springs, MD 20746, Phone: +1-301-763-8133, E-mail: thiebaux@sgi77.wwb.noaa.gov
OS19 Scientific Application of Observations from Spaceborne Scatterometers
Spaceborne scatterometers send microwave pulses to the surface of the Earth and measure the backscatter power which is affected by surface roughness. The roughness may indicate land vegetation and ice. Over the ocean the roughness is mainly due to small waves which are believed to be in equilibrium with the local wind stress. The European Space Agency ERS-1 and ERS-2 scatterometer data began in 1991 and are continuous to date. From September 15, 1996, to June 29, 1997, the NASA scatterometer (NSCAT) made global observations with improved resolution and coverage (at 25-km resolution, covering 80% of the world's ocean data). The NASA QuikSCAT mission is scheduled for launch in November 1998. Studies based on scatterometer data include numerical weather prediction, atmospheric storms, monsoons, hydrologic balance, air-sea fluxes, wind-wave interaction, wind-driven ocean circulation, ocean upwelling, biological productivity, sea ice morphology and dynamics, land vegetation, land flooding, and snow cover. Abstracts on any aspect of the scientific application of scatterometer measurements are welcome.
Conveners: W. Timothy Liu, Jet Propulsion Laboratory, Mail Stop 300-323, Pasadena, CA 91109, Phone: +1-818-354-2394, Fax: +1-818-393-6720, E-mail: liu@pacific.jpl.nasa.gov; and Robert A.Brown, Department of Atmospheric Sciences, AK-40 University of Washington, Seattle, WA 98195 USA; Tel: +1-206-543-8438; Fax: +1-206-543-0308; E-mail: rabrown@atmos.washington.edu
OS20 Reconstructing Glacial Sea Surface Temperatures
Accurate glacial sea surface temperature (SST) reconstructions are a high priority in paleoclimatology, especially in light of apparent discrepancies between marine and terrestrial reconstructions and among different marine estimates. Previous SST reconstructions that were mostly microfossil-based are being reevaluated by a number of different proxy methods, including coral Sr/Ca, alkenone undersaturation ratios, and foraminiferal Mg/Ca as well as refined biotic and stable isotopic methods. This session brings together researchers in this area to compare proxy SST methods and results. A particular focus is LGM tropical and high-latitude temperature evolution and phasing.
Conveners: Will Howard, Cooperative Research Centre for the Antarctic and Southern Ocean Environment, University of Tasmania, GPO Box 252-80, Hobart, Tasmania 7001, Australia, Tel: +61-3-6226-7859, Fax: +61-3-6226-2973, E-mail: Will.Howard@utas.edu.au; David Lea, Department of Geological Sciences, University of California, Santa Barbara, CA 93106-9630 USA, Tel: +1-805-893-8665 (office) and +1-805-893-7182 (Lab), Fax: +1-805-893-2314, E-mail: lea@magic.geol.ucsb.edu
OS21 Ocean Remineralization
The remineralization of organic matter in the ocean provides nutrients for primary production and closes the "biological pump," the process that maintains spatial gradients in a myriad of chemical species in the ocean. Compared to primary production, which has seen rapid advances in its understanding and quantification in recent years, remineralization remains enigmatic. Many fundamental questions about remineralization have not been fully answered, such as What is the spatial and temporal distribution of remineralization rates in the ocean? What are the relative contributions of dissolved and particulate organic matter to remineralization? What are the relative roles of zooplankton and bacteria in remineralization? What are the relative contributions of sedimentary and water column processes to remineralization? What is the role of the dissolved oxygen concentration in remineralization, and how does this affect denitrification? and Where is it feasible to use Redfield ratios to convert remineralization rates of one element to another? This session calls for papers that attempt to answer these and related questions.
Conveners: Raymond G. Najjar, Department of Meteorology, 522 Walker Building, Pennsylvania State University, University Park, PA 16802-5013, Phone: +1-814-863-1586, Fax: +1-814-865-3663, E-mail: najjar@essc.psu.edu; and Dennis A. Hansell, Bermuda Biological Station for Research, Inc., St. Georges GE-01, Bermuda, Phone: +1-441-297-1880 x210, Fax: +1-441-297-8143, E-mail: dennis@bbrs.edu
OS22 Shifting Paradigms: Interpreting Pre-Mesozoic Isotopic Records of Climatic, Oceanographic, and Biogeochemical Change
The extreme isotopic variations that characterize Paleozoic and Proterozoic oceans are difficult to reconcile in terms of Cenozoic models of climatic, oceanographic, and biogeochemical change. However, over a decade of research has shown that these variations are primary features of ancient oceans and not the result of diagenetic insults. Interpretation of these radical isotopic changes and closely related evolutionary and climatic events requires a significant shift in our view of Earth system history, particularly in light of (1) unusual continental configurations and patterns of ocean circulation, (2) decreased solar luminosity and increased atmospheric CO2, (3) modulation of oceanic alkalinity and acidity, (4) the extent of global anoxia and its effect on the biogeochemical cycling of carbon, sulfur and phosphorous, and (5) key biological innovations and extinctions. Especially welcome are abstracts that apply Cenozoic models to Paleozoic and Proterozoic problems using a wide variety of empirical measurements and modeling results.
Conveners: Alan J. Kaufman, Department of Geology, University of Maryland, College Park, MD 20742-4211, Phone: +1-301-405-0395, Fax: +1-301-314-9661, E-mail: kaufman@geol.umd.edu; and Lee R. Kump, Pennsylvania State University, Department of Geosciences and Earth System Science Center, University Park, PA 16802, Phone: +1-814-863-1274, Fax: +1-814-863-7823, E-mail: lrk4@psu.edu
OS23 The Subduction Factory
The MARGINS office and JOI sponsored a Subduction Factory Workshop in June 1998 to encourage researchers interested in convergent margin processes to focus their future research efforts. Participants strongly endorsed work in Central America and recognized the need to study a nonaccretionary convergent margin, as the opposite end member to the accretionary Central American margin. The Mariana, Izu-Bonin, and Tonga systems are all nonaccretionary margins where key forcing functions are distinctly different from those of Central America. At the Workshop, however, the time necessary to evaluate the potential for concentrated efforts in these margins was not available. This special session will draw together presentations of the structure, geochemical cycling, tectonics, volcanology, magma genesis, and general geophysics of these margins. The session is offered in part to permit a larger portion of the marine geological community than was able to be accommodated at the Workshop an opportunity to participate in deliberations related to the MARGINS efforts.
A short introduction summarizing the results of the Subduction Factory Workshop will start the session and a 15 minute interval will be held in reserve at the end of the session for a plenary discussion. We hope to schedule a poster session to precede the oral presentations. We plan to schedule a separate room for a longer discussion and planning session to follow the special session. This discussion/planning meeting will be open to all interested.
Conveners: Patricia Fryer, SOEST/Planetary Geosciences, University of Hawaii, 2525 Correa Road, Honolulu, HI 96822, Phone: +1-808-956-3146, Fax: +1-808-956-3188, E-mail: pfryer@soest.hawaii.edu; and Eli Silver, Earth Sciences Department, University of California, Santa Cruz, CA 95064, Phone: +1-831-459-2266, Fax: +1-831-459-3074, E-mail: esilver@es.ucsc.edu
Planetology (P) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
P01 Mars Pathfinder Science Results: One Year Later
Mars Pathfinder successfully landed on the surface of Mars on July 4, 1997, deployed and navigated a small rover, and collected data from 3 science instruments for three months. In the year since landing, analyses of the data returned by the mission have continued beyond that reported at the last Fall AGU meeting, resulting in refined or new insights into Martian surface and atmospheric processes. The purpose of this session is to highlight some of the new results and questions that have been raised by the data.
Convener: Matthew Golombek and Nathan Bridges, Jet Propulsion Laboratory, Mail Stop 230-235, 4800 Oak Grove Drive, Pasadena, CA 91109, Phone: +1-818-393-7948 (Golombeck), +1-818-393-7799 (Bridges), Fax: +1-818-393-1227, E-mail: mgolombek@jpl.nasa.gov and Nathan.Bridges@jpl.nasa.gov
P02 Early Results of the Galileo Europa Mission
In December 1997 the Galileo prime mission was completed and the Galileo Europa Mission (GEM) began. GEM includes eight Europa close flybys of Europa through February of 1999 to be followed by dedicated studies of the Jupiter Magnetosphere and Io torus and, finally, two close passes by Io. This special session will focus on results from the first GEM encounters with Europa, including data obtained from altitudes as low as 200 km. The session will include GEM results on other aspects of the Jovian system and syntheses of data from the Galileo prime mission.
Conveners: Robert T. Pappalardo, Department of Geological Sciences, Box 1846, Brown University, Providence, RI 02912, Phone: +1-401-863-3454, Fax: +1-401-863-3978, E-mail: Pappalardo@brown.edu; and Torrence V. Johnson, Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 264-419, Pasadena, CA 91109, Phone: +1-818-393-7957; Fax: +1-818-354-6256, E-mail: tjohnson@jpltvj.jpl.nasa.gov
P03 Spectroscopy of Solar System Objects: A Session Celebrating the Contributions of John Adams
This session will focus on recent results on the remote sensing of the Earth, Moon, Mars, asteroids, and outer solar system satellites that utilize or extend spectroscopic techniques pioneered by John Adams, the 1998 Planetary Sciences Section Whipple Award recipient. Contributions to this special session should focus on the use of spectroscopy or multispectral imaging to address outstanding planetary issues like surface mineralogy, geochemistry, spectral mixing and classification, surface weathering, or the correlation of laboratory and remote sensing observations.
Conveners: Jim Bell, Department of Astronomy, Cornell University, 424 Space Sciences Building, Ithaca, NY 14853-6801, Phone: +1-607-255-5911; Fax: +1-607-255-9002; E-mail: jimbo@marswatch.tn.cornell.edu
P04 Latest Results From Mars Global Surveyor Observations
New Mars Global Surveyor image, thermal emission, altimetric, radio
science, and magnetic field observations will be discussed, focusing on data acquired during the science phasing orbits of the mission. Papers will cover mission operations and aspects of the atmospheric, geologic, and geophysical characteristics of the planet and implications for the evolution of Mars.
Conveners: Ray Arvidson, Washington University, Campus Box 1169, 1 Brookings Drive, St. Louis, MO 63130, Phone: +1-314-935-5609, Fax: +1-314-935-4998, E-mail: arvidson@wunder.wustl.edu; and Bruce M. Jakosky, University of Colorado, LASP, Campus Box 392, Boulder, CO 80309, Phone: +1-303-492-8004, Fax: +1-303-492-2606, E-mail: jakosky@argyre.colorado.edu
Seismology (S) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
S01 Seismic Structure and Tectonics of Africa (Joint with T and VGP)
The purpose of this session is to bring together studies focused on seismic structure, tectonics, and formation of the African continent. Topics will include but are not limited to the seismic, thermal, and viscosity structure of the African crust and mantle, geochemical constraints on mantle composition and age, plateau uplift, plume-lithosphere interactions, the nature and origin of kimberlites, and the origin and structure of rifts and swells. Abstracts are welcome in all areas of geophysics and geochemistry, and both modeling and observational studies are encouraged.
Conveners: Andy Nyblade, Department of Geosciences, Penn State University, University Park, PA 16802, Phone: +1-814-863-8341, Fax: +1-814-863-7823, E-mail: andy@geosc.psu.edu; and David James, Carnegie Institution, Department of Terrestrial Magnetism, 5241 Broad Branch Road, NW, Washington, DC 20015, Phone: +1-202-686-4370, E-mail: james@dtm.ciw.edu
S02 The March 25, 1998, Antarctic Earthquake (Mw = 8.1)
The March 25, 1998, earthquake occurred within the oceanic margin of the Antarctic plate, and is the largest recorded oceanic intraplate earthquake. This session focuses on the seismological modeling of the earthquake, its tectonic setting, and implications for the evolution of the Antarctic-Australian-Pacific triple junction.
Conveners: Terry C. Wallace, Department of Geosciences, University of Arizona, Box 210077, Tucson, AZ 85721, E-mail: wallace@geo.arizona.edu; and Doug Wiens, Department of Earth and Planetary Sciences, Washington University, Campus Box 1169, One Brookings Drive, St. Louis, MO 63130, E-mail: doug@kermadec.wustl.edu
S03 The Fine Structure of the Base of the Mantle (Joint with T and VGP)
Recent advances in seismology, mineral physics and geodynamics have given us an increasing understanding of the complex, three-dimensional structure of the base of the mantle. Seismic observations of anisotropy, ultralow velocities, triplications, scattering, and strong lateral and vertical gradients are being interpreted in light of mineral physics experiments, theory, and modeling of anisotropy, melting temperatures, chemical reactions, and phase transitions. Geodynamic modeling is revealing the kinds of mantle flow that could provide the shear stresses and mixing for creating the observed lateral and vertical CMB-region variations. This session will highlight attempts to discover and understand these details of CMB structure.
Conveners: Michael Wysession, Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130; Phone +1-314-935-5625; Fax: +1-314-935-7361; E-mail: michael@wucore.wustl.edu; and Lars Stixrude, Department of Geological Sciences, University of Michigan, 425 East University Avenue, Ann Arbor, MI 48109-1063, Phone: +1-734-647-9071, Fax: +1-734-763-4690, E-mail: stixrude@umich.edu
S04 Seismic and Transient Deformations (CANCELLED)
S05 Dynamics of Space-Time Patterns in Seismicity (Joint with T)
The focus of this session will be on recent advances in the understanding of space-time patterns in seismicity with applications to earthquake prediction. A major question is whether seismicity exhibits self-organization and/or critical behavior. Papers are solicited on modeling, field observations, and relevant laboratory studies. Models may include massive simulations of fault interactions (general earthquake models) as well as more modest simulations such as slider-block models. Observations include such space-time patterns as
clustering, seismic activation, and log-periodic behavior. Mining and other induced seismicity are certainly relevant. Laboratory studies include acoustic emissions and other simulations. A dialog between statistical physicists and seismologists is a major goal.
Conveners: Don Turcotte, Department of Geological Sciences, Cornell University, Ithaca, NY 14853, Phone: +1-607-255-7282, Fax: +1-607-254-4780, E-mail: turcotte@geology.cornell.edu; William Klein, Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, Phone: +1-617-353-2188, Fax: +1-617-353-9393, E-mail: klein@buphyc.bu.edu; and John Rundle, CIRES, University of Colorado, Boulder, CO 80309, Phone: +1-303-492-5642, Fax: +1-303-492-5070, E-mail: rundle@cires.colorado.edu
S06 Dynamics of Earthquake Rupture Propagation
The physical processes that govern fault slip during dynamic rupture during earthquakes are not well understood. This session will highlight recent observational and theoretical work on processes that may be important during dynamic rupture in the Earth.
Conveners: Greg Beroza, Department of Geophysics, Stanford University, Stanford, CA 94305, Phone: +1-650-723-4958, E-mail: beroza@pangea.stanford.edu; and Bill Ellsworth, USGS, 345 Middlefield Road, MS 977, Menlo Park, CA 94025, Phone: +1-650-329-4784, E-mail: ellswrth@andreas.wr.usgs.gov
S07 Regional Investigations of the North America Cordillera (Joint with T, V, and G)
With a degree of coverage and detail never before attained, recent seismic, petrologic, and geodetic investigations of western North America are providing a look at lithospheric construction and deformation across an active orogenic belt. In particular, studies are revealing the structure of the major crustal fragments sutured to make the ancient continent, the establishment of a new tectonic fabric within the previously stable craton, the asthenospheric and lithospheric effects of the Yellowstone hotspot, and the nature of transform and subduction margins. Abstracts for presentations of seismic, petrologic, and geodetic research on the structure and processes of young and ongoing deformation and magmatism in the western United States are invited.
Conveners: Eugene Humphreys, Department of Geological Sciences, University of Oregon, Eugene, OR 97403, Phone: +1-541-346-5575; Fax: +1-503-346-4692, E-mail: gene@newberry.uoregon.edu; and Alan Levander, Department of Geology and Geophysics, Rice University, Houston, TX 77005, E-mail: alan@geophysics.rice.edu
S08 Glimpsing the Inner Core of Faults
Knowledge of the internal workings of lithospheric faults is crucial for the explanation of earthquake rupture dynamics and important for the evolution of tectonic plates. Recent proposals to drill into the San Andreas fault and into a fault at a convergent margin will spur advances in studying fault zone structure. This session will focus on recent results about the imaging of fault zones and ideas for future fault zone investigations. Topics span seismology and other geophysical probes, laboratory studies, and the study of exhumed faults.
Conveners: John E. Vidale, Department of Earth and Space Sciences, UCLA, 595 East Circle Drive, Los Angeles, CA 90095-1567; Phone: +1-310-206-3935, Fax: +1-415-329-5163, E-mail: vidale@ucla.edu; and Cliff H. Thurber, Department Geology and Geophysics, University of Wisconsin, 1215 West Dayton Street, Madison, WI, 53706, Phone: +1-608-262-6027, E-mail: clifft@geology.wisc.edu
S09 Aseismic Deformations (Joint with G and T)
There is increasing evidence for the existence of transient aseismic deformations from geodetic and strainmeter observations in California, Japan, and other areas. There appear to be a wide variety of transients, including afterslip, and creep and strain anomalies. While some are closely associated with earthquakes, others apparently are not. In general, a characterization of the spatial/temporal spectrum of these aseismic transients may provide a crucial link between the occurrence of earthquakes and the plate motions that ultimately cause them. This session will focus on observations of aseismic deformation, the modeling of these data, and their implications for earthquakes
and crustal/mantle rheology. In addition, issues of programmatic and technical considerations will be addressed, such as the optimal design of networks for the detection of aseismic transients.
Conveners: Yehuda Bock, IGPP, Scripps Institution of Oceanography, La Jolla, CA 92093-0225, Phone: +1-619-534-5292, Fax: +1-619-534-9873, E-mail: ybock@ucsd.edu; and Paul Silver, Carnegie Institution of Washington, DTM, 5241 Broad Branch Road, NW, Washington, DC 20015, Phone: +1-202-686-4370 x4386, E-mail: silver@dtm.ciw.edu
S10 Volcano Seismoacoustics (Joint with VGP)
Simultaneous acoustic and seismic recordings of tremor and long period events at active volcanoes have conclusively shown that these events can be generated by acoustic processes within the volcanic interior. Because infrasonic recordings provide a means to discriminate between seismic propagation effects and "true" volcanogenic signals, we can evolve toward a more profound understanding of the mechanisms driving volcanic eruptions. Five distinct issues must be addressed in order to utilize acoustic and seismic waves to decipher the physics of volcanic processes. These are (1) the identification of source processes that produce transient and sustained vibrations, (2) the propagation of pressure fluctuations in the fluid multiphase mixtures within the volcanic plumbing and the eruption column, (3) the propagation of acoustic waves from the eruption region to the pressure sensors, (4) the propagation of seismic waves from the walls of the volcanic conduit or the flanks of the volcano to the seismometers, and (5) the coupling between the acoustic and seismic fields at the air-ground interface. Papers are requested that address the aforementioned issues and present seismo-acoustic data associated with volcanic activity.
Conveners: Milton A. Garces, University of Hawaii, Manoa, P.O. Box 1599, Kailua-Kona, HI, 96745-1599, Phone: +1-808-325-1558, E-mail: milton@hialoha.net; and Michael T. Hagerty, University of California, Santa Cruz, Earth Sciences Department, Santa Cruz, CA, 95064, Phone: +1-408-459-4426, E-mail: mth@es.ucsc.edu
S11 The Scale of Mantle Convection: How Can Geophysical and Geochemical Views Be Reconciled? (Joint with VGP and T)
We have made significant progress in understanding the chemical and thermal evolution of our planet, but some outstanding issues remain.
Noble gas isotopes of basalts support the existence of geodynamic entities that remain isolated over long periods of time (geochemical reservoirs). In the conventional model of layered convection this is accounted for by separate circulation in the upper and lower mantle, with very little flow across the "660-km" seismic discontinuity, but this view may not be tenable for the present-day Earth. Numerical flow simulations demonstrate that long-term separation of such convective systems requires a significant increase in intrinsic density (i.e., chemical stratification), but evidence from seismic imaging for slabs sinking across the transition zone argues against such density contrast and implies mixing between the upper and (at least part of) the lower mantle. Chemical stratification may occur at a larger depth, but the nature and whereabouts of the elusive reservoirs of relatively undegassed mantle material remains enigmatic.
This session reviews our current understanding of this outstanding issue and explores hybrid models and evolutionary scenarios that satisfy the seismological and geochemical constraints in a geodynamically plausible way. We invite contributions from a wide range of disciplines. Of particular interest are seismological constraints on flow trajectories and on variations of chemistry in the deep mantle (e.g., scatterers and inversions for Poisson ratio), theoretical and experimental mineral physics constraints on elasticity parameters, composition, and rheology of the deep mantle (e.g., preservation of viscosity contrasts), the dynamics (stability and heat budget) of reservoirs of primordial mantle, and the timescales and efficiency of mixing, the reassessment of geochemical mass balances for geometries other than stratification at 660-km depth, and any compelling geological and geophysical evidence for variable convection regimes over the Earth's history.
Conveners: Rob van der Hilst, Massachusetts Institute of Technology, Room 540514, Cambridge, MA 02139, Phone: +1-617-253-6977, Fax: +1-617-258-9697, E-mail: hilst@mit.edu; and Francis Albarede, Ecole Normale Superieure de Lyon, 69364 Lyon cedex 7, France, Phone: +33-472-72-8414, Fax: +33-472-72-86-77, E-mail: albarede@ens-lyon.fr
S12 Digital Communications in Seismology: Glimpses of the 21st Century Seen Today?
The explosive growth in digital communications brought on by widespread public interest in the internet has profoundly changed seismic instrumentation. Digital communication links to seismic stations for real-time data collection, near-real-time data collection, or for least state of health data are becoming standard experimental procedure. The rapid evolution of this technology, however, has led to a proliferation of different approaches to solving the same problem. The primary goal of this session is to provide a forum for comparison of the different technologies currently available. Our hope is that this will help move the community toward a set of standards that
will allow for a more transparent exchange of data between networks and for distribution to the broader community. In addition, widespread availability of digital communication links to sensors and between sensor networks promises to profoundly change the scientific infrastructure of seismology. Papers are also solicited on ideas for scientific problems that could be addressed by a network of networks of seismic instruments on a national to global scale with thousands of broadband seismic stations.
Conveners: Gary L. Pavlis, Department of Gelogical Sciences, Indiana University, 1005 10 Street, Bloomington, IN 47405, Phone: +1-812-855-5141, Fax: +1-812-855-7899, E-mail: pavlis@indiana.edu; and Steve Malone, Geophysics Program, University of Washington, Box 351650, Seattle, WA 98195, Phone: +1-206-685-3811, Fax: +1-206-543-0489, E-mail: steve@geophys.washington.edu
S13 Broadband Seismology in the Oceans (Joint with OS)
This session will focus on marine seismology in the frequency band 0.001-10.0Hz and the issues involved in extending the global seismic network to the seafloor.
These issues include observations and theory of the ambient noise field, earthquake signal detection, comparison of results with land stations, borehole versus seafloor stations, seismometer design and coupling, and the engineering challenges of providing power to and recovering data from long-term sea floor seismic observatories. The relevance of ocean floor seismic data to imaging the earth at regional and global scales and the effects of oceanic processes on the broadband ambient noise field will also be addressed.
Conveners: Ralph Stephen, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA, Tel: +1-508-289-2583, Fax: +1-508-457-2150, E-mail: rstephen@whoi.edu; Fred Duennebier, Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 98622 USA, Tel: +1-808-956-4779, Fax: +1-808-956-4780, E-mail: fred@akule.soest.hawaii.edu
S14 The July 17, 1998 Sandaun, Papua New Guinea, earthquake and tsunami (Joint with T and OS)
On July 17, 1998 a relatively moderate earthquake in the Sandaun province of
PNG (with a maximum reported magnitude of 7.1) unleashed a catastrophic tsunami,
which obliterated several villages, and killed upwards of 2100 people. When all
fatalities are accounted for, this event may end up being the most tragic
tsunami of the 20th century. The generation of this tsunami is intriguing,
given the disparity between the size of the parent earthquake and the
catastrophic amplitude of its waves (up to 15 m) along a relatively short
segment of coastline (30 km), which fuels speculation as to the possible
involvement of an underwater landslide in the tsunamigenic process. We solicit
papers on (i) seismological studies of the source of the Saundaun earthquake;
(ii) tectonics of the Northern Coast of New Guinea, in relation to the Saundaun
earthquakes; (iii) background and historical seismicity of the epicentral
region; (iv) preliminary results of the Tsunami Inundation Survey Team; (v)
modeling simulations of run-up and inundation along the Sandaun coast; and more
generally (vi), general aspects of earthquake/tsunami dynamics, and problems of
tsunami hazard mitigation.
Conveners: Emile A. Okal, Department of Geological Sciences, Northwestern University, Evanston, IL USA; Tel:+1-847-491-3194; Fax: +1-847-491-8060; E-mail: emile@earth.nwu.edu; Costas E. Synolakis, Department of Civil Engineering, University of Southern California, Los Angeles, CA USA; Tel: +1-213-740-0613; Fax: +1-213-744-1426; E-mail: costas@mizar.usc.edu; Fumihiko Imamura, Disaster Control Research Center, Tohoku University, Sendai, Japan; Tel:+81-22-217-7513; Fax: +81-22-217-7514; E-mail: imamura@tsunami2.civil.tohoku.ac.jp; Horst Letz, Geophysical Observatory, Box 323, Port Moresby, PNG; Tel: +675-321-4500; Fax: +675-321-3976; E-mail: hletz@compuserve.com; and Hugh L. Davies, Department of Geology, University of Papua New Guinea, Port Moresby, PNG; Tel: +675-326-7395; E-mail: hdavies@upng.ac.pg
SPA: Aeronomy (SA) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
SA01 Odd Nitrogen in the Upper Atmosphere (Joint with A)
Odd nitrogen species, such as nitric oxide, nitrogen dioxide, and atomic nitrogen, have important effects on thermosphere and mesosphere chemistry and thermal structure and on ion composition and density. Created wherever molecular nitrogen is ionized or dissociated by energetic photons and charged particles, odd nitrogen is a significant channel for the interaction of solar and magnetospheric events with the upper atmosphere. This session solicits papers on current and past measurements of odd nitrogen species throughout the upper atmosphere and model calculations describing their distribution, variation, and consequences.
Convener: Stanley C. Solomon, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309-0392, Phone: +1-303-492-6423, Fax: +1-303-492-6946, E-mail: solomon@lasp.colorado.edu
SA02 Mesosphere Inversion Layer Structure: New Results and New Theories
The midlatitude mesosphere thermal structure from 60 to 100 km, especially during the winter, is often charaterized by a region of enhanced temperatures when compared with model predictions hence the term the mesosphere inversion layer. It was first discovered in results obtained by falling sphere experiments and has been observed routinely by Rayleigh and Na temperature lidar observations and also by observations of the limb thermal structure from space. The amplitude of this increase is typically 20 - 40 K. The frequency of occurrence approaches that of 100% for winter but is ~35% for summer. Recent observations have indicated that this structure will often display a descending phase progression at a rate similar to that of the diurnal tide. New theoretical work has suggested the structure arises from the interaction of gravity waves with thermal tides. Other work has pointed to the development of a critical layer caused by a strong shear in the background wind field. The recent work has also shown that the increased thermal stability of this region may give rise to a phenomonon known as the mesosphere bore, which is charaterized by a region of enhanced OH and OI airglows. What is evident is that the physics of the formation of this interesting feature are generally unknown and remain a challenge to our understanding of the complexities of mesosphere dynamics. Papers are invited on recent observational and theoretical aspects of this phenomenon.
Conveners: John Meriwether, Department of Physics and Astronomy, Clemson University, 206 Kinard Laboratory, Clemson, SC 29634-1911, Phone: +1-864-656-0915, Fax: +1-864-656-0805, E-mail: john.meriwether@ces.clemson.edu; and Chet Gardner, Electro-Optics Laboratory, University of Illinois, 1308 West Main Street, Urbana, IL 61801, Phone: +1-217-333-4682, Fax: +1-217-244-7705, E-mail: cgardner@uiuc.edu
SA03 High-Latitude Inputs to the Ionosphere/Thermosphere/Mesosphere System (Joint with SM and A)
Recent work has highlighted the importance of high-latitude inputs into the mesosphere, thermosphere, and ionosphere. These inputs include particle precipitation, joule heating, and momentum forcing, which produce significant changes in the composition, chemistry, temperature, and dynamics on both the local and global scales. The global magnitude of these inputs, their distributions in space and time, their dependence on variable solar/interplanetary/magnetospheric conditions, and their impact on the ionosphere/thermosphere/mesosphere system are still not well understood. This session solicits papers dealing with measurements, modeling, and parameterizations of the high latitude inputs and of the atmospheric response to those inputs.
Conveners: Geoff Crowley, Instrumentation and Space Research Division, Southwest Research Institute, San Antonio, TX 78238-5166, Phone: +1-210-522-3475, Fax: +1-210-647-4325, E-mail: crowley@picard.space.swri.edu; and Art Richmond, High Altitude Observatory, National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307, Phone: +1-303-497-1570, Fax: +1-303-497-1589, E-mail: richmond@ucar.edu
SA04 Results from the Coqui II Campaign: Studies of Mesosphere and Lower Thermosphere Layering Phenomena
The NASA/NSF Coqui II campaign was carried out in Puerto Rico in February and March 1998 to study intermediate layers, sporadic E layers, turbulent layers, and sudden atom layers. Extensive ground-based observations were made during the period including measurements by the Arecibo incoherent scatter radar and sodium lidar, portable VHF and HF radars, and ground-based imagers. Eight rockets were launched as part of five separate experiments to provide in situ measurements. The session will describe results from the campaign and related results that pertain to the various types of layering phenomena.
Convener: Miguel F. Larsen, Department of Physics, Clemson University, Clemson, SC 29634, Phone: +1-864-656-5309, Fax: +1-864-656-0805, E-mail: mlarsen@maxwell.phys.clemson.edu
SPA: Heliospheric Physics (SH) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
SH01 Interstellar Medium and Its Interaction With the Heliosphere: Current Knowledge and Future Exploration
Continued analyses of data obtained by astronomical means and using an array of spacecraft distributed widely about the solar system have provided a rich variety of new information about the structure of the outer heliosphere and its interaction with the local interstellar medium. These data and their analyses have spawned many new questions and related ideas to find answers, through new exploration initiatives. Papers are solicited that (1) present new work on the properties of the interstellar medium surrounding the solar system and its interaction with the heliosphere and (2) suggest new exploration initiatives.
Conveners: Mike Gruntman, University of Southern California, Aerospace Engineering Department, MC 1191, Los Angeles, CA 90089-1191, Phone: +1-213-740-5536, Fax: +1-213-740-6342, E-mail: mikeg@spock.usc.edu; and Eberhard Moebius, University of New Hampshire, Space Science Center, Morse Hall, Durham, NH 03824, Phone: +1-603-862-3097, Fax: +1-603-862-1915, E-mail: Eberhard.Moebius@unh.edu
SH02 Coronal Heating and Solar Wind Acceleration: TRACE, SOHO, and Solar Probe
The brand new TRACE results and recent SOHO observation and analyses suggest strongly that the inner and midlevel corona are much more active than previously thought. These results have spawned a considerable number of new models of the corona that have been used to organize these observations and to make theoretical predictions pertaining to the future Solar Probe mission. Papers are solicited that report both new observations, summaries of models that help to organize these observations, and theoretical works that pertain to the general topic of coronal heating and solar wind acceleration.
Conveners: B. Tsurutani, Jet Propulsion Lab, 4800 Oak Grove Drive, Mail Stop 169-506, Pasadena, CA 91109, Phone: +1-818-354-7559, E-mail: btsurutani@jplsp.jpl.nasa.gov; W. Feldman, Los Alamos National Lab, Mail Stop D-466, Los Alamos, NM 87545, Phone: 505-667-7372; E-mail: wfeldman@sstcx1.lanl.gov, G. Gloeckler, University of Maryland, Department of Physics, College Park, MD 20742, Phone: +1-301-405-6206, Fax: +1-301-314-9547, E-mail: gloeckler@umsp.umd.edu; B. Goldstein, Jet Propulsion Lab, 4800 Oak Grove Drive, Mail Stop 169-506, Pasadena, CA 91109, Phone: +1-818-354-7366, Fax: +1-818-354-8895, E-mail: bgoldstein@jplsp.jpl.nasa.gov; C. Korendyke, Naval Research Lab, 4555 Overlook Avenue, SW, Code 7662K, Washington, DC 20375, Phone: +1-202-767-3114, Fax: +1-202-767-5636; E-mail: koren@cyclops.nrl.navy.mil; E. Marsch, Max-Planck-Institute for Aeronomie, Postfach 20, Katlenburg-Lindau 37189, Germany, Phone: +49-555-641-292; E-mail: marsch@linax1.dnet.gwdg.gov; A. Poland, NASA Goddard Space Flight Center, Greenbelt, MD 20771, Phone: +1-301-286-7076, E-mail: a.poland@sohops.gsfc.nasa.gov; and A. Title, Lockheed-Martin, E-mail: title@sag.space.lockheed.com
SH03 Radio Emission Processes in Space Plasma (Joint with SM and P)
High time resolution data from numerous current space missions (e.g., Wind, FAST, Polar, Geotail, and Galileo) and ground-based facilities have provided evidence for new phenomena as well as new tests and reasons to revise existing models of radio emissions from space plasmas. This session will focus on theoretical and observational papers that address the fundamental physics of both direct and indirect (collective) radio emissions. Papers on solar and interplanetary radio bursts, magnetospheric and auroral radio emissions from Earth and the other planets, and ionospheric emissions are particularly welcome.
Conveners: S. D. Bale, Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450, Phone: +1-510-643-3324, Fax: +1-510-643-8302, E-mail: bale@ssl.berkeley.edu; and I. H. Cairns, School of Physics, University of Sydney, NSW 2006, Australia, Phone: +61-2-9351-3779, fax: +61-2-9351-7726, E-mail: cairns@physics.usyd.edu.au
SH04 First Solar Activity of the Approaching Solar Maximum (title change) (Joint with SH and SA)
After an extended minimum of solar activity the Sun has recently started to become active again. Coronal mass ejections observed by SOHO have been accompanied by magnetic clouds, interplanetary shocks, and energetic particles; new isotope measurements and unusual compositions of ion charge states have been reported. Spacecraft such as ACE, Ulysses, Wind, and SOHO carry instruments with better resolution and sensitivity than those which were available at the previous solar maximum. Papers are solicited which present these recent data, which expand our understanding of dynamic solar phenomena, or which consider the implications of the renewed solar activity for the heliosphere.
Conveners: Tycho von Rosenvinge, Code 661, NASA Goddard Space Flight Center, Greenbelt, MD 20771, Phone: +1-301-286-6721, E-mail: tycho@lheamail.gsfc.nasa.gov; and Thomas H. Zurbuchen, Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143, Phone: +1-734-647-6835, E-mail: thomasz@umich.edu
SH05 Origin, Initiation, and Three-Dimensional Structure of CMEs
Observations from ground-based and satellite platforms are providing new information on the origin and initiation of CMEs, which have not been well observed in the past. Observations of this type should lead to an understanding of the three dimensional structure and dynamics of CMEs, which is important to help define the physical processes that are relevant to the CME phenomenon. A discussion of these issues should help to clarify further the scientific goals of a STEREO mission. Papers are invited on observational, theoretical, and modeling aspects of these topics.
Conveners: K. P. Dere, Space Science Division, Code 7663, Naval Research Laboratory, Washington, DC 20375-5320, Phone: +1-202-767-2161, Fax: +1-202-767-5636, E-mail: dere@halcyon.nrl.navy.mil; and R. A. Howard, Code 7666, Naval Research Laboratory, Washington, DC 20375-5320, Phone: +1-202-767-3137, Fax: +1-202-767-5636, E-mail: howard@cronus.nrl.navy.mil
SH06 Coronal and Interplanetary Shocks
Shock waves play an essential role in Sun-Earth connection. Near the solar surface, a number of activities can cause shocks: reconnection flows, flare blast waves, chromospheric evaporation, and various fast ejecta. In the interplanetary medium, coronal mass ejections and co-rotating interaction regions are important shock sources. The shocks propagate through the dynamic corona and interplanetary medium structured by magnetic fields, producing radio
emissions, energetic particle events and other measurable effects in the Earth's
magnetosphere. New observations from the SOHO and WIND spacecraft on coronal Moreton waves and hectometric radio bursts have added new information to the shock study. We are in a better position to resolve the long-standing controversy regarding the relationship between coronal and interplanetary shocks. This special session attempts to bring together observers and theorists to evaluate the current status of the field. Papers that discuss
coronal and interplanetary the shocks and their inter-relationship are requested.
Conveners: N. Gopalswamy, The Catholic University of America, Room G-1, Building 26, Code 682.3, NASA/GSFC, Greenbelt MD 20771 USA; Tel: +1-301-286-5885; Fax: +1-301-286-0264; E-mail: gopals@fugee.gsfc.nasa.gov; and S. W. Kahler, Phillips Lab/GPSG, 29 Randolph Rd, Hanscom AFB, MA 01731 USA; Tel: +1-781-377-9665; Fax: +1-781-377-3160; E-mail: kahler@plh.af.mil
SPA: Magnetospheric Physics (SM) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
SM01 Thirty Years of Ionospheric Outflow: Causes and Consequences (Joint with SA)
On the 30th anniversary of the first quantitative descriptions of the light
ion polar wind and after 30 years of observing terrestrial ionospheric outflows it is fitting that our understanding of these flows and their consequences in planetary magnetospheres should be assessed. That the solar wind wake of magnetized planets indeed imposes a vacuum boundary condition on their polar ionospheres, leading to a supersonic plasma enhancement of Jeans' atmospheric escape, and that solar wind energy is dissipated as heat in the auroral ionosphere, locally increasing the escaping mass flux of plasma (and inevitably, fast neutral atoms, though these have not been observed to date) are known. The composition and mass density of magnetospheric plasmas vary widely over the range of solar and magnetospheric activity and are in some storms dominated by heavy ions. However, what solar wind characteristics control the mass flux supplied by the ionosphere, and how do they control it? Some plasma and all fast atoms are permanently lost from the ionosphere to the downstream solar wind while much of the plasma outflow is recirculated through the magnetotail neutral sheet and accelerated to form energetic plasmas. Neutral gas escape produces a geocoronal charge exchange medium that has been found to be a useful means of imaging the energetic ion populations. However, what are the consequences of varying ionospheric outflows in magnetospheric dynamical behavior? Observational studies and theoretical models are solicited that assess the enhancement of escaping plasma mass flux and the resultant internal source of magnetospheric plasmas. Work addressing the effects of ionospheric plasma participation in storm dynamics is especially welcome.
Conveners: T. E. Moore, NASA Goddard Space Flight Center, Code 692, Greenbelt, MD 20771, Phone: +1-301-286-5236, Fax: +1-301-286-1683, E-mail: thomas.e.moore@gsfc.nasa.gov; and J. L. Horwitz, Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899, Phone: +1-256-890-6662, Fax: +1-256-890-6575, E-mail: horwitzj@cspar.uah.edu
SM02 The Earth's Dynamic Cusps: New Results From Rockets, Satellites, and Ground-Based Instruments (Joint with SA)
The Earth's magnetospheric cusps are regions where the shocked solar wind plasma penetrates most deeply and interacts most strongly with the magnetosphere, ionosphere, and upper atmosphere. Although the cusp regions have been a focus of magnetospheric and ionospheric research for over 20 years, recent state-of-the-art ground and space-based measurements with unprecedented resolution in time/space, energy, frequency, and mass have revealed several important new features concerning the physical processes of the cusp regions and their interactions with the Earth's space environment. Among these new data sets are two sounding rocket missions that gathered data along vertical trajectories to altitudes near 450 km in the dark cusp on the dayside during both IMF Bz north and south conditions, as well as comprehensive fields and particle data gathered by the FAST satellite near 4000 km and the Polar satellite near 5-7 Re. In addition to a limited number of invited papers, this session will be devoted to contributed papers describing new results from space and ground-based instruments, theory, and modeling that illustrate the dynamic nature of cusp plasmas in the magnetosphere and ionosphere and their interactions with the Earth's upper atmosphere.
Conveners: W. K. Peterson, Lockheed Martin Space Physics Lab, LASP, 1234 Innovation Drive, Boulder, CO 80303, Phone: +1-303-492-0686, Fax: +1-303-492-6444, E-mail: pete@spasci.com; R. F. Pfaff, Jr, NASA Goddard Space Flight Center, Mail Code 696, Greenbelt, MD 20771, Phone: +1-301-286-6328, Fax: +1-301-286-1648, E-mail: rob.pfaff@gsfc.nasa.gov; and W. Jeffrey Hughes, Department of Astronomy, Boston University, Center for Space Physics, 725 Commonwealth Avenue, Boston, MA 02215, Phone: +1-617-353-2471, Fax: +1-617-353-6463, E-mail: hughes@buasta.bu.edu
SM03 Solitary Waves, Ion and Electron Beams, and Related Auroral Accelertion Physics (Joint with SA)
The FAST, Polar, Freja, and Geotail satellites have provided new and unique observations of electric field structures and waves that accompany ion and electron beams. Understanding the dynamic processes that accelerate these particles and transfer momentum to and from various particle populations is crucial to developing a comprehensive model of auroral acceleration. In addition to observations of strong double layers and wave-particle interactions, a renewed interest in solitary wave structures has emerged with new in situ observations that identify three-dimensional electron and ion holes having bipolar parallel and unipolar perpendicular electric field signatures. These structures likely play a fundamental role in both energy and momentum exchange within the beams and may help maintain large-scale parallel electric fields. This session will serve as a forum to present new findings of auroral
microphysics related to solitary waves, ion and electron beams, downward and upward auroral current regions, and related acceleration processes and to discuss their theoretical interpretations. All scientists with new experimental and theoretical results concerning auroral acceleration processes and related physics are encouraged to submit abstracts.
Conveners: James P. McFadden, Space Sciences Laboratory, University of California, Berkeley, California 94720, Phone: +1-510-642-9918, Fax: +1-510-643-8302, E-mail: mcfadden@ssl.berkeley.edu; and Anders Eriksson, Swedish Institute of Space Physics, Uppsala Division, SE-755 91 Uppsala, Sweden, Phone: +46-18-303645, Fax: +46-18-403100, E-mail: Anders.Eriksson@irfu.se
SM04 Solar Maxium/Solar Minimum: What's the Difference? (Joint with SH and SA)
In this session we propose to investigate the differences in the solar activity, solar wind composition, and geospace response to coronal mass ejections which occur during the minimum and maximum phases of the solar cycle. In particular, solar flares, coronal moreton waves, solar energetic particle events, ring current variations, energetic trapped electrons, auroral particle precipitation and the ionospheric source contribution to the plasma sheet. In addition, we will also look at how the community is preparing for the upcoming solar maximum - the different operations modes which will be implemented to achieve the best monitoring of the solar cycle variation. For example, in the 1999-2000 time frame, just as the solar cycle approaches maximum, the ULYSSES spacecraft will be in the inner heliosphere and well positioned relative to WIND to make simultaneous observations of CME shock fronts and together provide true 3D localization measurements as the CMEs propagate through the interplanetary medium. The eventual launch of CLUSTER in 2000 will add high time resolution, 3D measurement capabilities in the high latitude, near-Earth environment, providing additional information about solar wind phenomena and its coupling to the global processes.
Conveners: Nicola J. Fox, ISTP Science and Operations Coordinator, NASA/GSFC, Code 696 Greenbelt, MD 20771, Phone: +1-301-286-8872, Fax: +1-301-286-1648, E-mail: nicola.fox@gsfc.nasa.gov; Stephen Fuselier, Lockheed Palo Alto Research Lab, Dept 91-20/Bldg 252, 3251 Hanover St, Palo Alto, CA 94304-1191, Phone: +1-415-424-3334, Fax: +1-415-424-3333, E-mail: fuselier@space.lockheed.com; Manuel Grande, Rutherford Appleton Lab, Space Science Dept, Chilton/Didcot, Oxon 0X11 0Q, England, Phone: +1-44-1-235-446501, Fax: +1-44-1-235-446509, E-mail: m.grande@rl.ac.uk, Jack Gosling, Los Alamos National Lab, Phone: +1-505-667-5389, E-mail: jgosling@lanl.gov; Richard Harrison, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom, Phone: +1235-446884, Fax: +1235-446509, E-mail: r.harrison@rl.ac.uk
SM05 Magnetosphere-Ionosphere-Thermophere Coupling: Models for the New Millenium (Joint with SA)
Large-scale models of the magnetosphere and ionosphere-thermosphere system have reached remarkable capabilities in modeling the complex dynamics of these regions. However, in order to better understand the energy flow from the solar wind all the way into the atmosphere a new class of global geospace circulation models is required that couples all the respective regions of space and the upper atmosphere. Thus the most important aspect of the "models for the new millenium," and the focus of this session, is the coupling between the different regions which has hitherto drawn little attention. Papers are solicited that(1) present results from global coupled models, (2) address theoretical aspects of the magnetosphere-ionosphere-thermosphere coupling, (3) discuss observations relevant to model coupling and observational constraints, (4) discuss sub-models and parameterizations that are needed to implement coupling processes which exceed the timescales and spatial scales that can be handled by global models, such as processes on auroral field lines. The above list is not exclusive. Papers addressing other issues of magnetosphere-ionosphere-thermosphere modeling and coupling are also welcome.
Conveners: Joachim Raeder, IGPP/UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1567, Phone: +1-310-267-2338, Fax: +1-310-206-3051, E-mail: jraeder@igpp.ucla.edu; and Maura Hagan, NCAR/HAO, P.O. Box 3000, Boulder, CO 80307-3000, Phone: +1-303-497-1537, Fax: +1-303-497-1589, E-mail: hagan@ncar.ucar.edu
SM06 Nonlinear Methods in Space Plasma Analyses (Joint with SH and U)
Recent observations of solar, interplanetary, and terrestrial plasmas emphasize their self-organization and formation of stable complex structures (e.g., plasmoids, large-scale convection cells, and systems of electric currents) where the system activity is eventually determined by a small number of modes. These states are produced not only by local instabilities but also by the coherent interaction of adjacent plasma domains with a resulting strongly nonlinear response to system inputs. On the basis of theoretical arguments and earlier observations for this type of "self-organization" a series of applied mathematics methods have been combined with standard analysis tools in studies of space physics data: nonlinear time series analysis, classification, and prediction, including neural network methods, of solar wind, geomagnetic, and ionospheric observations; empirical and first-principles models with few degrees of freedom for the solar wind-magnetosphere-ionosphere coupling; self-organized criticality as a model for flare and magnetotail stability and statistics; spatiotemporal geomagnetic and electrodynamic modeling; and applications in space weather forecasting. Early successes of several of these models provided additional validation for the self-organization hypothesis. It is now time to assess several of the methods and their potential for future applications and breakthroughs in the understanding of plasma dynamics.
Conveners: Dimitris Vassiliadis, NASA/GSFC/USRA, Code 696, Greenbelt, MD 20771, Phone: +1-301-286-9060, Fax: +1-301-286-1648, E-mail: vassi@lepgst.gsfc.nasa.gov; Daniel N. Baker, Laboratory of Astrophysics and Space Physics, 1234 Innovation Drive, University of Colorado, Boulder, CO 80309-0590, Phone: +1-303-492-4509, Fax: +1-303-492-6444, E-mail: baker@lynx.colorado.edu; and Henrik Lundstedt, Solar-Terrestrial Physics Division, Swedish Institute of Space Physics/Lund Observatory, Box 43, S-22100 Lund, Sweden, Phone: +46-46-222-7294, Fax: +46-46-222-4614, E-mail: henrik@astro.lu.se
SM07 Multispacecraft Missions and Sun-Earth Connections (Joint with SH and SA)
With the upcoming launch of the ESA Cluster mission and the recent establishment of the NASA Solar Terrestrial Probe Line a new class of missions has been created which employ multiple platforms to provide stereo viewing for remote sensing instruments and the separation of temporal and spatial effects for in situ measurements. These new multiprobe missions require new approaches in mission design, spacecraft autonomy, instrument intercalibration, data analysis, and theoretical modeling and simulation if their full potential is to be realized. This session will serve as a forum to present both current and proposed solutions to the challenging problems of implementing this new mission class. Emphasis should be placed on how proposed solutions and missions will push back the frontiers of modern space physics whether at the Sun, in the heliosphere, in terrestrial and planetary magnetospheres, or in terrestrial and planetary ionospheres and upper atmospheres.
Conveners: Steven Curtis, NASA Goddard Space Flight Center, Code 695, Greenbelt, MD 20771, Phone: +1-301-286-9188, Fax: +1-301-286-1683, E-mail: steven.curtis@gsfc.nasa.gov; Joseph Grebowsky, NASA Goddard Space Flight Center, Code 695, Greenbelt, MD 20771, Phone: +1-301-286-6853, Fax: +1-301-286-1683, E-mail: joseph.grebowsky@gsfc.nasa.gov; Joseph Davila, NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771, Phone: +1-301-286-8366, Fax: +1-301-286-1683, E-mail: joseph.davila@gsfc.nasa.gov; and Leonard Burlaga, NASA Goddard Space Flight Center, Code 692, Greenbelt, MD 20771, Phone: +1-301-286-5956, Fax: +1-301-286-1683, E-mail: leonard.burlaga@gsfc.nasa.gov
SM08 Magnetic Reconnection in the Sun-Earth Connected System: Recent Progress
In recent years our understanding of the magnetic reconnection process and its consequences has increased considerably. New empirical knowledge was obtained primarily through the analysis of space plasma observations in the ISTP era and through laboratory measurements. Remote and in situ space observations covered the entire Sun-Earth Connected System, ranging from the solar corona, to the Earth's magnetosphere including the magnetopause. These new results were accompanied by new laboratory efforts and progress in theoretical investigations facilitated by the availability of improved and extended numerical models. This session summarizes the state of research involving the process of magnetic reconnection and its consequences and attempts to define directions for future research. Contributions are solicited primarily from observational as well as theoretical reconnection research in the Sun-Earth Connected System but also from recent laboratory experiments addressing related issues.
Conveners: Michael Hesse, NASA Goddard Space Flight Center, Code 696, Greenbelt, MD 20771, Phone: +1-301-286-8224, Fax: +1-301-286-1648, E-mail: hesse@gsfc.nasa.gov; and Tsugunobu Nagai, Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551, Japan, Phone: +81-3-5734-2621, Fax: +81-3-5734-3537, E-mail: nagai@geo.titech.ac.jp
SM09 Substorm Onset Timing (Joint with SA)
The temporal relationship of substorm signatures is an important part of substorm research. Determining the relative timing between signatures leads to a clarification of cause and effect that contributes to our understanding of substorm onset mechanisms. ISTP and GEM campaigns of multiple satellite and ground station studies have contributed to our understanding of substorm processes. However, much confusion still persists between studies that utilize different substorm signatures for their onset time. Recently, finding a readily available and local time-independent relative timing fiducial for substorm studies. At the last GEM/Snowmass Workshop, midlatitude pi 2 accompanied with an H component bay was suggested as such a signature. This session seeks contributions that illuminate the substorm timing problem and those that examine the feasibility of using a global, widely available, sub-one-minute-accuracy reference time for substorm onset identification.
Conveners: Shin Ohtani, Johns Hopkins University Applied Physics Laboratory, Johns Hopkins Road, Laurel, MD 20723-6099, Phone: +1-240-228-3641, Fax: +1-240-228-6670; E-mail: ohtani@fluxgate.jhuapl.edu; and Mark Moldwin, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901, Phone: +1-407-674-7208, Fax: +1-407-674-7482, E-mail: moldwin@pss.fit.edu
SM10 SPA Education and Outreach (Joint with SA and SH)
Education and public outreach (EPO) continue to play an important role in how science is funded by the federal government. The SPA science community has a responsibility to share our exciting science with the American public. Two national programs, the multiagency National Space Weather Program (NSWP) and NASA's Sun-Earth Connection (SEC) program, have recognized the importance of creating an EPO infrastructure for our science. They have been important catalysts in helping SPA scientists and educators develop a number of high-quality projects. Besides these programs, spacecraft missions require an EPO component. Lastly, NASA's Office of Space Science has funded a number of small grants for scientists to become engaged in EPO activities through their IDEAS program.
The NSWP lists among its critical goals (1) "to heighten public awareness of the impact of space weather on human activities" and (2) "to make space weather an important part of science curricula in grade schools." The Sun-Earth Connection (SEC) is one of the four main science themes within NASA's Office of Space Sciences. There are many education and outreach efforts which are ongoing with various SEC missions as well as other organizations and individuals, and new ones are appearing regularly. The tremendous interest students have in space means that the materials and programs that have been developed as part of SPA member activities is having widespread impact. Impact from these activities is also felt in museums, on the web, and in the media.
An oral session with invited and contributed speakers and a poster session are planned. These sessions are intended to provide information to the SPA science community of the many excellent programs underway, describe the various ways SPA scientists can become involved, and foster cooperation among programs so that resources might be used to maximize impact.
Conveners: P. B. Dusenbery, Space Science Institute, 1540 30th Street, Suite 23, Boulder, CO 80303, Phone: +1-303-492-2013, Fax: +1-303-492-3789, E-mail: dusenbery@colorado.edu; I. Hawkins, Berkeley Space Sciences Laboratory, Center for EUV Astrophysics, University of California, Berkeley, CA 94720, Phone: +1-510-643-5662, Fax: +1-510-643-5660, E-mail: isabelh@cea.berkeley.edu; and J. Thieman, NASA Goddard Space Flight Center, Code 633, Greenbelt, MD 20771, Phone: +1-301-286-9790, Fax: +1-301-286-1771, E-mail: thieman@nssdc.gsfc.nasa.gov
Tectonophysics (T) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
T01 Equation of State and Elastic Properties of Minerals in Earth's Mantle: A Commemorative Session to Orson L. Anderson
This special session is to commemorate the contribution that Orson L. Anderson has made to the field of mineral physics. Indeed, by most accounts, O. L. Anderson is considered the founder of mineral physics. His pioneering work over the past 40 years encompasses a broad range of geophysical topics, but the most consistent themes in his nearly 200 published papers are the equations of state and elastic properties of mantle minerals. This session is appropriate for papers that directly pertain to the mineral composition of Earth's upper and
lower mantle and address the equations of state and the elastic properties of mantle minerals at elevated pressure and temperature conditions.
Conveners: Donald Issak, IGPP, University of California, Los Angeles, CA, 90024-1567, Phone: +1-310-825-3565, Fax: +1-310-206-3051, E-mail: disaak@adam.igpp.ucla.edu; and Robert Liebermann, Department of Geosciences, ESS Building, State University of New York, Stony Brook, NY 11794-2100, Phone: +1-516-632-8139 (Chair's Office), Phone: +1-516-632-8214 (Faculty Office), Fax: +1-516-632-8240, E-mail: Robert.Liebermann@sunysb.edu
T02 Earthquakes, Crustal Deformation, and Neotectonics of the Cascadia and Nankai Subduction Zones (Joint with G and S)
At both the Cascadia margin in western North America and the Nankai margin in southwest Japan, young and hot oceanic plates obliquely underthrust accreted continental margin terranes. The stress regimes, major active structures, and geodetic deformation patterns in both upper plates are very similar. A major difference is in the frequency of great subduction earthquakes in the past 2000 years. Comparative studies of the two subduction zones can help us understand the fundamental geodynamic processes responsible for the similarities and differences. This special session will provide a forum for people working on Nankai or Cascadia to share recent findings and ideas and for examining the earthquake processes and hazards of the two subduction zones from an integrated, multidsciplinary perspective. Contributions dealing with earthquake processes and history, neotectonics, crustal deformation, and margin structure for either subduction zone are welcome.
Conveners: Kelin Wang, Geological Survey of Canada, 9860 West Saanich Road, Sidney, B.C., Canada V8L 4B2, Phone: +1-250-363-6429, Fax: +1-250-363-6565, E-mail: wang@pgc.nrcan.gc.ca; Ray E. Wells, U.S. Geological Survey, 345 Middlefield Road, MS 975, Menlo Park, CA 94025, Phone: +1-650-329-4933, Fax: +1-650-329-4936, E-mail: rwells@usgs.gov; and Masataka Ando, Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto 611, Japan, Phone: ++0774-38-4195, Fax: ++0774-38-4190, E-mail: ando@rcep.dpri.kyoto-u.ac.jp
T03 Seismic and Electromagnetic Imaging of Mid-Ocean Ridges (Joint with S)
After decades of study, the mechanisms of mantle upwelling, melt generation
and transport, and crustal construction continue to challenge geoscientists.
However, recent high-resolution seismic and electromagnetic experiments have begun to provide direct observational constraints on the processes of mantle flow, and crustal accretion at oceanic spreading centers. This session will bring together results from electromagnetic studies and from a variety of seismic techniques (reflection, refraction, tomography, teleseismic and microearthquake studies) which have been used to image the mid-ocean ridge system.
Scientific objectives will include (but are not limited to):
-Temporal and spatial scales of variability.
-Interactions of magma with the lithosphere and crust.
-Crustal magma plumbing system
-Rates and mechanisms of melt transport
Papers are welcomed which discuss electromagnetic and seismic results from crustal and upper-mantle studies of any of the world's ridges, as well as studies of hot-spot interaction with active spreading centers.
Conveners: Laura Magde, Department of Geological Sciences, Cascade Hall, University of Oregon, Eugene, OR 97403 USA; Tel: +1-541-346-4653; Fax: +1-541-346-4692; E-mail: laura@newberry.uoregon.edu and Graham Kent, Institute of Geophysics and Planetary Physics, 9500 Gilman Drive, La Jolla, CA 92093-0225 USA; Tel: +1-619- 534-7386; Fax: +1-619-534-2902; E-mail: gkent@ucsd.edu
T04 Hydrology-Tectonophysics Special Session Honoring the Career and Research of Arthur H. Lachenbruch (Joint with H)
The session honors Art Lachenbruch's many definitive contributions to understanding Earth's thermal budget and their implications for active tectonics, climate change, and surface processes. Lachenbruch's seminal studies on permafrost are not only elegant and physically appealing but their thermal implications led to the abandonment of plans to bury the Trans-Alaska pipelinebeneath the surface. His many studies of surface heat flux in the western United States clearly elucidated the role of thermal regime in active tectonic deformation. He was one of the first to recognize and exploit the near-surface temperature profile in the Arctic to bound global climate change in the Holocene.
Conveners: Bernard Hallet, University of Washington, Quaternary Research Center, Box 351360, Seattle, WA 98195-1360 USA; Tel: +1-206-685-2409; Fax: +1-206-543-3836; E-mail: hallet@u.washington.edu; Wayne Thatcher, U. S. Geological Survey, Mailstop 977, 345 Middlefield Road, Menlo Park, CA 94025; Tel: +1-650-329-4810; Fax: +1-650-329-5163; E-mail: thatcher@thepub.wr.usgs.gov; and John Sass, USGS, Flagstaff, AZ USA; Tel: +1-760-934-4059 (Voice); Fax: +1-760-924-5919; E-mail: jsass@flagmail.wr.usgs.gov
T05 Mineral Transformations (Joint with V)
Phase transformations and transitions in minerals are a fundamental influence on the properties and behavior of minerals with an impact from the geophysical scale (seismic discontinuities in the mantle) to the microscopic scale (e.g., anharmonic behavior). On the intermediate length scale, structural phase transformations can dominate the thermodynamic properties of individual minerals. The integration of properties on such diverse length scales requires a sound basis in the physical theory of the solid state as well as thermodynamics. The promotion of such integration is the aim of this symposium. Contributions are encouraged on all aspects of mineral transformations including experimental, theoretical, and geophysical approaches. The symposium is sponsored by the European Community TMR Network on Mineral Transformations (http://www.esc.cam.ac.uk/mintrans/index.html).
Conveners: Ross Angel, Bayerisches Geoinstitut, Universitaet Bayreuth, D-95440 Bayreuth, Germany, Phone: +49-921-553736, Fax: +49-921-553769, E-mail: ross.angel@uni-bayreuth.de; and Bob Hazen, Geophysical Laboratory, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015-1305, Phone: +1-202-686-4370, E-mail: hazen@geolab.ciw.edu
T06 Integrated Studies of Continental Accretion in the Coast Mountains of British Columbia and Southeast Alaska
This session emphasizes multidisciplinary results pertaining to continental accretion in the northeast Pacific. Papers are requested that address interpretations of seismic reflection and refraction data, correlations of seismically imaged features to surface geology, terrane affinity studies, age and kinematic interpretations of the rock fabrics including relations to large-scale plate motions, paleomagnetic evidence for crustal-scale displacements or deformations, and processes and timing of batholith generation and emplacement.
Conveners: L. S. Hollister, Department of Geosciences, Princeton University, Princeton, NJ 08544, Phone: +1-609-258-4106, Fax: +1-609-258-1274, E-mail: linc@geo.princeton.edu; and R. F. Butler, Department of Geosciences, University of Arizona, Tucson, AZ 85721, Phone: +1-520-621-2324, Fax: +1-520-621-2672, E-mail: butler@geo.arizona.edu
T07 Structure and Deformation of the New Zealand Transpressional Plate Boundary (Joint with S)
The Indo-Australian/Pacific plate boundary in the South Island, New Zealand, is characterized by rapid transcurrent movement and high uplift rates of the associated Southern Alps orogen. This poster session examines the structure and deformation arising from the continent-continent transpressive collision at this plate boundary. Recent studies have focused on crustal structure, crustal shortening, and the processes of crustal deformation, uplift, and strain partitioning. Results will be presented from studies using methods such as onshore and offshore seismic refraction, vertical incidence seismic reflection, regional and teleseismic passive seismology, eletrical and magnetotellurics, gravity, laboratory petrophysical measurements, geodynamics, and regional geologic investigations.
Conveners: David Okaya, Department of Earth Sciences, University of Southern California, University Park, Los Angeles, CA 90089, Phone: +1-213-740-7452, Fax: +1-213-740-0011, E-mail: okaya@usc.edu; and Tim Stern, Research School of Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand, Phone: +64-4-472-1000 ext 83282, Fax: +64-4-495-5186, E-mail: tim.stern@vuw.ac.nz
T08 Accretionary Processes at Ultraslow Spreading Ridges: Recent Field Results From the Arctic and Southwest Indian Ridges
In the global ridge system, ultraslow spreading ridges represent by length the largest single class. Papers are solicited to present new data acquired on the Arctic and Southwest Indian ridges and theoretical models on geodynamics of these spreading systems. This session will examine the influence of spreading rate and thermal structure on accretionary processes in the ultraslow spreading environment, and will address topics on partial melting, lithospheric thickness, axial segmentation, morphology, architecture of the crust, and basalt and mantle chemistry as well as its ultimate interaction with the seawater above.
Conveners: Kathleen Crane, Hunter College (CUNY), New York, NY 10021, Phone: +1-202-404-1107, Fax: +1-202-767-0167, E-mail: kathyc@qur.nrl.navy.mil; Catherine Mevel, Laboratoire de Petrologie, UPRES-A CNRS 7058, UPMC, Boite 110, 4 place Jussieu, 75252 Paris, cedex 05 France, Phone: +33-1-44-275193, Fax: +33-1-44-273911, E-mail: cam@ccr.jussieu.fr; Kensaku Tamaki, ORI, University of Tokyo, Tokyo, Japan, Phone: +81-3-5351-6443, Fax: +81-3-5351-6445, E-mail: tamaki@ori.u-tokyo.ac.jp; Jennifer Georgen, MIT-WHOI Joint Program in Oceanography, Woods Hole, MA 02543, Phone: +1-508-289-2491, Fax: +1-508-457-2187, E-mail: jgeorgen@mit.edu; and Bernard Coakley, Lamont-Doherty Earth Observatory, 107 Oceanography, Palisades, New York, 10964, USA, Phone: +1-914-365-8552, Fax: +1-914-365-8179, E-mail: bjc@ldeo.columbia.edu
T09 Mantle Rheology: Constraints From Mineral Physics and Geodynamic Observations
The rheology of the Earth's mantle is one of the most important properties that controls both the pattern of mantle convection and the surface geophysical observables associated with this circulation (e.g., the gravity field, plate motions, and dynamic topography). On the basis of the physics of plastic deformation of solids it is expected that mantle rheology must vary significantly, both radially and laterally. Robust constraints on mantle rheology, both from mineral physics and from geodynamic studies, have been difficult to obtain, and a number of fundamental issues remain unresolved and actively debated. Nevertheless, in recent years significant progress has been made in both these areas toward better constraining the rheological structure, and some consensus has begun to emerge. This interdisciplinary session will include presentations on mantle rheology, both from mineral physics and geodynamic modeling, to define the current status of this important subject. Issues to be discussed include: (1) Is transient creep important in post-glacial rebound? (2) Is there any rheological stratification at around the 660 km discontinuity and if so what is its nature? (3) How large is the viscosity of the lower mantle and is it nearly constant with depth? (4) Is the rheology of the Earth's mantle Newtonian or non-Newtonian? (5) How strong are subducted slabs? (6) Does dissolved water weaken the minerals of the deep mantle? (7) How do phase transformations affect rheological properties? (8)Is the mantle viscosity profile consistent with a nearly adiabatic temperature gradient? (9 How do rheological properties change laterally?
Conveners: David C. Rubie, Bayerisches Geoinstitut, Universitaet Bayreuth, D-95440 Bayreuth, Germany, Phone: +49-921-553711, Fax: +49-921-553769, E-mail: dave.rubie@uni-bayreuth.de; Jerry X. Mitrovica, Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON, Canada M5S 1A7, Phone: +1-416-978-4946, Fax: +1-416-978-7606, E-mail: jxm@physics.utoronto.ca
T10 New Methods in High-Resolution, Near-Bottom Seafloor Mapping and Imaging
In recent years, high-resolution mapping of seafloor terranes in diverse tectonic settings using a variety of near-bottom deep submergence sonar and vehicle technologies has provided a large volume of information on the detailed morphology and topography of the ocean floor. This has been coupled to the advent of routine digital electronic imaging of the seafloor and the
compilation of digital mosaics of seafloor features. The session will permit a wide range of investigators to present new data resulting from use of high-resolution, near-bottom seafloor mapping and imaging technologies. Presentations that focus on both the technical characteristics of the systems and the scientific applications and results are enouraged.
Conveners: Daniel J. Fornari, Woods Hole Oceanographic Institution, Geology and Geophysics Department, Mail Stop 22, Woods Hole, MA 02543, Phone: +1-508-289-2857, Fax: +1-508-457-2187, E-mail: dfornari@whoi.edu; and Daniel Scheirer, Brown University, Department of Geological Sciences, Box 1846, Providence, RI 02912, Phone: +1-401-863-7573, Fax: +1-401-863-2058, E-mail: scheirer@emma.geo.brown.edu
T11 Investigations of Rock Fracture: Lessons for Understanding Fluid Flow in Fractured Rock
Attempts to understand the complex processes controlling fluid flow in fractured rock include a diversity of field, laboratory, and theoretical approaches using both direct measurements of exposed fractures and indirect measurements based on the effects of fractures on the physical properties of rock, such as seismic travel times. Contributions reflecting this variety of investigative approaches are sought to provide a venue for discussing what the different perspectives tell us about controls on fluid flow in fractured rock.
Conveners: Carl Renshaw, Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, Phone: +1-603-646-3365, Fax: +1-603-646-3922, E-mail: Carl.E.Renshaw@dartmouth.edu; and Stephen Brown, New England Research Inc., 76 Olcott Drive, White River Junction, Vermont 05001, Phone: +1-802-296-2401, Fax: +1-802-296-8333, E-mail: sbrown@ner.net
T12 Fire and Ice--The Geomorphology of Metamorphism: Mesoscale Linking Between Surficial and Crustal Processes. (Joint with H and V)
It is widely appreciated that at an orogenic scale, surface processes provide a crucial control on crustal evolution. That more local-scale interactions between structural, metamorphic, and surface processes can have profound tectonic consequences is a more novel and controversial notion. To foster understanding about the spatial scale and manner in which surficial mass transfer influences subsurface thermal, mechanical, and chemical processes, this session welcomes contributions from workers involved in cross-fertilizing studies in geomorphology, geophysics, petrology, tectonics, and geodynamics; contributions reporting relevant datasets or theoretical considerations are equally welcome.
Conveners: Peter K. Zeitler, Department of Earth and Environmental Sciences, Lehigh University, 31 Williams Drive, Bethlehem, PA 18015, Phone: +1-610-758-3671, Fax: +1-610-758-3677, E-mail: pkz0@lehigh.edu; C. Page Chamberlain, Dept. of Earth Sciences, Dartmouth College, Fairchild Sciences Center, Hanover, NH 03755, Phone: +1-603-646-3624, Fax: +1-603-646-3922, E-mail: pkz0@lehigh.edu; and Bernard Hallet, University of Washington, Quaternary Research Center, Box 351360, Seattle, WA 98195-1360, Phone: +1-206-685-1166, Fax: +1-206-543-3836, E-mail: hallet@u.washington.edu
T13 Multidisciplinary Approaches to Studying Midocean Ridge Processes
The formation of new ocean crust involves geological, thermal, chemical, and biological processes interacting on a variety of spatial and temporal scales. Unraveling the relationships between these interconnected processes is receiving increasing attention in midocean ridge studies, and has been a long-term goal of the RIDGE program. Consequently, the approach to investigating these processes is evolving from sharply focused cruises dedicated to a particular discipline to multidisciplinary cruises with a holistic strategy. This evolution is driven by economic as well as scientific efficiency, as the cost of field work is increasing even as access to large platforms is decreasing. This session solicits papers from field expeditions dealing with multidisciplinary aspects of midocean ridge research, and offers an opportunity to bring together cross-cutting but related groups of observations that might otherwise be fragmented in separate sessions. Laboratory or modelling studies on the same theme are also welcome.
Conveners: Edward T. Baker, NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA 98115-0070, Phone: +1-206-526-6251, Fax: +1-206-526-6054; E-mail: baker@pmel.noaa.gov; and Richard N. Hey, Hawaii Institute of Geophysics and Planetology, University of Hawaii, 2525 Correa Rd, Honolulu HI 96822, Phone: +1-808-956-8972, Fax: +1-808-956-9225, E-mail: hey@soest.hawaii.edu
T14 Tectonic Evolution of Forearc Highs at Convergent Margins
Forearc highs provide an important window into the interior of subduction-related accretionary wedges. Actively growing emergent forearc highs, as observed at the Aleutian, Barbados, Cascadia, Hellenic, Hikurangi, Makran, Nankai, and Sumatrian subduction zones, provide information about long-term deformation and metamorphism within the wedge and uplift and exhumation at the surface of the wedge. A better understanding of this tectonic setting will provide critical tests for a wide range of tectonic and geodynamic models. Papers are welcome that report on tectonic processes operating at active forearc highs or at well-constrained ancient forearc highs. Of particular interest is quantitative information about deformation and metamorphic processes operating within the accretionary wedge, about the balance between accretionary and erosional fluxes, about the rates and modes of uplift, topographic growth, and exhumation, or about the near-surface displacement field ajacent to the forearc high.
Conveners: Mark T. Brandon, Department of Geology and Geological Sciences, Yale University, P.O. Box 208109, New Haven, CT, 06520-8109, Phone: +1-203-432-3135, Fax: +1-203-432-3134, E-mail: mark.brandon@yale.edu; Sean D. Willett, Department of Geosciences, Pennsylvania State University, University Park, PA 16802, Phone: +1-814-865-3951, Fax: +1-814-863-7823, E-mail: sean@geosc.psu.edu; Uwe Ring, Institut fuer Geowissenschaften, Universitaet Mainz, 55099 Mainz, Germany, Phone: +49-6131-392164, Fax: +49-6131-394769, E-mail: ring@mail.uni-mainz.de; and Bernhard Stoeckhert, Geologisches Institut, Ruhr Universitaet, Universitaetsstrasse 150, 44721 Bochum, Germany, Phone: +49 (234) 700-7254, Fax: +49 (234) 709-4752, E-mail: Bernhard.Stoeckhert@rz.ruhr-uni-bochum.de
T15 Tectonics and Crustal Structure of Oceanic Plateaus and Arcs
This poster session will focus on the tectonics and crustal-mantle structure of oceanic plateaus and arcs of the western Pacific and other oceans. Crustal structure data will include OBS refraction, deep MCS reflection, and EM results from the Ontong Java, Ogaswara, Shatsky, and other oceanic plateaus as well as data from the Solomon, Izu-Bonin-Marianas, and other oceanic arc systems. These data provide important constraints on the accretion, subduction, and oblique collision of arcs with plateaus, on the crustal growth of plateaus and arcs through magmagenesis, and on the deep crustal and mantle structure of oceanic plateaus and their relation to mantle plumes.
Conveners: Asahiko Taira, Ocean Research Institute, University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan, Phone: +81-3-5351-6437, Fax: +81-3-5351-6527, E-mail: ataira@ori.u-tokyo.ac.jp; and Paul Mann, Institute for Geophysics, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, TX 78759-8500, Phone: +1-512-471-0452, Fax: +1-512-471-8844, E-mail: paulm@utig.ig.utexas.edu
Volcanology, Geochemistry,Petrology (V) If you are submitting an abstract to a special session, you must also send a copy of your abstract to the primary special session convener (first listed or marked with a *). Sending a copy of your abstract to a convener, however, does not constitute sending it to AGU. Abstracts MUST be received at AGU headquarters by August 26, 1998 (Mail and E-mail); September 2, 1998 (Interactive Web Form).
V01 Ultrahigh-Pressure Metamorphism and Geodynamics in Collision-Type Orogenic Belts
Study of ultrahigh-P metamorphic rocks and their implications in the role of fluid in geochemical cycling and slab/mantle interactions has continuously attracted international attention. Recently committed continental drilling in the Sulu UHP terrane of eastern China and a Japanese mapping project of the diamondiferous Kokchetav terrane of northern Kazakstan are just a few examples of these studies. Through the support of the International Lithosphere Project the Task Group III-6 members have made significant contributions in many global UHP terranes; some findings are summarized in this special session. Additional contributions that incorporate new data, interpretations, and geodynamic models on rocks and minerals are welcome.
Conveners: J.G. Liou and W.G. Ernst, Department of Geology and Environmental Sciences, Stanford University, Stanford, CA 94305, Phone: +1-650-723-2716, E-mail: liou@pangea.stanford.edu; Shige Maruyama, Earth and Planetary Sciences, Tokyo Institute of Technology, O-Okayama 2-12-1, Meguro, Tokyo 152, Japan. Phone: +81-3-5734-2618, E-mail: smaruyam@geo.titech.ac.jp; Bolin Cong, Institute of Geology, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China, Phone: +86-10-6492-3051, E-mail: congbl@public3.bta.net.cn
V02 In Situ Carbon Dioxide Measurements At High Flux Localities
High concentrations of CO2 and other gases associated with volcanic, geothermal, and tectonic regions have prompted interest in estimation of the total CO2 flux for these areas. CO2 flux measurement techniques have evolved from the manual collection of soil-gas samples with subsequent gas analyses performed in a laboratory to the use of more sophisticated instrumentation that permits real-time measurement of CO2 flux in the field. As the use of portable infrared gas analyzers has grown, researchers have found that often there is strong small-scale spatial and temporal variability in gas fluxes. Differences in sampling techniques and instrumentation have generated discussion as how best to deal with these natural variations in order to achieve the most accurate estimate of the total flux. This special session is intended to provide a forum for researchers working in high-flux environments to discuss planning and execution of these types of studies and examine the results of ongoing research.
Conveners: Deb Bergfeld, Los Alamos National Laboratory Mail Stop D-462, EES-1, Los Alamos NM, 87544, Phone: +1-505-667-1812, Fax: +1-505-665-3285, E-mail: debberg@lanl.gov; Cindy Werner, Pennsylvania State University, Phone: +1-814-863-8055, Fax: +1-814-863-7823, E-mail: werner@farallon.geosc.psu.edu; and Fraser Goff, Los Alamos National Laboratory, Mail Stop D-462, EES-1, Los Alamos, NM, 87544, Phone: +1-505-667-8060, Fax: +1-505-665-3285
V03 Seafloor Event Detection and Response: The 1998 Event at Axial Volcano
Since the introduction of real-time acoustic monitoring in the NE Pacific in 1993, understanding of the physical, chemical, and biological consequences of mid-ocean ridge diking events has grown rapidly. The February 1998 event at Axial Volcano on the Juan de Fuca Ridge was the most seismically active mid-ocean ridge event yet monitored and the first to occur at a site with a preexisting suite of seafloor and water column monitoring instruments. A quick response cruise by RIDGE and NOAA/VENTS investigators following the event found evidence of a substantially invigorated hydrothermal system at the summit of Axial Volcano. Follow-up surface ship, ROV, and submersible cruises are planned for further investigations and to recover those instruments in place during and immediately after the event. This event holds particular interest in light of multi-institutional plans to focus on Axial Volcano as the site of a New Millennium Observatory (NeMO) for the long-term study of the effects of magma movement on the hydrothermal environment and the subsurface biosphere. This session solicits papers on specific results obtained on the detection of and response to the 1998 Axial event, on mature results from previous events, and on new methods and instruments designed to enhance our present capabilities for responding to and monitoring the aftereffects of diking events.
Conveners: Edward T. Baker, NOAA/PMEL, 7600 Sand Point Way, NE, Seattle, WA 98115-0070, E-mail: baker@pmel.noaa.gov, Phone: +1-206-526-6251, Fax: +1-206) 526-6054; and James P. Cowen, Department of Oceanography, University of Hawaii, 1000 Pope Road, Honolulu, HI 96822, Phone: +1-808-956-7124, Fax: +1-808-956-9225, E-mail: jcowen@soest.hawaii.edu
V04 Volcanic Eruptions That Form Lava Domes
Volcanic eruptions that form lava domes have received greatly increased scientific attention in the past 20 years, in large part because of the significant number of fatalities they have caused. Studies of Soufriere of St. Vincent, Mount St. Helens, Unzen, Galeras, Merapi, Soufriere Hills, and others have provided new insights into the hazards associated with dome growth, how to interpret domes and associated pyroclastic deposits in the geologic record, how degassing and crystallization affect eruptive style, and how geophysical, geochemical, geodetic, and remote sensing methods can be used to monitor dome-forming eruptions. Presentations are invited that deal with any aspects of this relatively neglected class of eruptive activity.
Conveners: Jonathan Fink, Office of the Vice Provost for Research, Box 872703, Arizona State University, Tempe, AZ 85287-2703, Phone: +1-602-965-3195, Fax: +1-602-965-8293, E-mail: jon.fink@asu.edu; and Steve Sparks, University of Bristol, E-mail: Steve.Sparks@bristol.ac.uk
V05 Restless Calderas
There are a number of calderas around the world which are currently exhibiting restlessness, as shown by continued seismicity, deformation, and/or degassing. Yet the origin or origins of this restlessness can be enigmatic. At the same time, researchers are applying new techniques, interdisciplinary studies, and integrated models to improve understanding of caldera activity. This session seeks to shed light on the magmatic-hydrothermal plumbing systems of calderas by bringing together researchers from various disciplines. Contributions on the geology, petrology, geochemistry, and geophysics of restless calderas are invited. Submissions which examine a particular caldera from different but related angles are encouraged. Contributions include, but are not limited to, the following questions: (1) the interplay between shallow-level and deeper magmatic processes beneath calderas, (2) the spatial and temporal nature of magma storage beneath calderas, (3) the mechanisms and rates of magma transport under calderas, (4) the timescales over which calderas behave as open and closed systems, (5) the mechanisms and timescales of magma replenishment into caldera magmatic systems, (6) estimates of material mass balance into and out of
calderas, (7) the role of the hydrothermal system and its interaction with the magmatic system, (8) the influence of regional tectonics, structure, and faults on the caldera magmatic system, and (9) general models of how calderas work. Contributions from the fields of seismology, deformation (leveling, geodimetry, GPS, interferometry, and paleodeformation), gas geochemistry, hydrothermal/geothermal systems, gravity, petrology, high-temperature, low-temperature, and isotope geochemistry, tectonics, and modeling are invited.
Conveners: John Stix, Departement de Geologie, Universite de Montreal, Montreal, Quebec H3C 3J7, Canada, Phone: +1-514-343-6832, Fax: +1-514-343-5782, E-mail: stix@ere.umontreal.ca; and Dave Hill, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, Phone: +1-650-329-4795, Fax: +1-650-329-5163, E-mail: hill@andreas.wr.usgs.gov
V06 Mitigation Of Volcano Hazards In The 21st Century
Volcanic eruptions transcend geopolitical boundaries. Continued growth in world
population, economic development, urbanization, and air traffic in the next
century will exacerbate the mitigation of volcano hazards on the ground and in
the skies. Despite recent advances in volcano monitoring, successful
forecasting of explosive eruptions, with rare exception (e.g., Mount Pinatubo
in 1991), remains a goal unattained. Moreover, the 1985 eruption at Nevado del
Ruiz (Colombia) provides a tragic reminder that good science alone is not
enough. Interested possible participants from the United States and abroad are
invited to address any of the following: lessons learned from previous
volcanic crises; new methods for hazards assessment, volcano monitoring (space-
and ground-based), and data interpretation; and, given the quantum leaps in
telecommunications (e.g., WWW and E-mail), how information sharing can be
facilitated and more effective communications between scientists,
emergency-management officials, and the public can be built to reduce volcano
risk?
Conveners: Robert I. Tilling, U.S. Geological Survey, Mail Stop 910, 345 Middlefield Road, Menlo Park, CA 94025-3591 USA; Tel: +1-650-329-5228; Fax: +1-650-329-5203; E-mail: rtilling@mojave.wr.usgs.gov; John Eichelberger, University of Alaska, Fairbanks, AK, E-mail: eich@gi.alaska.edu
V07 Constraints on the Isolation of Mantle Domains
The issue of convective isolation of mantle domains has long been the focus of considerable debate among geophysicists and geochemists. Simple models of whole versus layered mantle convection have, in general, given way to new ideas which attempt to satisfy recent observational constraints. Continental crust, chemically buoyant lithosphere, mantle wedge, and lower mantle can all, in principle, isolate components for long periods of time. Even in a fully convicting mantle, there may be isolated domains, on opposite sides of the Earth, perhaps, or within rheologically distinct "blobs". What are the plate tectonic and convective options for isolating a reservoir? Are homogeneous reservoirs homogeneous because they are well stirred by convection or because of the way that they are sampled by diapirism and melting? How are chemical heterogeneities of greatly varying scale lengths destroyed? The intent in this session is to bring together seismologists, geochemists, dynamicists, and mineral physicists to discuss the current state of the art as it bears on these questions. Contributions which relate to the presence or absence of any type of isolation within the mantle, including lateral isolation of large convective regimes, buoyant isolation of materials in the upper mantle or in lithospheric or tectospheric domains, inferences of mantle-core interactions evidenced at the surface, constraints imposed by geochemical mass balance, and seismological evidence for large-scale material fluxes within the mantle are encouraged.
Conveners: Alan Zindler, National High Magnetic Field Lab and Department of Geoscience, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32306, Phone: +1-850-644-4331, Fax: +1-850-644-0827, E-mail: zindler@magnet.fsu.edu; Don Anderson, California Institute of Technology, 1200 East California Bouelvard, Seismology Lab, Mail Stop 252-21, Pasadena, CA 91125, Phone: +1-626-395-6901, Fax: +1-626-564-0715, E-mail: dla@gps.caltech.edu
V08 Melting and Melt Extraction
Study of mantle melting continues to attract great attention, owing to the close relationship between melting and the ongoing geodynamic and geochemical evolution of the Earth. This special session will bring together geochemists, geophysicists, and petrologists to highlight recent progress in understanding mantle melting beneath ridges and arcs and to discuss how integration of these disciplines can advance a consistent understanding of material properties and processes in partially molten regions.
Understanding of mantle melting and melt extraction has been enhanced by new observations of U-series nuclides as well as new experimental data and improved geochemical and geophysical models. Nevertheless, substantial uncertainty remains regarding key aspects of melting that are required for a well-integrated understanding of this process. This is particularly true for melting beneath volcanic arcs, which is complicated by the flux of subduction-related components, but also true in the less-complicated environment beneath ridges. Improved understanding of melting in both regimes requires better constraints on many of the same key parameters. These include (but are not limited to) the relationship between mantle flow and melting, the mechanism of melt segregation, the rate of melt formation and melt transport, and the geometric distribution of melt production. An additional key parameter of great importance to melting beneath arcs is the relationship between the flux of subducted components and melt production. Contributions that address these and related questions are welcome A key goal of this session is to facilitate cross-pollination of ideas and methodologies between those working on sub-ridge melting with those working on sub-arc melting.
Conveners: Marc Hirschmann, Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, Phone: +1-612-625-6698, Fax: +1-612-625-3819, E-mail: hirsc022@tc.umn.edu; Marc Spiegelman, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, Phone: +1-914-365-8425, Fax: +1-914-365-8150, E-mail: mspieg@ldeo.columbia.edu; Tim Elliott, Faculteit der Aardwetenschappen, Vrije Universiteit Amsterdam, Netherlands, Phone: +31-20-444-7326, Fax: +31-20-646 2457, E-mail: ellt@geo.vu.nl
V09 In Situ Chemical and Isotopic Analyses
Large ion microprobes such as the Cameca 1270 and SHRIMP types offer unprecedented transmission and resolution for geological in situ chemical and isotopic analyses. Spatial resolutions of the order of 1 micrometer or less are achievable, but the application of these spot sizes is often limited by the number of ions required for a given precision. As such, there is a tradeoff in the spatial resolution that can be achieved and the nature of the information required. At this level an ion probe analysis may involve several orders of magnitude less material than a conventional analysis relying on dissolution techniques, and different philosophies have resulted for data analysis and interpretation. Whereas conventional techniques strive for the highest accuracy and precision in an analysis to allow the identification of the presence of multiple components, the goal of ion microprobe analysis is to achieve the measurement of a single domain in a given analysis at the expense of the analytical precision achievable on a larger sample volume. The increasing sensitivity of conventional methods and the advent of laser ICPMS with intermediate sample consumption will probably require that the practical differences will eventually disappear. The intent of this session is to bring together geochemists working on obtaining the maximum information from the smallest amounts of material. The prime focus is on ion microprobe analysis and the particular philosophies and experimental techniques that have been adopted to achieve in situ chemical and isotopic analysis.
Conveners: Trevor Ireland, Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115, Phone: +1-650-725-6835, Fax: +1-650-725-0979, E-mail: tri@pangea.stanford.edu; and Kevin McKeegan, Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095-1567, Phone: +1-310-825-3580, Fax: +1-310-825-2779, E-mail: kdm@ess.ucla.edu
V10 Recent Submarine Research Studies of Hawaiian Volcanoes
Hawaiian volcanoes continue to be a prime venue for studying processes associated with active volcanoes including some of the largest and most dynamic landslides on Earth. Several recent major marine expeditions have mapped and run seismic profiles of some of these landslides, surveyed submarine rift zones and examined the products of recent eruptions using submersibles and a ROV. These expeditions are providing new insights into ocean island volcanic construction and destruction processes as well as valuable analogs to volcanic rifting processes at mid-ocean ridges. This session offers researchers from many different disciplines the chance to share their latest results with colleagues in other disciplines. This kind of cross discipline interaction is essential for developing a comprehensive understanding of processes in volcanic environments. Papers are invited in the areas of petrology and geochemistry, volcanic processes, seismology, tectonics, landslide processes and other related areas.
Conveners: Michael O. Garcia, Dept. of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822 USA; Tel: +1-808-956-6641; Fax: +1-808-956-5521; E-mail: garcia@soest.hawaii.edu and Kevin T. M. Johnson, Bishop Museum, Honolulu, HI 96817 USA, Tel: +1-808-848-4124; Fax: +1-808-847-8252; E-mail: kevinj@soest.hawaii.edu
V11 Continental Scientific Drilling
Drilling is the only method available for collection of rock and fluid samples from the subsurface, and many advancements in earth sciences and paleoclimatology will depend upon experiments that are based on drilling or include drilling as an important component. Presently active projects are investigating such diverse topics as the architecture of a young caldera, sequence stratigraphy of a passive margin, the anatomy of a mantle plume, and detailed paleoclimatic variations as recorded in long-lived lakes. In recent years, the environment for scientific studies related to drilling has undergone a transformation; scientific drilling has become less of a stand-alone activity and more of a component of an integrated package of data collection that involves geological, geochemical, and geophysical studies. A number of current projects are utilizing the well bore to establish long-term subsurface observatories. With more emphasis on the continental margins, continental and ocean drilling projects will become more integrated with one another. The International Continental Scientific Drilling Program (ICDP) has been established to coordinate and fund projects that address topics that have international scientific significance and participation. Contributions from scientific drilling projects in all stages of planning and implementation are invited to present goals, schedules and preliminary results. This session will provide an opportunity to introduce significant drilling proposals and projects to the scientific community and funding agencies.
Conveners: Dennis L. Nielson, DOSECC, Inc. and University of Utah, 423 Wakara Way, Salt Lake City, UT 84108 USA; E-mail: dnielson@egi.utah.edu and Vicki S. McConnell, University of Wisconsin, Department of Geology and Geophysics, Weeks Hall, 1215 West Dayton Street, Madison, WI 53706 USA; E-mail: vicki@geology.wisc.edu
