Union [U]

U13B
 MC:Hall D  Monday  1340h

International Polar Year II Posters


Presiding:  M Tedesco, CUNY / NASA / UMBC; D Carlson, IPY International Programme Office; J C Ellis-Evans, British Antarctic Survey

U13B-0049

Integration of Science and Outreach: Setting New Precedents during IPY

* Salmon, R A ipy.ras@gmail.com, IPY International Programme Office, BAS, High Cross, Madingley Rd, Cambridge, CB3 0ET, United Kingdom
Munro, N ipy1@bas.ac.uk, IPY International Programme Office, BAS, High Cross, Madingley Rd, Cambridge, CB3 0ET, United Kingdom
Carlson, D ipy.djc@gmail.com, IPY International Programme Office, BAS, High Cross, Madingley Rd, Cambridge, CB3 0ET, United Kingdom
Pauls, M Margarete.Pauls@awi.de, Alfred-Wegener-Institut für Polar- und Meeresforschung, An der Neuen Schleuse 32, Bremerhaven, 27570, Germany
Zicus, S Sandra.Zicus@utas.edu.au, International Antarctic Institute, University of Tasmania, Hobart, Tas 7001, Australia

IPY has been a phenomenal opportunity for scientists to engage in exciting research as part of a large interdisciplinary and international effort. It has also been an opportunity to share this research with the public, and demonstrate how individual projects fit into a much larger picture. Through international and interdisciplinary cooperation, IPY has catalysed thousands of local initiatives that have collectively had a global impact. Teachers, artists, journalists, parents, scientists, policy makers, polar visitors, film-makers, book readers and internet enthusiasts from around the world have become excited by polar research as a result of IPY. Coordinated IPY events during this time have engaged these new enthusiasts and catalysed a range of local activities that focus on polar research. These activities, often involving international dialogue, occur concurrently and thus help each participant feel they are part of a greater global event, much like the structure of IPY. The overall impact has therefore been to raise awareness of polar issues and research globally. This talk will present some of the achievements and highlights of IPY Education, Outreach and Communication that have occurred on a local, national, and international scale.

http://www.ipy.org/

U13B-0050

IPY Progress and Prospects

* Carlson, D ipy.djc@gmail.com, IPY International Programme Office, British Antarctic Survey High Cross, Madingley Road, Cambridge, CB1 1EL, United Kingdom

We can summarize the IPY goals as: (a) make major advances in polar knowledge and understanding; (b) leave a legacy of new or enhanced observational systems, facilities and infrastructure; (c) excite a new generation of polar scientists and engineers, and (d) elicit exceptional interest and participation from polar residents, schoolchildren, the general public, and decision-makers, worldwide. This talk reports on the progress and prospects in each of those areas from an overall international view; separate talks will describe details of future researcher and the IPY outreach efforts. To achieve major advances in knowledge, IPY has entrained the intellectual resources of thousands of scientists, many more than expected, often from 'non- polar' nations, and representing an unprecedented breadth of scientific specialties; integration of those efforts across disciplines to achieve integrated system-level understanding remains a substantial challenge. Many national and international organizations prepare plans to sustain new and improved observational systems, but clear outcomes and the necessary resources remain elusive. International outreach networks gradually build breadth and strength, largely through IPY Polar Science Days and other internationally- coordinated IPY events. A new Association of Polar Early Career Scientists (APECS) devotes talent and energy to shaping the future of polar research. These activities and networks may, with time and with continued international coordination, achieve an exceptional level of interest and participation. In all areas, much work remains.

http://www.ipy.org

U13B-0051

Satellite Monitoring of Disturbances in Arctic Ecosystems

* Prieto-Blanco, A ana.prieto@ucl.ac.uk, University College of London, Geography, Pearson Building Gower Street, London, WC1E 6BT, United Kingdom
Disney, M mdisney@geog.ucl.ac.uk, University College of London, Geography, Pearson Building Gower Street, London, WC1E 6BT, United Kingdom
Lewis, P plewis@geog.ucl.ac.uk, University College of London, Geography, Pearson Building Gower Street, London, WC1E 6BT, United Kingdom

We explored the capability of satellite remote sensing to detect temporal changes in northern Fennoscandian regions through the application of a temporal model of surface bidirectional reflectance. Remote sensing offers the potential to monitor changes over large areas and at hard to access locations. Specifically in remote Arctic locations, where ground surveys and aircraft observations are constrained by weather conditions and logistics, remote sensing provides a unique capability for repetitive and frequent sampling. A major disturbance in mountain birch forests typical of northern Sweden and Finland is caused by outbreaks of defoliating insects such as the autumn moth (Epirrita autumnata) and the winter moth (Operophtera brumata). These outbreaks occur more or less cyclically every 9-10 years and attack mainly birch (Betula spp.) leaving a mosaic of open woodland within the forest. It is expected that global warming will affect the incidence and the intensity of this outbreaks. The ecological and economical consequences can be severe hence the importance of close monitoring of shifts in the distribution of events. Defoliated areas of up to 6000 to 7000 ha of birch forest have been reported. Severely affected areas could potentially be detected by satellite providing valuable data to understand the behavior, estimate the damage and predict the development of forest pests. Quantification of the impact of such outbreaks will also permit far more accurate estimation of the terrestrial carbon budget of such regions. Here we applied a generic algorithm to detect sudden changes on land surface cover to daily 500m MODIS surface reflectance data over the Fennoscandian area. Moderate Resolution Imaging Spectraradiometer (MODIS) sensors on board the polar orbiting satellites Terra and Aqua provide an overpass at least once a day over the area of interest. Unfortunately, frequent cloud cover limits the acquisition of satellite imagery and persistent cloud cover may preclude image acquisitions for long periods of time. Burn scar detection algorithms detect sudden changes in the surface bidirectional reflectance distribution function (BRDF) which indicate a loss of vegetation due to burning. These algorithms are hence suitable for identifying forest pest insect outbreaks as they can potentially detect the loss of foliar biomass caused by the moth caterpillar activity. Ideally, to successfully apply these algorithms, the surface state should remain static prior to any sought-after disturbance. Dealing with deciduous forest this condition can only be accomplished working over a sliding window of a couple of weeks (unless some concept of phenology is included in the model). A further complication is the potential scarcity and sparseness of data available due to cloud cover. To tackle these problems we use data of both Terra and Aqua satellites in order to have as many samples as possible. The incorporation of BRDF effects in the algorithm allows us to use reflectance data obtained on different days and under different geometries and also accounts for underlying changes that can be due to vegetation phenology. The methodology here proposed represents a new approach to monitor forest damage by pest insects, which is valuable in climate change, ecology and economic studies. This work also exemplifies a new insight in the optimal use of satellite data at northern latitudes where atmospheric conditions limit the availability of useful data.

U13B-0052

Increased sensitivity of Arctic climate to atmospheric CO2 during the Pliocene

* Ballantyne, A ashley.ballantyne@colorado.edu, University of Colorado, 2200 Colorado Ave., Boulder, CO 80309, United States
Eberle, J Jaelyn.Eberle@colorado.edu, University of Colorado, 2200 Colorado Ave., Boulder, CO 80309, United States
White, J James.White@colorado.edu, Canadian Museum of Nature, PO Box 3443, Ottawa, ON K1P 6P4, Canada
White, J James.White@colorado.edu, University of Colorado, 2200 Colorado Ave., Boulder, CO 80309, United States
Rybczynski, N NRybczynski@mus-nature.ca, Canadian Museum of Nature, PO Box 3443, Ottawa, ON K1P 6P4, Canada
Greenwood, D GreenwoodD@BrandonU.CA, Brandon University, 270-18th Street, Brandon, MB R7A 6A9, Canada
Sinninghe Damste, J damste@nioz.nl, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59,Texel, Den Burg, AB NL-1790, Netherlands

Temperatures in the Arctic have increased by an astounding 1.5°C in response to greenhouse gas forcing over the 20th century. Although previous warm intervals in the Arctic have been well documented, the physical mechanisms responsible for the climatic forcing during these intervals are poorly understood. The Pliocene (1.8 to 5.3 Ma) is of particular interest as an analog for future warming because global temperatures were significantly warmer than today while continents were configured similar to today. Here, we combine several techniques for estimating past mean annual temperature (MAT), CO2, and relative humidity from an early Pliocene (3 to 5 Ma) peat deposit on Ellesmere Island, Canada (78° N 82°W and 200 MASL). Our independent proxies of paleotemperature - oxygen isotopes in cellulose (MAT= -5.5± 1.9°C), paleovegetation (MAT= - 0.4± 4.1°C), and tetraethers (MAT= -0.6± 0.8°C) - yield consistently warmer temperature estimates during the Pliocene. Although it is uncertain how much of the seasonal temperature cycle is integrated by these proxies, the consensus among these proxies suggests that Arctic temperatures were between 15 and 20°C warmer than present during the Pliocene. However, preliminary estimates based upon carbon isotopic analyses of sedges and mosses indicate that Pliocene atmospheric CO2 levels (386± 90 ppm) were approximately the same as today (385 ppm). We are currently working to corroborate these estimates of CO2 by investigating the stomatal density of paleoflora from the site. Our results indicate that current levels of atmospheric CO2 may be sufficient to produce significant additional warming in the Arctic.

U13B-0053

Ocean Current Observations From Nares Strait to the West of Greenland: Interannual to Tidal Variability and Forcing

* Muenchow, A muenchow@udel.edu, University of Delaware, 112C Robinson Hall, Newark, DE 19716, United States
Melling, H mellingh@dfo-mpo.gc.ca, Institute of Ocean Sciences, POS Box 6000, Sidney, BC V8L 4B2, Canada

During 2003-06, as part of the Arctic Sub-Arctic Ocean Flux (ASOF) experiment, an array of ocean-sensing instruments was deployed at 80.5N latitude to investigate the flux of seawater from the Arctic Ocean via the pathway to the west of northern Greenland. Full-depth current profiles data from this experiment provide, for the first time at periods longer than a single season, the seawater flux and its variability via this important channel through the Canadian Archipelago. The average flux of volume during this three-year period was 0.57±0.09 Sv (1 Sv=106m3s-1) southward over a section 300 m deep and 37 km wide. A linear trend of the along-channel flow, statistically significant at the 95% confidence level, indicates an increase in the volume flux of 20±10% between 2003 and 2006. The flow is, however, dominated by mixed diurnal and semi-diurnal tidal currents with kinetic energy an order of magnitude larger than that of the sub-tidal flow. Seasonal variation is an order of magnitude weaker than the long-term mean flow: the largest southward flow occurs in mid-March when the ice cover is land-fast and the smallest southward flow occurs in November when a mobile ice cover responds directly to wind. Variations in flow of daily to monthly period are comparable in magnitude to the average flow. The net flow over the cross-section is the result of a larger southward flux in the deep main channel occupying the western two thirds of the strait and a northward flux within about 5 km of Greenland. The latter is about 8% of the former. Spectral analyses indicated that the cross-channel pressure gradient is highly correlated with the sectionally averaged flow consistent with geostrophy. Along-channel pressure gradient explains 70% of the variance at 33-day period with a phase lag consistent with a frictional response; at 3-7 day period the response is weaker (<30%) with a phase relation suggestive of contributions by both friction and local acceleration.

http://newark.cms.udel.edu/~muenchow/papers/MuenchowMelling2008JMR.pdf

U13B-0054

Wet Chemical Analysis of Antarctica Dry Valley Soils

* Stroble, S shannon.stroble@tufts.edu, Tufts University, 62 Talbot Avenue, Medford, MA 02155, United States
Anderson, R , Tufts University, 62 Talbot Avenue, Medford, MA 02155, United States
Hredzak, P , Tufts University, 62 Talbot Avenue, Medford, MA 02155, United States
Young, S , Tufts University, 62 Talbot Avenue, Medford, MA 02155, United States
Kounaves, S samuel.kounaves@tufts.edu, Tufts University, 62 Talbot Avenue, Medford, MA 02155, United States
Douglas, S , Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
McKay, C , NASA Ames Research Center, MS 245-3, Moffett Field, CA 94035, United States
Ming, D H, ARES, NASA Johnson Space Center, Houston, TX 77058, United States
Smith, P , University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721, United States
Tamppari, L K, Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
Zent, A , NASA Ames Research Center, MS 245-3, Moffett Field, CA 94035, United States

The Antarctic Dry Valleys are considered one of the closest terrestrial analogs to the environment at the surface of Mars. Given Antarctica's relative remoteness coupled with a harsh environment, relatively little research has been performed on the soil across the continent compared to less remote locations around the world. Even fewer groups have focused on the soluble ionic species present in the soils of the Dry Valleys. This research utilizes two complementary analytical techniques, ion chromatography and ion selective electrodes (ISEs) to determine the soluble anionic and cationic species present in soil samples collected at varying depths in several of the Antarctic Dry Valleys. This study has shown the presence of several common ions including: Na+, K+, Ca2+, Cl-, NO3-, and SO42-. In addition to the further insight gained into the soil chemistry of the Antarctic Dry Valleys, this research had additional applications to the study of Martian soil chemistry. The ISEs are identical to the sensor array present in the Wet Chemistry Laboratory (WCL) on the 2007 Phoenix Mars Lander, which has analyzed and identified the ionic species present in the polar regions of Mars. This sensor array contained ISEs for Ca2+, Mg2+, K+, Na+, NH4+, Cl-, NO3-, and SO42-, as well as special electrodes for pH, and conductivity. By analyzing the Antarctic soil with both ion selective electrodes and ion chromatography, a better understanding of Antarctic soil chemistry is being achieved while simultaneously gaining insight and direction for the deconvolution of the recently obtained Martian WCL data.

U13B-0055

Drilling Induced Fracture (DIF) Characterization and Stress Pattern Analysis of the Southern McMurdo Sound (SMS) Core, Victoria Land Basin, Antarctica

* Patlan, E , School of Earth Sciences, The Ohio State University, 275 Mendenhall Laboratory, 125 South Oval Mall, Columbus, OH 43210, United States
Wilson, T J, School of Earth Sciences, The Ohio State University, 275 Mendenhall Laboratory, 125 South Oval Mall, Columbus, OH 43210, United States
Millan, C , School of Earth Sciences, The Ohio State University, 275 Mendenhall Laboratory, 125 South Oval Mall, Columbus, OH 43210, United States

There is a significant lack of data about present day stress fields in Antarctica. Stresses provide valuable information data about the forces acting on the plates. In Antarctica, stresses may be related to ridge forces such as rifting and/or uplifting, to ice loading/unloading related processes, or both. This project involves the study of drilling induced fractures from core recovered in the Victoria Land rift basin of Antarctica. Drilling induced fractures form ahead of the drill bit during drilling from stress imbalances due to the removal of excess weight pressure around the rock. Because horizontal stresses strike parallel to the planes made by drilling induced fractures, they can be used to measure modern day stress fields. Whole core images obtained during core logging by digitally scanning the outside of the core are stitched into longer intact intervals. Drilling induced fractures in the core are 'picked' in order to obtain their azimuth. Magnetically oriented acoustic images of the inside of the drill hole are then compare side by side with the stitched whole core images and visually scanned for matching features. Once the same set of fractures is found in the core and the borehole is then possible to rotate to core images to match the orientation of the borehole image. This will result on a core image with all the fractures in that interval re-oriented to true north. This final orientation of drilling induced fractures in the core will thus provide the direction of maximum horizontal compressional stress in this area.

U13B-0056

Upper Jurassic-Lower Cretaceous sincollisional sedimentary sequences of Chukotka: sedimentation, structural style and geodynamic implications

* Tuchkova, M I tuchkova@ginras.ru, Geological Institute of RAS, 7 Pyzhevsky, Moscow, 119017, Russian Federation
Sokolov, S D sokolov@ginras.ru, Geological Institute of RAS, 7 Pyzhevsky, Moscow, 119017, Russian Federation
Verzhbitsky, V E vladimir.verzhbitsky@tgsnopec.ru, TGS-NOPEC Geophysical Company Moscow Ltd, Donskaya St 4, Bld. 3, Office 303, Moscow, Office 303, Russian Federation

Upper Jurassic-Lower Cretaceous sincollisional sedimentary sequence, exposed on the Central part of Northern Chukotka is critical for understanding the timing, dynamics and sedimentary setting evolution of Chukotka-Eurasia collisional process (e.g., Sokolov et al., 2002) and so, represents one of the key regional stratigraphic units (Til'man, 1973; Tibilov, 1982; Miller et al., 2002,2007). From the other hand, this research may shed the light on the widely discussing problem of the Canadian and Makarov basins opening (e.g., Miller, Verzhbitsky, in press). Field observations reveal moderately to weakly deformed terrigenous sediments of the first stage of deposition with visible and dispersal plants remnants and containing organic-rich beds. Widely distributed and intensively deformed Triassic sequences (Tuchkova et al., 2007) and discussing Jurassic-Cretaceous units both intruded by Aptian-Albian postcollisional plutons and dikes (e.g., Katkov et al., 2006). Collisional-related fabric and subsequent granitoids are complicated by small-scale latest normal faults, in particular related to the westernmost segment of South Chukchi (Hope) basin development in Upper Cretaceous(?)-Cenozoic. We believe, that Upper Jurassic-Lower Cretaceous chukotkian formation, overthrusted by Triassic (and Paleozoic?) sequences (Tibilov, 1982; Baranov, 1995), continues offshore to the Eastern Siberian and Chukchi Seas and play significant role in the structure of the Eastern Arctic Russian shelf. The work is supported by the Russian Foundation for Basic Research (grant 08-05-00547), program of ONZ RAS, and NSH-3172.2008.5.

U13B-0057

Permo-Triassic hypabyssal mafic intrusions and associated tholeiitic basalts of the Kolyuchinskaya Guba, Chukotka (NE Russia): Significance for interregional correlations

* Ledneva, G V ledneva@ilran.ru, Geological Institute of RAS, 7, Pyzhevsky per., Moscow, 119017, Russian Federation
Pease, V L vicky.pease@geo.su.se, Department of Geology and Geochemistry, Stockholm University, Stockholm, SE-106 91, Sweden
Sokolov, S D sokolov@ginras.ru, Geological Institute of RAS, 7, Pyzhevsky per., Moscow, 119017, Russian Federation

In order to test tectonic hypotheses regarding the evolution of the Arctic Alaska-Chukotka microplate prior to the opening of the Amerasian basin, we investigated rocks exposed near Kolyuchinskaya Guba, eastern Chukotka. Hypabyssal mafic rocks and associated basaltic flows enclose terrigenous sediments, minor cherts and limestones in pillow interstices. The hypabyssal mafic rock yields a U-Pb zircon age of 252+/-4 Ma and indicates intrusion of basic magma at the Permo-Triassic boundary, contemporaneous with voluminous magmatism of the Siberian large igneous province (LIP). The lava flows and hypabyssal mafic rocks of the Kolyuchinskaya Guba region have major and trace element compositions identical the tholeiitic flood basalts of the main plateau stage of the Siberian LIP. They are strongly differentiated, the result of high-pressure equilibrium crystallization of a low-Ti/Y tholeiitic melt, and contaminated. The compositional variations in these rocks, however, neither proves nor disproves a correlation between the Permo-Triassic tholeiitic flood basalts of eastern Chukotka and the Siberian LIP. Thus, two alternative geodynamic interpretations are possible: 1) The hypabyssal mafic rocks and associated tholeiitic flows crystallized from a plume-derived melt; 2) The rocks are not related to plume activity, consequently eastern Chukotka was probably part of a passive rifted or extensional continental margin in the Permo-Triassic. Nonetheless, we prefer the first of these two possibilities. Funding for this work is gratefully acknowledged from the Swedish Polar Research Secretariat ("Beringia-2005"), the Swedish Research Council, the Russian Foundation for Basic Research (grant No 08-05-00547), Leading Scientific School (NSH-3172.2008.5) and ONZ RAS. Thanks are also extended to M.J. Whitehouse and the Nordsim facility - the Nordsim facility is funded by the research councils of Denmark, Norway, Sweden, the Geological Survey of Finland, and the Swedish Museum of Natural History.