PA13B-1342
Educating a Community Impacted by an Earthquake Swarm: 106 Volunteers Host Earthscope Flexible Array Recorders During the Mogul, Nevada Sequence
From February 28, 2008 residents of Reno and Sparks, Nevada experienced continuous earthquake shocks.
On some days the number of shocks exceeded 100. The local-magnitude 4.7 earthquake on April 25 shook
not only the Reno urban basin, but also people's patience. Intense and widespread public interest developed
in the earthquakes and in seismology generally. The Nevada Seismological Laboratory (NSL) was able to
conduct the Reno Basin Deployment to capitalize on this general interest. With the help of the NSF
Earthscope Observatory and the PASSCAL Instrument Center at New Mexico Tech, the NSL was able to
borrow ninety Flexible Array single-channel Ref Tek RT-125A recorders for this experiment. We carried out
five deployments across Reno and Sparks from May 15 to July 15, 2008. In advance of the deployments, we
asked for volunteer recorder hosts from among the public. About 200 people and institutions responded.
Unfortunately, not all those who volunteered could be included in the deployments. Since the earthquake
swarm was in the Mogul and Somersett neighborhoods, we conducted the deployments mostly in West Reno.
The five deployments recorded at a total of 106 locations. There were 67 locations in the first deployment;
the second, third, fourth, and fifth deployments were carried out using 60, 9, 15, and 11 locations
respectively. Many of the locations were repeated between the different deployments. Each deployment
recorded shaking on a vertical 4.5-Hz, leveled geophone for a four-day period. The results, primarily from a
magnitude 3.1 event on May 31, show that the shaking intensity and duration varied clearly at different
locations, even though the distances from the epicenter to those locations were about equal. Deep-basin
sites recorded longer shaking durations than the shallow-basin and rock sites, and rock sites often produced
waveforms of lesser amplitude. P-wave arrival times from the experiment will contribute critical tomographic
data toward understanding the structure of the Reno basin. Without public awareness and participation, this
experiment could not have been completed.
http://www.seismo.unr.edu
PA13B-1343
Linking International Development Actors to Geophysical Infrastructure: Exploring an IRIS Community Role in Bridging a Communications Gap
Over the past quarter century, national investments in high-fidelity digital seismograph networks have
resulted in a global infrastructure for real-time in situ earthquake monitoring. Many network operators adhere
to community-developed standards, with the result that there are few technical impediments to data sharing
and real-time information exchange. Two unanswered questions, however, are whether the existing models of
international collaboration will ensure the stability and sustainability of global earthquake monitoring, and
whether the participating institutions can work with international development agencies and non-
governmental organizations in meeting linked development and natural hazard risk reduction goals. Since the
2004 Indian Ocean tsunami, many of these actors are enlarging their commitments to natural hazard risk
reduction and building national technical capacities, among broader programs in poverty alleviation and
adaptation to environmental stress. Despite this renewed commitment, international development
organizations, with notable exceptions, have been relatively passive in discussions of how the existing
earthquake monitoring infrastructure could be leveraged to support risk-reduction programs and meet
sustainable development goals. At the same time, the international seismological community – comprising
universities and government seismological surveys – has built research and education initiatives such as
EarthScope, AfricaArray, and similar programs in China, Europe and South America, that use innovative
instrumentation technologies and deployment strategies to enable new science and applications, and
promote education and training in critical sectors. Can these developments be combined?
Recognizing this communication or knowledge gap, the IRIS International Working Group (IWG) explores the
link between the activities of IRIS Members using IRIS facilities and the missions of international development
agencies, such as US AID, the World Bank, other international development banks, and agencies of the
United Nations. Interests of US seismologists are served by encouraging development of modern
seismographic systems in countries around the world to collect data that are useful in research as well as
hazard mitigation and other national interests. Activities of the IWG to date include communicating the
benefits of geophysical infrastructure and training to disaster risk reduction programs within the United
Nations and development banks, coordinating an initiative to leverage retired PASSCAL data loggers through
long-term loans to network operators in foreign countries, preparing a white paper outlining IRIS capabilities
relevant to international development, and conducting a workshop, "Out of Africa", on modernizing
geophysical infrastructure in the Americas and Southeast Asia through projects that are closely tied to
university education and academic research.
http://www.iris.edu/
PA13B-1344
Leveraging Educational, Research and Facility Expertise to Improve Global Seismic Monitoring: Preparing a Guide on Sustainable Networks
Building a sustainable earthquake monitoring system requires well-informed cooperation between commercial
companies that manufacture components or deliver complete systems and the government or other
agencies that will be responsible for operating them. Many nations or regions with significant earthquake
hazard lack the financial, technical, and human resources to establish and sustain permanent observatory
networks required to return the data needed for hazard mitigation. Government agencies may not be well-
informed about the short-term and long-term challenges of managing technologically advanced monitoring
systems, much less the details of how they are built and operated. On the relatively compressed time scale of
disaster recovery efforts, it can be difficult to find a reliable, disinterested source of information, without
which government agencies may be dependent on partial information. If system delivery fails to include
sufficient development of indigenous expertise, the performance of local and regional networks may decline
quickly, and even data collected during an early high-performance period may be degraded or lost.
Drawing on unsurpassed educational capabilities of its members working in close cooperation with its facility
staff, IRIS is well prepared to contribute to sustainability through a wide variety of training and service
activities that further promote standards for network installation, data exchange protocols, and free and open
access to data. Members of the Consortium and staff of its Core Programs together could write a guide on
decisions about network design, installation and operation. The intended primary audience would be
government officials seeking to understand system requirements, the acquisition and installation process,
and the expertise needed operate a system. The guide would cover network design, procurement, set-up,
data use and archiving. Chapters could include advice on network data processing, archiving data (including
information on the value of standards), installing and servicing stations, building a data processing and
management center (including information on evaluating bids), using results from earthquake monitoring, and
sustaining an earthquake monitoring system. Appendices might include profiles of well-configured and well-
run networks and sample RFPs. Establishing permanent networks could provide a foundation for
international research and educational collaborations and critical new data for imaging Earth structure while
supporting scientific capacity building and strengthening hazard monitoring around the globe.
http://www.iris.edu
PA13B-1345
Model of the Tidal Variation in the Geoid and Deflection of Vertical in the Korean Peninsula
Recently in Korea, there is growing scientific interest and technological need about the tidal variation of the geoid and deflection of vertical around the Korean peninsula. Due to the gavitational attraction by the moon and the sun, tidal oscillation exists both in soild earth and the sea. And the ocean tide loads the earth crust and cause the secondary deformation. Numerical modelling or numerical fitting is necessary for the ocean tide model. We are developing the local tidal perturbation model of Korea to predict those variation in the geoid and deflection of vertical.
PA13B-1346
Application of Global Real-Time Landslide Forecasting System for International use
The variability of natural hazard events by category significantly vary in their spatial and temporal extents and onsets, requiring a catered, and focused approach to appropriately address the risk and vulnerability of the specific hazard event. The advent of satellite data products has helped to monitor tropical cyclones, droughts, and flooding conditions and consequent impacts. Geophysical events such as earthquake are continually monitored on a global seismic network. However, a warning or monitoring system has not been established at larger scales for landslides, a hazard with the smallest spatial extent but highest frequency and arguably largest impacts globally. One of the major challenges in landslide hazard research is the field's focus on site specific investigations, drawing on high resolution surface data as well as detailed landslide inventories and rainfall information to provide an estimate of static landslide hazard susceptibility. Few studies have approached the issue of landslide risk and susceptibility from a dynamic standpoint to estimate the potential for landslide susceptibility conditions in a time frame that allows for a better understanding of the physical processes both scientifically and as it relates to societal response. To present a more dynamic representation of landslide hazard risk at larger spatial scales new research has developed an algorithm which couples a landslide hazard susceptibility map with real-time satellite derived rainfall to forecast areas with high landslide potential at the global scale. The algorithm draws on near-real time Tropical Rainfall Measuring Mission (TRMM) data as well as other satellite products to obtain a 3-hourly picture of locations across the world where the surface susceptibility conditions are high and the rainfall accumulation exceeds a defined threshold. The resulting forecasts are updated every 3 hours on a website, highlighting pixels satisfying these conditions on a 0.25º grid. The spatial and temporal distribution of vulnerable areas can then be mapped out by integrating population data, road networks, and socio-economic information. This work is underway at both the regional and global scales. This algorithm is in evaluation stages and requires revisions of the input parameters and rainfall information to improve the prototype and algorithm performance. Improvements needed for enhanced performance include increasing the resolution of the susceptibility map with a higher resolution Digital Elevation Model (DEM) and discarding surface parameter data which increase uncertainty without contributing additional information such as the current soils information; additional quantification of the rainfall threshold relationship; and introduction of more dynamic variables like soil moisture which can improve the memory of the system. With the suggested modifications, this algorithm can serve as a useful tool for government officials, international aid organizations, and general societal education to better quantify landslide impacts and extent of hazard risk as well as more expediently respond to susceptible areas, particularly in more remote locations.
PA13B-1347
Comparison of Vs30 Measurements Against Predictions in Southern California
We have measured shallow shear-wave velocity at close vicinity to eighty-three California Integrated Seismic
Network recording sites and at 188 sites along the San Gabriel River in southern California (Thelen et al.,
2006), using SeisOpt® ReMiTM (© 2007 Optim). Data for CISN stations
were collected usually within 100 meters of the instrument to better understand the shallow shear-velocity
structure. Average shear wave velocities (Vs) have been determined to 10-, 30-, 50-, and 100-meter depths;
as well, modeled velocity constraints often extended to more than 200 m when possible. The depths at
which the measured shear wave velocity reaches ±20% of the values of 0.5, 1.0, and 1.5 km/s were
computed; the Z0.5, Z1.0, and Z1.5 respectively. These interface depths (ZV) are
estimated due to their importance in geotechnical calculations of resonant frequency. Topographic-slope
estimates for Vs30 do not address interface depths. To examine subsets of the data set, we defined "basin"
sites as those for which the SCEC CVM v4 predicts a Vs30 of <800 m/s. We find strong correlation at
basin sites between our measured Vs30 values and the SCEC CVM Vs30 predictions, but no correlation at
rock sites (as defined by the SCEC CVM). We also find that the Wald and Allen (2007) predictions of Vs30
using topographic slope are in agreement with our measured values at 57% of the sites, after allowing for a
±20% prediction error. As we expect, the standard deviation of the measured values is greater than for
the predicted values (174 and 134 m/s respectively), reflecting the heterogeneity between the sites. For 270
sites we measured across southern California, the topographic prediction for Vs30 has a mode that is 20%
less than the measured Vs30. This consistent bias in the Wald and Allen (2007) prediction remains even if
we select the 113 measurements that are within the flattest part of the Los Angeles Basin.
http://www.seismo.unr.edu/hazsurv
PA13B-1348
Understanding socio-economic impacts of geohazards aided by cyber-enabled systems
Due to an increase in the volume of geohazards worldwide, not only are impoverished regions in less developed countries such as Haiti, vulnerable to risk but also low income regions in industrialized countries, e.g. USA, as well. This has been exemplified once again by Hurricanes Gustav, Hanna and Ike and the impact on the Caribbean countries during the summer of 2008. To date, extensive research has been conducted to improve the monitoring of human-nature coupled systems. However, there is little emphasis on improving and developing methodologies to a) interpret multi-dimensional and complex data and b) validate prediction and modeling results. This presentation tries to motivate more research initiatives to address the aforementioned issues, bringing together two academic disciplines, earth and social sciences, to research the relationship between natural and socio-economic processes. Results are presented where cyber-enabled methods based on artificial intelligence are applied to different geohazards and regions in the world. They include 1) modeling of public health risks associated with volcanic gas hazards, 2) prediction and validation of potential areas of mining-triggered earthquakes, and 3) modeling of socio-economic risks associated with tropical storms in Haiti and the Dominican Republic.