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SSA 2009 Annual Meeting

Sessions

Click session titles to view the abstracts submitted for that session.

Active-Source Seismic Imaging—Characterizing the Subsurface

Poster Session - Friday AM, April 10

This session focuses on the use of active-source seismic studies to image faults, basin geometry, groundwater, geologic hazards (including volcanoes and landslides), and the local and regional tectonic setting. Studies are invited that lie within a broad range of scales and resolving abilities. Submissions are encouraged that demonstrate the use of seismic reflection, refraction tomography, ground-penetrating radar, other geophysical methods, and especially combinations of these approaches.

Conveners

  • Michael J. Rymer <mrymer [at] usgs [dot] gov>
  • Rufus D. Catchings <catching [at] usgs [dot] gov>

Advances in science, engineering, public policy, and hazard mitigation as a result of the 1989 Loma Prieta earthquake

Oral Session - Thursday PM, April 9

The 17 October 1989 M 6.9 Loma Prieta earthquake was in many respects, a monumental event in the history of the San Francisco Bay region. The first significant earthquake to strike the Bay area in modern times and the largest since 1906, the event advanced the earthquake sciences on a number of fronts, initiated major changes in engineering, disaster response, and public policy, and promoted hazard awareness in all sectors of the population. Direct observations and instrumental recordings of the earthquake and its damaging effects on the region's infrastructure, as portrayed in images of the Cypress Expressway, the Bay Bridge, and the Marina District, have led to improved understanding in earthquake processes, including earthquake forecasting, fault interaction, ground motions, site response, liquefaction and building response as well as significant improvements to the buildings codes. Major programs such as the Caltrans bridge seismic retrofit program, San Francisco's Building Occupancy Resumption Program (BORP), and the California Seismic Hazards Mapping Program came about because of the 1989 earthquake. In this session, a retrospective of the last 20 years will be taken and the advances in science, engineering, public policy, and hazard mitigation as a result of the Loma Prieta earthquake will be reviewed.

Conveners

  • Mary Lou Zoback <marylou [dot] zoback [at] rms [dot] com>
  • Ivan Wong <ivan_wong [at] urscorp [dot] com>
  • Chris Poland <cpoland [at] degenkolb [dot] com>
  • Tom Holzer <tholzer [at] usgs [dot] gov>

Applications of LiDAR Data to the Study of Active Faults

Oral Session - Wednesday PM, April 8/Poster Session - Wednesday AM

LiDAR data has become an increasingly important tool in the study of active faults. New LiDAR acquisitions, such as those carried out by GeoEarthScope in the western U.S., provide high-resolution digital elevation models (DEMs) that are freely available to researchers interested in studying geomorphic features related to active tectonics. This new community resource, as well as other LiDAR datasets, is being used to advance the understanding of active faults in many areas. This session will highlight results of research using high-resolution DEMs derived from LiDAR data, and will explore the potential of LiDAR data to improve the understanding of seismic hazards and geomorphic processes associated with active faults.

Conveners

  • Carol Prentice <cprentice [at] usgs [dot] gov>
  • Tim Dawson <Timothy [dot] Dawson [at] conservation [dot] ca [dot] gov>
  • Ashley Streig <streig [at] lettis [dot] com>

Central California Coast Earthquake Hazards

Oral Session - Thursday AM, April 9/Poster Session - Thursday PM

Following the M6.5 San Simeon earthquake in 2003, there has been renewed interest in re-evaluating the earthquake potential of the Central California Coast. This area of increasing urban growth lies west of the San Andreas Fault, between Monterey Bay and the Western Transverse Ranges. This special session seeks to assemble a comprehensive overview of recent studies from seismology, geology, geophysics, geodesy, engineering ground motions, and other fields that have provided new data and interpretations of regional earthquake hazards. Speakers will overview recent data syntheses and hazard models to provide frameworks for the interpretation of the new data. Special consideration will be made for providing extra poster space for displaying data. Innovative data visualizations and analysis products are encouraged.

Conveners

  • Stu Nishenko <spn3 [at] pge [dot] com>
  • Jeanne Hardebeck <jhardebeck [at] usgs [dot] gov>

Deterministic Simulated Ground Motion Records Under ASCE/SEI 7-05: Guidance for the Geotechnical Industry

Oral Session - Thursday AM & PM, April 9/Poster Session - Wednesday PM, April 8

According to new requirements of the American Society of Civil Engineers Standard (ASCE/SEI 7-05 Chapter 21 Site-Specific Ground Motion Procedures for Seismic Design) at least five recorded or simulated horizontal ground motion acceleration time histories shall be selected from events having magnitudes and fault distances that are consistent with those that control the Maximum Considered Earthquake (MCE). For some cases (e.g. from M7 to M8, less than 10 km from the fault zone), there may not be five sets of recorded ground motions that are appropriate and simulated ground motion would be needed. We invite papers for simulating ground motions that satisfy ASCE/SEI 7-05 and address one or more of the following aspects: 1) procedures for simulation ground motion records for planar and nonplanar fault topology; 2) comparisons of analytical and numerical solutions for different deterministic models; 3) site-specific design ground motion parameters for landslides and slope stability analyses with time history procedures; 4) site-specific design ground motion parameters for essential facilities with time history procedures; 5) procedures for simulation ground motion records for subsonic and supersonic rupture front propagation. 6) effects of surface topography on deterministic procedures for simulation ground motion records.

Conveners

  • Alexander Bykovtsev <abykovtsev [at] earthsys [dot] com>
  • Vladimir Graizer <vladimir [dot] graizer [at] nrc [dot] gov>

Earthquake Damage and Loss Assessment

Oral Session - Wednesday PM, April 8/Poster Session - Wednesday AM

We seek to gather contributions related to earthquake damage assessment and loss modeling. We consider damage and loss as broad categories that include causalities; financial, economic, and infrastructure impacts; and, recovery times. Both near real-time assessments after an earthquake and a priori risk forecasts are of interest. The range of relevant studies includes the necessary hazard input, loss data collection and analyses, and all aspects of damage and loss modeling, including their uncertainties.

Conveners

  • David Wald <wald [at] usgs [dot] gov>
  • Nicolas Luco <nluco [at] usgs [dot] gov>

Earthquake Source Mechanics

Oral Session - Wednesday AM, April 8/Poster Session - Wednesday PM

Session Chairs:  Justin Rubinstein and Nick Beeber


Earthquake Source Scaling: Advances, Applications, and Outstanding Issues

Oral Session - Thursday PM, April 9/Poster Session - Thursday AM

For many years and particularly over the past decade, earthquake source scaling studies have been undertaken in a variety of tectonic settings and in some cases, on the same data sets using different methodologies. More often than not, there is usually no clear consensus on scaling behavior and hence the underlying dynamics of faulting for that particular region. In addition to the academic pursuit of earthquake physics, there are the societal applications of differentiating explosions from natural earthquakes, predicting strong ground motion, and hazard mitigation. Though seismic network quality and station coverage has improved, and significant advancements have been gained in fault rupture models and high-resolution 3-D structure, the accurate prediction of strong ground motion requires a priori knowledge of the regional source scaling. This session is focused on the following questions and contributions from a variety of sub-disciplines are encouraged. What is the current state-of-the-art? Are systematic variations region-dependent? Is the observed scatter real and, if so, what are the causes? Can spatial variations in apparent stress be reliably mapped? Are slow earthquakes, super-shear earthquakes, and typical sub-shear tectonic earthquakes three different phenomena or part of a continuous spectrum of earthquake rupture behavior?

Conveners

  • Kevin Mayeda <kmayeda [at] yahoo [dot] com>
  • William R. Walter <bwalter [at] llnl [dot] gov>
  • Luca Malagnini <malagnini [at] ingv [dot] it>

Earthquake-induced Ground Failure and Site Response: Theory to Observations

Oral Session - Wednesday PM, April 8/Poster Session - Wednesday AM

Recent earthquakes have provided many new recorded ground motions and earthquake-induced ground failure case histories. Additionally, increased computing capabilities, improved technologies, and advanced methodologies allow for better forecasting of future liquefaction, landsliding, fault surface rupture, and site response. This session will be used to highlight new theoretical and empirical models and describe validation of these models with observations. Case history descriptions and site-specific studies using new methods are welcome.

Conveners

  • Laurie G. Baise <laurie [dot] baise [at] tufts [dot] edu>
  • Keith L. Knudsen <keith_knudsen [at] urscorp [dot] com>

Global Collaborative Earthquake Predictability Research

Oral Session - Friday PM, April 10/Poster Session - Friday AM

Modern earthquake science requires rigorous experimentation, with recent earthquake predictability studies emphasizing the importance of testing forecast models. Several nations are currently operating or developing regional centers for such tests, and the findings may yield a better understanding not only of the models' basic features, but also of particular physical aspects of earthquake occurrence. Now is the time to extend testing and model development to a global scale, and to do so via global collaboration. We solicit submissions that address one or more of the following issues as they relate to earthquake predictability: status of current (and plans for future) regional and global experiments; application of new models and multi-model combinations; and methods for testing and evaluation. A special focus of this session will be experiments that involve multi-national collaboration.

Conveners

  • Danijel Schorlemmer <ds [at] usc [dot] edu>
  • J. Douglas Zechar <zechar [at] usc [dot] edu>
  • Matt Gerstenberger <m [dot] gerstenberger [at] gns [dot] cri [dot] nz>

Global Seismotectonics

Oral Session - Wednesday AM, April 8/Poster Session - Wednesday PM

Session Chair:  Allison Bent


 

Great Surface Ruptures

Oral Session - Friday AM, April 10/Poster Session - Friday PM

On-land surface ruptures that extend 100s of kilometers with average displacements of 5m or more and maximum offsets larger than 7m are not common. These typically produce earthquakes of M 7.9 and their signal to noise ratio provides important insights into fundamental earthquake processes. Since 1850 there have been a limited number of these events: San Andreas, CA 1857; Wairarapa, New Zealand 1857; Bulnay. Mongolia, 1905; San Andreas, CA 1906: Haiyuan, China 1920; North Anatolia, Turkey 1939; Gobi-Altay, Mongolia 1957; Kunlun, Tibet 2001; Denali, Alaska 2002; and, most recently, Sichuan, China 2008 (the first thrust event in this group). The session will focus on new observations of slip distribution for these great surface ruptures, including comparison of historical slip with paleoseismic slip. For the more recent events we are looking for a) comparisons between surface slip and slip distributions modeled from seismologic and geodetic data; and b) relationships between abrupt changes in the amount of slip at the surface and strong ground motion. Basic questions include: how well does surface slip track slip distribution at depth, can detailed paleoseismic slip distributions can be used to improve ground motion models of future earthquakes, and what new techniques can be applied to improve measurement of slip at the surface? While were are emphasizing great ruptures we encourage contributions on other large historical surface ruptures on all fault types world wide, particularly those where measured surface slip can be compared to seismologic and geodetic slip models.

Conveners

  • David P. Schwartz <dschwartz [at] usgs [dot] gov>
  • Tom Rockwell <trockwell [at] geology [dot] sdsu [dot] edu>

Ground Motions/Earthquake Hazards

Oral Session - Friday AM, April 10/Poster Session - Friday PM

Session Chairs: Joe Andrews, Melanie Walloing, Hamid Haddadi and Tony Shakal


Imaging and Discovery from USArray and EarthScope

Oral Session - Friday PM, April 10

EarthScope USArray Transportable Array, Flexible Array and Magnetotelluric instruments are providing data that are being used to develop a new generation of high-resolution Earth models and understanding of structure and processes. These instruments have been deployed at unprecedented densities spanning multiple spatial and temporal scales; as of late 2008, data are available from over 650 Transportable Array sites, numerous Flexible Array experiments, and 170 Magnetotelluric Transportable Array sites. A great variety of existing and new techniques have been developed to capitalize on these data and address long-standing questions about structure and wave propagation. This session will focus on studies of Earth structure and processes, ranging from the crust to the core, as facilitated by EarthScope and associated data sets. Papers presenting new processing and interpretation results made possible through the unique aspects of USArray data are particularly encouraged.

Conveners

  • Richard Aster <aster [at] ees [dot] nmt [dot] edu>
  • Robert Woodward <woodward [at] iris [dot] edu>

M5.4 Mt. Carmel, Illinois, Earthquake, 18 April 2008

Oral Session - Wednesday AM, April 8

The 18 April 2008 M5.4 Mt. Carmel earthquake is the most densely recorded moderate-sized earthquake to date in the Eastern U.S. It is also the largest earthquake to strike the central U.S. in 40 years. The main event and 35 aftershocks were widely recorded by ANSS seismographs across the central U.S. offering an opportunity to study earthquake ground motions having a variety of site conditions including the thick soils of the Mississippi Embayment. Based on USGS Did You Feel It reports the earthquake was widely felt up to 500 km from the epicenter including the cities of Chicago, IL, Indianapolis, IN, Lexington, KY, Atlanta, GA, Memphis, TN, and St. Louis, MO. A fairly energetic aftershock sequence was also recorded by temporary seismograph networks deployed by the University of Memphis and Indiana University. This session seeks contributions on source rupture models, fault plane characterization from aftershocks, site response and basin effects, attenuation, and shaking effects to the built environment and free-field related to this earthquake.

Conveners

  • Steve Horton <shorton [at] memphis [dot] edu>
  • Robert Williams <rawilliams [at] usgs [dot] gov>
  • Mitch Withers <mwithers [at] memphis [dot] edu>

Maximum Earthquake Magnitudes for Seismic Hazard Analyses

Oral Session - Thursday PM, April 9/Poster Session - Thursday AM

One important parameter that is needed for seismic hazard calculations is the maximum earthquake magnitude that can take place on an active fault or within a seismic source region. In most areas maximum earthquake magnitudes are uncertain because the known earthquake history is short compared to the repeat times of the strongest earthquakes. This special session focuses on ideas for estimating maximum earthquake magnitudes for seismic hazard analyses. Methods for estimating maximum earthquake magnitudes for seismic sources in the U.S. and Canada are especially encouraged.

Conveners

  • John E. Ebel <ebel [at] bc [dot] edu>
  • Mark Petersen <mpetersen [at] usgs [dot] gov>

New Developments in Seismic and Acoustic Monitoring of Earthquakes and Explosions

Oral Session - Wednesday AM & PM, April 8/Poster Session - Thursday AM, April 9

We welcome submissions on all aspects of earthquake and explosion monitoring, including source physics, wave propagation, sensor development, and signal analysis. Of particular interest are the generation of S-waves from explosions, improved prediction of seismic signals using 3-dimensional models, advances in small low-power sensors, and waveform matching techniques. Methods that complement seismic monitoring, such as acoustics, are also encouraged. Advances that may change the current monitoring paradigm (manual analysis and minimization of scalar arrival times and amplitudes) are of particular interest.

Conveners

  • Lee Steck <lsteck [at] lanl [dot] gov>
  • Chris Young <cjyoung [at] sandia [dot] gov>
  • Steve Myers <smyers [at] llnl [dot] gov>
  • Shane Detweiler <shane [at] usgs [dot] gov>

 

New Views of the Earth's Interior from Array Analysis

Oral Session - Wednesday PM, April 8/Poster Session - Wednesday AM

The availability of data from dense arrays around the world and application of a variety of array techniques are starting to reveal complexities of Earth's structure from the inner core to the crust. This session aims to bring together a wide range of results based upon array analysis, and invites contributions on all aspects of seismic imaging based upon array data. Submissions involving advances in array data processing and results that complement traditional tomography models are particularly encouraged.

Convener

  • Miaki Ishii <ishii [at] eps [dot] harvard [dot] edu>
  • Keith Koper <kkoper [at] gmail [dot] com>

Non-Volcanic Tremor

Oral Session - Friday AM, April 10

Session Chairs: Dave Hill and Dave Shelley


 

Seismic Imaging: Recent Advancement and Future Directions

Oral Session - Friday AM, April 10/Poster Session - Friday PM

Seismic imaging is a powerful tool for geophysicists to probe the Earths interior. The demand for higher resolution and broader range of applications is rapidly increasing. This session welcomes contributions from seismic imaging in various scales and application arenas, with special emphasis on recent advances and future directions. Examples may include innovations and advances in 3D traveltime tomography, waveform tomography, receiver function mapping, surface wave inversion, and joint inversion of multiple geophysical observations. We also encourage case study papers using seismic imaging to solve real problems. Discussions on the pitfalls, limitations, and artifacts of common seismic imaging methods and potential remedies are most welcome.

Conveners

  • Youshun Sun <youshun [at] mit [dot] edu>
  • Monica Maceira <mmaceira [at] lanl [dot] gov>

 

Seismological Field Work: The Good, Bad, and Ugly

Oral Session - Thursday AM, April 9/Poster Session - Thursday PM

Many advances in seismology can be attributed to the data collected from seismological field studies; however, many in the scientific community are unfamiliar with the problems that are often encountered in the field. Such problems can include malfunctioning equipment, missed shipping dates, permitting nightmares, freakish weather, impassable roads, curious animals, and angry humans. The purpose of this special session is for experimental seismologists to convene and share their experiences - good, bad, and ugly - from these experiments. Presenters will be encouraged to discuss their approach to planning an experiment, from the early stages that might include hypothesis generation or seismological calculations, to later stages like obtaining permits and equipment. Other presenters may chose to share some of the strange, unpredictable occurrences that have threatened their projects, and more importantly, offer how they solved these problems. Others may chose to focus on lessons learned after the experiment, often when analyzing their data, and how they might do things differently during their next experiment.

Conveners

  • Jessie Bonner <bonner [at] westongeophysical [dot] com>
  • Jim Fowler <jim [at] iris [dot] edu>
  • Noel Barstow <barstow [at] passcal [dot] nmt [dot] edu>

Seismotectonics and Geologic Hazards along the Basin and Range-Colorado Plateau Transition

Oral Session - Friday PM, April 10/Poster Session - Friday AM

The transition between the Basin and Range and Colorado Plateau represents a planetary-scale geologic feature that hosts numerous types of geologic hazards affecting several states (including Nevada, Arizona, Utah, Idaho, Wyoming). The rapid increase in population along parts of this transition increases risk factors from potential landslides, debris flows, floods, and earthquakes. This session seeks to bring together studies on specific geologic hazard features (e.g., Wasatch fault zone and other Holocene faults; Hurricane fault; Intermountain Seismic Belt; Hebgen Lake earthquake area; etc.) as well as include more general seismic hazard-related studies in western North America that would inform current research on the Basin and Range-Colorado Plateau transition. Analog studies from other tectonic margins worldwide that could suggest means to improve the understanding of seismic-related or seismic-triggered hazards in the transition would be especially useful.

Conveners

  • John H. McBride <john_mcbride [at] byu [dot] edu>
  • William J. Stephenson <wstephens [at] usgs [dot] gov>

Site Effects: Vs30 and Beyond?

Oral Session - Friday AM & PM, April 10/Poster Session - Thursday PM, April 9

To mitigate the devastating effects from damaging earthquakes, realistic ground motion predictions require advancements in the characterization of near surface geological structure. An important step taken towards this goal is the consensus between the earthquake engineering and seismological community that the response of soft sediments to strong ground motion aggravates the catastrophic consequences of large earthquakes. Source and path effects are accounted for in maps showing the results of probabilistic seismic hazard analyses (PSHA), and are prepared for a particular site condition referred to as the reference site. Site conditions at the area of interest are parameterized on the basis of the average shear wave velocity in the upper 30 meters of the site (Vs30) to improve the accuracy of ground motion predictions by the: (1) adjustment of PSHA predictions with site amplification factors; or (2) site-specific geotechnical analyses of local site response effects. While the Vs30 classification system does provide a quantitative description about the stiffness of near-surface soil layers, it does not address the susceptibility of other site factors, such the influence of: linear and nonlinear soil behavior, scatter, directivity, focusing effects, wave-guide effects, shallow geology, basin depth and the effects of deeper crustal structures. As a result, observed empirical amplification factors deviate significantly from the predicted site response. To ascertain the current state of knowledge about the role of site effects on strong ground motions and in particular, the effectiveness of the Vs30 index to characterize site effects, we invite papers that address the performance of Vs30 as an indicator of site amplification, as well as results from new and established approaches on characterizing site effects.

Conveners

  • Alan Yong <yong [at] usgs [dot] gov>
  • Dominic Assimaki <dominic [at] gatech [dot] edu>

Statistics of Earthquakes

Oral Session - Thursday AM, April 9/Poster Session - Thursday PM

The purpose of this session is to solicit a wide range of papers concerned with the statistics and statistical physics of earthquakes. Subject matter includes but is not limited to frequency-size statistics, correlations in space-time-magnitude, patterns, forecasting, time series analyses, peaks-over-threshold analyses, record-breaking analyses, detrended fluctuation analyses, first passage time statistics, and similar phenomenology and analyses.

Conveners

  • Donald Turcotte <turcotte [at] geology [dot] ucdavis [dot] edu>
  • John Rundle <rundle [at] physics [dot] ucdavis [dot] edu>
  • Mark Yoder <yoder [at] physics [dot] ucdavis [dot] edu>

 

Supershear Earthquake Rupture Speeds

Oral Session - Wednesday AM, April 8

It is now clear that very fast rupture speeds do occur during earthquakes, resulting in increased ground shaking. With several examples of such high rupture speeds being found recently, it is an appropriate time to review the state-of-the-art today, and consider where we need to go in future. We invite contributions in the theoretical, experimental and observational aspects of this very important problem, and hope to communicate this to the earthquake engineering community.

Conveners

  • Shamita Das <das [at] earth [dot] ox [dot] ac [dot] uk>
  • Michel Bouchon <Michel [dot] Bouchon [at] ujf-grenoble [dot] fr>

Volcano Monitoring Using Seismology and Complementary Methods

Oral Session - Thursday PM, April 9/Poster Session - Thursday AM

The field of volcano seismology increasingly faces a dual challenge. On the one hand, volcano observatories are increasingly using data from multiple monitoring fields (seismology, geodesy, gas geochemistry, remote sensing, hydrology, and others), often collected in real time, to achieve a broader understanding and reduce uncertainty in the interpretation of precursory and eruptive phenomena. To take full advantage of such datasets, new analytical programs, graphical user interfaces, and databases are needed for integrating, displaying, and modeling such multiparametric and large datasets. On the other hand, it is still the case that the majority of volcanoes around the world are monitored by just a handful of seismometers. Thus it is also paramount that progress be made in analyzing and modeling such instrument-poor datasets. We invite contributions on any aspect of volcano monitoring, but encourage those that focus either on analyzing multi-parametric datasets or on squeezing as much information as possible from limited monitoring datasets. We especially encourage presentations regarding monitoring and hazard assessment/mitigation at North American volcanoes; however, contributions from other regions are also welcome.

Conveners

  • Seth Moran <smoran [at] usgs [dot] gov>
  • Charlotte Rowe <char [at] lanl [dot] gov>

Wave Propagation

Poster Session - Wednesday AM, April 8


 

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SSA 2010
April 20-23, 2010. Portland, OR.

Last Modified: 2009 May 15

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