SSA 2013 Annual Meeting
The following sessions have been organized for the 2013 Annual Meeting program. Click any session name to view the schedule and list of abstracts for that session.
Recent advances in high-performance computing and efficient wave propagation methods render it computationally tractable to simulate earthquakes using physics-based, deterministic modeling approaches at frequencies up to 10 Hz within the next decade. There are, however, a series of challenges that will need to be overcome in order to generate realistic synthetic seismograms that resemble records from past earthquakes, so that they can be used with confidence in engineering design. These challenges include the realistic characterization of both the earthquake source and the surrounding media at unprecedented fine scales, and the accurate and efficient solution of wave propagation problems at high frequencies, as well as the uncertainty associated with these and other aspects involved in earthquake simulations. This session solicits contributions in the broad range of earthquake systems simulation, oriented to advancing the field of physics-based, deterministic earthquake simulations at frequencies valid for engineering applications: source generation including random parameters, dynamic rupture with small-scale complexity in fault geometry and time variations, construction and improvement of seismic velocity models, numerical techniques in anelastic wave propagation, efficient grid and mesh generation, material attenuation models, integration of geotechnical data in structural velocity models, stochastic representation of near-surface soft-soil deposits, off-fault and near-surface plasticity, incorporation of surface topography, efficient simulation algorithms, and other related topics. This session will also serve as a forum for scientists interested in participating in the High-F project of the Southern California Earthquake Center.
<rtaborda [at] cmu [dot] edu>
<kbolsen [at] mail [dot] sdsu [dot] edu>
<jbielak [at] cmu [dot] edu>
<tjordan [at] usc [dot] edu>
Technical and engineering advances in the past several years have resulted in an expansion in a variety of instruments available to the community to make broadband seismic observations on the seafloor. This includes the development of instruments designed to mitigate effects of currents and trawling on OBSs deployed in waters depths <1000 m on continental margins, which allowed the community to go forward with the Cascadia Initiative, a community-planned deployment of a 4-year US-Array-like deployment covering the Juan de Fuca plate and its boundaries. There have also been a number of PI-driven experiments around the globe. The objective of this session is to bring together researchers working with broadband OBS data, in general and those of the Cascadia deployments, to present results from recent experiments and compare notes on the particularly challenging aspects of recording broadband data on the seafloor.
<trehu [at] coas [dot] oregonstate [dot] edu>
<glaske [at] ucsd [dot] edu>
Fault identification and characterization are important for estimating the magnitudes and recurrence intervals of earthquakes on individual faults as part of seismic hazard assessments. Fault location, geometry and displacement are important for assessing potential levels of ground shaking, and deducing a history of past events is crucial for estimating recurrence intervals. These parameters can be investigated through geophysical imaging, modeling, and geologic, geodetic and paleoseismic studies. The goal of this session is to highlight and illustrate methods that can be used for characterizing faults. We invite papers that describe novel techniques for fault characterization and case studies, especially those that integrate several methods or succeed in difficult urban settings.
<sfinn [at] cgiss [dot] boisestate [dot] edu>
Thomas L. Pratt
<tpratt [at] ocean [dot] washington [dot] edu>
Pier Paolo Bruno
<PierPaolo [dot] Bruno [at] utah [dot] edu>
Data products derived from raw data or synthesized from models are becoming increasingly important with the advancement of processing techniques and growing volumes of raw data. These data products often serve as stepping-stones to further research. Data product offerings from organizations such as the IRIS DMC, the USGS NEIC, UNAVCO and others in the scientific community have grown significantly recently. Examples include simple record sections and other even-oriented waveform plots, standardized receiver-functions (EARS), Earth model repositories, integrations of cross-disciplinary research (e.g., the USGS Slab1.0 model), and repositories of synthetic seismograms. We welcome abstracts highlighting new or potential products of interest to the SSA community including, but not limited to, products relating to earthquake, global, regional and strong-motion seismology, geodesy and infrasound. We hope this session will broaden the awareness of available products and spur the development and sharing of new products.
<chad [at] iris [dot] washington [dot] edu>
<velasco [at] geo [dot] utep [dot] edu>
<ghayes [at] usgs [dot] gov>
The session welcomes studies of the mechanics of earthquakes, from interseismic loading to earthquake nucleation, dynamic rupture propagation and arrest, and post-seismic relaxation. Of particular interest are studies that integrate fault constitutive laws consistent with laboratory experiments into models that relate to the full range of seismological, geodetic, and geologic observations.
<segall [at] stanford [dot] edu>
<edunham [at] stanford [dot] edu>
Earthquake Source Studies (Poster Only Session)
This session includes a wide range of papers focused on inferring seismic source properties. Topics include earthquake detection and location, magnitude scales, and moment tensor estimation.
Implementation of Physics-Based Earthquake Source and Ground Motion Findings in Engineering Solution Models
This session is organized jointly by SSA and the European Seismological Commission (ESC). To reduce the impact of earthquakes on human lives and our environments it is essential to connect earthquake science with engineering practice. To reach this goal it is necessary to promote the continued integration between earthquake science and engineering, which is the purpose of this session. Recent developments of physics-based earthquakes models have contributed to substantial advances in our understanding of the earthquake mechanism and spatial distribution of near source ground motion. A further collaboration with the engineering community certainly would improve our ability to merge these physics-based findings into engineering solution models. We welcome novel studies that promote the implementation of seismology research advancements into engineering practice. These advances range from increased understanding in the basic physics of earthquake ground motions and fault rupture mechanics to fundamental inputs for hazard maps, risk assessment, ground motion prediction equations (GMPE), ground motion spatial variability and coherency models, seismic designs, building codes and construction practices.
<dalguer [at] sed [dot] ethz [dot] ch>
<sakkar [at] metu [dot] edu [dot] tr>
<cornouc [at] obs [dot] ujf-grenoble [dot] fr>
<aaskan [at] metu [dot] edu [dot] tr>
<eser [dot] cakti [at] gmail [dot] com>
Liquefaction, lateral spread, and landslides are all ground failures that can result from earthquake shaking. The inclusion of these secondary effects in scenario events, rapid response, and loss estimation is not common practice; yet, these effects can cause significant losses. This session will highlight developments in ground failure models as well as efforts to integrate ground failure in regional event specific hazard and loss estimates.
<eric [dot] thompson [at] tufts [dot] edu>
<laurie [dot] baise [at] tufts [dot] edu>
<kknudsen [at] usgs [dot] gov>
In the past two years, there has been a renewed interest in induced seismicity largely because of the apparent increase in seismicity and felt events in parts of the central and eastern U.S. The causes of induced earthquakes and how such earthquakes may be controlled, including seismicity from hydraulic fracturing and the injection of its waste fluid, have become important research topics. In this session, papers on induced seismicity associated with waste water-injection, geothermal exploration, hydraulic fracturing, and mining will be presented. These papers include several of the most recent and controversial cases of fluid-induced seismicity.
<Ivan [dot] Wong [at] urs [dot] com>
<brownwa1 [at] sfasu [dot] edu>
The combination of infrasound and seismology is yielding new insights into the coupling of mechanical waves in the solid earth and atmosphere as well as a more complete characterization of the source physics for manmade and natural events near the solid-earth atmosphere boundary. These advances are being driven by new datasets, such as those from the Transportable Array network of seismometers and microbarometers, and by improved atmospheric specifications and advances in infrasound modeling. This session invites contributions from all aspects of infrasound and seismoacoustics including instrumentation, data analysis methods, and source and propagation studies.
<arrows [at] lanl [dot] gov>
<burlacu [at] seis [dot] utah [dot] edu>
This session will address the seismo-volcano processes and related hazards of the Basin-Range Province including Utah, Nevada, Idaho, Montana, and surrounding areas. Specific topics include characterization of physical processes of intraplate lithospheric extension, normal faulting active faulting and seismicity, and volcanism including the large calderas of Long Valley, CA, and Yellowstone National Park. Data from modernized earthquake and GPS monitoring networks and new compilations of Quaternary fault properties provide key information for probabilistic earthquake assessments including block-tectonic models for the next U.S. National Hazard Map. In addition, topics in Basin-Range implementation of dynamic and kinematic models for assessing strong ground motion in fault-adjacent valleys, stress-triggering by earthquakes and volcanoes, liquefaction, and importantly, how seismologists can interact more effectively and provide timely information for emergency management agencies and the public during times of increased activity.
<baerschmeid [at] gmail [dot] com>
David P. Hill
<hill [at] usgs [dot] gov>
<kkoper [at] gmail [dot] com>
<whammond [at] unr [dot] edu>
<ivan [dot] wong [at] urs [dot] com>
Major and mega-earthquakes have arguably become more prevalent in the 21 st century than in preceding decades. The ability of the global community to rapidly and accurately respond to such events has also significantly improved over the same period of time, and seismologists are now regularly served with detailed source characteristics of a recent earthquake within several hours of the event occurring. Seismological meetings over the past few years – both AGU and SSA -- have involved special, late-breaking sessions incorporating such studies for earthquakes that have occurred between session proposal and abstract deadlines. This session solicits abstracts that address such studies for recent earthquakes of import – those that have already occurred in 2012, such as the extraordinary April Sumatra sequence and M7+ events in late August and early September in El Salvador and Costa Rica – and also earthquakes which occur in the intervening period between now and April 2013. We welcome all aspects of analyses of these significant earthquakes, from teleseismic to regional studies using seismic data, to co- and post-seismic GPS and InSAR analyses, and in particular research which tackles such event characterization from a multi-disciplinary approach.
<ghayes [at] usgs [dot] gov>
<pearle [at] usgs [dot] gov>
<benz [at] usgs [dot] gov>
Networks and Instrumentation (Poster Only Session)
This session consists of papers on new developments in seismic networks and instrumentation. These include reports on new types of instrumentation, upgrades of existing seismic networks, and innovations in rapid deployments aimed at recording aftershocks of major events.
The Tohoku (Japan) and Christchurch (New Zealand) events of last year have stimulated research on time-dependent earthquake forecasting models that can improve seismic hazard assessments. Much of this research is being carried out under the auspices of the international Collaboratory for the Study of Earthquake Predictability (CSEP), which provides an infrastructure for the blind prospective testing of earthquake forecasting models using standardized, community-accepted statistical methods. Researchers are expanding CSEP capabilities into the testing of ground-motion predictions and hazard assessments as well as the testing of earthquake early warning procedures, and they are exploring the assimilation of new types of data into physics-based forecasting models.We solicit submissions addressing one or more of the following issues related to earthquake predictability, with special focus on global and regional CSEP experiments:- status of completed or ongoing regional and global forecasting experiments, and plans for future experiments;- retrospective and prospective testing of new models and multi-modelcombinations;- new and more effective methods for testing and evaluation of forecasting models;- assimilation of new data types into forecasting models; and- prospective testing of ground-motion predictions and hazard assessments.
<ds [at] usc [dot] edu>
<tjordan [at] usc [dot] edu>
<m [dot] gerstenberger [at] gns [dot] cri [dot] nz>
New analysis techniques can reveal hitherto hidden structures and can enhance the study of critical data features that are not optimally revealed by traditional methods. For example, wavelet analysis and the Hilbert Huang Transform can greatly improve upon the time/frequency resolution of traditional Fourier methods, allowing earthquake spectra to be examined in more detail, and curvelet, gradiometric, or other novel wavefield decomposition methods can reveal structures in array data that may not be apparent using F-K analysis. This session will focus on innovative ways of presenting and analyzing seismic data, with an emphasis on new developments. We invite contributors who have developed or are exploring new techniques and/or who wish to offer relevant evaluations of widely used methodologies.
<haksaeng [at] live [dot] unc [dot] edu>
Jonathan M. Lees
<jonathan_lees [at] unc [dot] edu>
Richard C. Aster
<aster [at] ees [dot] nmt [dot] edu>
There are currently several ongoing efforts in the U.S. to develop ground motion prediction models. PEER is sponsoring two major efforts: the Next Generation of Attenuation (NGA) West 2 and NGA-East. The purpose of NGA West 2 is to update the 2008 NGA models for tectonically active regions. NGA East is an effort to develop a suite of new ground motion prediction models for the central and eastern U.S. using the community approach taken in the first NGA effort. EPRI is sponsoring an update of the 2004/2006 EPRI ground motion models for the central and eastern U.S. for use in re-assessing nuclear power plant safety. Outside the U.S., ground motion prediction models are being developed in many regions due to the availability of new strong motion data and improved techniques. In this session, presentations will be made to describe the ongoing efforts in the U.S. as well as internationally to develop the next generation of ground motion prediction models. Papers are welcome that describe the databases, methodologies, and results of these efforts.
<ivan [dot] wong [at] urs [dot] com>
<jdonahue [at] geosyntec [dot] com>
With the recent success of ambient noise surface wave tomography, interest in understanding sources of ambient seismic energy has grown tremendously. This session welcomes studies that detect, locate, characterize, interpret, and model seismic signals from a broad range of environmental and climate related sources. Topics can include characterizing the modal structure of microseismic energy, quantifying temporal variations in background noise properties, and interpreting seismic observations in the context of cryospheric, oceanographic and atmospheric source processes. We also welcome theoretical and numerical simulation studies.
<koper [at] seis [dot] utah [dot] edu>
<aster [at] ees [dot] nmt [dot] edu>
<mcnamara [at] usgs [dot] gov>
A major effort to develop earthquake early warning systems is underway in the western U.S. These approaches rely on real-time estimates of earthquake size and location that can be transmitted to relevant agencies and the general public before the arrival of damaging S and surface waves. This session highlights recent progress of these efforts, as well as related research in real-time seismic monitoring.
<peggy [at] seismo [dot] berkeley [dot] edu>
In this session, a wide range of topics on seismic hazards and ground motions will be presented. Recently there has been considerable debate on the validity of the probabilistic seismic hazard analysis approach and its implementation, in part due to the perceived underestimation of seismic hazard along the northern coast of Japan prior to the 2011 Tohoku-Oki earthquake. As a result, there has also been a renewed focus on seismic hazards to nuclear power plants in the central and eastern U.S. Papers on probabilistic seismic hazard analysis, seismic and tsunami hazards worldwide, and earthquake ground motions will be presented.
<yong [at] usgs [dot] gov>
<nilesh [at] stanfordalumni [dot] org>
The recent upgrade of ShakeMap (to Version 3.5) represents a major improvement in the way ground motions are geospatially interpolated. The weighted-average interpolation approach now accommodates intensity as well as ground-motion data, along with shaking estimates from prediction equations or modeling. While these new capabilities add important new functionality, they require more sophisticated validation of ground motion and intensity relations, and a fuller understanding of uncertainties and spatial correlation. This session explores current research in the modeling and validation of ground motion and intensity relations as well as new or emerging efforts to improve ground motion prediction, site correction and geospatial analyses (along with uncertainties) pertinent to ShakeMap. We also encourage presentations on research, operations, and applications related to ShakeMap. Such applications include, but are not limited to, earthquake scenarios, risk assessment, loss estimation, earthquake response tools, and engineering analyses that utilize ShakeMap ground motion estimates and associated uncertainty information.
<pankow [at] seis [dot] utah [dot] edu>
<cbworden [at] gmail [dot] com>
<klin [at] usgs [dot] gov>
Towards an Integrated Understanding of Slow Earthquakes: What We Know, What We Don’t Know, and How to Move Forward
Investigations of fault slip behavior in the last decade revealed a new class of slow earthquakes. Although rapid progress continues to be made in understanding these new phenomena, the mechanisms and relationships between the variety of slow fault slip behaviors remains enigmatic. Despite numerous studies that utilize observations, theoretical models, and/or laboratory measurements, a unified understanding of these fault slip behaviors does not appear to exist. The purpose of this session is to showcase the current state of knowledge of slow earthquakes, highlight the differences from one tectonic setting to the next, and propose an integrated perspective of the possible relationship between behaviors such as slow slip, tectonic tremor, slow earthquakes, and, ultimately, great earthquakes. Abstracts that combine models, laboratory measurements, and observations are strongly encouraged. We also encourage abstracts that highlight the similarities and differences of cross-disciplinary observations, and comparative studies that examine and explain the differences between geographic regions.
<jrbrown5 [at] gps [dot] caltech [dot] edu>
<colellhv [at] muohio [dot] edu>
Increases in the number of seismic events, both at close and remote distances, following large earthquakes are well documented and suggestive of some type of triggering mechanism. There are also studies suggesting a correlation between large earthquakes and volcanic events. However, the physics behind the triggering mechanism(s) is poorly understood. In addition, it is not always clear how to distinguish seismic and volcanic events that were triggered from those that would have occurred as a result of background stresses. In this session, we invite abstracts that address all aspects of triggering of seismic and volcanic events by large earthquakes. Example topics include interaction among large earthquakes and implications for seismic hazard, statistical analyses used to define triggered events, the role of static and dynamic stress in the near-field, possible triggering thresholds, and hypotheses and proposals for alternative triggering mechanisms such as afterslip, pore fluids, viscoelastic relaxations, or time-dependent frictional properties.
<pankow [at] seis [dot] utah [dot] edu>
<cwu [at] lanl [dot] gov>
Cessation of coseismic fault rupture has been suggested to result from a variety of mechanisms, ranging from fault-specific static properties to transient, rupture-history-driven dynamic effects. Field and modeling evidence alike implicate static or quasi-static properties such as fault geometry, frictional asperities or regions of creep, and time-dependent poro-elasticity as strong controls on rupture endpoints. However, static, dynamic, and quasi-dynamic numerical models, as well as mounting instrumental and field evidence demonstrate that, as stress evolves over multiple seismic cycles, transient effects may periodically overcome established static barriers, allowing rupture to continue. While much work has been done to investigate the effects of individual mechanisms on rupture cessation, the next step is to merge disparate studies of competing mechanisms in order to understand their relative roles within a given fault system. We invite presentations that summarize findings from numerical models, laboratory tests, observational analyses, and field and paleoseismic investigations that address various mechanisms that inhibit earthquake ruptures. We encourage comparison of these effects with one another, as well as discussion of how to evaluate which properties may dominate rupture through a given fault system, and of how to determine which effects are persistent over multiple earthquake cycles.
<ajelliott [at] ucdavis [dot] edu>
<jlozo001 [at] ucr [dot] edu>
This session highlights recently developed velocity and attenuation models derived at local, regional, and global scales. It includes presentations on various techniques of inferring Earth structure, such as ambient noise tomography, as well as tectonic and geodynamical implications of various Earth models.
<pasyanos1 [at] llnl [dot] gov>
<empaulso [at] usc [dot] edu>
Near-field and far-field observations for a number of chemical explosions point to inadequacies of P-wave source models to predict corner frequency and isotropic explosion moment for small and/or over-buried shots. These include the 1997 Kazakh Depth of Burial Experiments in Kazakhstan and recent Source Physics Experiments in Climax Stock. Some first-principle explosion source calculations point to issues surrounding the depth scaling of cavity radius, but the scope of the problem is unresolved and could involve issues related to chemical explosions as surrogates for nuclear tests and scaling to small yields. This problem highlights a source of uncertainty in nuclear test monitoring which arises from test emplacements that do not conform to standard containment practices used by the U.S. and former Soviet Union test programs. Available regional seismic data from past nuclear tests and models built from that data were influenced by those practices. We invite papers that shed light on this problem for both nuclear and chemical tests conducted under varying emplacement scenarios, particularly depth of burial and source medium. We encourage presentations documenting support for model predictions and/or variance from the predictions in order to assess the scope of the problem and identify future research directions.
Howard J. Patton
<patton [at] lanl [dot] gov>
William R. Walter
<walter5 [at] llnl [dot] gov>