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Technical Sessions

SSA Breakout Session

Below are 53 sessions submitted by members of the seismology community for the 2018 meeting. Abstract submissions open 1 December 2017 and close 24 January 2018. Abstracts may be submitted to one of the 53 approved sessions or to the general session. Abstracts submitted to the general session will be assigned or grouped at the discretion of the Program Committee.

3D/4D Seismic Imaging and Their Interpretation for Seismic Hazard Assessment

Thanks to the recent development of imaging and monitoring techniques, we can obtain much higher spatial resolution of subsurface structures and/or time-lapse changes of them. In previous years, imaging and monitoring techniques have developed rapidly due to the advent of high-density networks, new modeling techniques and unprecedented computation capacities. In addition to using them for interpreting subsurface geology and mechanics, such 3D/4D structural information is useful for modeling and interpreting high-frequency seismic waves or understanding the dynamic behaviors of structures, both of which are important for seismic hazard assessment.

In this session, we would like to cover both theoretical and methodological aspects as well as novel approaches for solving common practical problems for 3D/4D imaging and monitoring. We welcome contributions for the interpretation of obtained structural information for seismic hazard assessment such as ground motion prediction, more accurate estimation of earthquake magnitude and moment tensor and understanding the near-surface nonlinear effects. We further encourage abstracts focusing on multiscale imaging applications which involve novel processing such as higher-order correlations, double beamforming, multi-dimensional deconvolution, nonlinear optimization techniques, machine learning and large-scale data analysis or very dense receiver array analysis. Presentations related to amplitude extraction, attenuation, higher-mode Rayleigh/Love waves, body waves or usage of multi-component signals are also encouraged.

Session Conveners
Marco Pilz, Hemholtz Centre Potsdam, GFZ German Research Centre for Geosciences, <pilz@gfz-potsdam.de>
Nori Nakata, University of Oklahoma, <nnakata@ou.edu>

The 8th September Mw8.2 Tehuantepec and 19th September Mw7.1 Puebla-Morelos, Mexico Earthquakes: Reconnaissance Findings and Impact on Urban Areas in South-central Mexico

On September 8th, 2017 a Mw8.2 intermediate-depth, normal-faulting earthquake struck southeastern Mexico. The earthquake, with an epicentral location near the coast of Chiapas, is the largest recorded event in Mexico’s recent history. The Tehuantepec event resulted in many casualties and collapses, as well as landslides and damage to the infrastructure in several cities and towns in the states of Oaxaca and Chiapas. Soon after, on September 19th, 2017, a Mw7.1 intraslab, normal faulting earthquake occurred in central Mexico. The earthquake, approximately 120 km from Mexico City, caused the collapse of more than 40 buildings and affected infrastructure operation not only in the capital of Mexico, but in several urban areas near the epicentral region. The official death toll for both events is 471 people.

This session covers many engineering aspects of both events. Topics include, but are not limited to, strong ground motion observations and networks, macroseismic intensities, broadband ground motion simulations, site effects in the Mexico City Basin and other urban areas, soil-structure and site-city interactions, building codes and their implications in similar seismic prone regions together with hazard and risk management issues.

Session Conveners
Emel Seyhan, Risk Management Solutions, <emel.seyhan@rms.com>
Jorge Aguirre, Instituto de Ingeniería, UNAM, <joagg@pumas.iingen.unam.mx>
Leonardo Ramírez-Guzmán, Instituto de Ingeniería, UNAM, <LRamirezG@iingen.unam.mx>

Adaptation of New Technologies and Methods to Drive New Discoveries in Seismology and Geodesy

In recent years, advancements in seismology and geodesy have been made possible by innovative adaptation of new methods and technology from other fields. Improved earthquake detection and ground motion characterization have been achieved by using consumer MEMS accelerometers, consumer GPS chips, wireless nodal systems and other new sensor technology that enable dense sensor networks. Deep learning, fingerprinting and linkage methods originally developed for Internet search engines and image recognition can substantially improve our ability to detect and categorize seismic events, including earthquakes and low frequency earthquakes. In this session, we encourage submissions on any approach that expands the horizons of seismology and geodesy beyond traditional instruments and methods.

Session Conveners
Sarah E. Minson, U.S. Geological Survey, <sminson@usgs.gov>
Elizabeth S. Cochran, U.S. Geological Survey, <ecochran@usgs.gov>

Advances in Seismic Site Response Studies Given Limitations in Understanding of Site Conditions

Site response in seismic hazard assessment studies is significantly affected by the accuracy and resolution of the near-surface material properties. Within the limitations of the understanding of site conditions, our session brings together a wide variety of topics on the advances and limitations of current methodologies for site response analysis of earthquake-induced ground motions. Our purpose is to promote discussion that bridges the gap between the empirical and simulation-based methods in estimating seismic site response. We encourage presentations on state-of-the-knowledge and -art site response analyses; the role of ergodic and non-ergodic site response studies in reducing epistemic uncertainty; the effect of variability of shear-wave velocity (VS) profiles, as a result of non-uniqueness (inversion) or lateral variations in VS (2D effects), on site response; the correlation of the site-specific high-frequency spectral decay of Fourier amplitude spectra (κ0) to the time-averaged VS of the upper 30 m from the surface (VS30) and other proxies; the performance of κ0 for shallow and deep sedimentary basins; performance, estimation and correlations of basin-depth proxies with other parameters; regionalization of crustal velocity Q models; limitations of full-waveform inversion studies; and the effectiveness of derivation of site effects in the response spectra and Fourier domain. We cap the presentations with an open discussion with all speakers regarding the overall state of knowledge about the role of site conditions in advanced site response studies. We also welcome presentations on topics related to seismic site characterization, advances in invasive/non-invasive measurement techniques, microzonation studies and particularly developments in site characterization or ground motion studies in Latin America.

Session Conveners
Emel Seyhan, Risk Management Solutions, <Emel.Seyhan@rms.com>
Sean K. Ahdi, University of California, Los Angeles, <Sahdi@ucla.edu>
Eric M. Thompson, U.S. Geological Survey, <Emthompson@usgs.gov>
Alan Yong, U.S. Geological Survey, <Yong@usgs.gov>

Advances in Explosion Seismo-Acoustic Research

Seismo-acoustic approaches serve as primary tools in monitoring explosions around the world. Improvements in these fields have led to new analytical techniques including correlation methods, advanced array analysis, multimodal surface wave methods and quantitative uncertainty estimates for source and propagation models and derived parameters. We invite contributions highlighting research to improve detection, location and interpretation of explosion sources, as well as associated uncertainties.

Session Conveners
Charlotte Rowe, Los Alamos National Laboratory, <char@lanl.gov>
Catherine Snelson-Gerlicher, Los Alamos National Laboratory, <snelsonc@lanl.gov>
Sean Ford, Lawrence Livermore National Laboratory, <ford17@llnl.gov>
Christopher Young, Sandia National Laboratory, <cjyoung@sandia.gov>
Junghyun Park, Southern Methodist University, <junghyunp@mail.smu.edu>

Advances in the Theory, Modeling, and Observation of Anelastic Seismic Wave Propagation – Recent Anelastic Models of the Earth

Recent advances in the theory, modeling, and observation of anelastic seismic waves reveal new insights regarding methodologies to infer the anelastic structure of the Earth. For example, recent developments in general ray theory for anelastic media reveal ray paths and corresponding characteristics of travel time and attenuation curves, which are not predicted by elasticity theory or one-dimensional anelastic waves, yet have important implications for some forward modeling and inverse problems. Recent developments in elastic single- and multicomponent full waveform inversion and monitoring of exploration seismic data indicate that proper parameterization and incorporation of P- and S-wave quality factors is a critical need. This session invites papers on the latest advances in anelastic wave-propagation theory, processing/inversion methods for anelastic media, and anelastic (Q) models of the Earth, as inferred from exploration geophysics data, crustal reflection-refraction data, teleseismic data, surface-wave, ocean-acoustic, and normal-mode data. With many travel-time and amplitude anomalies yet to be explained, this session plans to be an exciting forum to review and explore implications of the latest advances in the theory and modeling of anelasticity towards explanation of some of these anomalies.

Session Conveners
Roger D. Borcherdt, U.S. Geological Survey, <borcherdt@usgs.gov>
Kristopher A. Innanen, University of Calgary, <kinnanen@ucalgary.ca>

Advances on the Parameterization of Seismic Attenuation: Current Challenges and Opportunities

The characterization of attenuation at various scales (e.g., regional or local attenuation) constitutes a critical aspect in the prediction of ground motions, site response analyses and the assessment of seismic hazards. However, isolating the effects of different attenuation mechanisms requires not only a fundamental understanding of the wave propagation phenomenon, but also a proper statistical treatment of the uncertainties associated with data collected in the field, the laboratory and through analysis of background noise and ground motion records. Hence, efforts toward defining parametric descriptors of seismic attenuation are inevitably associated with challenges in collecting reliable experimental data and the proper interpretation of their corresponding range of applicability.

There is a critical need for further research on current seismic attenuation parameters to improve methodologies that measure energy dissipation in earth materials and to better understand how to capture different attenuation mechanisms at different scales. In this session, we welcome studies focused on investigating the parameterization of seismic attenuation, the limitations of the existing methodologies to capture it, the associated uncertainties and the corresponding implications on ground motion modeling, site-specific seismic hazard analysis and site response analysis. Challenges and opportunities encountered in these processes are also welcome, whether they relate to limitations of a methodology to measure a specific parameter in the field, or the introduction of new analytical methods to better decouple the effects of different attenuation mechanisms in ground motions (e.g., separating inelastic attenuation from scattering effects).

Session Conveners
Ashly Cabas, North Carolina State University, <amcabasm@ncsu.edu>
Stefano Parolai, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, <sparolai@inogs.it>
Celine Gelis, Institute for Radiological Protection and Nuclear Safety, <celine.gelis@irsn.fr>
Albert Kottke, Pacific Gas & Electric, <albert.kottke@gmail.com>

Applications of Machine Learning and Data Science in Seismology

The increase in computational capability in the past decade has made it possible to introduce and apply novel machine learning/data science algorithms and tools to the field of seismology, with the hope of extracting useful information from large and complex seismic data sets. Recent attempts in the seismology applications have shown encouraging results in, for example, seismic signal detection and classification, seismic data interpolation, earthquake parameter estimation, seismic noise analysis and reduction, subsurface structure imaging and complex signals/models visualization. More advanced techniques and algorithms are emerging with new possibilities, for instance: deep learning based on learning data representations has the potential to extract superior results from large-scale datasets. The application of these new techniques can help improve our understanding of Earth structure and seismic sources from a brand new perspective. This session invites all abstracts relevant to applications and developments of machine learning and data science in seismology.

Session Conveners
Qingkai Kong, University of California, Berkeley, <kongqk@berkeley.edu>
Chengping Chai, University of Tennessee, Knoxville, <cchai1@utk.edu>
Zefeng Li, California Institute of Technology, <zefengli@gps.caltech.edu>
Min Chen, Michigan State University, <chenmi22@msu.edu>
Rongrong Wang, Michigan State University, <wangron6@msu.edu>

Challenges and Chances for the Widespread Implementation of Earthquake Early Warning (EEW)

The recent strong earthquakes in Southern Mexico with magnitudes of 8.0 and 7.3 have demonstrated the usefulness of Earthquake Early Warning (EEW) to a massive audience in Latin America and the world. In the social media people showed their surprise about the existence and functionality of the Mexican EEW system and discussed whether such a system could be established in their country. We invite contributions about the possible application of EEW in Latin America and other less developed regions taking into account the specifics of the prevailing building types (e.g. adobe) and construction practices. We invite contributions proposing how EEW can be implemented in less developed nations and whether EEW could be a relatively cheap and fast way for poor countries with high seismic risk to give some protection to their populations against the massive loss of life in great earthquakes and how it can be combined, in the long term, with measures to improve the building stock. We particularly solicit studies dealing with how EEW can be effectively established and operated, including: densification of seismic networks with new low-cost EEW-compatible seismic equipment; the development of new efficient EEW methods that are robust in the face of challenging seismicity and network operation; transfer of EEW methods into operational software compatible with general seismic monitoring; the establishment of new automatic seismic processing centers in many countries; and studies dealing with technical and social aspects for delivering alerts to the general population.

Session Conveners
Wilfried Strauch, Instituto Nicaraguense de Estudios Territoriales, <wilfried.strauch@yahoo.com>
Victor Huerfano, Puerto Rico Seismic Network, <victor.huerfano@gmail.com>

Development and Validation of Statistical Models of Small-scale Heterogeneities

Realistic small-scale variation of the media (velocity and/or density) and surface topography is important for modeling phases and coda amplitudes of broadband waves from regional seismic (earthquakes or explosions) sources. While the precise strength, locations, sizes and shapes of the heterogeneities are often unknown, statistical characterization of the heterogeneity can be used to simulate the ground motion variability due to seismic scattering processes. A wide variety of parameterizations, however, are available to characterize the statistical models (e.g., shape of the heterogeneity power spectrum and its depth dependence, as well as crack shapes, concentrations and orientations). Different parameterizations can produce similar seismograms that match aspects of observed ground motion, so association of observations with specific scattering mechanisms that can narrow the model space is critical to confident transport of prediction capability to new source-receiver paths.

We welcome submissions focused on constraining values of and reducing the number of free parameters of statistical models of media heterogeneity, on observations of seismic scattering processes and on methods and results for modeling the scattered wave fields.

Session Conveners
G. Eli Baker, U.S. Air Force Research Lab, <glenn.baker.3@us.af.mil>
Kim B. Olsen, San Diego State University, <kbolsen@mail.sdsu.edu>
Yang Shen, University of Rhode Island, <y.shen@icloud.com>
Vernon Cormier, University of Connecticut, <Vernon.cormier@uconn.edu>
W. Scott Phillips, Los Alamos National Laboratory, <wsp@lanl.gov>

Early Warning for Large Earthquakes and Tsunamis: Challenges, Case Studies and Innovations

Earthquake early warning (EEW) algorithms attempt to characterize earthquake ruptures and ground motion in real-time and provide advance notifications before the arrival of damaging seismic waves and subsequent hazards (e.g., tsunamis). EEW approaches and their products have evolved over the past decade with recent advances in instrumentation, rapid source characterization, real-time ground motion prediction and communication technologies. Today’s early warning systems can go much beyond this basic function, providing estimates of shaking intensity and potential damage for implementation of post-event emergency action plans. However, many challenges still exist in for creating effective EEW systems. For instance, while medium-sized earthquakes are sufficiently well described with very simple point source models, characterizing large ruptures is complex. Recent experiences with EEW systems that were in operation during large earthquakes (e.g. the Mw7.0 2016 Kumamoto, Japan and Mw7.1 2017 Morelos-Puebla, Mexico earthquakes), as well as offline studies, are starting to shape our expectations of the performance we can realistically expect from EEW systems.

In this session, we invite scientists, engineers, practitioners and policy makers to present work related to EEW applications and case studies. Some topics might include:
– innovative event recognition, source characterization and false alert avoidance algorithms;
– characterization of uncertainties stemming from EEW algorithms and ground motion prediction in real-time;
– comparison of point-source and finite-fault approaches;
– performance assessment for long-duration and complex ruptures;
– integration of real-time GPS data in EEW systems;
– real-time ground motion and damage prediction;
– exploration of local and global tsunami early warning;
– EEW case studies, testing and performance evaluation of existing systems; and
– discussion of implications for earthquake hazard, risk and response models with respect to the science community as well as private and government entities.

Session Conveners
Christine J. Ruhl, University of California, Berkeley, <cruhl@berkeley.edu>
Emrah Yenier, Nanometrics Inc., <emrahyenier@nanometrics.ca>
Men-Andrin Meier, California Institute of Technology, <mmeier@caltech.edu>
Neil Spriggs, Nanometrics Inc., <neilspriggs@nanometrics.ca>
Diego Melgar, University of Oregon, <dmelgarm@uoregon.edu>
Marlon D. Ramos, University of Michigan, <ramosmd@umich.edu>
David Easton, Nanometrics Inc., < davideaston@nanometrics.ca>

Earthquake Source Parameters: Theory, Observations and Interpretations

Understanding origin and spatio-temporal evolution of seismicity needs a careful quantitative analysis of earthquake source parameters for large sets of earthquakes in studied seismic sequences. Determining focal mechanisms, seismic moment tensors, static stress drop, apparent stress and other earthquake source parameters provides an insight into tectonic stress and crustal strength in the area under study, material properties and prevailing fracturing mode (shear/tensile) in the focal zone and allows the investigation of earthquake source processes in greater details. In addition, studying relations between static and dynamic source parameters and earthquake size is essential to understand the self-similarity of rupture process and scaling laws and to improve our knowledge on ground motion prediction equations.

This session focuses on methodological as well as observational aspects of earthquake source parameters of natural or induced earthquakes in broad range of magnitudes from large to small earthquakes, including acoustic emissions in laboratory experiments. Presentations of new approaches to focal mechanisms determination, seismic moment tensors and other source parameters as well as case studies related to analysis of earthquake source parameters are welcome. We also invite contributions related to scaling of static and dynamic source parameters and to self-similarity of earthquakes.

Session Conveners
Vaclav Vevrycuk, Institute of Geophysics, Czech Academy of Science, <vv@ig.cas.cz>
Grzegorz Kwiatek, GFZ Potsdam, <kwiatek@gfz-potsdam.de>
Douglas Dreger, University of California, Berkeley, <dreger@seismo.berkeley.edu>

Emergency Management, Resilience and Preparedness

Emergency and disaster management and preparedness approaches involve the mitigation, preparation, response and recovery and aim to reduce vulnerability to hazards and to cope with disasters from both natural events and human-induced events. The planning phase involves a coordinated, co-operative process of preparing to match anticipated urgent needs with all available resources. All the phases require research, evaluation, testing/validation, implementation and updating; the final product will be a living emergency plan that should be periodically reviewed and adapted to changing circumstances and real-life situations. In this session, we call for participants to focus on emergency planning, management, continuity of operations, technology, social processing and guidance. In a real world that is subject to accelerating physical, social and economic change, the challenge of managing emergencies well depends on effective planning and foresight and the ability to connect disparate elements of the emergency response into coherent strategies.

Session Conveners
Victor A. Huerfano, Puerto Rico Seismic Network, <victor@prsnmail.uprm.edu>
Christa G. von Hillebrandt, Caribbean Tsunami Warning Program / NWS, <christa.vonh@noaa.gov>
Elizabeth A. Vanacore, Puerto Rico Seismic Network, <elizabeth.vanacore@upr.edu>
Ronald Jackson, CDEMA, <ronald.jackson@cdema.org>

Environmental Seismology: Glaciers, Rivers, Landslides and Beyond

Environmental seismology is the study of seismic signals generated at and near the surface created by environmental forces in the atmosphere, hydrosphere or solid Earth. Contributions to this session are welcome on a wide variety of topics including (but not limited to) the seismic signals associated with landslides, rock falls, debris flows, lahars, snow avalanches, cliff or pinnacle resonance, bedload transport, fluid flow in open and confined channels, open water waves, tides, glacial stick-slip, iceberg calving, crevassing, extreme wind and weather and wind turbines or other anthropogenic sources. Contributions that seek to conduct monitoring, create physical or statistical models of source processes or systems, detect events, characterize a wave propagation environment, or interact with other branches of the Earth or social sciences are additionally encouraged.

Session Conveners
Bradley P. Lipovsky, Harvard University, Department of Earth and Planetary Sciences, <brad_lipovsky@fas.harvard.edu>
Kate Allstadt, U. S. Geological Survey, Geologic Hazards Science Center, <kallstadt@usgs.gov>
Rick Aster, Colorado State University, Geosciences Department, <Rick.Aster@colostate.edu>

Essentials of Seismic Risk Estimates

Estimating the seismic risk for a region is important for officials as well as for individuals for deciding what mitigating action, if any, is to be taken. The risk can be expressed in units of number of strongly affected people, fatalities, injured or monetary losses. This session will focus on methods of estimating risk and the data sets necessary to calculate it are essential elements that need to be discussed. The underlying question of seismic hazard must be understood for the region in general, although this session does not focus on it. The seismic risk problems in the regions of Central and South America are of special interest. Estimates of the differences in the seismic risk for the affluent and the poorer sections of society are invited. Methods for structural measures to reduce seismic risk have been developed, but new ideas, especially those applicable to Latin America, are welcome. Quantitative means to educate decision-makers and the public are also of interest.

Session Conveners
Max Wyss, International Centre for Earth Simulation Foundation, <max@maxwyss.ch>
Sergio Barrientos, National Seismological Center, University of Chile, <sbarrien@dgf.uchile.cl>
Ramón Zúñiga, Centro de Geociencias, Universidad Nacional Autónoma de México, <ramon@geociencias.unam.mx>

Exploring Rupture Dynamics and Seismic Wave Propagation along Complex Fault Systems

Investigations related to how complexities in fault parameters could potentially impact the behavior of earthquake rupture and affect seismic hazard are areas of active and challenging research. This session will highlight recent advances in rupture dynamics on complex fault systems. We are open to a wide range of studies related to numerical, experimental and observational fault rupture dynamic studies with heterogeneities such as fault geometry, fault roughness, frictional parameters, creeping mechanisms, stress asperities, off-fault material properties, bi-material interfaces and wedge structures along subduction zones. We also encourage contributions on research that explores links between earthquake source physics, tsunami generation/propagation and ground motion variability.

Session Conveners
Roby Douilly, University of California, Riverside, <roby.douilly@ucr.edu>
Kenny Ryan, U.S. Geological Survey, <kryan@usgs.gov>
David D. Oglesby, University of California, Riverside, <david.oglesby@ucr.edu>
Ruth Harris, U.S. Geological Survey, <harris@usgs.gov>
Eric Geist, U.S. Geological Survey, <egeist@usgs.gov>

Fault to Seismic Hazard Assessment (Fault2SHA) in Latin (Central and South) Americas

In seismic hazard analysis, increasing importance is given to geodynamic and tectonic data for modeling seismic sources by actual faults. Fast deforming countries like California, New Zealand, Japan and Turkey that have led the development of this practice since the 90s, are now facing new lessons, whilst slowly deforming areas (i.e., Europe) are learning how to deal with their datasets. Latin America is a broad region of interest for earth scientists as it is characterized by both intense seismic activity along the subduction zones and distributed continental faulting. Assessment and mitigation of seismic hazards from the growing set of active faults identified and mapped in Latin America poses unique challenges due to the high variability of data types and qualities.

This session aims to present new data sets and the latest integration of fault sources in SHA models. We invite contributions related to the description of earthquake sources, from the field to the modeling, as well as discussions about whether and how uncertainties in field data are transposed into the source models. In particular, we solicit studies that provide discussions about the comparison and analysis of fault parameters and fault models in South and Central America. We also solicit contributions on how 3D, geometrically complex fault segments are identified and defined, their impact on probabilistic seismic hazard results and studies that incorporate geodetical and geophysical observations. The session aims at linking the “New” and “Old” Worlds, i.e., the Americas and Europe, by strengthening common rules and procedures inside the international community that works on these subjects.

Session Conveners
Laurence Audin, IRD ISTerre UGA, <laurence.audin@ird.fr>
Felipe Aron, Pontificia Universidad Católica de Chile, <faron@ing.puc.cl>
Marianne Saillard, IRD Geoazur, <saillard@geoazur.unice.fr>
Laura Peruzza, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, <lperuzza@inogs.it>
Franck Audemard, Fundación Venezolana de Investigaciones Sismológicas, <faudemard@funvisis.gob.ve>
Oona Scotti, Institut de Radioprotection et de Sûreté Nucléaire, <oona.scotti@irsn.fr>

Forecasting Aftershock Sequences in the Real World

In the last few years, increasingly sophisticated earthquake forecast models have been applied in many regions around the globe in response to ongoing earthquake activity. Traditionally, aftershock models have been used to forecast short time-windows of days or weeks and this type of aftershock forecasting has remained the most common application. However, as demonstrated in recent New Zealand sequences (e.g., Canterbury in 2010-2011 and Kaikoura in 2016), when end-users become more familiar with forecast modelling, their need for other means of understanding the forecasting, such as through longer time frames, increases. Further, there is evidence that a variety of decisions were made by emergency managers, building engineers and key decision-makers based on these forecasts that had previously not been anticipated by the scientific community. Other complexities included forecasts and predictions made publicly by alternate theorists.

Experience from New Zealand has highlighted some of the limitations in our current understanding and modeling approaches, such as: 1) understanding the forecast skill of aftershock models as they extend to longer time-periods; 2) forecast models that provide useful information for medium-term time-frames; 3) spatial distribution of earthquake sequences; 4) forecasts of ground motion and losses; and 5) communication methods and tools that allow for successful uptake of relevant information during heightened earthquake response times. In this session, we welcome presentations that cover these or any other operational earthquake forecast model development and communication topics.

Session Conveners
Matthew C. Gerstenberger, GNS Science, <m.gerstenberger@gns.cri.nz>
Sara Mcbride, U.S. Geological Survey, <skmcbride@usgs.gov>
Nick Horpsool, GNS Science, <n.horspool@gns.cri.nz>
David A. Rhoades, GNS Science, <d.rhoades@gns.cri.nz>

The Future of Telemetered Seismic Arrays – Where the Operation of the Network Ends and the Science Begins

Seismic science generally starts with a quality waveform archive and a rich catalog of well located events with accurate magnitudes. This session will explore new and innovative ways of field operations and discuss input on more efficient approaches to delivering this scientific starting point. This could include cloud and network services, engineering services, improved instrumentation, co-located complimentary instruments and less expensive installations. An integrative approach to station building and management using many geophysical observations should become standard in most supported telemetered networks. Arrays of seismometer and geophysical instruments that address more use cases for less investment are the key going forward. We invite abstracts on a wide range of topics that affect the creation, management and type of geophysical stations built: early earthquake warning, public hazard reporting, environmental monitoring, science observatories, cost, performance, data use case, data latency, noise characteristics, regional concerns and the cost of data per gigabyte.

Session Conveners
Tim Parker, Nanometrics, <timbobparker@gmail.com>
Allison Bent, Natural Resources Canada-Ottawa, <allison.bent@canada.ca>

Increasing Testability – Expanding Possibilities and Future Developments of the Collaboratory for the Study of Earthquake Predictability

The Collaboratory for the Study of Earthquake Predictability (CSEP) has expanded over the years to many different testing areas hosted at multiple testing centers. Hundreds of earthquake forecast models have been submitted to CSEP and are being tested. New testing metrics were developed and implemented and a lot of progress was made to establish CSEP as an institution that cannot be ignored when issuing earthquake forecasts. Its rigor and independence became the standard in evaluating earthquake forecasts and in reporting on the results.

Although the tests CSEP has conducted have been successful and well-received, they have also shown the limitations of the CSEP approach. What is a sufficient testing period for models? Are time-invarying models really describing the long-term seismic activity? Are long-term models testable at all? Do short-term models provide significant information for the forecasting problem or do they only model aftershock sequences? What other signals should be included in forecasting models to improve them? Do improvements in forecasting models translate into improvements of hazard models? How can the tests be improved? Many aspects of seismic hazard or earthquake forecasting remain inherently untestable if only the model forecasts are tested and not the model ingredients. We propose to create new areas of activity for CSEP, namely targeted experiments that cannot be conducted with the current CSEP software system.
We solicit contributions addressing forecasting models, forecast testing problems, new ideas for CSEP experiments, possibilities of further CSEP developments, ways of expanding CSEP into the hazard and risk domain and more general views on the forecasting problem.

Session Conveners
Andrew J. Michael, U.S. Geological Survey, <michael@usgs.gov>
Danijel Schorlemmer, GFZ Potsdam, <ds@gfz-potsdam.de>
Maximilian J. Werner, University of Bristol, <max.werner@bristol.ac.uk>
Warner Marzocchi, Istituto Nazionale Geofisica e Vulcanologia, <warner.marzocchi@ingv.it>

Interaction Between Observations and Models in Seismo-volcanic Studies

Seismo-volcanic studies demand a deep understanding of volcanic systems. Such a study requires one to determine the internal structure of volcanic edifices to illuminate the configuration of the plumbing-feeding system, the nature and role of the fluids that fill internal cracks and cavities of complex geometries, the properties of seismic waves that cross the volcanic edifice, the role of tectonic stresses and faults and many other intriguing aspects of these complex systems. Numerous seismic instruments have been deployed on active volcanoes in recent decades either in a permanent role for volcano surveillance or for temporary campaigns. We extend this invitation to discuss recent contributions in the fields of modelling, based on a foundation of observations of volcanic activity ranging from simple seismic networks to high resolution multi-parametric approaches. We expect to have an exciting interactive session between seismologists and the personnel of volcanic observatories from Latin America, USA and elsewhere.

Session Conveners
Mario C. Ruiz, Instituto Geofisico, Escuela Politécnica Nacional, <mruiz@igepn.edu.ec>
Mauricio Mora, Universidad de Costa Rica, <mmorarsn@gmail.com>

Megathrust Earthquakes: Recurrence, Rupture Modes and Tsunamis

This session will address megathrust faulting at subduction zones. Topics include: 1) patterns of earthquake recurrence; 2) differences among fault ruptures that overlap; 3) interseismic, coseismic and postseismic deformation; 4) splay faults as clues to megathrust rupture mechanics and tsunami hazards; and 5) subduction zones, as in the Caribbean, where the very occurrence of great tsunamigenic earthquakes has yet to be demonstrated.

Session Conveners
Peter Molnar, University of Colorado, <molnar@colorado.edu>
Peter Haeussler, U.S. Geological Survey, <pheuslr@usgs.gov>
Brian F. Atwater, U.S. Geological Survey, <atwater@usgs.gov>

Microzonation Studies – Site Effects

As the world population increasingly moves to big metropolitan urban areas, the risk associated with earthquakes increases in these areas. This is particularly evident in developing countries. Local soil conditions are a first order parameter that controls seismic response and therefore building damage due to earthquake shaking. Careful planning of urban development with respect to soil conditions must be exercised to prevent loss of structures and fatalities. Due to restricted space and city regulations, microzonation studies have gained popularity over traditional geophysical methods over the past decades as rapid, cost-effective and environmentally friendly.

Damage that occurred in Mexico City due to the September 19, 2017 Puebla-Morelos earthquake, compared to damage from September 19, 1985 Michoacán earthquake, demonstrates the importance of understanding soil response and interaction with buildings for different source characteristics and soil conditions. Other recent earthquakes, such as the 2016 Pedernales earthquake in Ecuador, the 2010 Maule earthquake in Chile, and the 2010 earthquake in Haiti demonstrate the importance of site effects for damage distribution. Knowledge gained from these earthquakes can help mitigate damage from future earthquakes.

This special session is about case studies of seismic microzonation around the World, what we have learned about seismic response in urban areas, and how we can help planners to develop earthquake resilient cities.

Session Conveners
Ilias Papadopoulos, University of the West Indies, Seismic Research Centre, <ilias@uwseismic.com>
Michael Schmitz, La Fundación Venezolana de Investigaciones Sismológicas, <schmitzschutt@gmail.com>

New Frontiers in Seismic and Acoustic Data Analysis

Advances in computing power, novel sensing systems and analytical techniques have revealed valuable new perspectives on seismic and acoustic wave fields. For example, computationally intensive methods like the Empirical Wavelet Transform can give much sharper time/frequency representations than Fourier-based methods. Large N seismic arrays, free-flying infrasound stations and distributed fiber optic sensor cables acquire nontraditional data sets that then require new signal detection, association and location methods. 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.

Session Conveners
Daniel C. Bowman, Sandia National Laboratories, <dbowma@sandia.gov>
Sarah A. Albert, Sandia National Laboratories, <salber@sandia.gov>
Matthew M. Haney, Alaska Volcano Observatory, <mhaney@usgs.gov>

The Next Big Earthquake: The Usual and the Unusual Suspects

Recent large and great earthquakes have altered the terrain, economies and lives of people in Haiti, Chile, New Zealand, Nepal and Japan. The potential for future damaging earthquakes in these and other populated regions near tectonically active plate boundaries are well known and pose increasingly significant risk to societies there. But what observational evidence do we have to understand where next big earthquake will be? This session seeks paleoseismic and historical earthquake studies that examine large and great earthquakes around the world that pose such hazards. Analyses that include the number of people impacted, past and future effects on urban infrastructures or cultural systems and the size or level of ground deformation are of particular interest. Additionally, field investigation and analysis of recent surface-rupturing earthquakes and studies that examine the variability of past ruptures in size and time with a special emphasis on how such paleoseismic data can be used for seismic risk mitigation are welcome. Submissions from studies in Central and Latin America are particularly encouraged, as are studies of global fault networks.

Session Conveners
Sinan O. Akciz, California State University, Fullerton, <sakciz@fullerton.edu>
Kate Scharer, U.S. Geological Survey, <kscharer@usgs.gov>

Numerical Modeling of Earthquake Ground Motion, Rupture Dynamics and Seismic Wave Propagation

Continuous development of numerical modeling methods in seismology is driven by emerging requirements in observational seismology, advances in the mathematical sciences, evolution of computer architectures and programming models, adaptation of methods originating in other scientific fields, as well as by practical applications including site-specific seismic hazard assessment.

This session is a forum for presenting advances in numerical methodology, whether the principal context is observational, mathematical/numerical, computational or application-based.

We invite contributions focused on development, verification and validation of numerical-modeling methods and methodologically important applications especially to earthquake ground motion, seismic noise and rupture dynamics, including applications from the field of induced seismicity with particular focus on multi-physics aspects, for example, combining fluid migration and stress transfer in porous media with rupture dynamics and wave propagation in poro-elastic media and integration of dynamic event modeling with simulation of the full seismic cycle. We encourage contributions on the analysis of methods, fast algorithms, high-performance implementations, large-scale simulations, non-linear behavior, multi-scale problems and confrontation of methods with data.

Session Conveners
Peter Moczo, Comenius University Bratislava, <moczo@fmph.uniba.sk>
Steve M. Day, San Diego State University, <sday@mail.sdsu.edu>
Jozef Kristek, Comenius University Bratislava, <kristek@fmph.uniba.sk>

Observations and the Physics Behind Complex Earthquakes

New observations of large earthquakes are challenging the simple model of a smoothly expanding rupture on a planar fault. Some recent events have involved multiple faults (e.g., 2012 M 8.6 Sumatra, 2016 M 7.8 Kaikoura, New Zealand), re-rupturing of a single fault patch (e.g., 2015 M 7.5 Hindu Kush), dynamic triggering of later sub-events (e.g., 1997 M 7.1 Harnai, Pakistan) and the interaction between intraplate and interplate faults (e.g., 2009 M 8.1 Samoa-Tonga, 2016 M 7.9 Papua New Guinea). Are these earthquakes outliers? Or does our increased ability to resolve a detailed picture capture a new norm? How can we define a new common behavior? What are the physical mechanisms that control the signatures of complex earthquakes? We welcome contributions on geodetic, seismic and field observations of complex earthquakes, new source inversion/imaging techniques, as well as physical analysis and simulation of complex earthquakes.

Session Conveners
Zhongwen Zhan, California Institute of Technology, <zwzhan@gps.caltech.edu>
Gavin Hayes, U.S. Geological Survey NEIC, <ghayes@usgs.gov>
Marine Denolle, Harvard University, <mdenolle@fas.harvard.edu>

Observed Characteristics of Induced Seismicity: From Laboratory to Field Scale

A wide variety of methods have been employed to examine the physical mechanisms and site-specific conditions that control anthropogenically induced seismicity. Laboratory experiments and mesoscale experiments of fluid injection into active faults investigate the role of fluids and friction on fault stability and the contribution of aseismic slip to the nucleation process. Seismic array installations including large-N array deployments characterize the seismic wave-field, microseismicity and fault structure. Advanced earthquake detection and location techniques are being used to identify complex spatial and temporal migration patterns and statistical methods are used to differentiate between tectonic and induced events. Deployment of pressure monitoring networks explore the migration of fluids in the subsurface and illuminate how earthquakes modify the poroelastic environment. Geomechanical reservoir simulations relate fluid injection volumes/rates to subsurface fluid-pressure changes and numerical methods couple reservoir models to earthquake simulators to understand how induced seismicity sequences evolve due to changes in injection operations. These methods reveal that the character and evolution of induced seismicity are more complex than previously thought. We solicit contributions from laboratory/field experiments and observational, geomechanical and numerical modeling studies that explore the wide variety of characteristics, as well as the physical conditions and mechanisms, that control behavior of induced seismic sequences. In addition, we encourage contributions that discuss datasets and techniques needed to further understand and mitigate the risk associated with fluid injection.

Session Conveners
Kayla A. Kroll, Lawrence Livermore National Laboratory, <kroll5@llnl.gov>
Elizabeth S. Cochran, U.S. Geological Survey, <ecochran@usgs.gov>
Brett Carpenter, University of Oklahoma, <brett.carpenter@ou.edu>

Ocean Bottom Seismology – Hurdles, Strategies and Outcomes

The field of Ocean Bottom Seismology has been rapidly expanding, with many types of deployments for a wide variety of targets. Ocean floor sensors have been used for structural and geodynamic studies, enhanced seismic monitoring and improved source location. Different marine environments and tectonic settings require innovative solutions to deployment logistics, sensor emplacement and data recovery. Following the extraction of data, special problems relating to a sometimes very noisy environment pose new challenges to maximize data utility. We welcome contributions addressing all aspects of active and passive ocean-bottom seismology, technical innovations, data analysis and the scientific results obtained from OBS or amphibious projects.

Session Conveners
Charlotte A. Rowe, Los Alamos National Laboratory, <char@lanl.gov>
Francisco J. Nunez-Cornu, SisVOC, Centro Universitario de la Costa, <pacornu77@gmail.com>
Susan L. Bilek, New Mexico Institute of Mining and Technology, <sbilek@nmt.edu>

Onshore Quaternary and Contemporary Tectonics: Implications for Seismic Hazards

We solicit abstracts that focus on work related to earthquake history of onshore faults, regional or site-specific tectonic deformation (e.g., changes in marine terrace elevations or in stream gradients), current crustal stress orientations and/or seismicity, that contribute to the understanding of the hazards posed by onshore faults in the Caribbean region. Papers could also include the use of the information available about the activity of onshore faults in the assessment of seismic hazards for structures of various types or information from offshore studies that implicate onshore faults.

Session Conveners
Lucille Piety, Bureau of Reclamation, <lpiety@usbr.gov>
Joanna Redwine, Bureau of Reclamation, <jredwine@usbr.gov>

Plate Boundary Segmentation & Coupled-to-Creeping Plate and Block Boundary Faults

This session aims to begin characterizing the range of fault behaviors on plate and block-boundary faults in the Caribbean and Latin American regions. Presentation of case studies that use seismological, geodetic, geological, geomorphic and other approaches to study individual locked, creeping and intermediate faults and segments are invited. We also seek out the presentation of work that uses both empirical evidence and modeling to understand the physical causes for these differing fault behaviors. A major goal of the session is to begin understanding how and why individual plate and block boundaries are segmented and how locked and creeping segments link in space and time.

Session Conveners
John C. Weber, Grand Valley State University, <weberj@gvsu.edu>
Omar J. Perez, Universidad Simón Bolívar, <ojperez@usb.ve>

Present-day Plate Boundary Deformation and Seismic Hazard in the Caribbean

Seismic hazard is an integral part of the Caribbean. Earthquakes can be particularly devastating to countries of the region that have seen a significant rise in population density — often with a concentration in coastal areas and substandard building practices. A number of research and observation programs are however underway with the goal of better understanding seismic hazard and the physical processes that control the occurrence of earthquakes in the Caribbean, with the potential to inform decisions and contribute to capacity building. This session aims at bringing together geoscientists with an interest in seismic hazard characterization and active plate-boundary deformation in the Caribbean through seismology, paleoseismology, geodesy, tectonics, geodynamics or any other relevant discipline.

Session Conveners
Eric Calais, Ecole Normale Supérieure, <eric.calais@ens.fr>
Steeve Symithe, Université d’Etat d’Haiti, <symithesteevej@gmail.com>
O’Leary Gonzalez Matos, Centro Nacional de Investigaciones Sismológicas, <oleary@cenais.cu>
Valérie Clouard, Observatoire Volcanologique et Sismologique de Martinique, <clouard@ipgp.fr>

Real-time GNSS Network Operations and Advances towards Early Warning Systems

A fundamental aspect of Real-Time GNSS operations is the capability to obtain physical charactersitics of the rupture process after the onset of an earthquake. Of particular interest is the ability to use rupture parameters to assess the effects of strong ground motions and a potentially ensuing tsunami. This session seeks contributions of the latest approaches in using Real-Time GNSS data to be applied in source inversion algorithms and to produce seismic parameters in seconds to minutes after the occurrence of an earthquake. Contributions describing how such results are applied for shaking and tsunami intensity forecasts (i.e. for early warning systems) are highly welcome and desirable. The use of casters or other protocols to collect and distribute the data, the computer infrastructure required to manage data operations, correction schemes employed for precise point positioning, data manipulation, visualization of data and other steps carried out in the estimation of source parameters are likely contributions expected for this session. We also welcome contributions that discuss operational issues such as: what is required in the field to ensure highly reliable data flow, what can be done to maintain low-latency, high-rate data steams without overburdening communications, how can redundancy be built into data paths and how to leverage existing infrastructure in seismic networks to enable GNSS data flow and vice versa?

Session Conveners
Kathleen M. Hodgkinson, UNAVCO, <hodgkinson@unavco.org>
Alberto M. Lopez, University of Puerto Rico at Mayagüez, <alberto.lopez3@upr.edu>
David J. Mencin, UNAVCO, <dmencin@unavco.org>
Diego Melgar, University of Oregon, <dmelgarm@uoregon.edu>
Sebastian Riquelme, University of Chile, <sebastian@dgf.uchile.cl>
Victor Huérfano Moreno, University of Puerto Rico at Mayagüez, <victor@prsn.uprm.edu>

Recent Advances in Dense Array Seismology

The availability of dense seismic arrays is desired to record well-sampled and unaliased wavefields. The recording of full wavefields combined with advanced data analysis techniques has the potential to image the subsurface and to study source characteristics with unprecedented resolution. The recent availability of low-cost and easy-to-deploy seismic sensors and emerging technologies such as Distributed Acoustic Sensors (DAS) have made it possible to deploy large and dense arrays in a reasonable time frame. Data acquired by such dense systems promote the development of many new data analysis methods that study seismic signals in a more comprehensive fashion. This session aims to compile innovative efforts that engage in recent advances in dense array seismology. We invite contributions from all research focus areas that are broadly related to dense arrays. Example topics include, but are not limited to, instrument development, field experiment with Large-N or DAS array, high-resolution imaging of subsurface structure, full wavefield reconstruction, environmental seismology and seismic source characterization.

Session Conveners
Ting Chen, Los Alamos National Laboratory, <tchen@lanl.gov>
Fan-Chi Lin, University of Utah, <fanchi.lin@utah.edu>
Norimitsu Nakata, University of Oklahoma, <nnakata@ou.edu>
Catherine Snelson, Los Alamos National Laboratory, <snelsonc@lanl.gov>

The Recent Earthquakes that Shocked Mexico in September 2017

Last September, Mexico experienced two large earthquakes that seriously affected the south and central parts of the country. Both earthquakes were intraslab normal-faulting ruptures within the oceanic Cocos plate. The first one (Mw=8.1) occurred on September 8 in the Tehuantepec Gulf, collapsing thousands of small to medium size buildings in several provinces around the epicentral area. Numerous aftershock sequences (or triggered seismicity) followed the main earthquake increasing the damage to the Tehuantepec Isthmus. The second event (Mw=7.1) occurred eleven days later, on September 19, south of the border between the Morelos and Puebla States and close to important cities such as Cuernavaca and Mexico City (~100 km to the north of the epicenter), where hundreds of buildings collapsed or were seriously damaged. In total, the authorities estimate that about 400 people died nationwide as a consequence of both events. This session welcomes papers addressing various seismological aspects of both earthquakes, such as source modelling, aftershocks sequences, ground motion and tsunami modeling, strong motions, triggered seismicity and tectonic implications among others.

Session Conveners
Arturo Iglesias, Institute of Geophysics, UNAM, <arturo@geofisica.unam.mx>
Vala Hjörleifsdóttir, Institute of Geophysics, UNAM, <vala@geofisica.unam.mx>
Víctor M. Cruz-Atienza, Institute of Geophysics, UNAM, <cruz@geofisica.unam.mx>
Roberto Ortega-Ruiz, CICESE-Unidad La Paz, <ortegarobe@gmail.com>

Regional Seismic Network Approaches and Stakeholder Collaborations

Seismic monitoring is a collaborative effort typically carried out by a broad array of state, university and federal partners. This distributed approach provides standardized earthquake analysis while adapting to the needs of specific regions and stakeholders. Many seismic networks in the U.S. coordinate through the Advanced National Seismic System. There are numerous organizations, both long-established and new, that operate independently. This is the case for most national networks within the Americas and other regions of the world. This session highlights the unique observations, opportunities and adaptations of so-called regional seismic networks. The purpose of the session is to foster collaboration and showcase specific regional success stories.

We welcome a wide range of contributions spanning science, operations and/or stakeholder engagement and particularly encourage submissions based on lesser-known organizations. Examples include but are in no way limited to: response to major earthquakes, unique tectonic considerations, non-earthquake sources, industry applications, forensic seismology, detection and processing workflows, facilities monitoring, custom products and services and support for local stakeholders. The only prerequisites are (i) real-time data and (ii) adaptation to a regional need or phenomenon. If your hometown network does something you are proud of, this session is the place to show it off.

Session Conveners
Michael West, Alaska Earthquake Center, University of Alaska Fairbanks, <mewest@alaska.edu>
Sergio Barrientos, Chilean National Seismic Network, Universidad de Chile, <sbarrien@dgf.uchile.cl>
Paul Bodin, Pacific Northwest Seismic Network, University of Washingto, <bodin@uw.edu>
Victor Huerfano, Puerto Rico Seismic Network, University of Puerto Rico, <victor@prsnmail.uprm.edu>
Xyoli Perez-Campos, Servicio Seismológico Nacional, Universidad Naciónal Autonoma de México, <xyolipc@gmail.com>
Alexandros Savvaidis, Texas Seismological Network, Bureau of Economic Geology, University of Texas at Austin, <alexandros.savvaidis@beg.utexas.edu>

Retrieval of Fine Scale Information Using Seismic Noise

The use of ambient noise and other passive sources, coupled with the advent of large-N deployments, has been applied to an exponentially increasing number experiments in the last decade. Parallel advances in numerical methods and a deeper understanding of the physics and statistics of these passive wavefields has led to a number of highly inventive methodological advances affecting both the spatial and temporal resolution of recovered structures. Namely, ambient noise body wave tomography, passive temporal monitoring of dynamically varying structure through dt/t measurements or other approaches, full waveform modeling of the ambient field and improved statistical models for diffusely scattered coda, have made substantial impacts in the way researchers now approach classically intractable problems. In this session, we seek to display such advances in the use of passive sources, either through seismic interferometry or other novel approaches, that result in the retrieval of fine scale information in new settings or the improvement of algorithms allowing for retrieval of more accurate physical parameters from previously tested datasets and media. Submissions are encouraged for research tackling current difficulties in resolution and physical parameter retrieval, as well as computational limitations and solutions to such problems.

Session Conveners
Julien Chaput, Colorado State University, <jchaput82@gmail.com>
Thomas Lecocq, Royal Observatory of Belgium, <thomas.lecocq@oma.be>

Science Gateways and Computational Tools for Improving Earthquake Research

Science gateways allow research communities to access shared data, software, computing services, instruments, educational materials and other resources. Advances in earthquake science are becoming increasingly tied to the ability to fuse and model multiple data types, requiring advances in computational infrastructure. Earthquake scientists must rely on computational laboratories to integrate disparate data sets and perform simulation experiments, particularly because earthquake processes span multiple spatial and temporal scales, ranging from microscopic, millisecond source physics to long-term, global tectonic scales. This session focuses on advances in computational infrastructure and data synthesis for enhancing earthquake science, including software, supercomputing, simulation models, sensor technology, heterogeneous data sets, cloud computing, management of huge data volumes and development of community standards.

Session Conveners
Andrea Donnellan, Jet Propulsion Laboratory, California Institute of Technology, <andrea.donnellan@jpl.nasa.gov>
Lisa Grant Ludwig, University of California, Irvine, <lgrant@uci.edu>

Seismic Event Screening

One of the products from global seismic monitoring provisional to entry-into-force of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a Standard Event Bulletin (SEB). The SEB contains event characterization parameters that can be used to screen-out seismic sources that are almost certainly not nuclear test explosions. During the two decades since the CTBT was opened for signature, research has resulted in a wide range of new source characterization methods. Based partly on results from this research, many seismic sources currently included in the SEB could be confidently identified as naturally occurring earthquakes. The new developments include, but are not limited to, comparison with empirical templates based on well calibrated past events, more precise depth constraint through simultaneous location of multiple events, ratios of spectral amplitudes of local and regional phases, ratios of different magnitudes computed from local, regional and teleseismic data, determination of moment tensor solutions from regional and teleseismic data and joint use of seismic and infrasonic data. This session comprises contributions related to evaluating which methods have advanced sufficiently to be ready for operational use in CTBT monitoring and what further research would be required to implement other methods in operations.

Session Conveners
Raymond Willemann, Air Force Research Laboratory, <raymond.willemann@us.af.mil>
David Bowers, Atomic Weapons Establishment, <bowers@blacknest.gov.uk>

Seismic Hazards and Historic Earthquakes in Puerto Rico and the Northern Caribbean Region

The USGS seismic hazard assessment for Puerto Rico and the U.S. Virgin Islands was last updated in 2003. For this session, we solicit papers that discuss new developments in probabilistic seismic hazard analysis in PRVI and the broader Caribbean region, as well as studies of historical earthquakes that inform the modern hazard models. We invite researchers to present new results that are critical to seismic hazard modeling and evaluation, including ongoing efforts by GEM and the USGS. Seismic hazard evaluation requires: 1) high-quality earthquake catalogs; 2) fault slip rates; 3) earthquake recurrence models; 4) region-specific ground motion models; and 5) local site amplification models. We encourage presentations on novel and creative concepts that will contribute to advancing seismic hazard models in the region.

Session Conveners
Roland LaForge, LaForge Geoconsulting, <LaForgeGeoconsulting@gmail.com>
Dan McNamara, U.S. Geological Survey, <mcnamara@usgs.gov>
Charles Mueller, U.S. Geological Survey, <cmueller@usgs.gov>

Seismic Structure of Convergent Plate Margins

Convergence between tectonic plates is accomodated in multiple ways, including subduction, large-scale transform motion and continent-continent collision. This convergence is manifested through the creation of volcanic arcs, orogenic plateau formation and high seismicity rates. As a result, lithospheric-scale reworking of the converging plates is common in these systems.

The tectonics of convergent plate margins have been well studied. However, how convergence is manifested in the seismic structure of these regions is still debated due to the complexity of the regions and differences in datasets and methodology. This session aims to shed light on how the processes that accompany convergence are expressed in the lithospheric structure of the crust and upper mantle of these margins, in the context of the increased availability and coverage of seismic data and recent advances in seismic tomography and imaging techniques. Examples of convergent plate boundary systems include but are not limited to: the Mediterranean, Alpine-Himalayan, American Cordillera, Caribbean and western Pacific systems.

Session Conveners
Min Chen, Michigan State University, <chenmi22@msu.edu>
Jonathan R. Delph, Rice University, <jrdelph@rice.edu>

ShakeMap-Related Research, Development, Operations and Applications

ShakeMap Version 4 represents a major re-engineering of the entire ShakeMap software package, including the way ground-motion parameters are interpolated, both geospatially and as a function of frequency. The new multivariate-normal interpolation strategy naturally accommodates uncertain intensity as well as ground-motion parameters, along with the correlations between the different parameters. While this new software and capabilities add important new functionality, they require (among other gaps) additional R&D on ground motion and intensity models, duration/intensity models, model selection and spatial cross correlations. Thus, 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 amplification and geospatial analyses (along with uncertainties) pertinent to ShakeMap. Presentations on new ShakeMap products, formats and web-rendering are also encouraged.

A ShakeMap Workshop will be held on the Friday (May 18th) following the SSA meeting at the meeting venue. Workshop attendees are particularly encouraged to share their ShakeMap-related examples, research, operations and needs. We also encourage presentations on more general research, operations, or applications related to ShakeMap. Such applications include, but are not limited to: earthquake scenarios, risk assessment, loss estimation, earthquake response tools and engineering and other analyses that utilize ShakeMap ground motion estimates and associated uncertainty information.

Session Conveners
David J. Wald, U.S. Geological Survey, <wald@usgs.gov>
Eric M. Thompson, U.S. Geological Survey, <emthompson@usgs.gov>
Charles B. Worden, U.S. Geological Survey, <cbworden@usgs.gov>

Structure and Dynamics of Earth’s Mantle

Understanding the structure and dynamics of Earth’s mantle provides key insights into the fate of subducted slabs, the evolution of Earth, the dynamic forces that help drive large scale surface tectonics and core-mantle interactions amongst other topics of interest. Recent advancements in global seismic station coverage as well as advances in computational techniques have led to a current renaissance in studies of Earth’s interior. For example, recent P-coda scattering studies and waveform tomography have provided new insight into the distribution of mantle heterogeneity and axisymmetric 2.5D theoretical waveform modeling has provided insight into the influence of topography on waveforms on major boundaries including the transition zone and core-mantle boundary. This broad session invites submissions from observational or theoretical studies in seismology, geophysics and geodynamics exploring Earth’s mantle.

Session Conveners
Elizabeth A. Vanacore, Puerto Rico Seismic Network, <elizabeth.vanacore@upr.edu>
Fenglin Niu, Rice University, <niu@rice.edu>

Structure and Geodynamics of the Caribbean Plate Boundaries

The Caribbean plate (CAR) is unusual for a number of reasons. The region’s history includes numerous destructive large magnitude earthquakes and tsunamis. An intermediate sized plate (3.3x106 km2), CAR is surrounded on its north, east and south by the much larger American plates, but since much of CAR is an large igneous province (LIP), its buoyancy makes it difficult to subduct. As a consequence, it is girdled by inward directed subduction zones; the Antilles on the east, the Puerto Rico Trench in the northeast and the Central American Trench on the west. Further, the large El Pilar-San Sebastian strike-slip system along northeastern South America (SA) connects the southern Antilles trench to the Southern Caribbean Deformed Belt and a poorly defined subduction zone in northwestern SA, at which CAR subducts beneath northern Colombia and western Venezuela. The flat CAR subduction has created the Merida Andes, Perija and Santa Marta uplifts. Since the SA plate is subducting beneath CAR at the southern Antilles subduction zone and CAR is subducting southeastward beneath western SA, the two plates are subducting beneath one another. The number and volume of plates descending beneath CAR as imaged in different tomography studies (e.g., Bezada et al, JGR, 2010 and Van Benthem et al, JGR, 2013) create interesting space problems in the upper mantle beneath CAR and its neighbors, influencing upper mantle flow.

In north and northwestern CAR a complex series of strike slip and oblique slip faults extend from Puerto Rico across and around Hispaniola to join with the strike slip faults of the Cayman trough. These include what may be incipient northward subduction of CAR along the Muertos trough south of Hispaniola and Puerto Rico.

The plate boundaries around Panama are complicated and include what appears to be incipient CAR subduction just east of the Panama arc and the northeastern boundary of the recently identified Coiba and Malpelo plates (Zhang et al., GRL, 2017), bounded by the Panama arc, Cocos, Nazca and SA.

This diversity of tectonic boundaries provides an unusually rich source for seismicity and tsunamigenic earthquakes. Regional seismicity and GPS velocities suggest that a number of small tectonic blocks, moving quasi-independently and deforming internally, are caught in the boundary zones between CAR and the surrounding plates.

We invite contributions on any aspect of seismic structure, plate structure, deformation, seismicity and geodynamics in and around the Caribbean.

Session Conveners
Alan Levander, Rice University, <alan@rice.edu>
Fenglin Niu, Rice University, <niu@rice.edu>

Testing PSHA Input Data, Source Models and Hazard Estimates

Many open, transparent probabilistic seismic hazard assessment (PSHA) models have become available, each involving many types of input data and assumptions. To inspire confidence, their input data, source models (i.e., earthquake forecasts) and hazard estimates require rigorous testing and validation.

UCERF3, the most advanced and comprehensive earthquake forecast ever, serves as an important example of a PSHA source model. It uses earthquake history, geologic fault data, geodetic and geologic strain rates and many assumptions. It is used in the US National Seismic Hazard Maps and the Uniform Building Code. With 1440 logic tree branches in just the time-independent models, it calculates off-fault epicenter rate density and rates of about 250,000 fault rupture scenarios, offering targets to evaluate the internal consistency and influence of model parameters and data values.

We welcome contributions to testing PSHA input data, including earthquake history, paleo-seismic event rates, geological and geodetic fault slip rates; strategies for integrating those data into source models; ground motion prediction equations; and resulting hazard estimates.

Session Conveners
David D. Jackson, University of California, Los Angeles, <djackson@g.ucla.edu>
Yufang Rong, FMGlobal, <Yufang.Rong@fmglobal.com>
Harold Magistrale, FMGlobal, <harold.magistrale@fmglobal.com>
Jeremy Zechar, Axis Capital, Zurich, <jeremy.zechar@axiscapital.com>

Tsunami Outreach, Education and Warning Dissemination: Cross-disciplinary Opportunities for Increasing Tsunami Resiliency

Tsunami-vulnerable areas continue to grow as coastal development expands and more people reside in tsunami-at-risk areas. However, as time passes from the last major ocean-wide tsunami in 2011, the urgency for and attention on tsunami risk reduction has taken a back seat to more recent events such as hurricanes, wildland fires and earthquakes. This session provides a broad forum for tsunami outreach, education and warning studies and related mitigation efforts. We particularly invite contributions from researchers working across disciplines, including multi hazard frameworks, that involve solutions to evacuation and warning issues and have addressed how other more recent events such as hurricanes can be used to promote tsunami resilience and risk reduction.

Session Conveners
Lori Dengler, Humboldt State University, <Lori.Dengler@humboldt.edu>
Christa von Hillebrandt, Caribbean Tsunami Warning Program, NOAA and IAPSO, <christa.vonh@noaa.gov>
Rick I. Wilson, California Geological Survey, <Rick.Wilson@conservation.ca.gov>

Tsunami Modeling and Hazard Assessment

Many recent advances have been made in the fields of tsunami modeling and hazard assessment. For example, the U.S. National Tsunami Hazard Mitigation Program has sponsored benchmarking workshops on the numerical modeling of tsunami propagation and inundation, tsunami currents and tsunamigenic landslides. In addition, the study of tsunami hazard has evolved to include loss estimates and mitigation measures, and tsunami hazard analysis is scheduled to become part of the building codes in several states in the next few years. There has been an increase of capabilities for tsunami risk reduction for the Pacific, Caribbean and adjacent regions. We also seek contributions on how to address, in a consistent fashion, seismic source definition for seismic and tsunami hazard assessments. This session will provide a forum for all aspects of tsunami modeling and hazard assessment and also for studies of tsunamis with a non-megathrust source.

Session Conveners
Stephanie L. Ross, U.S. Geological Survey, <sross@usgs.gov>
Silvia Chacón, Universidad Nacional de Costa Rica, <silviachaconb@gmail.com>
Juan J. Horillo, Texas A&M University at Galveston, <horrillj@tamug.edu>
Alberto Lopez, University of Puerto Rico at Mayagüez, <alberto.lopez3@upr.edu>
Hong Kie Thio, AECOM, <hong.kie.thio@aecom.com>

Uncertainty in Ground Motion Estimation; Seismological and Engineering Perspectives

Quantifying, understanding sources of, and reducing uncertainty in, methods of ground motion estimation are critical for improving seismic hazard assessment, as well as for working towards an understanding of the underlying seismological processes behind ground motion. Large uncertainty has often plagued estimates of physical parameters; it is important to reduce this uncertainty to discern the underlying seismological trends. Collaboration between the engineering and seismological communities is mutually beneficial. This session aims to bring together these communities to increase communication of new developments in targeting and understanding sources of uncertainty or variability in ground motion estimation, as well as working towards quantifying and reducing uncertainty for appications of seismic hazard assessment.

We welcome studies focused on understanding the foundations of variability in the seismological processes or parameters affecting ground motion estimation (earthquake source parameters, source characterization, etc.), on improving crustal models and techniques for ground motion simulations, on methods of quantifying uncertainty in seismological processes, as well as on strategies for reducing aleatory uncertainty as represented in ground motion prediction equations and probabillistic seismic hazard analysis.

Session Conveners
Valerie J. Sahakian, U.S. Geological Survey, <vsahakian@usgs.gov>
Annemarie S. Baltay, U.S. Geological Survey, <abaltay@usgs.gov>
Kathryn E. Wooddell, Pacific Gas & Electric, <wooddell@seismo.berkeley.edu>

Urban Liquefaction and Lateral Spread Investigations and Mapping

Liquefaction and lateral spreading are major coseismic geohazards that have an especially large impact on lifelines, in particular when they occur in urban areas. A number of recent events (e.g. Christchurch, New Zealand and the recent 2017 Mexico City event) demonstrate that further geological and geotechnical investigations and models are required to better understand where liquefaction and lateral spreading will take place in order to avoid or design to mitigate these coseismic hazards. This session focuses on urban liquefaction and lateral spread investigations and mapping efforts to better understand occurrence and recurrence of this strong-ground motion derived geohazard. The field of liquefaction hazard mapping has advanced substantially since initial projects in the 1980s through 1990s established the practice. This session is focused on reviewing advances brought about by documentation of effects from earthquakes over the past few decades and ongoing advances and application of new technologies and analytical understanding.

Specific topics of interest include integration of remote sensing exploration (lidar, satellite observations, etc) of recent liquefaction and laterals spreading, in addition to geological (trenching), geotechnical (CPT and drilling) and geophysical (e.g. shear wave, seismic reflection or refraction mapping, resistivity or radar) investigations to advance the predictive capabilities of hazard mapping. Also of interest are comparative studies between predictive hazard maps and actual occurrence of damaging liquefaction to assess the effectiveness of current mapping techniques.

Session Conveners
Gregory P. De Pascale, University of Chile, <snowyknight@gmail.com>
Jeffrey Bachhuber, Pacific Gas & Electric, <JXBS@pge.com>

USGS Seismic Hazard User-Needs

The U.S. Geological Survey (USGS) National Seismic Hazard Modeling Project (NSHMP) invites our user community to present how they use the National Seismic Hazard Models and resulting products, such as hazard curves, ground motion maps, deaggregations, web services, computer codes, catalogs and source parameter data. Considering future updates in 2020 and beyond, and possibly including one-year forecasts for induced seismicity, the NSHMP would like to know more about how the user community uses its products and thereby how the models might need to be improved. In addition to changes to current products, we would also like to know what additional products would be helpful. Although the structural engineering community is the primary user of the National Seismic Hazard Models, many members of the SSA community consider the models and their components, in a broad array of research and industry applications, such as liquefaction and landslide stability studies and insurance risk assessments.

Session Conveners
Susan M. Hoover, U.S. Geological Survey, <shoover@usgs.gov>
Nico Luco, U.S. Geological Survey, <nluco@usgs.gov>
Peter M. Powers, U.S. Geological Survey, <pmpowers@usgs.gov>
Sanaz Rezaeian, U.S. Geological Survey, <srezaeian@usgs.gov>

U.S. National Seismic Hazard Model Updates: 2018, 2020 and Beyond

The U.S. Geological Survey (USGS) National Seismic Hazard Models (NSHMs) are a bridge for translating “best-available” earthquake science into public policy. Historically, the NSHM for the conterminous U.S. has been updated every six years. The 2018 update will be a four-year update. Compared to the six-year cycle, the 2018 update will have fewer changes, thereby distributing sensitivity testing that becomes difficult when numerous changes are considered at once. This session focuses on the 2018, 2020 and future updates to the conterminous U.S. model. The deadline for any suggested modifications or additions to be considered to the 2018 model has passed; during this session we will summarize the scientific improvements in the 2018 model and discuss the outcome of the USGS 2018 NSHM update workshop (March 2018) in California. Looking forward, the deadline for published research to be included into the 2020 model is quickly approaching (June 2018). For this session, we invite contributions in all topics and areas that will influence future hazard models, for example: NGA-East, NGA-Subduction, physics-based ground motion models (3D simulations) and source models (UCERF4), source model implementations, directivity methods, fault characterizations, scaling equations, site amplifications and catalogs, among others.

Session Conveners
Allison M. Shumway, U.S. Geological Survey, <ashumway@usgs.gov>
Susan M. Hoover, U.S. Geological Survey, <shoover@usgs.gov>
Morgan P. Moschietti, U.S. Geological Survey, <mmoschetti@usgs.gov>
Mark D. Petersen, U.S. Geological Survey, <mpetersen@usgs.gov>
Peter M. Powers, U.S. Geological Survey, <pmpowers@usgs.gov>

Ground Motion and Earthquake Engineering

Modeling of ground motion and analysis of the response of structures to earthquakes are key to increasing earthquake resiliency in communities. This session solicits presentations on advances in ground motion modeling, case studies of regional ground motions, and especially the response of man-made structures to earthquakes.

Session Conveners
Sinan Akkar, Bogazici University, Kandilli Observatory and Earthquake Research Institute Department of Earthquake Engineering, <sinan.akkar@boun.edu.tr>
Thomas Herring, MIT, <tah@mit.edu>

Seismic Studies of Earth’s Crust and Lithosphere

Seismicity, seismic catalogs, and structure of earth’s crust and lithosphere are key components to understanding regional seismic risk and tectonics. The session includes studies of seismicity and imaging of Earth’s crust and lithosphere as well as advances in seismic catalogs recording local seismicity.

Session Conveners
Elizabeth A. Vanacore, Puerto Rico Seismic Network, <elizabeth.vanacore@upr.edu>