Meeting Abstracts

SCEC Annual Meeting participants are invited to share recent results and activities relevant to SCEC priorities and initiatives during the poster sessions. The SCEC collaboration emphasizes the connections between information gathering by sensor networks, fieldwork, and laboratory experiments; knowledge formulation through physics-based, system-level modeling; improved understanding of seismic hazard; and actions to reduce earthquake risk and promote resilience.

Use the search form to view abstracts of presentations that have been accepted for this meeting.

Results 151-200 of 248

SCEC ID	Category	Title and Authors	SCEC Award
Poster 204	GM	Understanding Crustal Weak Zone Effects on Earthquake Rupture Kinematics Through Dynamic Rupture Modeling Arben Pitarka, Robert Graves The material state in the shallow crust transitions from ductile in the uppermost crust (0~4km) to brittle in the seismogenic zone (4~20 km). The depth variation of material frictional properties of the crust determines how the fracture energy is... more	18092
Poster 184	CXM	The Community Fault Model version 5.3 and new web-based tools Andreas Plesch, Scott Marshall, Craig Nicholson, John Shaw, Philip Maechling, Mei-Hui Su We present version 5.3 of the SCEC Community Fault Model (CFM). The CFM is an object-oriented, comprehensive three-dimensional (3D) model of faults in southern California deemed capable of generating damaging earthquakes. The model is designed as a... more	20081, 20047
Poster 014	Geology	Off-fault deformation, stress field rotation, and the mechanical conditioning for rupture through an earthquake gate along the Altyn Tagh fault, northwest China Veronica Prush, Michael Oskin, Jing Liu Historical rupture mapping shows that fault complexities, such as bends, stepovers, and branches, are associated with the endpoints of earthquake rupture. Modeling studies show that stress heterogeneities arising from prior earthquake ruptures... more
Poster 028	SAFS	Geophysical and Geodetic Characterization of the San Andreas Oasis at The Dos Palmas Preserve Nathan Pulver, Stacey Petrashek, Raul Contreras, Jascha Polet The San Andreas Oasis is a dwindling source of water in the Colorado Desert, located just east of the Hidden Springs Fault (HSF) and several kilometers from the northeastern shore of the Salton Sea. Recharge ponds have been placed in the area since... more
Poster 139	FARM	Diverse stress state evolutions of induced earthquake sequences in Oklahoma revealed through high resolution focal mechanism solutions Yan Qin, Xiaowei Chen, Ting Chen The increasing seismicity and improved seismic observation network in recent years provide a great opportunity to better understand the stress evolution during induced earthquake sequences in Oklahoma. In this study, we focus on four earthquake... more
Poster 063	Seismology	Detailed seismic imaging of the Mw7.1 Ridgecrest earthquake rupture zone from data recorded by dense linear arrays Hongrui Qiu, Yehuda Ben-Zion, Rufus Catchings, Mark Goldman, Amir Allam, Jamison Steidl We analyze seismograms recorded by four dense linear arrays oriented NE to SW with 100 m station spacing and apertures 4-8 km that cross the surface rupture of the July 5, 2019, Mw7.1 Ridgecrest earthquake in Southern California. The arrays extend... more
Poster 016	Geology	How does climate affect the evolution of offset channels on strike-slip faults? Insights from landscape evolution models Nadine Reitman, Karl Mueller, Greg Tucker Offset geomorphic piercing points, such as stream channels, are commonly used to determine fault slip rates from historical and paleoseismic earthquakes, under the assumption that they record coseismic slip. Though researchers dating back to Wallace... more	20025
Poster 223	GM	Basin and Site Effects in the U.S. Pacific Northwest Estimated from Small-Magnitude Earthquakes John Rekoske, Morgan Moschetti, Eric Thompson The U.S. Pacific Northwest has relatively high seismic hazard due to various types of earthquakes (e.g., shallow crustal, interface, and intraslab earthquakes), as well as the presence of deep sedimentary basins that amplify and prolong ground... more
Poster 043	Seismology	Crustal Structure Along a Nodal Seismic Line in the San Bernardino Basin From Teleseismic Receiver Functions Karlee Rivera, Patricia Persaud, Robert Clayton, Ritu Ghose, Rasheed Ajala The goal of the Basin Amplification Seismic Investigation (BASIN) project is to determine the structure, depths, and shape of San Bernardino and San Gabriel basins, which are expected to trap, channel, and amplify seismic waves, for the purpose of... more	19033, 18029
Poster 200	GM	Ground Motion Simulations and Site Response Corrections for MW 7.0 Hayward Fault Earthquakes Resolved 0-10 Hz Arthur Rodgers, Arben Pitarka, Ramesh Pankajakshan, Bjorn Sjogreen, Anders Petersson Large earthquake ground motion simulations in three-dimensional (3D) Earth models provide constraints on site-specific shaking intensities but have suffered from limited frequency resolution and ignored site response in soft soils. We report new... more
Poster 138	FARM	Does Slip Heterogeneity Drive Near-field Fracture and Aftershock Distribution? Examples from the 2019 Ridgecrest Sequence Alba Rodriguez Padilla, Michael Oskin, Chris Milliner The 2019 Ridgecrest earthquake sequence ruptured a set of orthogonal faults in the best monitored continental earthquake sequence to date. A year after the event, numerous high-resolution products capturing the sequence are publicly available,... more	19209
Talk	Geodesy	Pairing geodesy and earthquake catalogs to get at seismic hazard Chris Rollins Geodesy can provide crucial constraints on a region’s seismic hazard, particularly when paired with earthquake catalogs and other data. For example, geodetic data might show that tectonic strain is accumulating much more quickly than known... more
Poster 074	Seismology	Analyzing Stress drops and other earthquake parameters from the 2019 Ridgecrest Earthquake Sequence Vivian Rosas, Annemarie Baltay Stress drop is related to the energy released from an earthquake rupture. Of great interest is how stress drop scales with different variables such as magnitude, moment, depth, etc. Since stress drop is a key source parameter in describing the... more
Poster 201	GM	Simulation of Multi-surface Plasticity in the Discontinuous-Mesh GPU-powered Wave Propagation Code AWP Daniel Roten, Kim Olsen, Steven Day, Yifeng Cui Recent advances in wave propagation simulations and observations from geotechnical arrays suggest that strong ground motions are determined by nonlinear coupling between source, path and site effects. Accurate predictions of this shallow crust... more	20166, 19128
Poster 089	EFP	Repeating Earthquakes Trigger Themselves Justin Rubinstein, William Ellsworth Previous studies of repeating earthquake sequences in Parkfield, Taiwan, and Japan yield that repeating earthquake behavior is better predicted by a characteristic earthquake model with fixed inter-event time or fixed slip than it is by the time-... more
Poster 070	Seismology	Systematic Fault Plane Analysis in Complex Earthquake Sequences: Application to the 2019 Ridgecrest, CA and 2008 Mogul, NV Earthquakes Christine Ruhl, Rachel Abercrombie Earthquakes rupturing multiple faults and highlighting highly complex fault zone structures are often observed when good data coverage is available and advanced processing techniques are applied (e.g., earthquake relocation). The prevalence of these... more
Poster 022	SAFS	Reconstructing long-term subsidence and paleoseismic history of the ancient Lake Cahuilla along the southern San Andreas fault in Coachella, California Sourav Saha, Seulgi Moon, Thomas Rockwell, Katherine Scharer, Nathan Brown The most recent ground-rupturing earthquake (MRE) along the southernmost ~100 km of the San Andreas fault (SSAF) occurred ca. 300 years ago, just after the last filling of ancient Lake Cahuilla in the Salton Trough. At the northern end of the... more	20144
Poster 213	GM	Using historical intensity data to assess hazard map performance in California and beyond Leah Salditch, Molly Gallahue, Madeleine Lucas, James Neely, Seth Stein, Susan Hough Historical seismic intensity data are useful for myriad reasons, including assessment of the performance of Probabilistic Seismic Hazard Assessment (PSHA) models and corresponding hazard maps by comparing their predictions to a dataset of... more
Poster 169	CXM	Comprehensive InSAR analysis using ARIA standard products captures earthquake cycle processes across California Simran Sangha, David Bekaert, Gareth Funning Interferometric Synthetic Aperture Radar (InSAR) is an established technique for mapping displacements of the Earth's surface. The Advanced Rapid Imaging and Analysis (ARIA) Center for Natural Hazards project provides open and free access to an... more	20177
Poster 092	EFP	Covariance Analysis of the UCERF3-TI Logic Tree Jared Santa Maria, Luis Vazquez, Thomas Jordan The epistemic uncertainties in the event-rate vector lambda of the time-independent Uniform California Earthquake Rupture Forecast (UCERF3-TI) are represented by a weighted logic tree with K = 7 branching levels and L = 1440 leaves (Field et al.... more
Poster 141	FARM	Role of permeability enhancement in the growth of injection induced aseismic ruptures Pritom Sarma, Pathikrit Bhattacharya The spatio-temporal migration of fluid induced seismicity is classically connected to diffusive pore-fluid movement. However, a growing body of observations provide evidence for distant induced earthquakes at very short times since injection, which... more
Poster 214	GM	Incorporating ground-motion uncertainties into earthquake early warning alert distance strategies using the July 2019 M6.4 and M7.1 Ridgecrest, California, earthquakes Jessie Saunders, Brad Aagaard, Annemarie Baltay, Sarah Minson The ShakeAlert earthquake early warning system aims to alert people who experience Modified Mercalli Intensity (MMI) IV+ shaking during an earthquake by using source estimates (magnitude and location) to estimate the median-expected peak ground... more
Talk	EFP	Pseudoprospective Evaluation of UCERF3-ETAS Forecasts during the 2019 Ridgecrest Sequence William Savran The 2019 Ridgecrest sequence provides the first opportunity to evaluate Uniform California Earthquake Rupture Forecast v.3 with epidemic-type aftershock sequences (UCERF3-ETAS) in a pseudoprospective sense. For comparison, we include a version of... more
Poster 084	EFP	PyCSEP: An Open-Source Toolkit for Evaluating Earthquake Forecast Models William Savran, Asim Khawaja, Maximilian Werner, Philip Maechling, David Rhoades, David Jackson, Danijel Schorlemmer, Thomas Jordan, Yehuda Ben-Zion For government officials and the public to act on real-time forecasts of earthquakes, the seismological community needs to develop confidence in the underlying scientific hypotheses and assess models' predictive skills. The Collaboratory for... more
Poster 165	FARM	A forest fire model of earthquake faulting Cameron Saylor, John Rundle Much is still unclear about the complex nature of earthquake faulting, such as rupture propagation across a fault from its original failure point which can give rise to nonuniform slip distributions. To gain insight into this problem, we introduce a... more
Poster 212	GM	Ground motion prediction using ambient seismic noise on a large-N array in the LA basin Julian Schmitt, Tim Clements, Nan Wang, Kim Olsen, Marine Denolle The presence of a seismic waveguide can significantly amplify ground motion from large earthquakes, as shown by numerical simulations. For example, the predictions of shaking in Los Angeles due to a large, southern San Andreas fault (SAF) earthquake... more
Poster 128	SDOT	Anisotropic strength of fault zones suggested from geodesy and seismic imaging: Example from the Main Himalayan Thrust Vera Schulte-Pelkum, Shaoyang Li, William Barnhart, Marianne Karplus We combine InSAR, GPS, and seismic observations to jointly image the structure and behavior of the Main Himalayan thrust fault (MHT) in the vicinity of the 2015 M7.8 Gorkha earthquake. Data are geodetic observations of coseismic surface deformation... more	17097, 18083
Talk	EFP	Improving stress-based forecasts Margarita Segou This talk discusses an ongoing project aiming to improve our understanding of triggering mechanisms within earthquake sequences by developing and testing physics-based forecast models. The last 30 years stress changes, often coupled with continuum... more
Poster 015	Geology	San Andreas Fault Transition Zone: Where Large, Small, Coseismic, and Aeismic Slip Occurs: Parkfield-Cholame Gordon Seitz, Alana Williams, Douglas Cook, Thomas Rockwell, Ramon Arrowsmith A Caltrans highway improvement project has afforded us the opportunity to investigate the paleoseismology of the Parkfield/Cholame SAF segment transition. The Parkfield segment has experienced six ~M6.0 earthquakes since 1857, with the most recent... more
Poster 203	GM	Toward development of physics-based coherency models using deterministic broad-band earthquake ground motion simulations Elnaz Seylabi, Arben Pitarka, David McCallen We present a coherency analysis of synthetic earthquake ground motions and compare the computed lagged coherency to the existing empirical models. Our overarching goal is to study the effects of physical parameters -- such as subsurface... more	20064
Poster 122	SDOT	Triggered and Spontaneous Slow Slip Transients on the Anza Segment of the San Jacinto Fault Zone, Southern California Heather Shaddox, Susan Schwartz, Noel Bartlow Understanding the interplay of seismic and aseismic slip is key in seismic hazard evaluation. It is particularly important to know if the same fault can host different slip modes and understand the transition between modes of slip. We investigate... more	18160
Poster 094	EFP	Predicting the Magnitude and Location of Earthquake in Sichuan-Yunnan Region via a Convolutional Neural Network Weifeng Shan, Yuntian Teng, Shengfeng Zhang, Maofa Wang, Guanze Yang Deep learning algorithms have been successfully applied in the fields of micro-earthquake detection, earthquake locating, earthquake early warning and so on, which is obviously that seismic waveform data is mainly used in this research. At the same... more
Poster 030	SAFS	Structural properties of the Southern San Andreas fault around Thousand Palms, California, from analysis of large-N seismic array data Pieter-Ewald Share, Frank Vernon, Yuri Fialko, Amir Allam, Yehuda Ben-Zion We present preliminary results from a large-N seismic nodal array deployment spanning the Banning and Mission Creek strands (BF and MCF) of the Southern San Andreas fault (SSAF) near the Thousand Palms Oasis Preserve, CA. A number of key... more
Poster 097	EFP	Bayesian Framework for Aftershock Forecasting and Testing Robert Shcherbakov The occurrence of a significant mainshock presents an opportunity to test different existing or novel statistical approaches to model the evolution of the corresponding sequences of earthquakes that precede and follow the mainshock. Among several... more
Poster 037	Seismology	Calibrating Spectral Decomposition of Local Earthquakes using Borehole Seismic Records---Results for the 1992 Big Bear Aftershocks in Southern California Peter Shearer, Rachel Abercrombie Empirical Green's function (EGF) methods are widely applied to correct earthquake spectra for path effects in order to estimate corner frequencies and stress drops, but suffer from tradeoffs among source model parameters and the EGF shape.... more	20097
Poster 110	Geodesy	Resolve 3-Dimensional dimensional Crustal Deformation Field using GNSS and InSAR data Zheng-Kang Shen, Zhen Liu Three-dimensional (3-D) deformation field is essential in studying crustal deformation processes and natural hazards. We have recently developed an algorithm to integrate spatially limited GNSS and dimensionally limited InSAR data for a 3-D crustal... more	20182, 20074
Poster 202	GM	The SCEC Broadband Platform: Open-Source Software for Strong Ground Motion Simulation and Validation Fabio Silva, Philip Maechling, Christine Goulet, Yehuda Ben-Zion The Southern California Earthquake Center (SCEC) Broadband Platform (BBP) is a collection of open-source scientific software modules that can simulate broadband (0-20+ Hz) ground motions for earthquakes at regional scales, compare simulation results... more	20019, 20114, 20163, 20205, 19055, 19079, 19130, 19150
Poster 052	Seismology	Characterizing Stress Orientations in Southern Kansas Rob Skoumal, Elizabeth Cochran, Kayla Kroll, Justin Rubinstein, Devin McPhillips Induced seismicity predominantly occurs along faults that are optimally oriented to the local principal compressive stress direction, and the characterization of these stress orientations is an important component of understanding seismic hazards.... more
Poster 215	GM	Near-fault large-event ground motion models Norman Sleep Seismologists extrapolate ground motion models for near-fault (less than few a kilometers) stations during large earthquakes (slip > 1 m) from more distant and/or smaller events. I construct a nonstandard stochastic model for strong high-... more	20001
Poster 058	Seismology	ShakeAlert EEW System Improvements, Recent and Upcoming, Tested by the STP Working Group and the SP Working Group Deborah Smith, Jeff McGuire, Angela Chung, Jennifer Andrews, Men-Andrin Meier, Maren Böse ShakeAlert is a distributed West Coast earthquake early warning project that includes collaboration from a variety of institutions. The goal is to generate estimates of earthquake source parameters and ground motions as quickly and as reliably as... more
Poster 034	Seismology	EikoNet: Solving the Eikonal equation with Deep Neural Networks, with applications to earthquake location Jonathan Smith, Kamyar Azizzadenesheli, Zachary Ross The recent deep learning revolution has created an enormous opportunity for accelerating compute capabilities in the context of physics-based simulations. Here, we propose EikoNet, a deep learning approach to solving the Eikonal equation, which... more
Poster 009	Geology	Order and timing of high-angle conjugate strike-slip faulting in Walker Lane sequences Ken Smith, Rachel Hatch, Christine Ruhl, Rachel Abercrombie With the 2019 Ridgecrest sequence displaying a conjugate strike slip faulting geometry it is worth noting other Walker Lane earthquake sequences that show a similar behavior. The initial July 4 M6.4 NE striking Left-Lateral (LL) Ridgecrest event... more
Poster 142	FARM	The influence of lithology and preexisting damage on brittle fragmentation during dynamic tensile loading Zachary Smith, William Griffith Simulations of subshear rupture propagation on bimaterial fault interfaces show that a state of isotropic tension, exceeding the tensile strength of most rocks, is produced at distances up to 100 m from the fault, potentially explaining field... more
Poster 045	Seismology	Seismic structure of the upper mantle across California and the offshore Borderland A. Christian Stanciu, Eugene Humphreys We present new P, S, and Vp/Vs seismic tomography models of the upper mantle across California and the Outer and Inner Borderland regions to improve our understanding of the regional tectonic evolution and current physical state of the upper mantle... more	19231, 20176
Talk	EEII	Modeling site response effects in sedimentary basins Jonathan Stewart, Chukwuebuka Nweke, Scott Brandenberg, Christine Goulet, Robert Graves We investigate the benefits of regionalizing basin response in ergodic ground motion models. Using southern California data, we consider: (1) how should basin and non-basin site conditions be classified?; (2) how does mean site response and its... more	20133
Poster 149	FARM	Nucleation of earthquake slip on heterogeneous interfaces Kavya Sudhir, Nadia Lapusta Understanding how frictional instabilities initiate is an outstanding problem, with implications for earthquake forecasting and seismic hazard. The nucleation process on a uniform frictional interface has a relatively well-understood progression.... more	20080
Poster 046	Seismology	Crustal Architecture of S. California Imaged by A 2-Layer H-K Stacking Method and Its Implications on Crustal Composition Siyuan Sui, Weisen Shen The complex tectonic setting and fault system in California have produced a mosaic of crustal blocks for which their strength varies significantly across the region. To better quantify one of the most important factors that determine the crustal... more	20171
Poster 211	GM	Ground-Motion Time-Series Interpolation within the Community Seismic Network using Gaussian Process Regression: Application to the 2019 Ridgecrest Earthquake Aidin Tamhidi, Nicolas Kuehn, Monica Kohler, Farid Ghahari, Ertugrul Taciroglu, Yousef Bozorgnia At the present time, the density of ground motion recording stations within California is sparse. As a rough estimate, there are about 2000 recording stations within California. The Community Seismic Network is one of the strong-ground-motion... more
Poster 157	FARM	Observationally constrained multi-scale dynamic rupture modeling of the 2019 Ridgecrest earthquakes Taufiq Taufiqurrahman, Alice-Agnes Gabriel, Duo Li, Thomas Ulrich, Sara Aniko Wirp, Sara Carena, Alessandro Verdecchia, Frantisek Gallovic We present observationally and Coulomb stress modeling constrained 3D dynamic rupture scenarios combining the 2019 Mw6.4 Searles Valley and Mw7.1 Ridgecrest earthquakes, complemented by aftershock calibrated back-projection (Li & Ghosh, 2016)... more
Poster 180	CXM	The SCEC Community Thermal Model (CTM) Version 1.2 Wayne Thatcher Analysis of heat flow and seismic data provides glimpses of the dynamical processes shaping the thermal evolution of southern California since 30 Ma BP. Processes include (1) a continental analog of seafloor spreading beneath the Salton Trough and... more	19233

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