Meeting Abstracts | Southern California Earthquake Center

SCEC2021 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 101-150 of 292

SCEC ID	Category	Title and Authors	SCEC Award
Poster 057	Geology	Cosmogenic 3He exposure dating of alluvial surfaces using detrital magnetite enabled by microCT scanning Florian Hofmann, Emily Cooperdock, A. Joshua West, Dominic Hildebrandt, Kathrin Strößner, Kenneth Farley We have tested whether X-ray micro-computed tomography (microCT) scanning can be used to improve the quality of cosmogenic 3He exposure dating of magnetite by pre-selecting mineral grains without inclusions. We extracted detrital magnetite from a... more	20146
Poster 004	CEO	Which Earthquake Accounts Matter? Susan Hough In a recent study, Hough and Martin (2021) considered the extent to which socioeconomic factors influence the numbers and distribution of contributed reports available to characterize the effects of both historical and recent large earthquakes. I... more
Talk 15-Sep (15:00)	Seismology	The 2021 Nippes, Haiti, Earthquake Susan Hough Few earthquakes illustrate the challenges posed by interacting and cascading hazards as clearly and as tragically as the 14 August 2021 M7.2 Nippes, Southern Haiti earthquake. Earthquakes themselves pose a cascading hazard in Hispaniola, with... more
Poster 033	GM	Calibration of the Near-surface Seismic Structure in the SCEC Community Velocity Model Version 4 Zhifeng Hu, Kim Olsen, Steven Day The near-surface seismic structure (to a depth of about 1000 m), particularly the shearwave velocity (Vs), can strongly affect the propagation of seismic waves, and therefore must be accurately calibrated for ground motion simulations and seismic... more
Talk 14-Sep (15:00)	FARM	Characteristics of earthquakes in damaged, heterogeneous, and temporally evolving fault zones Yihe Huang, Prithvi Thakur Instead of single planes, faults are volumes of rocks containing fault cores surrounded by hundreds-meter-thick fractured rocks, i.e., the so-called fault damage zones. Major fault zones accommodate a significant portion of plate motion through... more	17071, 20091
Poster 051	GM	Laboratory Component of Next Generation Liquefaction Database and System Analysis of Important Case Histories Kenneth Hudson, Paolo Zimmaro, Scott Brandenberg, Jonathan Stewart The Next Generation Liquefaction (NGL) project has developed an online relational database of liquefaction case histories to support model development, which is available online at http://nextgenerationliquefaction.org/. The NGL field testing... more
Poster 267	EFP	A Test of the Earthquake Gap Hypothesis in Mexico Allen Husker, Maximilian Werner, Miguel Santoyo The seismic gap hypothesis to predict earthquakes holds that the seismic cycle implies quasi-regular, characteristic earthquakes that follow the build-up and release of stress. Mexico's subduction zone produces many earthquakes, and the... more
Poster 133	FARM	Tectonic Tremor as Friction-Induced Inertial Vibration Kyungjae Im, Jean-Philippe Avouac Slow slip events are often accompanied by a tremor but how the tremor is generated is yet elusive. In this study, we test the possibility that it is an inertial vibration. In the case of a single-degree-of-freedom spring and slider system with mass... more
Poster 222	Seismology	Earthquake detectability and depth resolution with dense arrays Asaf Inbal, Jean-Paul Ampuero, Robert Clayton Dense array seismology is an emerging field which is well-suited for signal detection in noisy environments, and hence may be used effectively for characterizing earthquake activity in urban areas. This application frequently employs detection and... more
Poster 259	EFP	Towards a distributed seismicity model for the New Zealand national seismic hazard update Sepideh J Rastin, David Rhoades, Matthew Gerstenberger, Chris Rollins, Annemarie Christophersen We aim to develop a distributed seismicity model to forecast the long-term (e.g., 100 years) spatial distribution of seismicity for the New Zealand National Seismic Hazard Model (NZNSHM) update. The distributed spatial rates combined with the rates... more
Poster 161	FARM	Nucleation and arrest of aseismic fault slip, during and after fluid pressurization Antoine Jacquey, Robert Viesca Fluid pressurization of preexisting faults due to subsurface energy and storage applications can lead to the onset of aseismic slip and microseismicity, and possibly to major induced seismic events. Fluid injection decreases the fault shear... more
Poster 139	FARM	Strength and fluid transmissivity evolution during shearing of laboratory faults under hydrothermal conditions Tamara Jeppson, David Lockner, Diane Moore There is significant evidence for healing in natural fault systems, including changes in fluid transport properties and earthquake recurrence. Healing results from coupled thermal, hydraulic, mechanical, and chemical interactions but most laboratory... more
Poster 237	Seismology	Average Static Stress Drop of Crustal Earthquakes Inferred From Source Spectra Chen Ji, Ralph Archuleta Most estimates of an earthquake’s average static stress drop ∆σ_s, particularly for small and even moderate magnitude earthquakes, have been made using observed source spectra following the seminal work of Brune (1970). However, depending on which... more	21115, 20114
Poster 209	Seismology	Evaluating a unified 3D velocity model for the Los Angeles Basin using ambient noise dispersions and earthquakes Zhe Jia, Robert Clayton The 3D velocity structure of the Los Angeles (LA) Basin plays an important role in prediction of regional ground motion and seismic hazard for this populated area. In this study, we integrate three high resolution velocity models derived using dense... more
Poster 165	FARM	Community Code Verification Exercises for Simulations of Earthquake Sequences and Aseismic Slip (SEAS): Three-Dimensional Problems Junle Jiang, Brittany Erickson, Valere Lambert, Jean-Paul Ampuero, Ryosuke Ando, Sylvain Barbot, Camilla Cattania, Luca Dal Zilio, Benchun Duan, Eric Dunham, Alice-Agnes Gabriel, Nadia Lapusta, Duo Li, Meng Li, Dunyu Liu, Yajing Liu, So Ozawa, Casper Pranger, Ylona van Dinther Crustal faulting and earthquakes are inherently multi-scale dynamic processes. Numerical modeling of sequences of earthquakes and aseismic slip (SEAS) provides a self-consistent framework to connect, interpret, and predict geophysical observations... more	18099, 19109, 20113, 21065
Poster 055	EEII	Tectonic and Geotechnical Review for Engineering Design and Seismic Risk Management in Bangladesh Mir Karim, MD Zillur Rahman, Arif Sikder, Daya Shanker Bengal basin is a classic and active natural laboratory due to its complex geological-setting and building up of an active depositional basin in a syntaxis of multidimensional differential stress conditions resulting from the relative motion of... more
Poster 244	Seismology	Testing Three Earthquake Early Warning Algorithms (EPIC, FinDer and PLUM) on Simulated Composite Offshore Earthquakes Debi Kilb, Colin O'Rourke, Maren Böse, Jennifer Andrews, Angela Chung, Julian Bunn, Jeff McGuire We test the performance of three Earthquake Early Warning (EEW) algorithms (EPIC, FinDer, and PLUM) using composite earthquake sequence pairs to better understand the behavior of each algorithm, as applied to offshore earthquake sequences. Our goal... more
Poster 058	Geology	Role of Confinement in Coseismic Pulverization of Sediments: Testing the Rock Record of Rupture Directivity on the San Jacinto Fault Caje Kindred Weigandt, W. Ashley Griffith, Thomas Rockwell Recent observations within Anza Borrego State Park, where the San Jacinto Fault juxtaposes Pleistocene Bautista Formation sediments against Cretaceous tonalite, display a stark contrast across the fault and at varying depths. In particular, while... more	20027
Poster 063	Geology	Assessing bedrock weathering patterns from P-wave and S-wave velocity profiles and their relationships to landscape positions. Christina Kitamikado, Seulgi Moon, Alan Yong P-wave and S-wave velocities (VP and VS) have historically been used to determine the geologic substrate, which directly influences localized earthquake ground-motions. Thus, knowledge about seismic site conditions is an important factor for... more	16076, 17030
Poster 225	Seismology	Time-Varying Shear-Wave Velocities in a High-Rise During the 2019 M6.4 and M7.1 Ridgecrest Earthquakes from Wavefield Interferometry Monica Kohler, German Prieto Seismic interferometric techniques for structural health monitoring are applied to data from Community Seismic Network MEMS accelerometers permanently installed on nearly every floor of a 52-story steel moment-and-braced frame building in downtown... more
Poster 129	FARM	Induced seismicity spikes during abrupt changes in injection and production rates in geothermal reservoirs Roshan Koirala, Emily Brodsky, Thomas Goebel, Grzegorz Kwiatek Fluid injection in deep geothermal reservoirs can result in fluid pressure changes that are sufficiently high to induce seismicity. There are, however, some examples of seismic activity during a decrease in injection rates. Here, we analyze the... more
Poster 052	EEII	A relational MySQL database for rupture-to-rafters simulations Swaminathan Krishnan Rupture-to-rafters simulations have been a major thrust area and an end goal for SCEC. Several researchers/research groups have performed end-to-end simulations in the last couple of decades. Unfortunately, much of this data is housed in... more
Poster 140	FARM	Resolving simulated sequences of earthquakes and fault interactions Valere Lambert, Nadia Lapusta There is growing interest in using numerical earthquake models to directly determine quantities of interest for seismic hazard, such as the probability of an earthquake rupture jumping from one fault segment to another. Here, we investigate the... more	20080, 21106
Poster 070	Geology	Tectonogeomorphic evidence for late Holocene complex rupture linking the Panamint Valley and Ash Hill faults, Eastern California Shear Zone Aubrey LaPlante, Christine Regalla The 2019 Ridgecrest sequence, 1992 Landers, and 1999 Hector Mine earthquakes reinforced the importance of understanding the timing and location of complex and multi-fault rupture as a contributor to seismic hazard in the Eastern California Shear... more
Poster 143	FARM	Modeling absolute stress levels on mature faults: Implications for seismic radiation and earthquake statistics Nadia Lapusta, Valere Lambert Accumulating geophysical evidence suggests that the shear resistance acting on mature faults must be low (< 20 MPa). Two hypotheses used to explain such low-stress, low-heat operation of mature faults are that they are either (I) chronically weak... more	20079, 21105
Poster 053	EEII	Impacts of CyberShake on Risk Assessments for Distributed Infrastructure Systems Yajie Lee, Christine Goulet, ZhengHui Hu, Kevin Milner, Scott Callaghan, Ronald Eguchi In characterizing the system-level seismic risk of a spatially-distributed infrastructure network, empirical ground motion models (GMMs) are typically used to quantify the spatially correlated ground motion hazard. One current weakness of such... more	20093
Poster 017	CXM	Late Quaternary activity of the San Diego Trough fault zone offshore Northwest Baja California Mark Legg The San Diego Trough fault zone stretches more than 340 km offshore southern and Baja California, from Dume submarine canyon in the north to Bahía Soledad in the south. The San Diego Trough section offshore southern California has a relatively... more	20117, 94017
Poster 041	GM	Low-Frequency Examination of Synthetic Reno-Area Basin Amplification from M3 Earthquakes at a Variety of Azimuths Lauren Lewright, Aditya Prathap, Chelsey Assor, Jenna Graham, John Louie Seismic waves travel with greater amplitude and slower speeds when moving through soft sedimentary rock, relative to hard bedrock. Seismic hazard in the Reno area is increased due to the city’s location within a thin (<1 km) sedimentary basin,... more
Poster 193	Seismology	Waveform-based moment tensor catalog in Southern California using 3D Community Velocity Model Jiaxuan Li, Zhongwen Zhan, Xin Wang Focal mechanisms in Southern California have been routinely determined using a 1D velocity model. However, recent tomography results show strong heterogeneities in the Southern California crust, which may lead to large uncertainties in the moment... more	19011
Poster 168	FARM	Subsurface Damage Zones of the Sinistral Faults at Ridgecrest in the Eastern California Shear Zone Characterized by Fault-Zone Trapped Waves Yong-Gang Li, Rufus Catchings, Mark Goldman We use fault-zone trapped waves (FZTWs) to characterize damage zones of the multiple immature sinistral faults in the Eastern California Shear Zone (ECSZ) associated with the 2019 M6.4 and M7.1 Ridgecrest earthquake sequence. In the ECSZ, a... more
Poster 101	Geodesy	Spatiotemporal variations of surface deformation, shallow creep rate and slip partitioning between the San Andreas and southern Calaveras faults constrained by InSAR Yuexin Li, Roland Bürgmann The Calaveras Fault (CF) is one of the main active faults in the San Andreas Fault (SAF) system in the San Francisco Bay Area, accommodating ~15 mm/yr of long-term slip along its central and southern sections. At the CF-SAF junction, the southern... more
Poster 215	Seismology	Microseismic monitoring using deep learning Cindy Lim, Sacha Lapins, Maximilian Werner, Margarita Segou Induced seismicity can pose great risks to subsurface fluid injection projects (e.g., hydraulic fracturing for shale gas, enhanced geothermal systems and wastewater injection) and more importantly, to local infrastructure and society. These risks... more
Poster 085	SAFS	Observation-constrained multicycle dynamic models of the southern San Andreas and San Jacinto faults: addressing complexity in paleoearthquake models with realistic fault geometry Dunyu Liu, Benchun Duan, Katherine Scharer, Doug Yule Understanding the mechanical conditions that lead to complexities in earthquake observations is important to seismic hazard analysis. In this study, we simulate physics-based multicycle dynamic models of the southern San Andreas fault (Cajon Pass to... more	20138, 19238
Poster 174	FARM	The importance of poroelastic effects in models of injection-induced slip on rate-and-state faults Shengduo Liu, Elias Heimisson, Nadia Lapusta Slip on faults induces compression and dilation in the surrounding rock, which can interact with pore fluids, modify pressure, and induce fluid flow; those fluid effects can, in turn, affect the slip evolution. The coupling of slip and pore fluids... more
Poster 220	Seismology	Ambient noise attenuation tomography of Love & Rayleigh waves applied to the Ramona reservation linear array across the San Jacinto Fault Zone with amplitude correction for focusing/defocusing Xin Liu, Gregory Beroza, Yehuda Ben-Zion We study seismic properties of near-surface fault zone structure from ambient noise data. The amplitude of the seismic wavefield contains information on seismic attenuation, which is sensitive to rock damage associated with concentrated fractures... more	20208
Poster 089	SAFS	A unified perspective of seismicity and fault coupling along the San Andreas Fault Yuan-Kai Liu, Zachary Ross, Elizabeth Cochran, Nadia Lapusta The San Andreas Fault (SAF) showcases the breadth of possible earthquake sizes and occurrence behavior, from repeating earthquakes to total quiescence, to large damaging earthquakes. In particular, the central SAF is a microcosm of such diversity.... more
Poster 169	FARM	Dynamic Rupture Simulations of Coseismic Interactions on Orthogonal Strike-Slip Faults Julian Lozos Strike-slip fault systems are typically classified by the strike direction and sense of slip of their primary faults. However, orthogonal faults with the opposite sense of slip can also exist in such systems, particularly in transpressional or... more	20204
Poster 212	Seismology	Validation of seismic velocity models in southern California with full-waveform simulations Yang Lu, Yehuda Ben-Zion We present a systematic workflow for assessing the accuracy of velocity models with full-waveform simulations. The framework is applied to four regional seismic velocity models for southern California: CVM-H15.11 (Shaw et al., EPSL, 2015), CVM-S4.26... more	21039
Talk 13-Sep (11:00)	Seismology	Distributed acoustic sensing using long range submarine fiber-optic cables Bin Luo, Robert Clapp, Ariel Lellouch, Victor Yartsev, Martin Karrenbach, Craig Dawe, Biondo Biondi The utilization of the emerging distributed acoustic sensing (DAS) technique with pre-existing submarine fiber-optic cables in recent years has demonstrated itself a promising strategy to deploy cost-effective dense arrays on the seafloor and to... more
Talk 15-Sep (15:00)	CS	Hazard from Landslide-Generated Tsunamis: Progress and Challenges Patrick Lynett Submarine mass movements can take a wide variety of forms, such as translational slides, rotational slumps, and debris flows, and each will have different tsunamigenic efficiency. Existing methods for assessment of landslide tsunami hazards rely on... more
Poster 016	CXM	The SCEC Unified Community Velocity Model (UCVM) Software Models and Tools Philip Maechling, Mei-Hui Su, Scott Marshall, Elizabeth Hearn, Laurent Montesi The Unified Community Velocity Model (UCVM) software framework facilitates the registration and distribution of seismic velocity models to the SCEC community. It is designed to provide a standard query interface to multiple, alternative velocity... more
Poster 096	Geodesy	UNAVCO State of NOTA Network / Southwest Regional Summary Sean Malloy, Doerte Mann, Shawn Lawrence, Andre Basset, Karl Feaux, Glen Mattioli The Network of the Americas (NOTA) Southwest region consists of 450 continuous GNSS/GPS stations located in Central and Southern California, Arizona, Nevada, and Mexico. 250 of these stations have full GNSS capabilities, with a mix of Trimble NetR9... more
Poster 234	Seismology	Space-Time Monitoring of Groundwater in the Coastal Los Angeles Basins via Seismic Interferometry Shujuan Mao, Albanne Lecointre, Robert van der Hilst, Michel Campillo Relative changes in seismic velocity (Δv/v) are associated with perturbations in mechanical properties of crustal materials. Interferometry of ambient noise enables the continuous monitoring of relative changes in seismic velocity (Δv/v), which have... more
Poster 216	Seismology	Active tectonic regime of Java Island, Indonesia from seismic strain rate analysis Gayatri Marliyani, Subagyo Pramumijoyo, Hurien Helmi Identifying high strain-rate regions is important to characterize areas of high tectonic activity. The highly populated island of Java is part of the volcanic arc of the Sunda subduction zone in Indonesia. The area is seismically active, as... more
Poster 125	FARM	Investigating the Effects of Fault Dip Angle on Rupture Propagation Along Branch Fault Systems Using Dynamic Rupture Simulations Evan Marschall, Roby Douilly An important consideration in assessing seismic hazards is determining what is likely to happen when an earthquake rupture encounters a geometric complexity such as a branch fault. Previous studies showed parameters such as branch angle, stress-... more	21084
Talk 17-Sep (08:00)	CXM	The SCEC community fault model: challenges, progress, and the future Scott Marshall, Andreas Plesch, John Shaw The Community Fault Model (CFM) is one of SCEC’s most established and widely used resource with applications in many aspects of SCEC science including crustal deformation modeling, wave propagation simulations, and probabilistic seismic hazards... more	21018, 20081, 19102
Talk 13-Sep (11:00)	CS	Advances in passive seismic algorithms for large-scale DAS data Eileen Martin, Joseph Kump, Sarah Morgan, Brandon Pearl, Tony Artis, Samantha Paulus Distributed acoustic sensing (DAS) allows us to more easily collect long-term data to study earthquake processes at fine scales across large regions, so DAS data rates are often thousands of times higher than traditional seismometer data rates. This... more
Poster 199	Seismology	Cutoff depth and coseismic slip zone for the large earthquake along the Sea of Japan Makoto Matsubara, Tomoko Yano, Tatsuya Ishiyama The subduction of the Pacific (PAC) plate from the east makes Japanese Islands under compressional stress. The cutoff depth of the seismogenic zone (D90) is important to estimate the maximum size of the earthquake with the active faults. We relocate... more
Poster 110	SDOT	Temperature Variations at the Base of the Seismogenic Zone throughout Southern California Suerken Matsuyama, Laurent Montesi Earthquakes activity stops at a depth of between 12 and 15 km on most continental fault strands, including in the San Andreas Fault System and the North Anatolian Fault. One possible explanation for this transition is that earthquakes are limited by... more	19145
Talk 15-Sep (11:00)	FARM	Precursory off-fault deformation preceding slip along healed preexisting faults in restraining and releasing step overs Jessica McBeck, Bruce Zhou, Yehuda Ben-Zion, Francois Renard Observations suggest that geophysical activity in the volume of crust surrounding the main fault may change in the years, days and hours before a large earthquake. However, some large earthquakes do not appear to produce detectable signals, casting... more

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SCEC2021 Meeting Abstracts

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