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 51-100 of 248

SCEC ID	Category	Title and Authors	SCEC Award
Poster 131	FARM	Composition and structure in the upper 2-4 km of major strike-slip faults James Evans, Kaitlyn Crouch, Caroline Studnicky Inversions of coseismic slip on continental strike slip faults show that maximum slip occurs at depths of 3-5 km, and above these depths fault slip decreases to ~ 50% of their maxima. Hypotheses to explain this slip deficit, and its long-term... more	18077
Poster 232	EEII	Critical assessment of probabilistic seismic demand analysis of ordinary bridge structures using Cybershake simulations Jawad Fayaz, Sanaz Rezaeian, Farzin Zareian There is a need for benchmarking and validating simulated ground motions for utilization by the engineering community. The validation method presented herein focuses on bridge engineering applications in Southern California. Catalogs of simulated... more	19114
Poster 194	CS	Combining CNN and RNN in Seismic Phase Picking Tian Feng, Lingsen Meng The recent expansion of seismic data and computing resources enables flourishing applications of deep learning in seismology. Many studies aim at automatically picking P and S arrivals, especially interested in microseismicity buried under noises.... more
Poster 007	Geology	Preliminary observations of Mw 5.1 Sparta (North Carolina) surface deformation – a first documented Mw 5 instrumental earthquake surface rupture in Eastern USA? Paula Figueiredo, Mark Carter, Bart Cattanach, Thomas Douglas, Jesse Hill, Eric Kirby, David Korte, Ashley Lynn, Arthur Merschat, Lewis Owen, Corey Scheip, Kevin Stewart, Sarah Wells, R. Wooten A Mw 5.1 earthquake near Sparta in North Carolina occurred on 08/09/2020. Preliminary estimates by the USGS have its focal depth at 7.6 km with a NW-SE reverse with oblique mechanism. The earthquake is the strongest recorded in North Carolina since... more
Poster 071	Seismology	Ground Motion Response Study of Urban Los Angeles following the 2019 Ridgecrest Earthquake Sequence Filippos Filippitzis, Monica Kohler, Thomas Heaton, Robert Graves, Robert Clayton, Richard Guy, Julian Bunn, Kanianthra Chandy We study ground motion response in urban Los Angeles during the two largest events (M7.1 & M6.4) of the 2019 Ridgecrest earthquake sequence, using recordings from multiple regional seismic networks as well as a subset of stations from the much... more
Poster 208	GM	Data-Driven Ground Motion Synthesis using Deep Generative Models Manuel Florez, Michaelangelo Caporale, Buabthong Pakpoom, Zachary Ross, Domniki Asimaki, Men-Andrin Meier Robust estimation of ground motions generated by scenario earthquakes is critical for many engineering applications. We leverage recent advances in Generative Adversarial Networks (GANs) to develop a new framework for synthesizing earthquake... more
Poster 170	CXM	Current status and future plans for the Community Geodetic Model (GNSS) products Michael Floyd, Thomas Herring, Zheng-Kang Shen, Jessica Murray, William Hammond, Mark Murray The Community Geodetic Model (CGM; https://www.scec.org/research/cgm) provides two sets of geodetic products, using GNSS and InSAR, and will ultimately provide a combined geodetic velocity field over southern California for use by the earthquake... more	20092, 20182
Talk	Geodesy	Results from the geodetic response to the 2019 Ridgecrest earthquakes Gareth Funning The July 2019 Ridgecrest earthquakes set new standards for the amount and quality of geodetic observations of large continental earthquakes. A rapid field response by several groups led to a dense deployment of campaign GNSS instruments around the... more	18201
Poster 158	FARM	3D dynamic rupture modeling with thermal pressurization Alice-Agnes Gabriel, Jagdish Vyas, Thomas Ulrich, Jean-Paul Ampuero, Martin Mai Thermal pressurization of pore fluids (TP, Sibson 1973) is expected to be a dominant dynamic weakening mechanism affecting earthquake rupture nucleation, propagation and arrest (e.g., Noda et al., 2009, Viesca and Garagash, 2015, Nir et al., 2020).... more
Poster 041	Seismology	Basin Structure Revealed in Teleseismic Receiver Functions from a Dense Nodal Seismic Array in the Northern Los Angeles Basins Ritu Ghose, Patricia Persaud, Robert Clayton As part of the BASIN (Basin Amplification Seismic Investigation) project, we are mapping the structure of the San Gabriel (SG) and San Bernardino (SB) basins. We are analyzing results from 232 nodal seismic stations installed along 5 profiles in the... more	19033, 18029
Poster 025	SAFS	Detecting creep event propagation along the San Andreas Fault Dan Gittins, Jessica Hawthorne The San Andreas Fault creeps at the surface along a 150 km-long section between San Juan Bautista and Parkfield. This creep occurs in bursts known as creep events. The creep events are well-recorded using decades-long USGS creepmeter records, but... more
Poster 053	Seismology	Injection-induced seismicity in the Raton Basin from 2016-2020 Margaret Glasgow, Ruijia Wang, Brandon Schmandt, Eric Kiser Wastewater injection-induced seismicity has been active in the Raton Basin for the past two decades, including several M>4.0 normal-faulting earthquakes. To characterize regional fault structures, we systematically analyzed two datasets: 1) an 8-... more
Poster 109	Geodesy	Distinguishing the Coseismic Phase of the Earthquake Cycle  with Seismogeodesy Dorian Golriz, Yehuda Bock, Xiaohua Xu Inversions for earthquake source and fault slip distribution models rely on reliable static surface displacements from GNSS stations. Recent studies have also demonstrated the utility of peak-ground-displacement in rapid magnitude estimation.... more
Poster 155	FARM	Investigating the Role of Seismic Waves on Multi-fault Rupturing Hector Gonzalez-Huizar, Roby Douilly This project seeks to assess the effect of dynamic triggering of multi-fault rupture with application to the Cajon Pass area. Dynamic triggering on a fault occurs when the passing of seismic waves alters the mechanical state or properties of the... more	20147
Poster 112	Geodesy	Expanding the GeoGateway Science User Community Lisa Grant Ludwig, Megan Mirkhanian, Andrea Donnellan, Jay Parker Science gateways allow research communities to access shared data, software and services. GeoGateway (http://geo-gateway.org) is a science gateway that provides online tools for analysis, and modeling of crustal deformation using geodetic imaging... more
Poster 206	GM	3D Simulation of Near Fault Ground Motions for the 2019 M7.1 Ridgecrest, CA Earthquake Robert Graves, Arben Pitarka We perform a suite of 3D ground motion simulations of the 2019 M7.1 Ridgecrest, CA earthquake to test the ability of the Graves and Pitarka (2016) kinematic rupture generator to model the main features of the near-fault recordings. In this work, we... more
Talk	EFP	A Stress-Similarity Triggering Model for Aftershocks of the Mw 6.4 and 7.1 Ridgecrest Earthquakes Jeanne Hardebeck The July 2019 Mw 6.4 and 7.1 Ridgecrest earthquakes triggered numerous aftershocks, including clusters of off-fault aftershocks in an extensional stepover of the Garlock fault, near the town of Olancha, and near Panamint Valley. The locations of the... more
Poster 151	FARM	Dynamic Rupture Scenarios of Large Earthquakes on the Rodgers Creek-Hayward-Calaveras-Northern Calaveras Fault System, California Ruth Harris, Michael Barall, David Ponce, Diane Moore, Russell Graymer, David Lockner, Carolyn Morrow, Gareth Funning, Donna Eberhart-Phillips The Rodgers Creek-Hayward-Calaveras-Northern Calaveras fault system in California dominates the hazard posed by active faults in the San Francisco Bay Area. Given that this fault system runs through a densely populated area, a large earthquake in... more
Poster 179	CXM	The SCEC Community Rheology Model (CRM) Elizabeth Hearn, Michael Oskin, Greg Hirth, Laurent Montesi, Wayne Thatcher, Whitney Behr, Edric Pauk The first version of the SCEC Community Rheology Model (CRM) is now complete. The CRM comprises a three-dimensional geologic framework model (GFM) of southern California’s lithosphere, and ductile flow laws for each GFM rock type. Together with... more	20190
Poster 087	EFP	Inconsistencies and lurking pitfalls in the magnitude-frequency distribution of high-resolution earthquake catalogs Marcus Herrmann, Warner Marzocchi Earthquake catalogs describe the distribution of earthquakes in space, time, and magnitude, which is essential information for statistical analysis, earthquake forecasting, and seismic hazard/risk assessment. With the availability of high-resolution... more
Poster 006	Geology	Surface rupture of the Little River fault in response to the August 9, 2020 Mw 5.1 earthquake near Sparta, North Carolina Jesse Hill, Bart Cattanach, Thomas Douglas, Paula Figueiredo, Eric Kirby, David Korte, Ashley Lynn, Arthur Merschat, Lewis Owen, Corey Scheip, Kevin Stewart, Sarah Wells, Richard Wooten On August 9, 2020, a Mw 5.1 earthquake shook the Blue Ridge Mountains south of Sparta, North Carolina, causing damage to buildings and pavement. It formed surface ruptures attributed to slide-related failures in anthropogenic fill and to a SSW-... more
Poster 175	CXM	Updating the USGS San Francisco Bay Area 3D Seismic Velocity Model: Special Focus on the North Bay Evan Hirakawa, Brad Aagaard We present the latest developments on our evaluation and adjustments to the USGS San Francisco Bay Area 3D Velocity Model, with the goal of more closely replicating observed seismic records with 3D ground-motion simulations. In previous work, we... more
Poster 136	FARM	Regional earthquakes that trigger creep on the northern central San Andreas fault Brenton Hirao, Heather Savage, Emily Brodsky The central San Andreas fault (cSAF) between San Juan Bautista and Parkfield fails in episodic, aseismic creep events. Episodic creep is still one of the most poorly understood aspects of fault motion. In particular, the interaction between creep... more
Poster 011	Geology	Geologic Effects of the March 2020 M 5.7 Magna, Utah, Earthquake Adam Hiscock, Emily Kleber, Greg McDonald, Rich Giraud, Ben Erickson, Jessica Castleton, Steve Bowman, Gordan Douglass, Adam McKean The March 18, 2020 M 5.7 Magna, Utah, earthquake was the most widely felt earthquake in an Intermountain West urban area in recent history. This normal-faulting earthquake occurred in the northwest part of Salt Lake Valley, home to over 1.2 million... more
Poster 060	Seismology	Revisiting California’s Past Great Earthquakes and Long-Term Earthquake Rate Susan Hough We revisit the three largest historical earthquakes in California – the 1857 Fort Tejon, 1872 Owens Valley, and 1906 San Francisco earthquakes -- to review their published moment magnitudes, and compare their estimated shaking distributions with... more
Poster 124	SDOT	Interplay between seismicity and hydrological and industrial processes in Salt Lake Valley, Utah Xie Hu, Roland Bürgmann, Liang Xue, Yuning Fu, Teng Wang A M5.7 earthquake hit the metropolitan Salt Lake Valley (SLV) on March 18th, 2020 during the COVID-19 pandemic. The shaking certainly added more worries to ~3 million people within a 160-km radius of the capital Salt Lake City. The M5.7 earthquake... more
Poster 205	GM	3D 0-5 Hz Wave Propagation Simulations of the 2014 Mw5.1 La Habra Earthquake with Small-scale Heterogeneities, Q(f) and topography Zhifeng Hu, Kim Olsen We perform a suite of 0-5 Hz deterministic simulations of the 2014 Mw 5.1 La Habra, CA, earthquake, with the parallel AWP-ODC-GPU code in a mesh from the Southern California Earthquake Center (SCEC) Community Velocity Model CVM-S4.26-M01. The finite... more
Poster 076	Seismology	Coseismic hydrogeologic response to the 2019 Ridgecrest Earthquake in the fault system at Devils Hole, Nevada Ruei-Jiun Hung, Matthew Weingarten Hydrogeologic responses to earthquakes, either statically or dynamically, are well-documented. Such responses provide information about physical properties of subsurface material and structure. Devils Hole, a fluid-filled fault cavern located in... more
Poster 051	Seismology	Investigating the role of thermo-poro-elastic stresses and deformation on induced seismicity Kyungjae Im, Jean-Philippe Avouac, Elias Heimisson, Derek Elsworth We investigate the influence of thermo- and poro-elastic stresses on induced seismicity in the context of geothermal energy production at Coso and Brawley in California. Coso geothermal field is one of the largest geothermal fields operated for ~30... more	19076
Poster 102	EFP	The Effect of Catalog Lead Time on Earthquake Forecasting Using the EEPAS Model Sepideh J Rastin, David Rhoades, Annemarie Christophersen ‘Every Earthquake a Precursor According to Scale’ (EEPAS) is a catalog-based model to forecast earthquakes within the coming months, years and decades, depending on magnitude. EEPAS performs well for seismically active regions including California... more
Poster 085	EFP	Grand challenges in earthquake science David Jackson After two decades of productive SCEC research, important basic questions remain. After another two decades, they may yet remain. Or, some outstanding earthquake research center might plan long-term experiments to address the questions head-on.... more	18219
Poster 218	GM	Refinements of UCSB Method Using a Double-Corner Frequency Source Spectrum Chen Ji, Ralph Archuleta A realistic spectral model of the general f^(-2) high-frequency and M_0 low-frequency asymptotes needs an intermediate f^(-1) branch (Brune, 1970). We introduced two such double-corner source spectral models JA19 and JA19_2S for 3.3≤ M ≤7.3,... more	20114
Poster 047	Seismology	Determination of Near Surface Shear-Wave Velocities in the Central Los Angeles Basin with Dense Arrays Zhe Jia, Robert Clayton The shallow velocity structure of the Los Angeles (LA) Basin plays an important role in the seismic hazard of this populated area. Most existing velocity models of the LA Basin are derived from sonic logging, industry reflection profiles or sparse... more
Poster 114	SDOT	Using Postseismic Relaxation Test Southern California Viscosity Models Kaj Johnson, Jacob Dorsett, Simone Puel, Thorsten Becker We continue to develop 3-D heterogeneous viscoelastic static Green's functions (GFs) for deformation in southern California for the SCEC Community Rheology Model. We are testing viscoelastic mantle models using GPS-derived postseismic... more	20149, 19212
Poster 021	SAFS	Trona-Ridgecrest Earthquake Sequence and Fault Complex, San Bernardino County Frank Jordan, Jr., Miles Wagner, Kerry Cato On July 4th and 5th 2019, two large earthquakes struck the extreme northwest corner of San Bernardino County. The MW6.4 foreshock occurred along branches of a poorly mapped, northeast-striking fault in on the Naval Air Weapons Station (NAWS) China... more
Poster 227	GM	Effects of Shallow-Velocity Reductions on 3D Propagation of Seismic Waves Alan Juarez, Yehuda Ben-Zion We perform 3D simulations of seismic wavefields to clarify the effects of strong reductions of shallow velocities on long-period seismic waves. The simulations use a reference Community Velocity Model of southern California and a modified version... more
Poster 126	SDOT	Detailed study of stress-related borehole features and the stress regime near the Wilmington Blind-Thrust Fault in the Los Angeles area Justin Kain, Patricia Persaud To obtain stress constraints near the inferred ~20-km-long Wilmington blind-thrust fault in the southwestern Los Angeles basin, we analyze digital 4- and 6-arm caliper data and resistivity image logs from 36 wells (16 with image logs). The wells are... more	20022
Poster 144	FARM	Two timescales of fault stabilization by dilatant hardening: slow slip events followed by prolonged dynamic rupture Taka Kanaya, Wen-lu Zhu Triaxial compression experiments were conducted on Fontainebleau sandstone with initial porosities of 4, 6, and 14% at a constant effective pressure of 70 MPa (produced by various combinations of confining and pore pressures) and strain rates... more	20202
Poster 005	Geology	Episodic Deformation Along a Blind Thrust in the Past 125 Kyr: The Santa Ynez River fault in the western Transverse Ranges of California Clay Kelty, Nate Onderdonk The Santa Ynez River fault is a major regional structure along the central California coast that separates the western Transverse Ranges and the Santa Maria Basin. Because the fault is not exposed at the surface, little is known about its kinematics... more
Poster 059	Seismology	The Plum Earthquake Early Warning Algorithm: A Case Study of Two West Coast, USA, Datasets Debi Kilb, Julian Bunn, Jessie Saunders, Elizabeth Cochran, Sarah Minson, Annemarie Baltay, Colin O'Rourke The PLUM (Propagation of Local Undamped Motion) earthquake early warning (EEW) algorithm differs from typical source-based EEW algorithms in that it forward-predicts shaking directly from observations. We apply PLUM to two retrospective datasets:... more
Poster 116	SDOT	Preseismic and Post-seismic Transient Strain Anomaly Patterns Before and After the 2019 Ridgecrest Earthquake Sequence Jeonghyeop Kim, Alireza Bahadori, William Holt Using cGPS displacements of Network of the Americas (NOTA), we quantify horizontal transient strain anomalies in regions near the epicenters of the 2019 Ridgecrest Earthquake Sequences. The preseismic seasonal strain changes in the regions repeat... more	16291, 18228
Poster 013	Geology	Role of confinement in coseismic pulverization of sediments: testing the rock record of rupture directivity on the San Jacinto fault Caje Kindred, William Griffith, Thomas Rockwell Pulverized fault zone rocks (PFZR) found in damage zones of large strike slip faults have been linked to dynamic earthquake rupture through experimental, numerical, and field based research. Recent observations of damage zone microfractures within... more	20027
Poster 234	EEII	Performance Quantification of Tall Steel Braced Frame Buildings Using Rupture-To-Rafters Simulations Swaminathan Krishnan, Ramses Mourhatch What is the probability of collapse of tall steel braced frame buildings under San Andreas earthquakes in the next 30 years? Using more than 38000 ground motion histories from simulations of 60 scenario earthquakes on the San Andreas fault with... more
Poster 163	FARM	The Cajon pass earthquake gate: clues from synthetic and realistic topography dynamic rupture models Christodoulos Kyriakopoulos, Baoning Wu, David Oglesby The Cajon Pass (CP) is a key area for the generation of large earthquakes in southern California and is thought to be an “Earthquake Gate” (EG). EG’s are locations of structural complexity along major faults that, depending on a series of mechanical... more	19223, 20151
Poster 156	FARM	Modeling the Rupture Dynamics of Strong Ground Acceleration (>1g) in Fault Stepovers Holland Ladage, Julian Lozos, Sinan Akciz Following the July 2019 Ridgecrest earthquakes, multiple field investigators noted that pebble- to boulder-sized rocks had been displaced from their place in the desert pavement along the right-lateral strike-slip M7.1 rupture trace. This implies... more	20199
Poster 164	FARM	Resolving simulated sequences of earthquakes and fault interactions Valere Lambert, Nadia Lapusta Physics-based numerical modeling of earthquake source processes aims to combine available real-world data and physical principles to improve our understanding of fault behavior. The ultimate aspiration is to develop models that have predictive... more	20080
Poster 127	SDOT	Impact of 3D Elastic Structure on Coseismic Green’s Functions for Static Slip Inversion Leah Langer, Stephen Beller, Jeroen Tromp Earthquakes often occur in regions with complex elastic structure, such as sedimentary basins and mantle wedges. However, the majority of coseismic modeling studies assume a simplified, often homogeneous elastic structure in order to expedite the... more
Poster 153	FARM	Relation between absolute stress levels, rupture style, and seismic radiation on mature faults Nadia Lapusta, Valere Lambert Accumulating geophysical evidence, including observations of heat flow, steep angles between inferred principal stress directions and fault traces, and the geometry of thrust-belt wedges, suggests that the shear resistance acting on mature faults... more	20079
Poster 140	FARM	Slip response to fluid depressurization constrains fault friction Stacy Larochelle, Nadia Lapusta, Jean-Paul Ampuero, Frederic Cappa Fluid injections are ubiquitous in the exploitation of geoenergy resources but can reactivate nearby faults. Whether the ensuing slip is seismic or aseismic and restrained to the fluid-pressurized zone or not is thought to be controlled by the level... more
Poster 090	EFP	Statistical Analysis of Paleoseismically Determined Earthquake Recurrence Winnie Lau, Michael Oskin We present a statistical analysis of 11 paleoseismic data sets from continental strike-slip faults in California (San Andreas [5], San Jacinto [2], Garlock [2]) and China (Altyn Tagh [1], Haiyuan [1]) to reveal general characteristics of earthquake... more

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