Meeting Abstracts

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 form below to search and view all poster and invited talk abstracts submitted to this meeting.

Results 151-200 of 305

SCEC ID ▲	Category	Title and Authors	SCEC Award
Poster 151	Geology	Late-Holocene Earthquakes on the Rose Canyon Fault at Old Town, San Diego CA Drake Singleton, Thomas Rockwell, Monte Murbach, Diane Murbach, Jillian Maloney, Yuval Levy, Eui-Jo Marquez, Luke Weidman We present the results of new paleoseismic trenches excavated across the main trace of the Rose Canyon fault (RCF) in Old Town, San Diego, to determine the timing of late Holocene earthquakes. The stratigraphy at the site consists of historical... more
Poster 152	Geology	Using GeoGateway Line-of-Sight (LOS) Tool to Explore Deformation along the San Andreas Fault in the Carrizo Plain, CA Lisa Grant Ludwig, Andrea Donnellan, Jay Parker Crustal deformation is spatially and temporally non-uniform as strain accumulates over long time scales, is rapidly released in earthquakes, and readjusts post-seismically. Because earthquake processes occur over widely varying temporal and spatial... more
Poster 153	Geology	3D Constraints On Fault Architecture and Strain Distribution of the Newport-Inglewood Rose Canyon and San Onofre Trend Fault Systems James Holmes, Neal Driscoll, Graham Kent The Inner California Borderlands (ICB) is situated off the coast of southern California and northern Baja. The structural and geomorphic characteristics of the area record a middle Oligocene transition from subduction to microplate capture along the... more
Poster 154	SAFS	Paleoseismic Investigation of Van Matre Ranch Site Along the Carrizo Plain Section of the San Andreas Fault Nick Inserra, Clayton Nelems, Radwan Muthala, Jeremy Torres, Sinan Akciz Correlation of paleoseismic data from both Bidart Fan and Frazier Mountain sites indicate recurrence intervals of ~100 yrs between large surface rupturing earthquakes in the Carrizo Plain and Big Bend sections of the San Andreas Fault during the... more
Poster 155	SAFS	A re-examination of the subsurface fault structure in the vicinity of the 1989 Loma Prieta Mw 6.9 earthquake, central California, from analysis of steep reflections, earthquakes, and potential-field data Gary Fuis, Edward Zhang, Rufus Catchings, Daniel Scheirer, Mark Goldman, Klaus Bauer We reinterpret the causative structure of the 1989 Mw 6.9 Loma Prieta earthquake, in central California, using reflection, earthquake, and potential-field data, prompted by recent interpretations of a two-part dip of the San Andreas fault (SAF)... more
Poster 156	SAFS	Preliminary paleoslip results from the Pearblossom site on the Mojave section of the San Andreas Fault Emery Anderson-Merritt, Eric Cowgill, Katherine Scharer, Amanda Keen-Zebert The late Quaternary slip rate along the Mojave section of the San Andreas fault (MSAF) (~30 mm/yr) [1] appears to be twice as large as geodetic estimates (~15 mm/yr) [2], although it is unclear if this difference is real or stems from assumptions in... more	17231, 12198, 11061
Poster 157	SAFS	Seismic imaging of the southern California plate-boundary around the South-Central Transverse Ranges using double-difference tomography Pieter-Ewald Share, Yehuda Ben-Zion, Clifford Thurber, Haijiang Zhang, Hao Guo We derive P and S seismic velocities within and around the South-Central Transverse Ranges section of the San Andreas Fault (SAF), using a new double-difference tomography algorithm incorporating both event-pair and station-pair differential times.... more
Poster 158	SAFS	Rupture propagation through the Big Bend of the San Andreas Fault: a dynamic modeling case study of the Great Earthquake of 1857 Julian Lozos The great San Andreas Fault (SAF) earthquake of 9 January 1857, estimated at M7.9, was one of California’s largest historic earthquakes. Its ~360 km rupture trace follows the Carrizo and Mojave segments of the SAF, including the ~30° compressional... more
Poster 159	SAFS	Preliminary ages of prehistoric earthquakes on the Banning Strand of the San Andreas Fault, near North Palm Springs, California Bryan Castillo, Sally McGill, Katherine Scharer, Doug Yule, Devin McPhillips, James McNeil, Alan Pace The southernmost section of the San Andreas Fault (SAF) is the only section of that fault that has not ruptured historically. It is not known whether this long quiescent period reflects a long average recurrence interval for this portion of the... more	15182
Poster 160	SAFS	Assessing stratigraphic correlations and fault zone extent at the 18th Ave trench site, Banning strand of the San Andreas Fault, North Palm Springs, California James McNeil, Doug Yule, Katherine Scharer, Sally McGill, Devin McPhillips, Bryan Castillo, Alan Pace A trench opened in March, 2017 by Petra Geoscience, Inc., provided a valuable opportunity to examine the previously unconstrained earthquake record of Banning strand of the San Andreas Fault (also see Castillo et al., this meeting). The initial... more	15182
Poster 161	SAFS	Puzzling results in a slip rate study for the Banning Strand of the San Andreas Fault near North Palm Springs Sally McGill, Paula Figueiredo, Lewis Owen To better understand the likely rupture paths and slip distribution on the southern San Andreas Fault, additional slip rate measurements are needed from the Mission Creek, Banning and Garnet Hill fault strands in northern Coachella Valley. We... more	15182
Poster 162	SAFS	Evidence for an active and evolving left-stepping San Andreas fault (Mission Creek fault strand) from the Little San Bernardino Mountains to Yucaipa Ridge Jesse Waco, Kimberly Blisniuk, Julie Fosdick This study presents new detailed field mapping and high-resolution topographical data to provide evidence for an alternative interpretation of fault geometry and slip transfer for the southern San Andreas fault zone, specifically the Mission Creek... more
Poster 163	SAFS	Measurements of Ground-Based Magnetics and Vertical Deformation From a Leveling Line Across the San Andreas Fault at Durmid Hill Karen Alvarez, Jascha Polet The Durmid Hill region is located near the termination of the San Andreas Fault (SAF) at Bombay Beach. This section of the fault has not experienced any major earthquakes in the past three centuries. Fuis et al. (2017) showed that the SAF is dipping... more
Poster 164	SAFS	Quaternary Slip History for the Agua Blanca Fault, northern Baja California, Mexico Peter Gold, Whitney Behr, Thomas Rockwell, John Fletcher The Agua Blanca Fault (ABF) is the primary structure accommodating San Andreas-related right-lateral slip across the Peninsular Ranges of northern Baja California. Activity on this fault influences offshore faults that parallel the Pacific coast... more	14719, 17197
Poster 165	FARM	3D Simulations of Earthquakes on Parallel Offset Faults with Homogeneous Stress Conditions Kayla Kroll, Keith Richards-Dinger, James Dieterich, David Oglesby Several recent large earthquakes including the 2002 Mw7.9 Denali, Alaska, 2010 Mw7.2 El Mayor-Cucapah, Mexico, and the 2016 Mw7.8 Kaikoura, New Zealand events ruptured up to a dozen fault segments. Understanding how ruptures are able to jump across... more
Poster 166	FARM	Slip partitioning and scaling relations of repeating earthquakes on rate-state faults Camilla Cattania, Paul Segall, Sebastian Hainzl Small repeating earthquakes, characterized by similar waveforms, are thought to represent the rupture of isolated asperities loaded by creep. They are very periodic, making them an ideal natural laboratory to study the factors determining the... more
Poster 167	FARM	Earthquake Cycles With Complex Fault Geometries Brittany Erickson, Jeremy Kozdon The overall goal of this project is to develop an understanding of the earthquake cycle that takes into account the interaction of remote tectonic loading and near-fault structure. To do this we are developing a model that uses a quasi-static... more
Poster 168	FARM	The effects of segmented fault zones on earthquake rupture propagation and termination Yihe Huang A fundamental question in earthquake source physics is what control the nucleation and termination of an earthquake rupture. Besides stress heterogeneities and variations in frictional properties, damaged fault zones (DFZs) that surround major... more	17071
Poster 169	FARM	Dynamic Models of Earthquake Rupture along branch faults of the Eastern San Gorgonio Pass Region in CA using Complex Fault Structure Roby Douilly, David Oglesby, Michele Cooke, Jennifer Beyer Compilation of geomorphic and paleoseismic data have illustrated that the right-lateral Coachella segment of the southern San Andreas Fault is past its average recurrence time period. On its western edge, this fault segment is split into two... more
Poster 170	FARM	Effect of Undrained Gouge Plasticity on Rupture Dynamics of Rough Faults Evan Hirakawa, Shuo Ma Recent rough fault models show that geometrical irregularities can have a significant effect on rupture propagation, leading to observations of rupture arrest, supershear rupture, fluctuations in rupture velocity, and high frequency ground motions.... more	17220
Poster 171	FARM	Dynamic Rupture Models of the 2015 Mw7.8 Nepal Earthquake Yongfei Wang, Steven Day, Marine Denolle The April 15th, 2015 Mw 7.8 Gorkha earthquake in Nepal occurred on a very shallowly dipping Main Himalayan Thrust (MHT) fault, where local fault geometry and proximity of the free surface will introduce asymmetry of stress and strain fields across... more
Poster 172	FARM	The material-geometry nexus: Understanding topographic effects on wave propagation Qianli Chen, Ahmed Elbanna Topographic effects are associated with the presence of strong topographic relief (hills, ridges, canyons, cliffs, and slopes), complicated subsurface topography (sedimentary basins, alluvial valleys), and geological lateral discontinuities (e.g.,... more
Poster 173	FARM	A Machine Learning Approach to Earthquake Rupture Dynamics Sabber Ahamed, Eric Daub Dynamic rupture propagation is a challenging problem due to uncertainty regarding the underlying physics of earthquake slip, and the stress conditions and frictional properties of fault are not well constrained. These unknown initial stresses and... more
Poster 174	FARM	Slip Patterns on Rate-and-State Faults with Heterogeneous Velocity-Weakening and Velocity-Strengthening Friction Kavya Sudhir, Nadia Lapusta Slip patterns on heterogeneous interfaces is a complex problem with a wide range of applications, including the nucleation of earthquakes in the transition band between the seismogenic zone and deeper, stably creeping regions and/or in rough fault... more	17154
Poster 175	FARM	Implications of depth-dependent variations in fault zone properties for the frequency content of seismic radiation Valere Lambert, Nadia Lapusta Seismic observations from several recent great earthquakes - the 2004 Mw 9.2 Sumatra-Andaman, 2010 Mw 8.8 Chile, and 2011 Mw 9.0 Tohoku-Oki events – suggest that more of the high-frequency radiation from the rupture process originated from the... more	17154
Poster 176	FARM	Incorporating anisotropic material properties into simulations of the earthquake cycle Maricela Best Mckay, Brittany Erickson We are developing a methodology for incorporating and studying the effects of anisotropy when simulating the full earthquake cycle. The method is developed for a vertical strike-slip fault in two-dimensions, with antiplane motion. Inertial terms are... more
Poster 177	FARM	Can the Southern San Andreas Fault be Triggered by Cross-Fault Earthquakes? Christodoulos Kyriakopoulos, David Oglesby, Aron Meltzner, Thomas Rockwell, Michael Barall The Brawley Seismic Zone (BSZ) is the step-over region between what is believed to be the southern terminus of the southern San Andreas Fault (SSAF), near Bombay Beach, and the northern end of the Imperial Fault. Within the past 30 years, numerous... more	16231
Poster 178	FARM	Dynamic rupture modeling of thrust faults with parallel surface traces. Paul Peshette, Julian Lozos, Doug Yule Fold and thrust belts (such as those found in the Himalaya or California Transverse Ranges) consist of many neighboring thrust faults in a variety of geometries. Active thrusts within these belts individually contribute to regional seismic hazard,... more
Poster 179	FARM	Towards dynamic rupture models with high resolution fault zone physics Ahmed Elbanna, Xiao Ma, Setare Hajaroalsvadi Earthquake processes span a wide range of length and time scales with the fault zone dynamics holding the key to resolving many outstanding seismological observations. The details of strength evolution in fault zones are dictated by the poro-thermo-... more	15088, 16143
Poster 180	FARM	Stick Slip Instabilities and Strain Localization Dynamics in a fluid-infiltrated fault gouge zone model Xiao Ma, Ahmed Elbanna Stick-slip instabilities and shear localization have been long observed in sheared fault gouge, yet their underlying microscopic mechanisms are still not fully understood. Although numerous studies of the stick slip behavior within fault gouge have... more
Poster 181	FARM	Comparison of actual and seismologically inferred stress drops in asperity-type dynamic source models of microseismicity Yen-Yu Lin, Nadia Lapusta Estimating source parameters for small earthquakes is commonly based on either Brune or Madariaga source models. These models assume circular rupture that starts from the center of a fault and spreads axisymmetrically with a constant rupture speed.... more	17154
Poster 182	FARM	Exploring seismological properties of asperity-type events in a rate-and-state fault model Natalie Schaal, Nadia Lapusta, Yen-Yu Lin Observations of foreshocks on both natural and laboratory faults suggest that the source of the foreshocks may be fault heterogeneities, such as bumps, that are driven to fail by aseismic processes of the mainshocks nucleation process [e.g., Dodge... more	17154
Poster 183	FARM	Pulse-Like Partial Ruptures and High-Frequency Radiation at Creeping-Locked Transition during Megathrust Earthquakes Sylvain Michel, Jean-Philippe Avouac, Nadia Lapusta, Junle Jiang Megathrust earthquakes tend to be confined to fault areas locked in the interseismic period and often rupture them only partially. For example, during the 2015 M7.8 Gorkha earthquake, Nepal, a slip pulse propagating along strike unzipped the bottom... more
Poster 184	FARM	Dynamics of Non-planar Thrust Faults Governed by Various Friction Laws Bin Luo, Benchun Duan Fault interface topography is a prevailing factor in earthquake rupture dynamics. In subduction zones, large-scale oceanic reliefs such as seamounts and plateaus on the incoming oceanic plate can be subducted with the downgoing plate, giving rise to... more
Poster 185	FARM	Modelling the spatio-temporal pattern of heterogeneous stresses and strain accumulation due to earthquake rupture on a geometrically complex fault Khurram Aslam, Eric Daub We perform physics-based simulations of earthquake rupture propagation on geometrically complex strike-slip faults. We consider many different realization of the fault roughness and obtain heterogeneous stress fields by performing dynamic rupture... more	17182
Poster 186	FARM	Earthquake cycles with dynamic weakening from flash melting with heterogeneous stress and near-fault anelastic strain Norman Sleep Major earthquakes may nucleate at high-shear-traction patches of strike-slip faults left over from heterogeneous slip in past events. Once an earthquake is underway, the slip-weakening distance can be less than 1 mm for rate and state friction and... more	17001
Poster 187	FARM	Quantifying the coalescence process of microcracks leading to a system-size failure Ilya Zaliapin, Yehuda Ben-Zion We analyze Acoustic Emission (AE) data with the goal of quantifying the transition from distributed events to a system-size failure. Several data sets from different experiments provide information on the failure process in different rock types (... more	16023, 17065
Poster 188	FARM	The Role of Dilatancy in Fluid-Induced Fault Slip Stacy Larochelle, Nadia Lapusta, Jean-Paul Ampuero Numerous industrial activities (e.g., hydraulic fracking, wastewater disposal and enhanced geothermal systems) involve fluid injections into the crust. That these anthropogenic fluid injections have the potential to induce fault slip has been known... more	17154
Poster 189	FARM	Granular Temperature Measured Experimentally in a Shear Flow by Acoustic Energy Stephanie Taylor, Emily Brodsky Granular temperature may control high-speed granular flows, yet is difficult to measure in laboratory experiments. Here we utilize acoustic energy to measure granular temperature in dense shear flows for the first time. We show that acoustic energy... more
Poster 190	FARM	Laboratory geophysical observation of grain compression and crushing in synthetic fault gouges Amin Gheibi, Ahmadreza Hedayat Active geophysical monitoring techniques are among the most powerful techniques to identify changes in soil fabric, grain to grain contact network, compressional strength, and void ratio in granular materials. We present experimental results in... more	17242
Poster 191	FARM	Experimental Study of Thermal Pressurization Weakening and the Role of Fault Roughness Nir Badt, Terry Tullis, Greg Hirth Dynamic weakening due to pore fluid thermal pressurization is controlled by the hydraulic properties of the host rock, including the permeability (k) and the available pore space. Rough sliding interfaces dilate and contract during slip, in... more	17249
Poster 192	FARM	Examination of multi-scale flash-heating at seismic slip rates in granite Monica Barbery, Omid Saber, Frederick Chester, Judith Chester As sliding velocities approach seismic slip rates, a significant reduction in the coefficient of friction of rock can occur as a result of weakening of microscopic asperity contacts by flash heating. Utilizing a high-speed, high-acceleration biaxial... more
Poster 193	FARM	Experimental Investigation on Poro-Elasto-Visco-Plastic Behavior of the Inner Accretionary Wedge Sediments at the Nankai Subduction Zone Szu-Ting Kuo, Manami Kitamura, Hiroko Kitajima The Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) has installed borehole observatories to monitor the evolution of physical and hydrological properties caused by crustal deformation at various... more
Poster 194	FARM	Investigating the physics behind VLFEs and LFEs: analysis based on dynamic rupture models with ductile-like friction Baoning Wu, David Oglesby, Abhijit Ghosh, Bo LI Very low frequency earthquakes (VLFE) and low frequency earthquakes (LFE) are two main types of seismic signal that are observed during slow earthquakes. These phenomena differ from standard (“fast”) earthquakes in many ways. In contrast to seismic... more
Poster 195	FARM	A Simple Spring-Mass-Dashpot Model for Slow Earthquakes on a Viscous Fault Rachel Lippoldt, Charles Sammis One and two dimensional spring-mass-dashpot models are used to simulate the propagation of slow events in a viscous fault zone that is pinned by an array of asperities. The asperities fail at stress thresholds that lie within a prescribed range. The... more
Poster 196	FARM	Earthquake Petrology: Insights into Fault Slip Localization and Fault Heating via Micro X-Ray Fluorescence Mapping and X-Ray Absorption Near Edge Spectroscopy James Evans, Krishna Borhara, Samuel Webb Theoretical and laboratory analyses propose a range of dynamic weakening mechanisms to explain fault slip behavior, especially on extremely thin slip surfaces. We use a synchrotron light source to use microscale X-ray fluorescence (μXRF) analytical... more	15111
Poster 197	FARM	Grain boundary sliding triggers coeval pseudotachylyte development in brittle-ductile transition mylonites: an Electron Backscatter Diffraction (EBSD) case study of mid-crustal interseismic and coseismic deformation Elena Miranda, Craig Stewart, Kelly Lourcey Exposures of coeval pseudotachylytes and mylonites are relatively rare, but are crucial for understanding the seismic cycle in the vicinity of the brittle-ductile transition (BDT). We use both field observations and electron backscatter diffraction... more	17063
Poster 198	FARM	Carbonaceous fault-related rocks in SAFOD Phase III core: Indicators of fluid-rock interaction and structural diagenesis during slip Krishna Borhara, Kelly Bradbury, James Evans At elevated temperatures, many carbon-bearing fault zones are subjected to thermal maturation, fluid-rock interactions, and/or shear-induced phase transformations, often yielding various fault weakening agents. Black carbonaceous material documented... more	17207
Poster 199	FARM	A Test Case for the Source Inversion Validation: The 2014 ML 5.5 Orkney, South Africa Earthquake William Ellsworth, Margaret Boettcher, Hiroshi Ogasawara The ML5.5 earthquake of August 5, 2014 occurred on a near-vertical strike slip fault below abandoned and active gold mines near Orkney, South Africa. A dense network of surface and in-mine seismometers recorded the earthquake and its aftershock... more	17096
Poster 200	FARM	Rupture of an Immature Fault in the Pawnee Mw5.8 earthquake Kathleen Keranen, Heather Savage, Genevieve Coffey, Rowena Lohman, Catherine Lambert, Nathan Stevens, Hannah Rabinowitz Earthquakes across north-central Oklahoma demonstrate considerable variability, with some areas remaining nearly aseismic despite abundant injection. Where earthquakes do occur, they largely rupture unmapped faults, even in regions where mapped... more

The Southern California Earthquake Center is committed to providing a safe, productive, and welcoming environment for all participants. We take pride in fostering a diverse and inclusive SCEC community, and therefore expect all participants to abide by the SCEC Activities Code of Conduct.

Category:
Author:
Title:
Abstract:
Format:
Only show abstracts with PDFs

Meeting Abstracts

IMPORTANT DATES

For Researchers

For The Media