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 1-50 of 248

SCEC ID	Category	Title and Authors	SCEC Award
Poster 186	CXM	Geomodelgrids: A storage scheme and API for multiscale Earth models Brad Aagaard Geomodelgrids provides a self-describing storage scheme and API for querying multiscale Earth models with the goal of standardizing storage and access of gridded community models. The storage scheme and API are agnostic to the model data values,... more
Poster 038	Seismology	Does earthquake stress drop increase with depth? Rachel Abercrombie, Daniel Trugman, Peter Shearer, Xiaowei Chen, Jiewen Zhang, Colin Pennington, Jeanne Hardebeck, Thomas Goebel, Christine Ruhl We combine earthquake spectra from multiple studies to investigate whether the increase in stress drop with depth, that is often observed in the crust, is real or an artefact of variation in attenuation (Q) with depth. Shearer et al. [2006]... more	19163, 20097
Poster 044	Seismology	Identifying the Moho and an intracrustal interface along a Nodal Seismic Line in the eastern San Bernardino Basin Brian Aguilar, Patricia Persaud, Robert Clayton We use receiver functions computed from the 2018 M 7.3 Venezuela earthquake recorded along the SB2 profile of the Basin Amplification Seismic INvestigation (BASIN) project to map the Moho discontinuity and an intracrustal interface. The SB2 profile... more	19033, 18029
Poster 189	CXM	Methodology for producing hybrid Earth models with improved waveform predictions near the southern San Andreas fault and updates to SCEC UCVM API Rasheed Ajala, Patricia Persaud, Alan Juarez We evaluated the latest SCEC community models and hybrid versions of these embedded with hi-res basin-scale models at low frequencies utilizing medium-magnitude events not used in developing any of the models in the assessment. We benchmark the... more	20023, 19014, 18074
Poster 177	CXM	Three definitions of ductile shear zones resulting from grain-size evolution below a frictional fault Kali Allison, Laurent Montesi Ductile shear zones act as the continuation of faults into the lower crust, and their structure depends in part on the faults’ frictional properties in the brittle-ductile transition (BDT) region. We explore how fault and ductile shear zone... more	19145
Poster 148	FARM	Viscoelastic earthquake sequence simulations in complex geometries Martin Almquist, Eric Dunham Earthquake sequence simulations are used to study earthquake source processes, relate fault slip to observable ground motions and crustal deformation, and set initial stresses for dynamic rupture simulations. Most previous earthquake sequence... more	20033
Poster 217	GM	A new model to explain the frequency-dependent decay of Fourier acceleration spectra at high frequencies John Anderson, Annabel Haendel, Marco Pilz, Fabrice Cotton Fourier amplitudes of acceleration rapidly decrease at high frequencies beyond the source corner frequency. This spectral decay is commonly modeled by a single parameter kappa introduced by Anderson and Hough (1984), which we will call the „kappa... more
Poster 132	FARM	Creating a multi-proxy approach to robustly capture earthquake temperature rise at the Punchbowl fault Emma Armstrong, Alexis Ault, Kelly Bradbury, Heather Savage, Pratigya Polissar During an earthquake, friction-generated heat occurs along localized fault surfaces. However, coseismic temperature rise, critical for identifying past earthquakes, is difficult to accurately quantify in the rock record. To address this issue, we... more	20153
Poster 197	GM	Deterministic ground motion simulations with shallow crust nonlinearity Domniki Asimaki, Elnaz Seylabi, Doriam Restrepo, Ricardo Taborda We perform a series of large-scale nonlinear ground motion simulations that account for the cyclic plastic behavior of sediments in the shallow crust. Our goal is to understand and quantitatively assess (1) how idealized models of sediment... more	18020, 19056
Poster 231	EEII	Implementation of Monte-Carlo earthquake catalogs in probabilistic seismic hazard analysis: An application to CyberShake Sarah Azar, Mayssa Dabaghi Conventional Probabilistic Seismic Hazard Analysis (PSHA) employs ground motion prediction equations (GMPEs) as ground motion models. However, alternative methods such as numerical simulations can also be used in predicting the intensity of a ground... more
Poster 229	EEII	Selection of CyberShake Simulated Ground Motion Time Series for Engineering Analysis Jack Baker, Sanaz Rezaeian, Christine Goulet, Nicolas Luco, Ganyu Teng This presentation will describe a subset of CyberShake numerically simulated ground motions that were selected and vetted for use in engineering response history analyses. CyberShake is a Southern California Earthquake Center (SCEC) high-performance... more	19060
Poster 073	Seismology	Stress drop and ground-motion source comparison of the July 2019 Ridgecrest earthquake sequence: A community validation study Annemarie Baltay, Rachel Abercrombie We propose a community stress drop validation study using the 2019 Ridgecrest earthquake sequence as a common data set. Earthquake stress drops are notoriously variable and attempts to correlate estimates of the same earthquake using different... more
Poster 145	FARM	Investigation of transient and hysteretic flash-weakening behavior observed in high-speed friction experiments Monica Barbery, Frederick Chester, Judith Chester Friction, µ, during seismic slip reflects deformation over a range of length-scales, but fundamentally arises from physical and chemical processes operating at µm-scale contact junctions. In past SCEC research we documented inhomogeneous flash-... more	17253
Poster 147	FARM	Excitation of San Andreas tremors by thermal instabilities below the seismogenic zone Sylvain Barbot, Lifeng Wang The relative motion of tectonic plates is accommodated at boundary faults through slow and fast ruptures that encompass a wide range of source properties. Near the Parkfield segment of the San Andreas fault, deep low-frequency earthquakes and slow-... more
Poster 221	GM	Region-specific Fourier-based site amplification modeling Jeff Bayless, Jonathan Stewart This SCEC study addresses the need for improved nonlinear site amplification models on the SCEC BBP. We infer site response in northern and southern California from earthquake recordings and develop appropriate models for frequency-dependent... more	19097
Poster 129	FARM	Small Magnitude Seismicity Helps Identify Transient Signals of Fault Creep on the North Anatolian Fault in Noisy GPS Recordings Eric Beauce, Michel Campillo, Rob van der Hilst The North Anatolian Fault (NAF), a major continental plate boundary, accommodates the motion between Eurasia and Anatolia with right-lateral strike-slip motion. Shallow aseismic slip has first been identified on the Ismetpasa segment of the NAF in... more
Poster 173	CXM	Joint MCMC Inversion of Rayleigh Wave Phase Velocity, Ellipticity, and Receiver Functions: Southern California Shear Velocity Model Expanding to the Shallower and Deeper Crust Elizabeth Berg, Fan-Chi Lin, Vera Schulte-Pelkum, Konstantinos Gkogkas, Hongrui Qiu We provide a new isotropic shear velocity model of Southern California with sensitivity from the near-surface into the upper mantle, including resolving Moho depths. We accomplish this through Bayesian joint inversion of Rayleigh wave phase... more	20058
Poster 091	EFP	Maximum Entropy Modeling of Earthquake Recurrence from Paleoseismic Event Time Series Glenn Biasi, Fred Bookstein Conditional probability estimates of a ground rupturing earthquake depend heavily upon something we do not know: the shape of the recurrence model distribution. We present a new recurrence model approach based on information theory and entropy... more
Poster 121	SDOT	Restoring California, part I: 0-18 Ma Peter Bird, Raymond Ingersoll We are computing incremental stepwise restorations of maps of faults and outcrops in the western United States and northern Mexico using kinematic F-E program RESTORE (v.4) and datasets of: fault traces, fault offsets, timing constraints,... more
Poster 171	CXM	Comparison of ground motions in earthquakes with SCEC CVM predictions Brianna Birkel, John Vidale, Alan Juarez, Thomas Jordan Southern California, and particularly the Los Angeles region, contains strongly heterogeneous crustal structures that have been carefully studied, mapped, and integrated into the SCEC Community Velocity Models (CVMs). Although the CVMs of Southern... more	20187
Poster 152	FARM	Numerical simulations of dynamic earthquake rupture with different failure laws Ekaterina Bolotskaya, Bradford Hager Geodetic and seismic observations indicate that most earthquakes result from unstable shear on quasi-planar faults, usually represented as shear cracks. Multiple failure laws have been proposed to describe fracture- and friction- related processes... more
Poster 209	GM	Detailed space-time variations of shallow velocity changes from dense array data Luis Bonilla, Yehuda Ben-Zion We compute high resolution space-time variations of subsurface seismic properties from autocorrelation functions (ACF) of noise and local earthquakes recorded at the Sage Brush Flat dense array, deployed around the Clark branch of the San Jacinto... more	19072
Poster 061	Seismology	The Nevada Seismological Laboratory’s 2020 M6.5 Monte Cristo Range, Nevada earthquake sequence rapid seismic deployment and data availability Jayne Bormann, Emily Morton, Ken Smith, Graham Kent, Will Honjas, Gabe Plank The Nevada Seismological Laboratory (NSL) installed 8 temporary seismic stations following the 15 May 2020 Mw 6.5 Monte Cristo Range (MCR) earthquake. The mainshock and resulting aftershock sequence occurred in an unpopulated and sparely... more
Poster 066	Seismology	Temporal Seismic Velocity Variations: Recovery Following from the 2019 Mw 7.1 Ridgecrest Earthquake Joshua Boschelli, Morgan Moschetti, Christoph Sens-Schönfelder We investigated seismic velocity changes (dv/v) associated with the 2019 Ridgecrest earthquake sequence from high-frequency autocorrelations of ambient seismic noise data. Daily autocorrelation functions were computed for the entirety of 2019 for... more
Talk	EFP	Lessons in earthquake nucleation drawn from subduction zones and ice streams Emily Brodsky The 2014 M8.1 Iquique earthquake and the 2011 M9.0 Tohoku earthquake have provided the most promising evidence to date that a slow precursory slip may exist before at least some earthquakes. These apparent precursors are observable because they are... more
Poster 027	SAFS	High Resolution Topography along 40 km of the Southern San Andreas Fault Michael Bunds, Chelsea Scott, Jui-Chi Lee, Brigham Whitney We produced a point cloud, digital surface model (DSM), and orthomosaic that cover ~ 40.5 km of strike length and ~31 km^2 area along the Southern San Andreas fault using small uncrewed areal system (sUAS) photographs and dGNSS camera positioning.... more	19123
Poster 002	Geology	Resolving the late Quaternary slip rate of the Santa Susana fault with in situ cosmogenic 36Cl profile dating Reed Burgette, Michael Reed, Nathaniel Lifton, Katherine Scharer, Devin McPhillips, Ronny Sholdt The Santa Susana fault (SSF) is a significant reverse fault in the western Transverse Ranges that connects structures bounding the Ventura and San Fernando basins. Based on published studies, the SSF is permitted a negligible to significant (0.5-10... more	18143
Poster 191	CS	Enhancing CyberShake simulations for engineering applications Scott Callaghan, Philip Maechling, Christine Goulet, Kevin Milner, Robert Graves, Kim Olsen, Fabio Silva, Yehuda Ben-Zion SCEC has developed the CyberShake platform to implement a physics-based probabilistic seismic hazard analysis (PSHA) method which uses 3D wave propagation simulations to calculate seismograms and ground motions from sources defined in regional... more
Poster 033	Seismology	A method for jointly measuring multi-mode surface wave phase velocities from one-component dense seismic arrays: A case study in Long Beach, California Jorge Castellanos, Robert Clayton In this study, we use ambient noise data recorded at stations of the Southern California Seismic Network and three dense petroleum industry surveys to show the occurrence of surface wave mode interference and prove that, if not properly accounted... more
Talk	Seismology	Results from dense nodal-array recordings of the 2019 Ridgecrest Sequence aftershocks Rufus Catchings, Mark Goldman, Malcolm White, Hongrui Qiu, Yehuda Ben-Zion The 2019 Ridgecrest, California earthquake sequence included Mw 6.4 and Mw 7.1 events on orthogonal faults, with tens of thousands of ensuing aftershocks. We recorded aftershocks and ambient noise for a 2-month period following the mainshock to: (1... more
Poster 106	Geodesy	Permanent Co-seismic Deformation of the 2013 Mw7.7 Baluchistan, Pakistan Earthquake from High-resolution Surface Strain Analysis Guo Cheng, William Barnhart Earthquake-generating faults are commonly surrounded by features such as topography and damage zones that indicate that earthquakes induce some degrees of permanent (inelastic) deformation. Quantifying the magnitude and extent of co-seismic... more
Poster 065	Seismology	Variations of earthquake properties before, during and after the 2019 M7.1 Ridgecrest, CA, earthquake Yifang Cheng, Yehuda Ben-Zion We attempt to clarify processes associated with the 2019 Ridgecrest earthquake sequence by analyzing space-time variations of seismicity, potency values and focal mechanisms of earthquakes leading to and during the sequence. Over the 20 years before... more	20042
Poster 174	CXM	An automated workflow for adjoint tomography applied to the North Island, New Zealand Bryant Chow, Yoshihiro Kaneko, Carl Tape, Ryan Modrak, John Townend We have developed an automated, open-source workflow for full-waveform inversion using spectral-element and adjoint methods (Chow et al., 2020). Our main objective is to attain high-resolution images of crustal structure and complex tectonic... more
Poster 193	CS	Cloud-Native Analysis of Southern California Waveform Data Tim Clements, Julian Schmitt, Marine Denolle Cloud computing offers a paradigm shift for data-heavy seismic analysis by bringing computation to data rather than data to computation. Southern California is the ideal testing ground for cloud-native analyses, as the entire archive of waveform... more
Poster 050	Seismology	Varied Fault Orientations in a Uniform Stress Field: The 2011 M5.7 Prague Earthquake Sequence Elizabeth Cochran, Rob Skoumal, Devin McPhillips, Zachary Ross, Kathleen Keranen The role of pore pressure changes in induced earthquake sequences can be inferred by the set of faults activated relative to the local stress orientations. Here, we examine the 2011 M5.7 Prague earthquake sequence that was induced by nearby... more
Poster 075	Seismology	Stress analysis and rupture dynamics of the 2019 Ridgecrest Sequence Jordan Cortez, David Oglesby, Christodoulos Kyriakopoulos, Baoning Wu, Abhijit Ghosh, Roby Douilly Stress transfer from long-term loading as well as prior earthquakes can initiate seismic triggering and strongly affect rupture propagation and slip patterns in a fault system. A prime example of this effect is the 2019 Ridgecrest earthquake... more
Poster 167	FARM	Unraveling scaling properties of slow slip events in 3D simulations of fault slip Luca Dal Zilio, Nadia Lapusta, Jean-Philippe Avouac Large megathrust faults produce a wide spectrum of slip modes, ranging from earthquakes to slow-slip events (SSEs). SSEs appear to have slip mechanisms similar to those of regular (fast) earthquakes and are often located in neighboring regions of... more
Talk	CS	Advancing earthquake science with robotics and AI Jnaneshwar Das, Ramon Arrowsmith, Zhiang Chen, Tyler Scott, Chelsea Scott, Devin Keating Unprecedented progress in AI in recent years has improved data-driven discovery in the earthquake sciences. Together, we envision robotics and AI to advance earthquake science through improved automation and reduced cognitive burden on scientists,... more	19179, 20129
Poster 086	EFP	Two Foreshock Sequences Post Gulia and Wiemer (2019) Kelian Dascher-Cousineau, Emily Brodsky, Thorne Lay Recognizing earthquakes as foreshocks in real time would provide a valuable forecasting capability. In a recent study, Gulia and Wiemer (2019) proposed a traffic‐light system that relies on abrupt changes in b‐values relative to background values.... more
Poster 001	Geology	Late-Quaternary slip rates along the plate boundary Magallanes Fault System, Patagonia Gregory De Pascale, Francisca Sandoval, Manuel Hernandez The megathrust plate boundary in Chile (responsible for the 1960 Mw 9.5 Valdivia Earthquake) dominates the seismic hazard discussion, strike slip faults play a major role in the neotectonic framework in Central-Southern Chile (including Patagonia)... more
Poster 134	FARM	Developing a Database for the Fragile Geologic Features at the Trona Pinnacles National Monument Savannah Devine, Xiaofeng Meng, Christine Goulet, Andrea Donnellan, Devin McPhillips, Gregory Lyzenga In places where recording instruments are not available, the damage state of fragile geologic features (FGFs), combined with appropriate analyses techniques, can be utilized to estimate the ground shaking from earthquakes. We propose to aggregate... more
Poster 137	FARM	Evidence for slow slip in Mecca Hills, CA, from microstructural and (U-Th)/He analysis of heterogeneous hematite coatings on shallow fault surfaces Alexandra DiMonte, Alexis Ault, Kelly Bradbury, Greg Hirth Geodetic and seismologic studies reveal slow slip events in the shallow portions of faults, but the influence of rheology on these events is poorly constrained. Outcrop to nanoscale structures and mineral textures observed in exhumed faults record... more
Poster 004	Geology	Late Pleistocene slip rate and 3D geometry of the Mid-Channel blind thrust, Santa Barbara Channel, CA, and their implications for earthquake hazards Jessica Don, John Shaw, Ana Luiza Nicolae, Christopher Sorlien, Craig Nicholson, Richard Behl The offshore Mid-Channel blind-thrust fault is located in the Santa Barbara Channel in the southern portion of the western Transverse Ranges. The fault is north dipping and overlain by an asymmetric anticline with a narrow steep forelimb and a wider... more	20085
Poster 133	FARM	Database Development for the Trona Pinnacles Fragile Geologic Features Andrea Donnellan, Christine Goulet, Xiaofeng Meng, Gregory Lyzenga, Devin McPhillips, Savannah Devine The 2019 Ridgecrest earthquake sequence, which included M6.4 and M7.1 earthquakes on orthogonal fault ruptures, occurred near the Trona Pinnacles. The Tona Pinnacles consist of more than 500 tufa spires located in the Searles Lake Basin, some of... more	20119
Poster 107	Geodesy	Comparison of ground-based and space-based surface rupture mapping of the May 15, 2020 M6.5 Monte Cristo Range earthquake, Nevada Austin Elliott, Seth Dee, Rich Koehler, William Barnhart, Rich Briggs, Camille Collett, Timothy Dawson, Stephen DeLong, Ryan Gold, Elizabeth Haddon, Evan Hartsorn, Alexandra Hatem, Chris Milliner, Alexandra Pickering, Ian Pierce, Gordon Seitz, Charles Trexler, Chuck Wicks, Xiaohua Xu, Judy Zachariasen The M6.5 Monte Cristo Range, Nevada earthquake of May 15, 2020 ruptured an intricate array of small faults at the Earth’s surface, most too small to map individually with satellite imaging, and with small offsets that were difficult to detect and... more
Poster 096	EFP	Foreshock Cascade to Failure in the M 6.4 July 4, 2019 Ridgecrest, California Earthquake William Ellsworth Our current understanding of how earthquakes nucleate leaves open critical questions about the physical processes that occur before dynamic rupture including whether or not foreshocks have other than weak statistical value as a precursor. Two end-... more
Poster 120	SDOT	An innovative technique combining forward and inverse approaches to resolve interseismic deep slip and locking depths on closely spaced faults Hanna Elston, Michele Cooke, Jack Loveless, Scott Marshall In the San Gorgonio Pass region, forward Boundary Element Method (BEM) models of complex 3D faulting show that multiple viable fault configurations can match some but not all geologic slip rates. Inversions of interseismic surface velocities often... more	20055
Poster 166	FARM	Community Code Comparisons for Simulating Sequences of Earthquakes and Aseismic Slip (SEAS): Exploring Full dynamics and 3D Effects Brittany Erickson, Junle Jiang, Michael Barall, Mohamed Abdelmeguid, Lauren Abrahams, Kali Allison, Jean-Paul Ampuero, Sylvain Barbot, Camilla Cattania, Benchun Duan, Eric Dunham, Ahmed Elbanna, Yuri Fialko, Ruth Harris, Benjamin Idini, Jeremy Kozdon, Valere Lambert, Nadia Lapusta, Meng Li, Dunyu Liu, Yajing Liu, Yingdi Luo, Xiao Ma, Casper Pranger, Paul Segall, Pengcheng Shi, Prithvi Thakur, Martijn van den Ende, Ylona van Dinther, Meng Wei Numerical simulations of Sequences of Earthquakes and Aseismic Slip (SEAS) have made great progress over past decades to address important questions in earthquake physics and fault mechanics. However, significant challenges in SEAS modeling remain... more	20113
Poster 083	Seismology	Monitoring the changing site response of the Mexico City basin Laura Ermert, Marine Denolle Many large cities are built on sedimentary basins, and considerable effort has been dedicated to study the specific seismic hazard associated with their particular geometries and lithologies. Recently, there is growing recognition of the evolving... more
Poster 113	Geodesy	Exploratory visualization and analysis of high resolution GPS data across California Ariel Espindola-Mercado, Amy Ferrick, Brendan Meade As part of the 2020 SOURCES program our team forayed into the Nevada Geodetic Laboratory’s high frequency 5-minute GPS dataset spanning 2013-2017. This dataset, over 350 GB and 20 million separate files, has remained underutilized and difficult to... more

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