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 1-50 of 323

SCEC ID	Category	Title and Authors	SCEC Award
Talk Wed 08:30	EEII	Earth Science Research Needs for Improving Earthquake Scenarios Brad Aagaard Earthquake scenarios provide important opportunities to showcase the effectiveness of integrating science from across the spectrum of earthquake hazards research. These scenarios complement probabilistic hazard assessments by examining specific... more
Poster 198	FARM	A novel hybrid numerical finite element-spectral boundary integral scheme for modeling earthquake cycles Mohamed Abdelmeguid, Xiao Ma, Ahmed Elbanna Modeling earthquake ruptures is a complex challenge due to the eclectic sources of nonlinearities, such as friction law, plasticity, and material damage. In addition to the nonlinearities, another challenging aspect of earthquake dynamic is the... more
Poster 155	SDOT	Numerical simulations of stress variations with depth in a model for the San Jacinto fault zone Niloufar Abolfathian, Christopher Johnson, Yehuda Ben-Zion Depth dependent crustal stress orientations produced in strike-slip faulting environments are explored using quasi-static numerical simulations with variations to the geometry and rheology of the layered substrate to test model conditions that... more	18026
Poster 202	FARM	Rupture Dynamics at the Interface Between a Thin Compliant Layer and Stiffer Underlying Half-Space Lauren Abrahams, Kali Allison, Eric Dunham In this study we examined the sliding dynamics of a frictional interface between elastic solids. Sliding dynamics is well understood for two identical or dissimilar half-spaces (e.g., Rice et al, 2001; Aldam et al., 2017). Sliding between a thin... more
Poster 022	GM	A Proposed Seismic Velocity Profile Database Model Sean Ahdi, Shamsher Sadiq, Okan Ilhan, Yousef Bozorgnia, Youssef Hashash, Dong Youp Kwak, Duhee Park, Alan Yong, Jonathan Stewart We describe the data model currently in use in a publicly available velocity profile database under development for the United States. The initial implementation of the database contains data primarily from California, but also currently includes... more
Talk Wed 09:00	EEII	Where We Have Been, Where We Are Going… And How We Can Work Together Marissa Aho More than 10 years after the 2008 ShakeOut scenario, the Mayor’s Office of Resilience is still working with many of the original authors and other partners to advance the region’s seismic resilience. ShakeOut and other related efforts have had a... more
Poster 103	Seismology	3-D upper crustal velocity structure of the Coachella Valley, Southern California: results from the salton seismic imaging project Rasheed Ajala, Patricia Persaud, Joann Stock, Gary Fuis, John Hole, Mark Goldman, Daniel Scheirer The Coachella Valley is host to the southernmost section of the San Andreas fault (SAF), which is generally considered to be overdue for a large magnitude (M≥7) earthquake. To improve seismic risk assessments in this region, accurate knowledge of... more	15190, 18074
Poster 233	Geology	Precariously Balanced Rocks in northern Utah: are Wasatch Fault earthquakes worse than expected? Amir Allam, Austin Sorscher, Alysha Armstrong, Cole Richards, Austin McKell, Sam Clairmont Where they persist in seismically active regions, precariously balanced rock [PBR] formations can be used to provide constraint on the strongest co-seismic ground motions which occurred during the largest prehistoric earthquakes. The Wasatch Fault... more
Poster 096	Seismology	New techniques in point cloud analysis of high-density seismic array data to determine three dimensional fault and crustal structures in the Long Beach Basin Andrew Allevato, Robert Clayton, Dayanthie Weeraratne The lack of knowledge of crustal structure and fault surface behavior at depth can adversley affect earthquake hazard analysis in highly populated areas. Interactions between faults and crustal layers at depth may also be important. Using passive... more
Poster 161	SDOT	Shear heating and the brittle-ductile transition: thermomechanical earthquake cycle simulations on continental strike-slip faults Kali Allison, Eric Dunham We investigate interactions between coseismic slip in the seismogenic zone, deeper interseismic fault creep, and off-fault viscous flow in the context of earthquake cycle simulations on a strike-slip fault in continental crust, like the San Andreas... more	18050
Poster 012	GM	Nonlinear Fourier-based Amplification Factors for the SCEC Broadband Platform Domniki Asimaki, Jian Shi We use nonlinear site response simulations to calculate Fourier-basad site amplification factors for California. The amplification factors are designed to correct Broadband Platform simulated time-series on reference site conditions, thus... more	16036, 16028
Poster 201	FARM	Modeling damage evolution in the near-fault region as a result of rupture on complex fault Khurram Aslam, Eric Daub We couple short-term (i.e. the co-seismic) and long-term (i.e. the inter-seismic) phase of an earthquake, in order to investigate how induced static stress changes during the co-seismic phase of an earthquake cycle influence the dynamics of strain... more	18095
Poster 275	SAFS	Focal mechanisms and seismicity of LFEs on Parkfield Miki Aso, Naofumi Aso, Satoshi Ide Tectonic LFEs have been found at plate boundaries worldwide and considered to be associated with regional slow deformation. Therefore, it is natural that the focal mechanisms of LFEs have been determined as low-angle thrust in subduction zones, such... more
Poster 173	FARM	Nanoscale evidence for transient rheology during an earthquake Alexis Ault, Jordan Jensen, Robert McDermott Nanoscale textures record the evolution of fault rock rheology and strength during the earthquake cycle. Earthquakes occur on thin fault surfaces and require a dramatic reduction in fault friction, potentially aided by a concomitant spike in fault... more	17164
Poster 118	Geodesy	Slow Slip Events: Earthquakes in Slow Motion Jean-Philippe Avouac, Sylvain Michel, Adriano Gualandi Faults can slip episodically during earthquakes, but also during transient aseismic slip events, commonly called Slow Slip Events (SSEs). The mechanisms at the origin of SSEs might be investigated based on their scaling properties. Previous... more
Poster 225	Geology	Contemporary and Paleoliquefaction Induced Lateral Spreading in Christchurch New Zealand Jeffrey Bachhuber, Gregory De Pascale, Ellen Rathje, michael Little, Peter Almond, Christian Ruegg, Michael Finnemore Earthquake triggered liquefaction and lateral spreading was widespread in Cantebury New Zealand during the 2010 to 2012 Cantebury earthquake sequence (CEF) and lead to $20 billion NZ dollars damage. Although the causes and timing of liquefaction... more
Poster 271	SAFS	Contrasts in integrated crustal strength drive the asymmetric distribution of topography and deformation within restraining bends Curtis Baden, George Hilley Restraining bends in the San Andreas Fault (SAF) generate zones of regional plate convergence along the Pacific-North American plate boundary. This causes uplift near them, and generates seismic activity as crust deforms. Interestingly, topography... more	17241
Poster 181	FARM	Thermal pressurization evolution with total slip Nir Badt, Terry Tullis, Greg Hirth Dynamic weakening by thermal pressurization is studied on nominally flat surfaces of Frederick Diabase with a rotary-shear apparatus. Experiments are performed at a normal stress of 50 MPa, confining pressure of 45 MPa and pore fluid pressure of 25... more	18097
Poster 163	SDOT	The role of rheological evolution on active deformation of Southwestern North America within the Pacific-North America Plate Boundary Zone since the Oligocene Alireza Bahadori, William Holt, Jeonghyeop Kim, Troy Rasbury, Weisen Shen, Julia Grossman Through a subduction to a transform dominated margin transition in western North America, highlands and thick crustal welts were dramatically altered to Basin and Range style topography and thin crustal structure. We incorporate the finite strain,... more	18187
Poster 084	Seismology	Mitigating Spatial Bias of Back-projections with the Slowness Enhanced Back Projection Han Bao, Lingsen Meng Benefiting from recently development of regional seismic arrays, the back-projection (BP) method images the dynamic rupture process and resolve their geometrical complexities with unprecedented details. Unlike source inversion methods, BP tracks... more
Poster 125	Geodesy	Co-seismic Vertical Offset Retrieval From High-Resolution, Stereogrammetric DEMs: Examples from the 2013 Baluchistan, Pakistan Earthquake William Barnhart, Hannah Shea, Katherine Peterson, Ryan Gold, Rich Briggs, David Harbor We highlight recent advances in the quantification of vertical offsets generated by earthquakes from time series of high-resolution stereogrammetric DEMs, with a focus on the 2013 Mw7.7 Baluchistan, Pakistan strike-slip earthquake. Topographic data... more	16147, 17086
Poster 038	EFP	Forecasting earthquake behavior on the Alpine Fault, New Zealand Nicolas Barth, Jamie Howarth, Keith Richards-Dinger, Sean Fitzsimons, Glenn Biasi New Zealand’s Alpine Fault is perhaps the world’s best example of a relatively simple, hypermature, active continental plate boundary transform. A 4000-year paleo-earthquake record from the Alpine Fault reveals the extent of the last 19 surface... more
Poster 011	GM	Implementing Inter-Period Correlations into SCEC BBP Simulations Jeff Bayless, Norman Abrahamson Methods for implementing the inter-period correlation of epsilon into two SCEC BBP simulation methods are explored. For Exsim (Atkinson and Assatourians, 2015), the correlated epsilons are introduced in the frequency domain and the Goulet et al. (... more	17138
Poster 157	SDOT	Orientation of faults, fault roots, rock fabric, stress, and deformation in Southern California: Geographical comparisons and field and numerical experiments Thorsten Becker, Vera Schulte-Pelkum, Whitney Behr, Robert Porritt, Meghan Miller How do faults root into the ductile deep crust? Do pre-existing faults and shear zones affect present-day faulting and deformation? Here, we discuss constraints from existing datasets across Southern California and introduce a new seismic experiment... more	18083, 17098
Poster 179	FARM	The effect of grain size and gouge microstructure on fault slip behavior John Bedford, Daniel Faulkner Conceptually, brittle fault zones are envisaged to be comprised of a localized fault core, or strands of multiple fault cores, surrounded by a distributed fractured damage zone. The core of fault zones, where the majority of slip is accommodated,... more
Poster 066	Seismology	Spatial variations of rock damage production by earthquakes in southern California Yehuda Ben-Zion, Ilya Zaliapin We perform a comparative spatial analysis of earthquake production of rupture area and volume in southern California using observed seismicity and basic scaling relations from earthquake phenomenology and fracture mechanics. The analysis employs the... more	18054
Poster 185	FARM	Fluid-induced aseismic slip can outpace pore-fluid migration – evidence from in situ data Pathikrit Bhattacharya, Robert Viesca Earthquake swarms attributed to subsurface fluid-injection are usually assumed to occur on faults destabilized by elevated pore-fluid pressures. But theory suggests that fluid-injection could also activate aseismic slip which might ultimately... more	18043
Poster 094	Seismology	Machine learning-based surface wave tomography of Long Beach, CA, USA Michael Bianco, Kim Olsen, Peter Gerstoft, Fan-Chi Lin We use a machine learning-based tomography method to obtain high-resolution subsurface geophysical structure in Long Beach, CA, from seismic noise processing on a "large-N" array. This locally sparse travel time tomography (LST) method... more
Poster 264	SAFS	The Current Unlikely Earthquake Hiatus at California’s Transform Boundary Paleoseismic Sites Glenn Biasi, Katherine Scharer Paleoseismic and historic earthquake records provide data used to quantify earthquake recurrence rates for seismic hazard estimation. Earthquake recurrence rates are equally useful to test the likelihood of seismically quiescent periods. At... more
Poster 226	Geology	Analysis of Offset Stream Channels – Deconstructing Creep and Coseismic Slip Components Using Very High Resolution SfM Imagery, Southern San Andreas Fault, Coachella Valley, California Chelsea Blanton, Thomas Rockwell, Allen Gontz, Josh Kelly The southern segment of the San Andreas fault (SAF) has historically been the subject of geologic and geodetic slip rate and creep studies. Our investigation expands this research by focusing on small-scale offsets potentially related to creep since... more	18038
Poster 039	EFP	Emergent failure process of a M4.2 earthquake offshore Istanbul observed from GONAF downhole recordings Marco Bohnhoff, Peter Malin, Murat Nurlu, Felix Bluemle The main branch of the North Anatolian Fault Zone below the Sea of Marmara is facing a high probability for a M>7 earthquake. Recently implemented monitoring efforts such as the downhole GONAF observatory nor allow for detecting low-magnitude... more
Poster 251	Geology	Rupture scenarios for the San Diego Trough and San Pedro Basin fault systems, offshore Southern California Jayne Bormann, Graham Kent, Neal Driscoll The hazard posed by offshore faults for coastal populations in Southern California is poorly characterized and may be considerable, especially when these communities are located near long faults that have the ability to produce large earthquakes.... more
Poster 249	Geology	Towards characterizing the geometry and potential fault system connectivity at the southern termination of the Palos Verdes fault, offshore southern California Dan Boyd, Jayne Bormann The Palos Verdes fault (PVF) is a northwest-striking, strike-slip fault that cuts young marine and terrestrial sediments in the Los Angeles area from Santa Monica Bay in the north, across the Palos Verdes Peninsula, across the San Pedro Shelf and... more
Poster 008	GM	Cybershake NZ v18.6: New Zealand simulation-based probabilistic seismic hazard analysis Brendon Bradley, Karim Tarbali, Robin Lee, Jonney Huang, D Lagrava, V Polak, J Motha, Sung Bae This poster presents the computational workflow and results of the June 2018 version (v18.6) of probabilistic seismic hazard analysis (PSHA) in New Zealand based on physics-based ground motion simulations (`Cybershake NZ'). A total of ~12,000... more
Talk Tue 09:00	EEII	Assessing Surface Fault Rupture Deformation Jonathan Bray Surface fault rupture can produce localized or distributed deformation. In addressing the surface fault rupture hazard, the potential patterns of ground deformation should be developed through the use of a comprehensive site investigation including... more
Poster 289	CS	Fused Earthquake Simulations on Deep Learning Hardware Alexander Breuer, Alexander Heinecke, Yifeng Cui We present the status of recent and ongoing extensions to the Extreme-scale Discontinuous Galerkin Environment (EDGE) for seismic wave propagation. EDGE uses the Discontinuous Galerkin (DG-) Finite Element Method (FEM) to solve hyperbolic partial... more	18211
Poster 043	EFP	Are we still seeing aftershocks from the M6.8 1872 Central Washington Earthquake? Thomas Brocher I investigate spatial and temporal relations between an ongoing and prolific seismicity cluster in central Washington state, near Entiat, and the December 14, 1872 Entiat earthquake, the largest historic crustal earthquake in Washington. A fault... more
Poster 183	FARM	The spatial footprint of injection wells in a global compilation of induced earthquake sequences Emily Brodsky, Thomas Goebel Fluid injection induced seismicity is commonly modeled by assuming purely fluid-pressure driven earthquakes. However, this assumption is challenged by induced sequences with observed far-field triggering. To unravel triggering mechanisms of... more
Poster 093	Seismology	Towards Seismic Inverse Problems Using Deep Learning Jared Bryan, Alexander Breuer, Yifeng Cui Understanding the behavior and state of fault systems is necessary to make thorough seismic hazard assessments, as well as to realistically model the evolution of earthquake ruptures. Estimation of the evolution of earthquake ruptures is a... more	18211
Poster 254	Geology	Quaternary Slip History of the Central Sierra Madre Fault, Southern California Reed Burgette, Katherine Scharer, Nathaniel Lifton, Austin Hanson, Devin McPhillips, Tammy Rittenour The Central Sierra Madre thrust fault (CSMF) accommodates uplift of the San Gabriel Mountains along the northern Los Angeles metropolitan area. A suite of Quaternary terrace and fan surfaces are preserved near Arroyo Seco and offset across strands... more	16066, 15179
Poster 140	Geodesy	Quantifying the bias introduced by vegetation in InSAR studies of ground deformation and surface processes Paula Burgi, Rowena Lohman With the advent of more frequently acquired SAR data, regions with significant vegetative cover are now easier to study. We explore the sensitivity of InSAR to vegetation and land cover variations, which can bias InSAR-based interpretations of... more
Poster 262	SAFS	Earthquake cycle stress accumulation disparities of the Cajon Pass region Liliane Burkhard, Bridget Smith-Konter, Lauren Ward, Katherine Scharer, David Sandwell As the San Andreas Fault System is known to participate in multi-segmented ruptures, it is important to understand how both fault segment properties and regional rheology can influence earthquake cycle stress accumulation. Here, we investigate... more	18149
Poster 234	Geology	Dating of Offset Geomorphic Features Along the Garlock Fault, Mojave Desert, California: Testing a Proposed Earthquake Supercycle Model James Burns, Sally McGill, Ed Rhodes, James Dolan, Nathan Brown Recent investigations into the Garlock Fault at the northern edge of the Mojave Desert point to a strongly irregular pattern of earthquake recurrence, which may be related to temporal variations in slip-rate on the fault. These previously published... more
Poster 232	Geology	Earthquake hazard assessment evaluated by fragile geologic features in coastal Central California Anna Caklais, Dylan Rood, Mark Stirling, Christopher Madugo, Norman Abrahamson, Klaus Wilcken, Tania Gonzalez, Albert Kottke, Alexander Whittaker Probabilistic seismic hazard (PSH) models typically provide estimates of ground motions for return periods that exceed historical observations. It is therefore important to develop methods to evaluate ground motion estimates for long return periods... more
Poster 295	CME	A SCEC CyberShake Physics-Based Probabilistic Seismic Hazard Model for Northern California Scott Callaghan, Philip Maechling, Christine Goulet, Kevin Milner, Mei-Hui Su, Robert Graves, Kim Olsen, Brad Aagaard, Kathryn Wooddell, Albert Kottke, Thomas Jordan, John Vidale The Southern California Earthquake Center (SCEC) has developed CyberShake, a simulation platform that performs physics-based probabilistic seismic hazard analysis (PSHA) using 3D deterministic wave propagation simulations. The CyberShake PSHA... more
Poster 176	FARM	Preliminary data on detecting asperity flash heating on hematite faults with laboratory experiments and hematite (U-Th)/He thermochronometry Gabriele Calzolari, Alexis Ault, Greg Hirth Friction-generated heat is a primary by-product of seismic slip on faults and can activate various mechanisms that lead to low coseismic strength. Hematite mineralization is ubiquitous in fault zones as striated or “mirrored” (high gloss, light... more	17164
Poster 135	Geodesy	Seasonal and long-term crustal stress modulation due to aquifer compaction and groundwater unloading during the 2007-2010 drought in California Grace Carlson, Manoochehr Shirzaei, Chandrakanta Ojha, Susanna Werth Fluctuations in terrestrial water storage (TWS) cause deformation of Earth’s crust. In regions with large seasonal TWS oscillations, subsidence is observed in the wet seasons and uplift in the dry, as the lithosphere responds elastically to changes... more
Poster 268	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 the fault that has not ruptured in the last 200 years. It is not known whether this long quiescent period reflects a long average recurrence interval for this portion of... more
Poster 095	Seismology	First-arrival traveltime tomography at Long Beach California using ambient seismic noise and the adjoint-state method Jorge Castillo Castellanos, Robert Clayton Knowledge of the fine-scale velocity structure of the subsurface is crucial for predicting ground motion and, thus, hazard assessment. In a recent study, Lin et al. (2013) showed that ambient noise surface wave correlations from a high-density oil-... more
Poster 190	FARM	Crack models of repeating earthquakes predict observed moment-recurrence scaling Camilla Cattania, Paul Segall Small repeating earthquakes are highly periodic events, and they are thought to occur on velocity weakening (stick-slip) asperities embedded in a velocity strengthening (creeping) fault. In contrast, intermediate and large earthquakes (above ~ M4)... more

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