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 301-350 of 355

SCEC ID	Category	Title and Authors	SCEC Award
Poster 051	FARM	Modeling the effect of roughness on the nucleation and propagation of shear rupture Yuval Tal, Bradford Hager Faults are rough at all scales and can be described as self-affine fractals. This deviation from planarity results in geometric asperities and a locally heterogeneous stress field, which affect the nucleation and propagation of shear rupture. We... more	16108
Poster 239	Seismology	Remotely triggered small earthquakes along the San Jacinto Fault Zone, CA Jennifer Tarnowski, Abhijit Ghosh Although there are an increasing number of studies documenting earthquakes triggered by dynamic stresses from teleseismic events, there is still much to understand about earthquake triggering on a regional scale. We focus on the central and southern... more
Poster 011	SDOT	Temperature exerts the strongest control on the 3D rheology of the southern California lithosphere Wayne Thatcher, David Chapman, Colin Williams Lithospheric temperature differences influence rheologic behavior, crustal deformation and earthquake occurrence in southern California. However, geotherms are poorly constrained, with those used in published deformation modeling studies typically... more	16250
Poster 034	FARM	The Scale-Dependence of Fault Roughness and Asperity Strength Christopher Thom, Emily Brodsky, David Goldsby The frictional properties of fault surfaces are controlled by the collective behavior of asperity contacts. For a single asperity, the force of friction is given by Ff = τa ∙ A, where τa is the shear strength of an asperity and A is its contact... more
Talk 9/13 08:00	Seismology	Constraints on the Source Parameters of Low-Frequency Earthquakes in Parkfield and Cascadia Amanda Thomas, Gregory Beroza, David Shelly, Michael Bostock, Allan Rubin, Genevieve Savard, Lindsey Chuang Low-frequency earthquakes (LFEs) are small repeating earthquakes that occur in conjunction with deep slow slip. Like typical earthquakes LFEs are thought to represent shear slip on crustal faults but when compared to earthquakes of the same... more
Poster 338	CS	Next Generation Boundary Element Models for Earthquake Science Thomas Thompson, Brendan Meade Modeling fault behavior and stress evolution in complex fault geometries throughout the earthquake cycle is a fundamental goal in earthquake science. To enable these studies we discuss the development of Tectosaur, a boundary element library for... more
Poster 213	Seismology	Development and validation of an improved seismic velocity model for the San Jacinto Fault region of Southern California Clifford Thurber, Amir Allam, Xiangfang Zeng, Yan Luo, Hongjian Fang, Haijiang Zhang We are improving 3D body-wave and surface-wave tomographic inversions in the San Jacinto Fault Zone (SJFZ) region, building on previous research by (1) further expanding the arrival time, phase velocity, and dispersion datasets, (2) extending the... more	16226
Poster 340	CS	Accelerating AWP-ODC-OS Using Intel Xeon Phi Processors Josh Tobin, Alexander Breuer, Charles Yount, Alexander Heinecke, Yifeng Cui AWP-ODC is software that simulates dynamic rupture and wave propagation, using a staggered grid finite difference scheme, and is widely used in the SCEC community. Recently a unified open source version AWP-ODC-OS has been released. We present an... more
Poster 156	Geodesy	Postseismic deformation and viscosity of the Mexicali region following the El-Mayor Cucapah earthquake inferred from GPS observations Xiaopeng Tong, Alejandro Gonzalez-Ortega, Bridget Smith-Konter, David Sandwell It is important to study the deformation of the lithosphere to understand the thickness, strength, and viscosity of the lithosphere and substrate. Two northwest-southeast trending fault systems connect the San Andreas Fault system to the rift system... more
Poster 200	Seismology	GrowClust: A hierarchical clustering algorithm for relative earthquake relocation, with application to the Spanish Springs and Sheldon, Nevada, earthquake sequences Daniel Trugman, Peter Shearer, Ken Smith Accurate earthquake locations are essential for providing reliable hazard assessments, understanding the physical mechanisms driving extended earthquake sequences, and interpreting fault structure. Techniques based on waveform cross-correlation can... more
Poster 030	FARM	Progress Report on Addition of a High-Speed Drive to High-Pressure, Rotary-Shear Apparatus Terry Tullis My rotary-shear, high-pressure machine at Brown University has been operational for over 35 years. It allows unlimited slip on annular samples at confining pressures up to 1 GPa. Nitrogen or argon gas is used as the pressure medium in order to... more
Poster 139	Geodesy	Toward the 3-component Crustal Motion Model: Integration of Sentinel-1A SAR interferometry and continuous GPS in the Los Angeles-Western Mojave area Ekaterina Tymofyeyeva, Homan Lau, Yuri Fialko The new Sentinel-1 mission, launched by the European Space Agency in April 2014, provides extensive coverage at high spatial resolution and frequent revisit intervals, which can dramatically improve measurements of secular and transient deformation... more	16301
Poster 341	CS	High performance earthquake simulations in viscoelastic media using SeisSol Carsten Uphoff, Michael Bader, Sebastian Rettenberger, Alice-Agnes Gabriel The software package SeisSol simulates seismic wave propagation and dynamic rupture. Being based on unstructured tetrahedral meshes, the software may be used in highly complex scenarios with respect to fault geometry and heterogeneous materials. The... more
Poster 224	Seismology	The Land-Atmosphere Interactions from Barometers and Seismometers Anne Valovcin, Jiong Wang, Toshiro Tanimoto Our understanding of seismic noise has improved dramatically in the last 50 years. Also the cross-correlation approach now allows us to make the Green’s functions and apply it to practical applications. However, depending on the frequency band, the... more
Talk 9/13 14:00	EFP	Induced earthquake magnitudes are as large as (statistically) expected Nicholas van der Elst, Morgan Page, Debbie Weiser, Thomas Goebel, Seyed Hosseini Injection-induced seismicity is a major contributor to seismic hazard in the central US. The question now is whether induced seismicity is amenable to statistical forecasting on any useful timescale. One of the major uncertainties affecting such a... more
Poster 275	GMP	On nonstationarity corrections and durations in ground motion applications of random vibration theory Chris Van Houtte, Tam Larkin, Caroline Holden Random vibration theory (RVT) is a method for approximating the peak time domain response of a signal from its Fourier amplitude spectrum, based on assumptions of stationarity over a portion of the signal duration, and random phase angles. In ground... more
Poster 237	Seismology	Status of ShakeAlert and G-FAST in the Pacific Northwest John Vidale, Brendan Crowell, J Hartog, Paul Bodin, Victor Kress, Ben Baker Here, we evaluate the real-time and historical performance of the ElarmS‐2 algorithm in the Pacific Northwest. Real‐time and pre-recorded seismic data from Oregon, California, and Washington in the United States and British Columbia in Canada have... more
Poster 068	FARM	Self-similar asymptotics of rate-strengthening faults Robert Viesca, Pierre Dublanchet We examine how slow slip progresses on rate-strengthening faults. We consider that the source of rate-strengthening may be a linear or non-linear viscous fault rheology, a logarithmic rate-dependence, or a Dieterich-Ruina dependence on slip rate and... more
Poster 345	CS	Using Coupled Geomechanical Modeling to Investigate Potential Production Induced Seismicity Robert Walker, Susan Hough, Birendra Jha, Victor Tsai, Morgan Page, Fred Aminzadeh Recent work has suggested that oil and gas industry operations may have triggered significant induced seismicity in several cases throughout the twentieth century. We have chosen one historic example to apply a coupled fluid flow and geomechanical... more
Poster 144	Geodesy	The California Plate Boundary Observatory GPS-GNSS Network Christian Walls, Doerte Mann, Ryan Turner, Andre Basset, Shawn Lawrence, Kenneth Austin, Stephen Dittman, Karl Feaux, Glen Mattioli The EarthScope PBO GPS-GNSS network in California, funded by the NSF and operated by UNAVCO, is comprised of 599 permanent GPS and GNSS stations spanning three principal tectonic regimes and is administered by separate management regions (Subduction... more
Poster 158	Geodesy	Observations and Models of Co- and Post-Seismic Deformation Due to the 2015 Mw 7.8 Gorkha (Nepal) Earthquake Kang Wang, Yuri Fialko The 2015 Mw 7.8 Gorkha (Nepal) earthquake occurred along the central Himalayan arc, a convergent boundary between India and Eurasian plates. We use space geodetic data to investigate co- and post-seismic deformation due to the Gorkha earthquake.... more
Poster 205	Seismology	Using coda waves to resolve the scattering and intrinsic attenuation structure of Southern California Wei Wang, Peter Shearer Measuring intrinsic and scattering attenuation is important for a variety of geophysical applications. Charactering scattering and absorbing properties and the power spectrum of crustal heterogeneity is a fundamental problem for informing strong... more
Poster 093	Geology	San Diego Earthquake Hazard: Geotechnical Data Synthesis Luke Weidman, Jillian Maloney, Thomas Rockwell With a population of ~1.3 million, the City of San Diego is the third largest city in California, and it is traversed by the Holocene-active Rose Canyon Fault Zone (RCFZ). The Rose Canyon Fault is a strike-slip fault with a slip rate of 1-2 mm/yr... more	16195
Poster 180	Seismology	Science-based decision making in a high-risk energy production environment Debbie Weiser Energy production practices that may induce earthquakes require decisions about acceptable risk before projects begin. How much ground shaking, structural damage, infrastructure damage, or delay of geothermal power and other operations is tolerable... more
Poster 314	CSEP	CSEP Evaluations of 24-Hour Earthquake Forecasting Models for California: New Results and Ensemble Models Maximilian Werner, Maria Liukis, Warner Marzocchi, David Rhoades, Matteo Taroni, Zechar Zechar, Thomas Jordan Operational Earthquake Forecasting requires credible earthquake probability estimates at short time scales. The objective of the Collaboratory for the Study of Earthquake Predictability (CSEP) is to evaluate earthquake forecasting models and... more	15169
Poster 095	Geology	Geological Observations on History and Future of Large Earthquakes along the Himalayan Frontal Fault Relative to the April 25, 2015 M7.8 Gorkha Earthquake near Kathmandu, Nepal Steven Wesnousky Steven G. Wesnousky1, Yasuhiro Kumahara2, Deepak Chamlagain3, Ian Pierce1, Alina Karki3, Dipendra Gautam4: 1 Center for Neotectonic Studies and Seismological Laboaratory, University of Nevada, Reno 89557, USA, 2 Graduate School of Education,... more
Poster 169	Seismology	Aftershock productivity of large megathrust earthquakes: regional variations and influence of mainshock source parameters Nadav Wetzler, Emily Brodsky, Thorne Lay Aftershock productivity is observed to increase with mainshock magnitude following a well-defined relationship for any given region. However, variation of this scaling relationship is still poorly characterized. We focus on variations of aftershock... more
Poster 247	Seismology	Comparisons between the 2016 USGS induced-seismicity hazard model and “Did You Feel It?” data Isabel White, Taojun Liu, Nicolas Luco, Abbie Liel The steep increase in seismicity rates in Oklahoma and southern Kansas led the U.S. Geological Survey (USGS) to develop a one-year induced seismicity probabilistic seismic hazard model for 2016 (Petersen et al., 2016). The increase has also led to... more
Poster 174	Seismology	A detailed automatic 1998-2015 earthquake catalog of the San Jacinto fault zone region Malcolm White, Zachary Ross, Frank Vernon, Yehuda Ben-Zion The Anza (AZ) network has collected continuous seismic data since 1998 focusing on the San Jacinto Fault Zone (SJFZ). Nearby stations of the regional CI network and several deployments (PB, SB and YN) around the SJFZ provide important additional... more
Poster 128	SoSAFE	Testing the shorter and variable recurrence interval hypothesis along the Cholame segment of the San Andreas Fault Alana Williams, Ramon Arrowsmith, Sinan Akciz, Thomas Rockwell, Lisa Grant Ludwig, Sally Branscomb The Cholame segment of the San Andreas Fault interacts with the Parkfield segment to the northwest with its creep and M6 earthquakes, and the locked Carrizo segment to the southeast. Although offset reconstructions exist for this ~75 km reach,... more
Poster 318	Simulators	Using Virtual Quake for GNSS tsunami early warning: coupling earthquakes, tsunamis, and ionosphere physics John Wilson, Kasey Schultz, John Rundle, Ramya Bhaskar In light of growing demand for fast Global Navigational Satellite System tsunami early warning in the Pacific Rim, computer simulations are being developed to play key roles at all stages. Virtual Quake is an earthquake simulator that can rapidly... more
Poster 178	Seismology	Validation of Deterministic Broadband Ground Motion and Variability with Ground Motion Kyle Withers The decay of energy at high frequencies, decay as a function of distance, source model, and complementary relations between scattering and apparent attenuation are all important features that simulations need to accurately capture to be used for... more
Poster 085	Geology	Characterizing emissivity spectra from geomorphic surfaces along the southern San Andreas Fault Ryan Witkosky, Paul Adams, Kerry Buckland, Kenneth Hudnut, Patrick Johnson, David Lynch, Katherine Scharer, Joann Stock, David Tratt Geologic mapping and cosmogenic exposure ages of alluvial surfaces along the southern San Andreas Fault provide independent data sets to evaluate corresponding emissivity spectra from thermal hyperspectral airborne imagery. We use new 1-m pixel... more
Poster 062	FARM	Off-fault plasticity in dynamic rupture simulations: 3D numerical analysis and effects on rupture transfer in complex fault geometries Stephanie Wollherr, Alice-Agnes Gabriel Estimating the potential dimension of a future earthquake hosted by a complex fault system depends crucially on rupture branching and jumping dynamics between adjacent fault segments. Numerical modelling of such earthquake source dynamics requires... more
Poster 064	FARM	Scaling of finite-source parameters at Parkfield, California Kathryn Wooddell, Doug Dreger, Taka'aki Taira, Robert Nadeau, Luca Matagnini We determine finite-source slip models for Parkfield earthquakes ranging in magnitude from M1.8 to M4.1 by inverting relative moment rate functions (RMRF) obtained from empirical Green’s function (eGF) deconvolution. The method is based on Mori and... more
Poster 241	Seismology	Stress Drop and Source Scaling of Recent Earthquake Sequences across the United States Qimin Wu, Martin Chapman Knowledge of source scaling and variation in stress drop are essential to a better understanding of source physics and strong ground-motion prediction. Due to the large uncertainties in stress drop measurements, many previous studies have found... more
Poster 143	Geodesy	Comparison of GPS Strain Rate Computing Methods and Their Application Yanqiang Wu Using modeled and simulated data for comparison of several methods to compute GPS strain rate fields in terms of their precision and robustness reveals that least-squares collocation is superior. Large scale (75°E–135°E and 20°N–50°N) analyses of 1... more
Poster 019	SDOT	Using Well Water Level To Measure Volumetric Strain Considering The Dissipation Effect Yuqing Xie, Yonghong Zhao, Lingsen Meng Water-levels in confined well can be used as a strain-meter. Periodic amplitude fluctuations of the water-level generally reflect the strain change induced by Earth’s tide. The measured value of well water-levels can be compared with the theoretical... more
Poster 168	Geodesy	Tectonic and Anthropogenic Deformation Surrounding the Cerro Prieto Geothermal Field from Sentinel-1 Interferometry Xiaohua Xu The Cerro Prieto Geothermal Field (CPFG) lies at the step-over between the Imperial and Cerrro Prieto Faults in northern Baja California. While this is the most tectonically active section of the San Andreas Fault system, the spatial and temporal... more	16072
Poster 105	Geology	Investigate fault zone hydrogeologic architectures by using water level tidal and barometric response Lian Xue, Emily Brodsky, Vincent Allegre, Patrick Fulton, L. Parker Beth , John Cherry Fault zone hydrogeologic architecture is critical to faulting processes; however, they are not well understood and difficult to measure in situ. Water levels inside conventional water wells can tap an artesian aquifer response to pressure head... more
Poster 216	Seismology	Comprehensive Detection and Relocation of the 2010 Mw7.2 El Mayor-Cucapah Foreshock Sequence Dongdong Yao, Zhigang Peng, Xiaofeng Meng, Xiaowei Chen, Raul Castro, Sizuang Deng Large earthquakes are sometimes preceded by foreshocks, and the exact relationship between foreshocks and mainshock nucleation is still unclear. Here we present a comprehensive foreshock detection of the 2010 Mw7.2 El Mayor-Cucapah, Mexico,... more	16168
Poster 243	Seismology	Strike-slip Faulting Energy Release Lingling Ye, Hiroo Kanamori, Thorne Lay, Jean-Philippe Avouac Teleseismic recordings of P waves from 26 large (mostly, MW ≥ 7.5) strike-slip earthquakes from 1990- 2015 have been analyzed to determine their radiated energy, ER, exploring the stability of the estimates with respect to the faulting geometry and... more	16173
Poster 303	EFP	ETAS 2.x: The 2015 Nepal aftershock forecast, a Global ETAS Code, and ETAS based Ground Motion Forecastint Mark Yoder, John Wilson, John Rundle, Margaret Glasscoe In this work, we present improvements, extensions, and refinements to an ETAS type aftershock seismicity model, originally developed and published by Yoder et al. (2015, 2014 online). In our previous work, we show that near-field aftershock rate-... more
Poster 226	Seismology	Preliminary report on site characterization using noninvasive single- and multi-station methods at southern California seismic stations Alan Yong, Antony Martin, Jennifer Pfau, Devin McPhillips, Marcos Alvarez, Scott Lydeen, Fiona Clerc, Nolan Leue In-situ measurements of shear-wave velocity (Vs) are used commonly to evaluate seismic response at earthquake monitoring station and project sites. Vs30, the time-averaged Vs in the upper 30 m, is a common parameter used to capture seismic site... more
Poster 194	Seismology	Earthquakes Induced by Hydraulic Fracturing and Wastewater Injection in Guy-Greenbrier, Arkansas Clara Yoon, Yihe Huang, William Ellsworth, Gregory Beroza The Guy-Greenbrier, Arkansas, earthquake sequence, which occurred from July 2010 through October 2011, was potentially induced by injection of wastewater from nearby hydraulic fracturing operations into disposal wells (Horton, 2012). To gain insight... more
Poster 036	FARM	Estimation of physical properties of a rock sample based on a laboratory transmitted wave experiment and 3D numerical simulations Nana Yoshimitsu, Takashi Furumura Elastic wave transmission during a rock compression test is an efficient way to estimate the characteristics of a sample. Full utilization of transmitted waveform would lead much better understanding of the sample interior, in addition to the... more
Poster 118	SoSAFE	New Holocene slip-rate sites along the Mojave San Andreas Fault near Palmdale, CA Elaine Young, Eric Cowgill, Katherine Scharer Geologic and geodetic slip rates for the Mojave segment of the San Andreas fault (MSAF) appear to be discrepant: the Quaternary geologic rate is as high as 37 mm/yr [1] while the geodetic slip rate is as low as ~15 mm/yr [2]. To better characterize... more	12198
Poster 204	Seismology	Constraints on residual topography and crustal properties in the western US from virtual deep seismic sounding Chunquan Yu, Wang-Ping Chen, Rob van der Hilst We use virtual deep seismic sounding (VDSS) and data from ~1,000 broadband seismic stations to provide high-resolution estimates of crustal structure in the western Cordillera of the United States (US). The most robust result is the geographic... more
Poster 198	Seismology	Products and Services Available from the Southern California Earthquake Data Center (SCEDC) and the Southern California Seismic Network (SCSN) Ellen Yu, Prabha Acharya, Aparna Bhaskaran, Shang-Lin Chen, Jennifer Andrews, Valerie Thomas, Egill Hauksson, Robert Clayton The SCEDC archives continuous data from 9429 data channels and 513 SCSN recorded stations. The SCEDC processes and archives an average of 16,000 earthquakes each year. The SCEDC provides public access to these earthquake parametric and waveform... more	16042
Poster 076	FARM	Kinematic Rupture Process of the 2016 Mw 7.1 Kumamoto Earthquake Sequence Han Yue, Mark Simons, Cunren Liang, Heresh Fattahi, Eric Fielding, Hiroo Kanamori, Donald Helmberger, Linjun Zhu, Michael Sylvain, Jean-Philippe Avouac On April 16th, 2016, the Mw 7.1 Kumamoto earthquake ruptured a portion of the Futagawa fault on the Kyushu island. This event was preceded by two (Mw 6.0 and 6.2) foreshocks happened two days earlier. We investigate the kinematic rupture process of... more

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