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 251-300 of 323

SCEC ID	Category	Title and Authors	SCEC Award
Poster 219	Geology	Sequence of cascading earthquakes on the Newport-Inglewood-Rose Canyon Fault zone from paleoseismic observations Drake Singleton, Thomas Rockwell, Jillian Maloney Approximately 10-20% of the estimated 50 mm/yr plate boundary deformation in southern California is accommodated by the offshore faults that comprise the Inner Continental Borderlands (ICB). The precise distribution of slip and earthquake history in... more
Poster 090	Seismology	Characterizing seismogenic fault structures in Oklahoma Rob Skoumal, J. Ole Kaven Oklahoma is now one of the most seismically active places in the United States as a result of industry activities. A principal challenge in investigating induced seismicity is the identification and characterization of seismogenic faults. Earthquake... more
Poster 212	FARM	Searching for Spot-Fire Earthquakes Triggered During the 2004 Parkfield Mainshock Norman Sleep Strong P waves have the potential to trigger earthquakes ahead of the main rupture front. The triggered daughter event may grow large and merge with the parent event as a supershear rupture. Alternatively, a daughter nucleation may die quickly, just... more	18001
Poster 053	EFP	ShakeAlert v. 2.0 Testing and Certification Deborah Smith, Monica Kohler, Jennifer Andrews, Angela Chung, Renate Hartog, Ivan Henson, Douglas Given, Stephen Guiwits Earthquake early warning algorithms have to undergo rigorous real-time and offline testing before being accepted into the ShakeAlert production system. In anticipation of the scheduled ShakeAlert v. 2.0 phase 1 rollout in late 2018, multiple... more
Poster 236	Geology	Tectonic and geometric constraints for the Wind Canyon fault block on the western Garlock fault: an apatite fission track analysis Iris Smith New apatite fission track analyses from the southeastern side of the Garlock fault near Mojave, CA were obtained in order to better understand the fault evolution and tectonics of the region. Apatite fission track analyses are commonly used to date... more
Poster 138	Geodesy	InSAR/GPS time series deformation of the 2018 Kilauea event: Preparation for a large Southern California event Bridget Smith-Konter, Xiaohua Xu, Lauren Ward, Liliane Burkhard, David Sandwell In preparation for the next major earthquake in Southern California, a key task of SCEC5 is to develop methods to integrate dense spatiotemporal geodetic datasets for post-earthquake rapid response. Events like the 2018 Kīauea Volcano eruption,... more
Poster 301	GM	Investigating the Ground Motion Characteristics of the 2016 Mw 5.5 Gyeongju, South Korea, Earthquake Using the SCEC Broadband Platform Seok Goo Song, Kwan-Hee Yun, Sangmin Kwak The 2016 Mw 5.5 Gyeongju, South Korea, earthquake is the largest instrumentally recorded seismic event in the country. This event provided a valuable set of recorded strong ground motion data in the Korean Peninsula. We investigated the ground... more
Poster 193	FARM	Investigation of Adaptive Time-Stepping Algorithms for Simulating Sequences of Earthquakes and Aseismic Slip (SEAS) Yanke Song, Valere Lambert, Nadia Lapusta Modeling earthquake behavior involves resolving the complex interaction of processes active across timescales ranging from hundreds to thousands of years of tectonic loading, down to milliseconds during the dynamic rupture process. To make such... more	18174
Poster 146	CXM	Assessing the Deep Geometry of the Los Angeles Basin Using Full H/V Spectral Ratio and Multimode Surface Waves Zack Spica, Mathieu Perton, Robert Clayton, Gregory Beroza The H/V spectral ratio (HVSR) of the auto-correlated signal at a seismic station is proportional to the ratio of the imaginary parts of the Green's function. Observations of H/V can be compared to their theoretical counterpart for a locally... more	17031
Poster 009	GM	Strong ground motions simulations for Dunedin city, New Zealand: First steps using the SCEC Broadband Simulation Platform Mark Stirling Our poster will present on-going QuakeCoRE-funded work (quakecore.nz) on developing strong motion simulations for the greater Dunedin city area. The city has never experienced strong ground motions in the entire 179 year historical record, and has... more
Poster 320	CEO	Preliminary Results of a Study to Identify Archaeological Artifacts from San Salvador in Colton, CA, Using Ground Penetrating Radar Chloe Sutkowski, Oscar Prado, Veronica Hernandez, Jascha Polet We will present the preliminary results of an ongoing archaeo-geophysical survey at Pellissier Ranch in Colton, CA. Historical archives suggest that the 200-acre vacant lot was home to a significant portion of San Salvador, the largest non-native... more
Poster 117	Geodesy	Monitoring Fault Creep on the Hayward Fault using Structure from Motion Jerlyn Swiatlowski, Gareth Funning Fault creep is an ongoing process that can be a problem for urban areas that lie along the fault trace. A prime example is Fremont, CA, on the creeping Hayward Fault, where the mean creep rate is ~6 mm/yr. Expressions of fault creep can be seen... more
Poster 003	GM	Evaluating and Improving Ground Motion Predictions for Scenario Earthquakes in The San Francisco East Bay by Integrating Earthquake Ground-Motion Simulations and Noise-Derived Empirical Green's Functions Taka'aki Taira, Arthur Rodgers Simulations of scenario earthquake ground motions play an increasingly important role in improving seismic hazard assessment. In the San Francisco Bay Area (SFBA) the USGS has developed a 3D geologic/seismic model. Simulations of large magnitude (M... more
Poster 174	FARM	Evolution of frictional shear resistance in response to rapid variations of normal stress Yuval Tal, Vito Rubino, Nadia Lapusta, Ares Rosakis A proper formulation of the shear-resistance evolution during rupture is essential for many earthquake source problems, including simulations of the ground motion. While the shear resistance is typically assumed to be proportional to normal stress,... more	18131
Poster 129	Geodesy	Lower-crustal rheology and thermal gradient in the Taiwan orogenic belt illuminated by the 1999 Chi-Chi earthquake Chi-Hsien Tang, Ya-Ju Hsu, Sylvain Barbot, James Moore, Wu-Lung Chang The strength of the lithosphere controls tectonic processes and seismic cycles. Laboratory rock experiments provide fundamental insights into rock rheology under various conditions, but an extrapolation to the strain-rate and length scale relevant... more
Poster 006	EEII	Evaluation of CyberShake ground motions for engineering practice Ganyu Teng, Jack Baker This poster presents the results from evaluation of CyberShake ground motions for high-rise building design in the Los Angeles region. The feasibility of CyberShake is studied by comparing simulated ground motions against recordings from past... more
Talk Mon 10:30	CXM	Heat Flow Data and Seismic Imaging Reveal Both Transient and Steady-State Thermo-Mechanical Processes at Work Beneath Southern California Wayne Thatcher, David Chapman Analysis of heat flow and seismic data provides glimpses of the dynamical processes shaping the thermal evolution of southern California. The present day thermal field bears an imprint of long-lived subduction prior to 30 Ma and subsequent growth of... more	18193
Poster 303	EEII	Sensitivities and Uncertainties in Probabilistic Fault Displacement Hazard Analysis in Southern California Hong Kie Thio, Jeff Bayless As applications of Probabilistic Fault Displacement Hazard Analysis (PFDHA) become more prevalent in California, it is of interest to understand the sensitivities and uncertainties in the models used, both for the source characterization as well as... more
Poster 274	SAFS	Unraveling a tectonic knot: structural domains, voluminous fault zones, creep, and dispersed strain between the San Andreas Fault and Brawley Seismic Zone Clara Thomann, Susanne Jänecke, Daniel Markowski, James Evans, Robert Quinn We report preliminary results from an ongoing analysis of the southern tip of the San Andreas fault (SAF) and northern Brawley seismic zone (BSZ). The SAF consists of the compressional Durmid ladder structure (DLS) along the northeast shore of the... more
Poster 287	CME	The New Zealand Velocity Model (NZVM) Version 2.0 and ground motion simulations of Hope Fault earthquakes Ethan Thomson, Brendon Bradley, Robin Lee This poster presents recent updates to the New Zealand Velocity Model (NZVM) for use in physics-based broadband ground motion simulation and scenario simulations of ruptures on the Hope Fault. The NZVM is based on the concept of embedding high-... more
Poster 223	Geology	The Thousand Lake Fault: Earthquake Geology of a Long Recurrence Normal Fault at the Eastern Edge of the Basin and Range Nathan Toke, David Marchetti, Christopher Bailey, Robert Biek, Joseph Phillips, Hanna Bartram, Clayton Forster The Thousand Lake fault (TLF) is 50-kilometer-long normal fault and a prominent structural boundary between the Basin and Range and the Colorado Plateau in southern Utah. Many of the most active faults in the Basin and Range (those with slip rates... more
Poster 137	Geodesy	Updating GPS site positions and velocities and improving GPS coverage in southern California for the Community Geodetic Model Eneas Torres Andrade, Gareth Funning, Jerlyn Swiatlowski We have conducted a GPS resurvey of geodetic benchmarks in the Inland Empire of southern California, with the goal of more precisely determining the rates of movement of the major strike slip faults in the region – the San Andreas, San Jacinto and... more
Poster 315	CEO	Visualization of Hazards Associated with Simulated Earthquakes in Southern California Ashlee Trotter, Ramon Mei, Paige Given, Christina Polcino, Elvis Carrillo, Jordan Wolz, Resherle Verna, Jozi Pearson, Gabriela Noriega, Thomas Jordan The 2018 Undergraduate Studies in Earthquake Information Technology (USEIT) internship program challenged the Hazard and Risk Visualization (HaRVi) Team to analyze and visualize threatening earthquake scenarios on the southern section of the San... more
Poster 177	FARM	Progress Report 2 on Addition of a High-Speed Drive to High-Pressure, Rotary-Shear Apparatus Terry Tullis Rotation of the sample in my rotary-shear, high-pressure machine is driven by two systems. The first uses an electrohydraulic stepping motor providing unlimited displacement at >7 orders of magnitude in speed from 0.001 microns/s to 10 mm/s. The... more
Poster 111	Seismology	Preliminary Site Response Results across the San Gabriel and San Bernardino Basins Utilizing the Ambient Noise Spectral Ratio Method Anisha Tyagi, Margaret Grenier, Rachel Kreuziger, Jacob Kays, Jascha Polet Sedimentary basins, such as the San Gabriel and San Bernardino Basins, are known to amplify earthquake ground motions; therefore, it is important to characterize these Basins and determine site response parameters across these structures to mitigate... more
Poster 114	Geodesy	Geodetic and geologic observations of creep on the Southern San Andreas Fault triggered by the 2017 Chiapas (Mexico) earthquake Ekaterina Tymofyeyeva, Yuri Fialko, Junle Jiang, Roger Bilham, David Sandwell, Thomas Rockwell, Chelsea Blanton, Allen Gontz Observations of shallow fault creep reveal increasingly complex time-dependent slip histories that include quasi-steady creep and triggered as well as spontaneous accelerated slip events. We report a recent slow slip event on the southern San... more	18005
Poster 210	FARM	Surface Displacement and Ground Motion from Dynamic Rupture Models of Thrust Faults with Variable Dip Angles and Burial Depths Sirena Ulloa, Julian Lozos Historic earthquakes and empirical studies show that thrust fault ruptures produce stronger ground motion than normal or strike-slip events of the same size. This is due to a combination of hanging wall effects, vertical asymmetry and higher stress... more	18218
Poster 045	EFP	New software for computing time dependent seismic hazard during aftershock sequences using the OpenSHA platform Nicholas van der Elst, Kevin Milner, Edward Field, Sara McBride, Morgan Page The chaos caused by a major earthquake does not end when the shaking stops. Search and rescue, damage assessment, and lifeline repairs all need to be carried out under the constant threat of damaging aftershocks. In some cases, aftershocks can be... more
Poster 042	EFP	Sequential Data Assimilation for Seismicity: Probabilistic Estimation and Forecasting of Fault Stresses Ylona van Dinther, Hans Rudolf Künsch, Andreas Fichtner Our physical understanding and forecasting ability of earthquakes is significantly hampered by limited indications on the evolving state of stress and strength on faults. Integrating observations and physics-based numerical modeling to... more
Talk Mon 11:00	CXM	On the Role of Temperature and Rheology in Seismicity in Convergent Margins Ylona van Dinther, Luca Dal Zilio, Mario D'Aquisto, Robert Herrendörfer, Taras Gerya Earthquake nucleation, propagation and arrest are governed by fault stress and strength. Thus understanding how these are regulated by long-term processes involving temperature, rheology and tectonic forcing - in combination with short-term... more
Poster 112	Seismology	Enhancing 0.4-1.0 Hz seismic signals in Green’s functions through judicious selection of time intervals Ian Vandevert, Aaron Anderson, Taro Okamoto, Toshiro Tanimoto When we compute cross-correlation of seismic noise, we typically see dominant signals in the microseism frequency band, approximately 0.05-0.3 Hz. Cross-correlations have been done for higher frequency ranges, say up to 2 Hz, but if we do not pay... more
Poster 158	SDOT	Assessing off-fault damage during development of a dismembered flower structure Emma Vierra, Bonnie Flynn, Mario Bermudez, Heather Webb, Gary Girty, Thomas Rockwell As part of our ongoing study of off-fault damage along the San Jacinto fault (SJF), southern California, we here document the physical and chemical properties controlling damage intensity NW of Hog Lake and compare these results to those published... more
Poster 189	FARM	The slow slip of viscous faults Robert Viesca, Pierre Dublanchet We examine a simple mechanism for the spatiotemporal evolution of transient, slow slip. We consider the problem of in-plane or anti-plane slip on a fault that lies within an elastic continuum and whose strength is proportional to sliding rate. This... more	17179
Poster 229	Geology	Geologic and Structural Characterization of The Rock Volume Imaged by the Dense Nodal Seismic Array Along the San Jacinto Fault at Sage Brush Flat, Southern California Adam Wade Characterization of fault zones is critical to understanding earthquake mechanics and seismic hazard evaluations. Investigations of fault zones often involve detailed surface mapping, and/or subsurface imaging through seismic waves and other... more
Poster 184	FARM	Understanding Injection-induced Seismicity Effects on Fault Damage Zones: Beyond Poroelastic Models Robert Walker, Mahshad Samnejad, Fred Aminzadeh A rise in earthquake activity attributed to anthropogenic causes has stressed the the need for physics based hazard mitigation, based on robust predictive models. Recent efforts have addressed the problem of modeling injection-induced fault slip... more
Poster 133	Geodesy	The Network of the Americas (NOTA) GNSS Network in California - Providing Reliable Data Streams for Early Warning Applications Christian Walls, Doerte Mann, Ryan Turner, Shawn Lawrence, Ken Austin, Glen Mattioli, Tim Dittman, Karl Feaux The Network of the Americas (NOTA) 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. The Plate Boundary Observatory (PBO) is being... more
Poster 102	Seismology	Mapping Near-Surface Rigidity Structure using Co-located Pressure and Seismic Sensors from the EarthScope Transportable Array Jiong Wang, Toshiro Tanimoto For frequencies below 0.05 Hz, Sorrells (1971) and Sorrells et al. (1971) proposed a promising model in which moving pressure waves on the surface of the Earth generate low-frequency seismic signals. By using Sorrells model, we can study the... more
Poster 058	Seismology	Earthquake catalog reconstruction from analog seismograms: Application to the Rangely Experiment microfilms Kaiwen Wang, William Ellsworth, Gregory Beroza, Gordon Williams, Miao Zhang, Dustin Schroeder, Justin Rubinstein Before the digital era of seismic recordings, decades of seismic data were recorded in analog form and read manually by analysts. Despite the abundance of analog recordings, surprisingly few recent efforts have been made to analyze them. One common... more
Poster 126	Geodesy	Probing fault frictional properties during afterslip up- and down-dip of the 2017 Mw 7.3 Iran-Iraq earthquake Kang Wang, Roland Bürgmann On November 12th, 2017, an earthquake of Mw 7.3 occurred near the Iran-Iraq border, causing hundreds of deaths in both countries. The earthquake occurred along the Zagros mountain range, a broad and complex zone of continental collision between the... more
Poster 010	GM	Implementing Inter-Frequency Correlations into the SDSU Broadband Ground Motion Method Nan Wang, Rumi Takedatsu, Kim Olsen, Steven Day Earthquake ground motion records reveal frequency-dependent correlations, which has implication for seismic risk (Bayless and Abrahamson, 2017). The empirical inter-frequency correlation model of within-event residual for the Effective Amplitude... more	17137
Poster 082	Seismology	Comparison of Brune-type Stress Drops Estimated from Direct P, S, and Coda Waves Wei Wang, Peter Shearer Analysis of seismograms recorded by local networks provides fundamental information on earthquake source spectra and site effects. Previous studies have used different parts of the seismograms, e.g., direct P, S, and coda waves, to study these... more
Poster 128	Geodesy	Post-seismic deformation mechanism of the Mw 9.0 Tohoku-Oki earthquake detected by GPS and GRACE observations Wuxing Wang, Xiaodong Zhang, Ming Liang, Jing Zhang Post-seismic deformation characteristics of the Mw 9.0 Tohoku-Oki earthquake are studied by using GPS and GRACE observations. GPS continuous observations show that the regional post-seismic displacements are characterized by exponential function,... more
Poster 244	Geology	Deducing Crustal-scale Reverse-Fault Slip Distribution from Folded River Terraces, Qilian Shan, China Yiran Wang, Michael Oskin, Youli Li Studies have shown that for many compressional orogens, such as the Andes, the North Los Angeles fault system, and the Longmenshan fault, rates of shortening from geodesy are faster than geologically determined rates. Lack of documented faulting or... more
Poster 216	FARM	A Physical Interpretation for Anomalous Source Spectra with a Deficit at Intermediate Frequencies Yongfei Wang, Steven Day, Peter Shearer Many small crustal events in the northern Ibaraki prefecture and the Fukushima prefecture Hamadori area of Japan deviate systematically from the standard omega-square model, with an intermediate-frequency deficit (concavity) in the spectra and low-... more	18204
Poster 260	SAFS	Strain rate dependence on crustal rheology for the Cajon Pass, California Lauren Ward, Bridget Smith-Konter, Xiaohua Xu, David Sandwell While the dependency of fault strain rates on locking depth and slip rate variations are reasonably well-understood, our understanding of the sensitivity of fault loading to rheologic controls is still developing. Furthermore, how strain rates... more	17169
Poster 110	Seismology	Shear wave velocity structure of a remnant slab beneath the western Transverse Ranges offshore southern California Dayanthie Weeraratne, Kaitlyn Amodeo, Sampath Rathnayaka, Escobar Lennin, Carlos Gomez, Monica Kohler Data from the amphibious ALBACORE (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) seismic array across the southern California continental margin allows us to simultaneously study oceanic and... more
Poster 041	EFP	How Much Farther? Estimating Rupture Length Probabilities After a Rupture Has Started Steven Wesnousky, Glenn Biasi The USGS ShakeAlert Earthquake Early Warning (EEW) system is designed to detect and alert within a few seconds of earthquake initiation. We investigate the probability that the rupture will grow, and develop estimates for eventual rupture length... more	17064
Poster 054	Seismology	Detailed seismic catalog for the San Jacinto fault zone region (2008-2016) from automated processing of raw waveform data Malcolm White, Yehuda Ben-Zion, Frank Vernon We develop an automated processing procedure and apply it to eight years of raw waveform data, amalgamated from five seismic networks operating in the San Jacinto Fault Zone region, to derive an earthquake catalog containing >119, 000 events with... more
Poster 267	SAFS	Refining the earthquake chronology of the last millennium along the Cholame segment of the San Andreas fault Alana Williams, Ramon Arrowsmith, Thomas Rockwell, Sinan Akciz, Lisa Grant Ludwig The Cholame section of the San Andreas Fault (SAF) is positioned between the Parkfield and Carrizo sections to the NW and SE, respectively. Motivated by its critical position along the SAF, we have developed the Annette site (20 km SE of Highway 46... more	17017
Poster 023	GM	Dense mapping of shallow velocity structure in the Raymond Basin using the Pasadena Distributed Acoustic Sensing Array Ethan Williams, Zhongwen Zhan, Martin Karrenbach, Steve Cole, Lisa LaFlame With the increasing ability of ground-motion simulations to accurately model earthquake wavefields at high frequencies and the dependence of the earthquake engineering community on site characterization metrics like Vs-30, the resolution of existing... more

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