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 355

SCEC ID ▲	Category	Title and Authors	SCEC Award
Poster 001	GMP	Next Generation SDSU BBP Module Validation Kim Olsen, Rumi Takedatsu The SDSU module (BBtoolbox V1.5), merging low-frequency deterministic signals with high-frequency scattering functions (Olsen and Takedatsu, 2015), participated in and passed the SCEC Broadband Platform validation exercise 1.0, where the focus was... more	16115
Poster 002	GMP	The SCEC Broadband Platform: Open-Source Software for Strong Ground Motion Simulation and Validation Fabio Silva, Christine Goulet, Philip Maechling, Scott Callaghan, Thomas Jordan The Southern California Earthquake Center (SCEC) Broadband Platform (BBP) is a carefully integrated collection of open-source scientific software programs that can simulate broadband (0-100 Hz) ground motions for earthquakes at regional scales. The... more
Poster 003	USR	CFM Version 5.1: New and revised 3D fault representations and an improved database. Andreas Plesch, Craig Nicholson, Christopher Sorlien, John Shaw, Egill Hauksson We present an updated version of the SCEC Community Fault Model (CFM) for southern California. For version 5.1, we focused on improving the database component of CFM which is critical for the internal consistency and maintainability of the model.... more	16122, 16065
Poster 005	USR	Structure of the San Andreas Fault Zone in the Salton Trough Region of Southern California: A Comparison with San Andreas Fault Structure in the Loma Prieta Area of Central California Gary Fuis, Rufus Catchings, Daniel Scheirer, Mark Goldman, Edward Zhang The San Andreas fault (SAF) in the northern Salton Trough, or Coachella Valley, in southern California, appears non-vertical and non-planar. In cross section, it consists of a steeply dipping segment (75 deg dip NE) from the surface to 6- to 9-km... more
Poster 006	USR	Anomalous Uplift at Pitas Point: Implications from Onshore & Offshore 3D Fault & Fold Geometry and Observed Fault Slip Craig Nicholson, Christopher Sorlien, Tom Hopps Based on four Recent ~8-m uplift events of coastal marine terraces at Pitas Point, many believe these represent earthquakes near M8 on the N-dipping Pitas Point-Ventura fault (PPVF), part of the larger primarily offshore North Channel-Pitas Point-... more	16065
Poster 007	USR	Displacement direction and 3D geometry for the south-directed North Channel – Pitas Point fault system and north-directed ramps, decollements, and other faults beneath Santa Barbara Channel. Christopher Sorlien, Craig Nicholson, Richard Behl, Marc Kamerling We use abundant seismic reflection data to interpret 3D fault geometry in the upper 5 to 8 km beneath Santa Barbara Channel and use dated and correlated seismic stratigraphy to study 3D fold geometry and its changes through Quaternary time. A set... more	15098
Poster 008	SDOT	Reconstruction Modeling of Topography and Lithosphere Dynamics using Western U.S. Strain History within the Pacific-North America Plate Boundary Zone Alireza Bahadori, Bill Holt, Lucy Flesch, Lijun Liu, Troy Rasbury, Gavin Piccione, Rubin Smith The complex deformation history of the western U.S. since 36 Ma involved a dramatic transition from a subduction-dominated to a transform-dominated margin, with widespread extension within the interior Basin and Range region. This deformation... more
Poster 009	SDOT	A new way to estimate shear tractions on active faults in southern California Peter Bird Two kinds of thin-shell finite-element (F-E) model of quasi-static neotectonics are available for southern California: (1) kinematic (or “inverse”) F-E models which fit geodetic and geologic data by weighted least-squares but contain limited physics... more	16048
Poster 010	SDOT	4D stress evolution models of the San Andreas Fault System using improved geodetic and paleoseismic constraints Bridget Smith-Konter, Karen Luttrell, Xiaopeng Tong, David Sandwell Major earthquakes of the San Andreas Fault System (SAFS) are thought to occur when accumulated fault stress in the upper locked portion of the crust exceeds some threshold value. 4D simulations of stress evolution provide rare insight into... more	16117
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 012	SDOT	Seasonal water storage modulating seismicity on California faults Christopher Johnson, Yuning Fu, Roland Bürgmann In California the accumulation of winter snowpack in the Sierra Nevada, surface water in lakes and reservoirs, and groundwater in sedimentary basins follow the annual cycle of wet winters and dry summers. The surface loads resulting from the... more	16006
Poster 013	SDOT	Towards Detailed Characterization of Spatio-temporal Variations in Stress Parameters along the San Jacinto Fault Zone Niloufar Abolfathian, Patricia Martínez-Garzón, Yehuda Ben-Zion Accurate determination of stress parameters (orientation of principal stress axes and stress ratio) operating on fault zones provides refined knowledge on source physics and deformation processes. We developed a refined stress inversion... more
Poster 014	SDOT	Can tectonic loading be observed as interseismic stress rotation? Jeanne Hardebeck The shear stress on major faults evolves through the seismic cycle, due to tectonic stress loading, coseismic stress release, and earthquake stress transfer. If the seismic cycle stresses are small compared to the background differential stress,... more
Poster 015	SDOT	Role of fault geometry on the spatial distribution of the slip budget Phillip Resor, Michele Cooke, Scott Marshall, Elizabeth Madden A fundamental problem in earthquake physics is how stress is transferred from plate motion to faults. Kinematic models assume that long-term fault slip rates will sum to the plate velocity; however, in a number of locations in southern California... more	16164
Poster 016	SDOT	Quantifying Late Quaternary deformation in the Santa Maria Basin: A OSL, GPS and soil chronosequence based model for determining strath terrace deformation in the Zaca Creek drainage, Santa Barbara County Andrew Farris, Nate Onderdonk The Santa Maria Basin is located on the Central Coast of California and comprises the area bound by the Santa Ynez Fault to the south, and the Little Pine-Foxen Canyon Fault Zone to the north. The Santa Maria Basin is a zone of convergence between... more
Poster 017	SDOT	Progress towards deriving the three-dimensional coseismic deformation field along the White Wolf fault during the Mw ~7.3 1952 Kern County earthquake Alexandra Hatem, James Dolan, Chris Milliner We present preliminary results of our efforts to constrain coseismic surface deformation during the Mw~7.3 1952 Kern County earthquake. We are using a modified workflow to difference point clouds derived from legacy air photos taken before and after... more	15200
Poster 018	SDOT	Learning viscoelasticity with neural networks Phoebe DeVries, Thomas Thompson, Brendan Meade Viscoelastic models have been widely used to explain geodetic observations of the earthquake cycle, time-dependent stress transfer, and delayed earthquake triggering. The calculations involved in these modeling efforts are often computationally... 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 020	SDOT	Coulomb stress evolution over the past 200 years and seismic hazard along the Xianshuihe fault zone of Sichuan, China Zhigang Shao, Jing Xu, Hongsheng Ma, Langping Zhang This study focuses on the M ≥ 6.7 earthquakes that have occurred since 1816 on the Xianshuihe fault zone in southwest China. The interseismic Coulomb stress accumulation and the Coulomb stress changes caused by coseismic dislocation and postseismic... more
Poster 021	SDOT	Calculating regional stresses for northern Canterbury: the effect of the 2010 Darfield earthquake Susan Ellis, Charles Williams, John Ristau, Martin Reyners, Donna Eberhart-Phillips, Laura Wallace We model regional stresses before and after the Mw 7.1 Darfield earthquake of September 2010 in Canterbury, New Zealand including crustal structure derived from seismic tomography. Models show that the Banks Peninsula volcanic assemblage acts as a... more	16193
Poster 022	SDOT	Evidence for strong lateral seismic velocity variation in the lower crust – upper mantle beneath the California margin Voon Hui Lai, Robert Graves, Shengji Wei, Donald Helmberger Regional seismograms from earthquakes in Northern California show a systematic difference in arrival times across central and southern California where long period (30 – 50 seconds) SH waves arrive up to 15 seconds earlier at stations near the coast... more
Poster 023	SDOT	Fault-parallel shear fabric in the ductile crust of Southern California imaged using receiver functions Vera Schulte-Pelkum, Karl Mueller We present results on deep crustal deformation fabric from a new receiver function method. The method uses the azimuthal variation of P-to-S converted arrivals on the radial and transverse component of receiver functions. Dipping isotropic velocity... more
Poster 024	SDOT	Discriminating Between Induced vs Tectonic Seismicity in Intraplate Regions: the Contribution of the Long-Term History of Fault Behavior Maria Beatrice Magnani, Michael Blanpied, Heather DeShon, Matthew Hornbach Since 2009 there has been an increase in rate of seismicity in the Central U.S. (CUS), a major fraction of which has been associated with shale gas production and related wastewater injection. The surge of seismicity has resulted in an increased... more
Poster 025	FARM	Biomarkers as a tool to measure coseismic temperature rise Genevieve Coffey, Heather Savage, Pratigya Polissar, Brett Carpenter, Cristiano Collettini During earthquake slip, frictional resistance within a fault can lead to the generation of extremely high temperatures. As a consequence, investigating temperature rise within fault zones provides a promising mechanism for the detection of past... more
Poster 026	FARM	Biomarker thermal maturity at seismic timescales in high-velocity rotary shear experiments Hannah Rabinowitz, Heather Savage, Elena Spagnuolo, Giulio Di Toro Studies of past seismicity on sampled fault structures often rely on evidence of frictional heating on slip surfaces. Estimates of temperature rise on a fault provide constraints on the size of previous earthquakes hosted on the fault, allowing for... more
Poster 027	FARM	Slip and Seismic Radiation Along Bi-material Faults: An Experimental Analysis Brett Carpenter, Ximeng Zu, Xiaowei Chen, Ze'ev Reches Large displacements along faults frequently juxtapose crustal blocks of different compositions and mechanical properties. Such juxtapositions have been termed bi-material faults (BFs). It has been theoretically shown that a BF setting may strongly... more
Poster 028	FARM	Laboratory investigation of friction along rock joints and identification of peaks in shear stiffness prior to the joint’s shear failure Ahmadreza Hedayat, John Hinton Laboratory studies of friction along synthetic and natural fault gauge materials have been instrumental in providing a better understanding of the fault deformation mechanisms and when combined with geophysical monitoring techniques, have been very... more
Poster 029	FARM	Earthquake source complexity? Near-fault velocity spectra from laboratory failures and their relation to natural ground motion N. Beeler, Brian Kilgore, David Lockner Natural earthquake sources have characteristic spectra, for example at high frequency the displacement amplitude spectrum of a body wave depends on frequency as 1 / f^2 [e.g., Hanks and Wyss, 1972] and velocity amplitude as 1/f. Such natural... 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 031	FARM	Multi-Scale Flash Heating and Frictional Weakening at Seismic Slip-Rates in Rock Frederick Chester, Omid Saber, J. L. Alvarado Sliding rock-samples at rates > 1 mm.s^-1 can lead to a significant reduction of friction, often referred to as dynamic weakening. Thermal effects are understood to be the cause of dynamic weakening, and the Flash Weakening (FW) mechanism that... more
Poster 032	FARM	Dynamic Weakening of Sliding Friction and the Influence of Gouge Development Monica Barbery, Frederick Chester, Judith Chester, Omid Saber Previous experiments demonstrate that as sliding velocity approaches seismic slip rates, the coefficient of sliding friction (u) typically reduces significantly and may reflect flash heating of surface contacts. Experiments further demonstrate... more
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
Poster 035	FARM	Laboratory Earthquakes Nucleated by Fluid Injection Marcello Gori, Vito Rubino, Ares Rosakis, Nadia Lapusta Fluids play an important role in earthquake source processes. Numerous field observations have highlighted the connection between fluids and faulting in triggering events ranging from earthquakes to creeping motion. Our newly developed laboratory... 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 037	FARM	The Action of water films at Å-Scales in the Earth: Implications for Midcrustal Eathquakes and Overpressuring Kevin Brown, Dean Poeppe, IODP Leg 348 Shipboard Party Water properties change with confinement within nanofilms trapped between natural charged clay particles. We investigated nanofilm characteristics utilizing sediments from deep drilling of the Nankai subduction zone at Site C0002 of the Integrated... more
Poster 038	FARM	Physical controls of spontaneous and triggered slow-slip and stick-slip at the fault gouge scale Behrooz Ferdowsi, David Goldsby Fault slip modes span a continuum of behaviors from tremors and slow slips to earthquakes. Recent laboratory studies reveal that a spectrum of slow-slip responses emerge near the threshold between stable and unstable failure, governed by the complex... more	16059
Poster 039	FARM	Dynamic friction in sheared fault gouge: implications of acoustic vibration on triggering and slow slip Jean Carlson, Charles Lieou, Ahmed Elbanna Friction and deformation in granular fault gouge are among various dynamic interactions associated with seismic phenomena that have important implications for slip mechanisms on earthquake faults. To this end, we propose a mechanistic model of... more	16135
Poster 040	FARM	Localization and instability in sheared granular materials: Role of friction and vibration Konik Kothari, Ahmed Elbanna Shear banding and stick-slip instabilities have been long observed in sheared granular materials. Yet, their microscopic underpinnings, interdependencies and variability under different loading conditions have not been fully explored. Here, we use a... more
Poster 041	FARM	How we learned to stop worrying and start loving bulk nonlinearities Setare Hajarolasvadi, Ahmed Elbanna The Finite Difference (FD) and Boundary Integral (BI) methods have been extensively used in computational earthquake dynamics. The FD method provides a powerful tool for simulating a variety of rupture scenarios including nonplanar faults and bulk... more
Poster 042	FARM	Brittle to ductile transition in a model of sheared granular materials Xiao Ma, Ahmed Elbanna Understanding the fundamental mechanisms of deformation and failure in sheared fault gouge is critical for the development of physics-based earthquake rupture simulations that are becoming an essential ingredient in next generation hazard and risk... more	16143
Poster 043	FARM	Flexible implementation of multiphysics and discretizations in PyLith crustal deformation modeling software Brad Aagaard, Charles Williams, Matthew Knepley We are creating a flexible implementation of multiphysics and finite-element discretizations in PyLith, a community, open-source code (http://geodynamics.org/cig/software/pylith/) for modeling quasi-static and dynamic crustal deformation with an... more
Poster 044	FARM	Earthquake cycles on rate-state faults: how does recurrence interval and its variability depend on fault length? Camilla Cattania, Paul Segall The concept of earthquake cycles consisting of periodic events on the same patch is often invoked or assumed when discussing seismic risk. However, large faults exhibit more complex behavior than periodic stick-slip cycles. Some events, such as the... more	16248
Poster 045	FARM	Plasticity Throughout the Earthquake Cycle Brittany Erickson, Eric Dunham, Jeremy Kozdon We are developing an earthquake cycle model to simulate multiple ruptures in complex geometries, with material heterogeneity and off-fault plastic response. This initial study focuses on the 2D antiplane shear case of ruptures on strike-slip faults... more
Poster 046	FARM	Localization and delocalization of shear in fault gouge from thermal pressurization Shanna Chu, Eric Dunham Field observations of extreme shear localization in fault gouge have been attributed to a number of factors, including thermal pressurization. The extent of the localization is affected by various parameters such as diffusion, friction, and gouge... more
Poster 047	FARM	Aiming for Validation – The SCEC/USGS Dynamic Earthquake Rupture Code Comparison Exercise Ruth Harris The SCEC/USGS Dynamic Earthquake Rupture Code Group is an international collaboration among scientists who use 3D spontaneous rupture computer codes to numerically simulate physics-based earthquake rupture and the resulting ground motions. In the... more	16056
Poster 048	FARM	Spontaneous Dynamic Rupture Simulation on Geometrically Complex Faults Governed by Different Friction Laws Bin Luo, Benchun Duan The constitutive law describing how friction resistance evolves dynamically on the existing shear fault surface is one of the major factors controlling the behavior of dynamic earthquake rupture. The laboratory-derived rate- and state- friction laws... more
Poster 049	FARM	Linking grain-scale and fault-scale earthquake simulations Ryan Payne, Benchun Duan, David Sparks Geologically active faults are complex structures, marked by an interaction of many different physical processes at varying time and length scales. Much progress has been made utilizing advanced computer models as an effective way of studying the... more
Poster 050	FARM	Stress heterogeneity at restraining double bends under multicycles and its effect on rupture propagation in 3D Dunyu Liu, Benchun Duan The conditions under which a rupture is able to propagate through geometrical complexity, such as restraining double bends, are crucial to the estimation of potential maximal event size on a fault system like the central Altyn Tagh Fault. Previous... more
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 052	FARM	Friction and stress drop controlled by fault roughness and strength heterogeneity Olaf Zielke, Martin Galis, Paul Mai An earthquake's stress drop is a fundamental quantity of the rupture process, intimately related to the decrease of frictional resistance to sliding during rupture evolution. A number of recent high-speed laboratory friction experiments have... 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