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 51-100 of 355

SCEC ID ▲	Category	Title and Authors	SCEC Award
Poster 053	FARM	Comparison of Source Inversions and Stress Drops with In-Situ Observations of Faulting Pamela Moyer, Margaret Boettcher, William Ellsworth A Mw 5.4 earthquake, which occurred on 5 August, 2014 beneath the Moab Khotsong gold mine, in Ornkey, South Africa provides a unique opportunity to directly compare seismological inferences with in-situ observations of faulting. The Mw 5.4... more
Poster 054	FARM	Natural polish in granitic rocks Shalev Siman-Tov, Emily Brodsky, Greg Stock Fault mirrors are highly smooth and reflective rock surfaces that are found in many shear zones around the world. Recent studies suggest that fault mirrors are formed during high velocity slip on faults and therefore may serve as an indicator for... more
Poster 055	FARM	Asperity break after 12 years: The Mw6.4 2015 Lefkada (Greece) earthquake Frantisek Gallovic, Efthimios Sokos, Jiri Zahradnik, Anna Serpetsidaki, Vladislav Plicka, Anastasia Kiratzi The Mw6.4 earthquake sequence of 2015 in western Greece is analyzed using seismic data. Multiple point source modeling, nonlinear slip patch, and linear slip inversions reveal a coherent rupture image with directivity toward the southwest and... more
Poster 056	FARM	A possible joint San Andreas-Imperial fault rupture in the Salton Trough region David Oglesby, Christodoulos Kyriakopoulos, Aron Meltzner, Thomas Rockwell We investigate the potential for large through-going ruptures across the Salton Trough using both field data and numerical simulations. Geological records from paleoseismic trenches inform us of details of past ruptures (length, magnitude, timing),... more	16231
Poster 057	FARM	Investigating the high-frequency, weak-motion nucleation phase initiating the June 10th, 2016 Mw 5.2 Borrego Springs Earthquake Adam Arce, Mareike Adams, Chen Ji A nucleation phase, when present, offers insight into an earthquake’s rupture mechanics and may corroborate the “cascade” rupture model. In cascade rupture, slip initiates on a relatively small patch progressing into slip on a larger patch and so on... more
Poster 058	FARM	Estimates of fault tractions in the San Gorgonio Pass region consider fault interaction Aviel Stern, Michele Cooke, Jennifer Beyer, Jennifer Tarnowski, David Oglesby, Roby Douilly In order to estimate absolute tractions along the southern San Andreas fault, we simulate the regional deformation using three-dimensional quasi-static mechanical models. These models simulate the stressing rates both over multiple earthquake... more
Poster 059	FARM	Development of extensional step overs within anisotropic systems: Implications for the Rodgers Creek-Hayward step over Jessica McBeck, Michele Cooke The Rodgers Creek-Hayward extensional step over, within the San Pablo bay in northern CA, USA, is estimated to pose one of the highest likelihoods of rupture in northern CA. To better constrain the fault geometry of the step over at seismogenic... more
Poster 060	FARM	Sensitivity of deformation to activity along the Mill Creek strand of the San Andreas fault within the San Gorgonio Pass Jennifer Beyer, Michele Cooke A significant portion of the deformation budget across irregular fault networks can be accommodated by permanent off-fault deformation that accumulates between earthquakes. This deformation may correspond to a reduction in the slip rates along the... more	16187
Poster 061	FARM	Dynamic Models of Large Ruptures on the Southern San Andreas Fault Julian Lozos The southern San Andreas Fault is a heterogeneous structure. Despite being a primary plate boundary fault, it has major geometrical complexities in the Big Bend and San Gorgonio Pass, and also shows substantial variation in maximum horizontal stress... 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 063	FARM	Earthquake source parameter validation using multiple-scale approaches for induced seismicity in Oklahoma Rachel Abercrombie, Xiaowei Chen The rapid increased seismicity rate in central US has drawn significant attention to the associated earthquake hazards in intraplate regions. Whether induced earthquakes have similar stress drops to tectonic events is an important question for... 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 065	FARM	Geodetic Measurements of Slow Slip and Tremor in Parkfield, CA Brent Delbridge, Roland Bürgmann, Robert Nadeau It has been proposed that large bursts of deep tremor ( >20km depth) near Parkfield, CA are associated with quasi-periodic shear dislocations on the deep extent of the San Andreas Fault. Geodetic studies have shown that slow slip accompanies... more
Poster 066	FARM	Reconciling seismicity and geodetic locking depths on the Anza segment of the San Jacinto Fault Junle Jiang, Yuri Fialko The depth extent of fault locking can be independently estimated from seismic and geodetic observations. In Southern California, available observations for the San Andreas and San Jacinto Faults suggest a general agreement between the two estimates... more	16121
Poster 067	FARM	Rupture evolution and high-frequency radiation during mega/large earthquakes, resolved by hybrid backprojection technique Ryo Okuwaki, Yuji Yagi Tracking spatio-temporal evolution of high-frequency (HF) sources during rupture is a key to understand nature of earthquake rupture process since HF radiation reflects an abrupt change of rupture velocity and/or slip-rate. We have been developing... 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 069	FARM	Coseismic Strengthening of the Shallow Subduction Megathrust Further Enhances Inelastic Wedge Failure and Efficiency of Tsunami Generation Evan Hirakawa, Shuo Ma The shallow portion (upper 5 – 10 km) of the subduction megathrust fault, governed by velocity-strengthening friction, has generally been considered to reduce near-trench slip and tsunamigenesis. However, Kozdon and Dunham (2013) showed that large... more
Poster 070	FARM	How does fault geometry control earthquake magnitude? Quentin Bletery, Amanda Thomas, Leif Karlstrom, Alan Rempel, Anthony Sladen, Louis De Barros Recent large megathrust earthquakes, such as the Mw9.3 Sumatra-Andaman earthquake in 2004 and the Mw9.0 Tohoku-Oki earthquake in 2011, astonished the scientific community. The first event occurred in a relatively low-convergence-rate subduction zone... more
Poster 071	FARM	Dehydration-Induced Porosity Waves and Episodic Tremor and Slip Robert Skarbek, Alan Rempel Episodic tremor and slip (ETS) at plate interfaces takes place where there is abundant evidence for elevated, near-lithostatic pore pressures. In subduction zones and on the San Andreas fault, tectonic tremor occurs at depths where there is... more
Poster 072	FARM	Tremor and Slow Slip in the West Antarctic Ice Sheet Bradley Lipovsky, Eric Dunham The Whillans Ice Plain region of the West Antarctic Ice Sheet experiences twice-daily, tidally-modulated slow slip events. During each event, 0.5 m of slip occurs over a 150x150 km area. Sliding initiates at one of several recurring locations and... more
Poster 073	FARM	Modern earthquake ruptures on contrasting fault systems in the Laguna Salada region of northwestern Mexico. Ronald Spelz, John Fletcher, Thomas Rockwell, Alejandro Hinojosa, Michael Oskin, Lewis Owen, Jaziel Cambron, Víctor Villaverde, Laura Vallin, Abel Gutierrez, Keene Karlsson The Laguna Salada region of northwestern Mexico is located near the axis of the Pacific-North American plate margin and hosts a wide variety of active faults that accommodate the three dimensional strain of transtensional shearing. Individual fault... more	16190
Poster 074	FARM	The mechanics of multifault ruptures and the keystone fault hypothesis John Fletcher, Michael Oskin, Orlando Teran Regardless of global tectonic regime, most large earthquakes activate slip on more than one fault. Likewise, the magnitude of an earthquake increases substantially with the number of faults that become activated. Despite the importance of multifault... more	1697, 16190
Poster 075	FARM	Effects of elastoplastic material properties on shallow fault slip and surface displacement fields Johanna Nevitt, Benjamin Brooks, Todd Ericksen, Craig Glennie, Christopher Madugo, David Lockner, Diane Moore, Sarah Minson, Kenneth Hudnut Inadequate knowledge of fault slip and off-fault deformation within the shallow crust (<1 km depth) limits our understanding of fundamental fault physics and seismic hazard associated with near-surface rupture. Recent technological advances in... more
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
Poster 077	FARM	Shallow level incipient pulverization found with a restraining bend of the Clark segment of the San Jacinto Fault, southern California Daniel Peppard, Heather Webb, Gary Girty This poster characterizes the properties of incipient pulverization within a contractional bend along the Clark segment, San Jacinto fault. About 1.5 km SE of the study site, the Clark segment bifurcates into two branches. The NE-most splay, the... more
Poster 078	FARM	Post-seismic ductile flow beneath the brittle-plastic transition: constraints on rheology from microstructural and electron backscatter diffraction (EBSD) analyses of mylonitized pseudotachylite, South Mountains metamorphic core complex, Arizona Craig Stewart, Elena Miranda Post-seismic ductile flow promotes the upward rebound of the brittle-plastic transition (BPT) after an earthquake, but it is difficult to determine the rheologic controls on post-seismic flow due to compositional and structural heterogeneities in... more
Poster 079	Geology	Fault Scarp Degradation Analysis At Dragon’s Back Using High Resolution Topography Data Emil Chang, Gilles Peltzer, Seulgi Moon Fault scarps degrade over time, and their geomorphic forms may provide information of relative activity of surface processes or formation ages. The recent advances in remote sensing techniques and high-resolution topographic data allow us to... more
Poster 080	Geology	Cumulative offsets revealed by airborne LiDAR along a “creeping” section of the Haiyuan fault, northern Tibetan plateau Jing Liu, Tao Chen, Yanxiu Shao, Peizhen Zhang, Kenneth Hudnut, Qiyun Lei, Zhanfei Li Airborne LiDAR is a powerful and efficient tool for acquiring topographic data with cm- to mm-resolution, a resolution high enough for detailed description of landforms and their small displacements along faults. It is therefore very appealing and... more
Poster 081	Geology	New Investigations on the Hollywood-Raymond Fault Zone, Los Angeles, California Janis Hernandez, Rufus Catchings, Robert Sickler, Mark Goldman South of the Transverse Ranges in southern California, the transition zone between the Hollywood and Raymond faults has been mapped as a series of left-stepping, E-NE-trending faults (Weber et al., 1980). Geomorphic expression of faulting in this... more
Poster 082	Geology	Structural Architecture of the Western Transverse Ranges and Potential for Large Earthquakes Yuval Levy, Thomas Rockwell Fold-and- thrust belts evolve over time, can produce large-scale faults and potentially accommodate large magnitude earthquakes. The thrust fronts of these structures typically form large fold structures in their hanging walls, and they tend to... more
Poster 083	Geology	Marine terraces, isostasy, earthquakes, and uplift rates Alexander Simms, Helene Rouby, Kurt Lambeck, Angela Roman Marine terraces line the southern California coast and have been used for decades to constrain rates of tectonic uplift. However, despite years of study two fundamental questions remain concerning their relationship to tectonic uplift. First, how... more
Poster 084	Geology	Geology of liquefaction-induced lateral spreading, new results from Christchurch, New Zealand Gregory De Pascale, Jeffrey Bachhuber, Ellen Rathje, Jing Hu, Peter Almond, Christian Ruegg, Mike Finnemore Earthquake triggered liquefaction and lateral spreading was widespread in Canterbury, New Zealand during the 2010-2012 Canterbury Earthquake Sequence (CES) and led to ~$20 Billion NZD of damage to infrastructure. Permanent lateral ground... 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 086	Geology	Paleoseismic investigation of the Rose Canyon fault zone, San Diego, CA Eui-jo Marquez, Jillian Maloney, Thomas Rockwell, Neal Driscoll, Scott Rugg, Jeff Babcock The Rose Canyon fault zone (RCFZ) bisects the City of San Diego, the 8th largest city in the U.S., and represents a major seismic hazard to the greater metropolitan area that includes Tijuana and surrounding cities. Onshore studies have shown that... more	16195
Poster 087	Geology	Evidence for Abrupt Subsidence Event in Carpinteria Marsh at 2 ± 0.2 ka Laura Reynolds, Alexander Simms, Thomas Rockwell, John Bentz, Robert Peters Recent work by Simms et al., 2016 suggests Carpinteria Marsh, Carpinteria, California, has experienced an average of 1.2±0.4 mm/yr of subsidence in the last 7ka. However, the nature (ongoing vs. abrupt) of this subsidence remained unclear. Here we... more	14008, 13008, 15156, 16132
Poster 088	Geology	Aerial2lidar3d: A New Point Cloud-Optical Image Matching Technique to Quantify Near-Field, Surface Co-Seismic Deformation in 3D: Application to the 1999 Mw 7.1 Hector Mine Earthquake and New Surface Offset Measurements of the 1999 Mw 7.6 Izmit earthquake Chris Milliner, James Dolan, Robert Zinke, James Hollingsworth, Sebastien Leprince, Francois Ayoub Measurements of co-seismic surface deformation of large magnitude earthquakes are of critical importance for the characterization of distributed deformation and understanding fault zone mechanics. Recent developments in geodetic matching techniques... more	15194
Poster 089	Geology	Preliminary results on Late Quaternary slip rate of the central Haiyuan Fault constrained by terrestrial in situ cosmogenic nuclides dating, UAV and LiDAR surveys Yanxiu Shao, Jing Liu, Michael Oskin, Jerome Van der Woerd, Jinyu Zhang, Peng Wang, Pengtao Wang, Wang Wang, Wenqian Yao Kinematic parameters of active faults are essential for understanding active tectonics, and evaluation of regional tectonic and crustal deformation models. Many study focus on large active faults and acquisition of their slip rates of multiple time... more
Poster 090	Geology	Published Quaternary geochronologic data show the importance of dating geomorphic surfaces with multiple geochronometers Peter Gold, Whitney Behr Quaternary fault slip rates rely on geochronologic dating methods for interpreting the ages of displaced geomorphic surfaces such as alluvial fans and fluvial terraces. Most commonly employed among these are cosmogenic exposure dating, uranium-... more
Poster 091	Geology	Site-specific earthquake hazard characterization for Dhaka City, Bangladesh Mir Karim, Zillur Rahman, Maksud Kamal, Sumi Siddiqua Seismic hazard characterization is the foremost module for earthquake risk management in a seismically vulnerable region. The mega city Dhaka in Bangladesh is considered by many researchers as one of the riskiest cities in the world due to many non-... more
Poster 092	Geology	Late Holocene rupture history of the Ash Hill fault, Eastern California Shear Zone Christine Regalla, Hannah Pangrcic, Eric Kirby, Eric McDonald Recent paleoseismic investigations in the Eastern California Shear Zone (ECSZ) suggest that the Panamint, Garlock, and Owens Valley faults may have experienced a late Holocene cluster of seismicity, concurrent with an ongoing <~1.5 ka cluster... 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 094	Geology	Quaternary Expression of Northern Great Valley Faults and Folds: Accommodating North-South Contraction in the Northeastern California Shear Zone Stephen Angster, Thomas Sawyer, Steven Wesnousky The Northern California Shear Zone accommodates North American intraplate right-lateral transpressional shear driven by the relative motions of the northwest translating Sierran microplate and clockwise rotating Oregon Costal block. Within this... more
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 096	Geology	Late Quaternary slip rates from offset alluvial fan surfaces along the Central Sierra Madre fault, southern California Austin Hanson, Reed Burgette, Katherine Scharer, Nikolas Midttun The Sierra Madre fault (SMF) is an east-west trending reverse fault system along the southern flank of the San Gabriel Mountains near Los Angeles, California. The ~140 km long SMF is separated into four segments; we focus on the multi-stranded, ~85... more	15179
Poster 097	Geology	New slip rates and characterization of active faults in the northern Walker Lane Ian Pierce, Steven Wesnousky, Lewis Owen Antelope, Mason and Smith Valleys are half-grabens within the Northern Walker Lane, east and south of Carson City and Reno, Nevada. We apply recently acquired 0.5-1 m/pixel lidar data and terrestrial cosmogenic nuclide (TCN) surface exposure ages to... more
Poster 098	Geology	Reevaluation of high slip rates on the Eglington Fault Las Vegas, NV utilizing new chronostratigraphic and geologic evidence Kathleen Springer, Jeffrey Pigati The Eglington fault is a northeast striking monoclinal landform that offsets middle-late Pleistocene groundwater discharge deposits in the Las Vegas Valley by ~14 m vertically. Most of the exposure of the fault has been lost to extensive... more
Poster 099	Geology	Testing for slip rate changes on the Sierra Madre fault: Progress on dating an offset terrace surface of possible middle Pleistocene age Reed Burgette, Nathaniel Lifton, Katherine Scharer, Devin McPhillips, Austin Hanson The Sierra Madre fault (SMF) system juxtaposes the San Gabriel Mountains against a series of basins along the northern margin of the Los Angeles metropolitan area. Previous studies have suggested that deformation rates on this fault vary spatially... more	16066
Poster 100	Geology	Lidar mapping and luminescence dating reveal highly variable latest Pleistocene-Holocene slip rates on the Awatere fault at Saxton River, South Island, New Zealand Robert Zinke, James Dolan, Russ Van Dissen, Ed Rhodes, Christopher McGuire We use high-resolution lidar micro-topographic data and luminescence dating to constrain incremental Holocene–late Pleistocene slip rates at the well-known Saxton River site along the Awatere fault, a primary dextral strike-slip fault in the... more
Poster 101	Geology	Progress towards a comprehensive incremental slip rate and paleo-earthquake age and displacement record for the central Garlock fault James Dolan, Sally McGill, Ed Rhodes, Thomas Crane As part of our ongoing studies of the incremental slip-rate and paleo-earthquake age and displacement record of the Garlock fault, we present new slip rate results from our Pilot Knob Valley (PKV) site along the east-central part of the fault. These... more	14217
Poster 102	Geology	Observations from preliminary 1:24,000 scale bedrock mapping in the western Joshua Tree region: Potential connections between historic seismicity and evolving fault systems Ann Hislop, Robert Powell, Sean Bemis, David Moecher, Luke Sabala Bedrock mapping in the epicentral areas of the 1992 Joshua Tree earthquake (Mw 6.1) and Landers aftershocks (Mw 5.7, 5.8) south of Pinto Mountain Fault in southern California has further delineated the geometry, distribution, and relative chronology... more

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