Publications
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Evaluation of simulated ground motions using probabilistic seismic demand analysis: CyberShake (ver. 15.12) simulations for Ordinary Standard Bridges
There is a need for benchmarking and validating simulated ground motions in order for them to be utilized by the engineering community. Such validation may be geared towards a specific ground motion simulation method, a target engineering application, and a specific location; the validation presented herein focuses on a bridge engineering application in southern California. Catalogs of simulated g
Authors
Jawad Fayaz, Sanaz Rezaeian, Farzin Zareian
Apparent earthquake rupture predictability
To what extent can the future evolution of an ongoing earthquake rupture be predicted? This question of fundamental scientific and practical importance has recently been addressed by studies of teleseismic source time functions (STFs) but reaching contrasting conclusions. One study concludes that the initial portion of STFs is the same regardless of magnitude. Another study concludes that the rate
Authors
M.-A. Meier, P. Ampuero, Elizabeth S. Cochran, Morgan T. Page
A ground‐motion prediction model for shallow crustal earthquakes in Greece
Using a recently completed database of uniformly processed strong‐motion data recorded in Greece, we derive a ground‐motion prediction model (GMPM) for horizontal‐component peak ground velocity, peak ground acceleration, and 5% damped pseudoacceleration response spectra, at 105 periods ranging from 0.01 to 10 s. The equations were developed by modifying a global GMPM, to account for more rapid att
Authors
David Boore, Jonathan P. Stewart, Andreas Skarlatoudis, Emel Seyhan, Basil Margaris, Nikos Theodoulidis, Emmanual Scordilis, Ionnis Kalogeras, Nikos Klimis, Nikos Melis
A unified model of crustal stress heterogeneity from borehole breakouts and earthquake focal mechanisms
Observations of crustal stress orientation from the regional inversion of earthquake focal mechanisms often conflict with those from borehole breakouts, possibly indicating local stress heterogeneity, either laterally or with depth. To investigate this heterogeneity, we compiled SHmax estimates from previous studies for 57 near‐vertical boreholes with measured breakout azimuths across the Los Ange
Authors
Karen Luttrell, Jeanne L. Hardebeck
Spatial clustering of aftershocks impacts the performance of physics‐based earthquake forecasting models
I explore why physics‐based models of earthquake triggering rarely outperform statistical models in prospective testing, outside of limited spatial‐temporal windows. Pseudo‐prospective tests on suites of synthetic aftershock sequences show that a major factor is the level of unmodeled spatial clustering of the direct aftershocks triggered by the mainshock. The synthetic sequences are generated fro
Authors
Jeanne L. Hardebeck
A long-term geothermal observatory across subseafloor gas hydrates, IODP Hole U1364A, Cascadia accretionary prism
We report 4 years of temperature profiles collected from May 2014 to May 2018 in Integrated Ocean Drilling Program Hole U1364A in the frontal accretionary prism of the Cascadia subduction zone. The temperature data extend to depths of nearly 300 m below seafloor (mbsf), spanning the gas hydrate stability zone at the location and a clear bottom-simulating reflector (BSR) at ∼230 mbsf. When the hole
Authors
K. Elizabeth Becker, E. E. Davis, M. Hessemann, J. A. Collins, Jeffrey McGuire
The normal faulting 2020 Mw5.8 Lone Pine, Eastern California earthquake sequence
The 2020 Mw 5.8 Lone Pine earthquake, the largest earthquake on the Owens Valley fault zone, eastern California, since the nineteenth century, ruptured an extensional stepover in that fault. Owens Valley separates two normal‐faulting regimes, the western margin of the Great basin and the eastern margin of the Sierra Nevada, forming a complex seismotectonic zone, and a possible nascent plate bounda
Authors
Egill Hauksson, Brian J. Olsen, Alex R. R. Grant, Jennifer R Andrews, Angela I. Chung, Susan E. Hough, Hiroo Kanamori, Sara McBride, Andrew J. Michael, Morgan T. Page, Zachary E. Ross, Deborah Smith, Sotiris Valkaniotis
Revisiting California’s past great earthquakes and long-term earthquake rate
In this study, we revisit the three largest historical earthquakes in California—the 1857 Fort Tejon, 1872 Owens Valley, and 1906 San Francisco earthquakes—to review their published moment magnitudes, and compare their estimated shaking distributions with predictions using modern ground‐motion models (GMMs) and ground‐motion intensity conversion equations. Currently accepted moment magnitude estim
Authors
Susan E. Hough, Morgan T. Page, Leah Salditch, Molly M. Gallahue, Madeleine C. Lucas, James S. Neely, Seth Stein
Site response, basin amplification, and earthquake stress drops in the Portland, Oregon area
Site response, sedimentary basin amplification, and earthquake stress drops for the Portland, Oregon area were determined using accelerometer recordings at 16 sites of 10 local earthquakes with MDMD 2.6–4.0. A nonlinear inversion was applied to calculate site response (0.5–10 Hz), corner frequencies, and seismic moments from the Fourier spectra of the earthquakes. Site amplifications at lower freq
Authors
Arthur Frankel, Alex R. R. Grant
The Alaska convergent margin backstop splay fault zone, a potential large tsunami generator between the frontal prism and continental framework
The giant tsunami that swept the Pacific from Alaska to Antarctica in 1946 was generated along one of three Alaska Trench instrumentally recorded aftershock areas following great and giant earthquakes. Aftershock areas were investigated during the past decade with multibeam bathymetry, ocean bottom seismograph wide‐angle seismic, reprocessed legacy, and new seismic reflection images. Summarized an
Authors
Roland von Huene, John J. Miller, Anne Krabbenhoeft
Characteristics of frequent dynamic triggering of microearthquakes in Southern California
Dynamic triggering of earthquakes has been reported at various fault systems. The triggered earthquakes are thought to be caused either directly by dynamic stress changes due to the passing seismic waves, or indirectly by other nonlinear processes that are initiated by the passing waves. Distinguishing these physical mechanisms is difficult because of the general lack of high‐resolution earthquake
Authors
Wenyuan Fan, Andrew Barbour, Elizabeth S. Cochran, Guoqing Lin
Characterizing strain between rigid crustal blocks in the southern Cascadia forearc: Quaternary faults and folds of the northern Sacramento Valley, California
Topographic profiles across late Quaternary surfaces in the northern Sacramento Valley (California, USA) show offset and progressive folding on series of active east- and northeast—trending faults and folds. Optically stimulated luminescence ages on deposits draping a warped late Pleistocene river terrace yielded differential incision rates along the Sacramento River and indicate tectonic uplift e
Authors
Stephen J. Angster, Steven G. Wesnousky, Paula Figueiredo, Lewis A. Owen, Thomas Sawyer