Publications
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A fault‐based model for crustal deformation in the western United States based on a combined inversion of GPS and geologic inputs
We develop a crustal deformation model to determine fault‐slip rates for the western United States (WUS) using the Zeng and Shen (2014) method that is based on a combined inversion of Global Positioning System (GPS) velocities and geological slip‐rate constraints. The model consists of six blocks with boundaries aligned along major faults in California and the Cascadia subduction zone, which are r
Authors
Yuehua Zeng, Zheng-Kang Shen
Evaluating spatial and temporal relationships between an earthquake cluster near Entiat, central Washington, and the large December 1872 Entiat earthquake
We investigate spatial and temporal relations between an ongoing and prolific seismicity cluster in central Washington, near Entiat, and the 14 December 1872 Entiat earthquake, the largest historic crustal earthquake in Washington. A fault scarp produced by the 1872 earthquake lies within the Entiat cluster; the locations and areas of both the cluster and the estimated 1872 rupture surface are com
Authors
Thomas M. Brocher, Richard J. Blakely, Brian L. Sherrod
Evaluating a kinematic method for generating broadband ground motions for great subduction zone earthquakes: Application to the 2003 Mw 8.3 Tokachi‐Oki earthquake
We compare broadband synthetic seismograms with recordings of the 2003 MwMw 8.3 Tokachi‐Oki earthquake to evaluate a compound rupture model, in which slip on the fault consists of multiple high‐stress‐drop asperities superimposed on a background slip distribution with longer rise times. Low‐frequency synthetics (<1 Hz<1 Hz) are calculated using deterministic, 3D finite‐difference simulations and
Authors
Erin A. Wirth, Arthur Frankel, John E. Vidale
Refining fault slip rates using multiple displaced terrace risers-An example from the Honey Lake fault, NE California, USA
Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and lower terrace surfaces (a factor of 2.4 difference ob
Authors
Ryan D. Gold, Richard W. Briggs, Anthony J. Crone, Christopher DuRoss
Holocene earthquakes of magnitude 7 during westward escape of the Olympic Mountains, Washington
The Lake Creek–Boundary Creek fault, previously mapped in Miocene bedrock as an oblique thrust on the north flank of the Olympic Mountains, poses a significant earthquake hazard. Mapping using 2015 light detection and ranging (lidar) confirms 2004 lidar mapping of postglacial (<13 ka) and Holocene fault scarps along the 22‐km‐long eastern section of the fault and documents Holocene scarps that ex
Authors
Alan R. Nelson, Stephen Personius, Ray Wells, Elizabeth R. Schermer, Lee-Ann Bradley, Jason Buck, Nadine G. Reitman
Persistent slip rate discrepancies in the eastern California (USA) shear zone: Reply
No abstract available.
Authors
Eileen Evans
Rock friction under variable normal stress
This study is to determine the detailed response of shear strength and other fault properties to changes in normal stress at room temperature using dry initially bare rock surfaces of granite at normal stresses between 5 and 7 MPa. Rapid normal stress changes result in gradual, approximately exponential changes in shear resistance with fault slip. The characteristic length of the exponential chang
Authors
Brian D. Kilgore, Nicholas M. Beeler, Julian C. Lozos, David Oglesby
Viscoelastic lower crust and mantle relaxation following the 14–16 April 2016 Kumamoto, Japan, earthquake sequence
The 2016 Kumamoto, Japan, earthquake sequence, culminating in the Mw=7.0 16 April 2016 main shock, occurred within an active tectonic belt of central Kyushu. GPS data from GEONET reveal transient crustal motions from several millimeters per year up to ∼3 cm/yr during the first 8.5 months following the sequence. The spatial pattern of horizontal postseismic motions is shaped by both shallow aftersl
Authors
Fred Pollitz, Tomokazu Kobayashi, Hiroshi Yarai, Bunichiro Shibazaki, Takumi Matsumoto
Aftershocks driven by afterslip and fluid pressure sweeping through a fault-fracture mesh
A variety of physical mechanisms are thought to be responsible for the triggering and spatiotemporal evolution of aftershocks. Here we analyze a vigorous aftershock sequence and postseismic geodetic strain that occurred in the Yuha Desert following the 2010 Mw 7.2 El Mayor-Cucapah earthquake. About 155,000 detected aftershocks occurred in a network of orthogonal faults and exhibit features of two
Authors
Zachary E. Ross, Christopher Rollins, Elizabeth S. Cochran, Egill Hauksson, Jean-Philippe Avouac, Yehuda Ben-Zion
Integrated geophysical characteristics of the 2015 Illapel, Chile, earthquake
On 16 September 2015, a Mw 8.3 earthquake ruptured the subduction zone offshore of Illapel, Chile, generating an aftershock sequence with 14 Mw 6.0–7.0 events. A double source W phase moment tensor inversion consists of a Mw 7.2 subevent and the main Mw 8.2 phase. We determine two slip models for the mainshock, one using teleseismic broadband waveforms and the other using static GPS and InSAR surf
Authors
Matthew W. Herman, Jennifer Nealy, William L. Yeck, William D. Barnhart, Gavin P. Hayes, Kevin P. Furlong, Harley M. Benz
A synoptic view of the Third Uniform California Earthquake Rupture Forecast (UCERF3)
Probabilistic forecasting of earthquake‐producing fault ruptures informs all major decisions aimed at reducing seismic risk and improving earthquake resilience. Earthquake forecasting models rely on two scales of hazard evolution: long‐term (decades to centuries) probabilities of fault rupture, constrained by stress renewal statistics, and short‐term (hours to years) probabilities of distributed s
Authors
Edward H. Field, Thomas H. Jordan, Morgan T. Page, Kevin R. Milner, Bruce E. Shaw, Timothy E. Dawson, Glenn Biasi, Thomas E. Parsons, Jeanne L. Hardebeck, Andrew J. Michael, Ray J. Weldon, Peter M. Powers, Kaj M. Johnson, Yuehua Zeng, Peter Bird, Karen Felzer, Nicholas van der Elst, Christopher Madden, Ramon Arrowsmith, Maximillan J. Werner, Wayne R. Thatcher
Modified mercalli intensities for nine earthquakes in central and western Washington between 1989 and 1999
We determine Modified Mercalli (Seismic) Intensities (MMI) for nine onshore earthquakes of magnitude 4.5 and larger that occurred in central and western Washington between 1989 and 1999, on the basis of effects reported in postal questionnaires, the press, and professional collaborators. The earthquakes studied include four earthquakes of M5 and larger: the M5.0 Deming earthquake of April 13, 1990
Authors
Thomas M. Brocher, James W. Dewey, John F. Cassidy