Publications
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Strain accumulation across the Prince William Sound asperity, Southcentral Alaska Strain accumulation across the Prince William Sound asperity, Southcentral Alaska
The surface velocities predicted by the conventional subduction model are compared to velocities measured in a GPS array (surveyed in 1993, 1995, 1997, 2000, and 2004) spanning the Prince William Sound asperity. The observed velocities in the comparison have been corrected to remove the contributions from postseismic (1964 Alaska earthquake) mantle relaxation. Except at the most seaward...
Authors
James C. Savage, Jerry L. Svarc, Michael Lisowski
Quaternary tephrochronology and deposition in the subsurface Sacramento–San Joaquin Delta, California, U.S.A. Quaternary tephrochronology and deposition in the subsurface Sacramento–San Joaquin Delta, California, U.S.A.
We document characteristics of tephra, including facies and geochemistry, from 27 subsurface sites in the Sacramento-San Joaquin Delta, California, to obtain stratigraphic constraints in a complex setting. Analyzed discrete tephra deposits are correlative with: 1) an unnamed tephra from the Carlotta Formation near Ferndale, California, herein informally named the ash of Wildcat Grade (~0...
Authors
Katherine L. Maier, Emma Gatti, Elmira Wan, Daniel J. Ponti, Mark Pagenkopp, Scott W. Starratt, Holly A. Olson, John Tinsley
The Red Atrapa Sismos (Quake Catcher Network in Mexico): assessing performance during large and damaging earthquakes. The Red Atrapa Sismos (Quake Catcher Network in Mexico): assessing performance during large and damaging earthquakes.
The Quake‐Catcher Network (QCN) is an expanding seismic array made possible by thousands of participants who volunteered time and resources from their computers to record seismic data using low‐cost accelerometers (http://qcn.stanford.edu/; last accessed December 2014). Sensors based on Micro‐Electromechanical Systems (MEMS) technology have rapidly improved over the last few years due to...
Authors
Luis A. Dominguez, Battalgazi Yildirim, Allen L. Husker, Elizabeth S. Cochran, Carl Christensen, Victor M. Cruz-Atienza
Revisions to some parameters used in stochastic-method simulations of ground motion Revisions to some parameters used in stochastic-method simulations of ground motion
The stochastic method of ground‐motion simulation specifies the amplitude spectrum as a function of magnitude (M) and distance (R). The manner in which the amplitude spectrum varies with M and R depends on physical‐based parameters that are often constrained by recorded motions for a particular region (e.g., stress parameter, geometrical spreading, quality factor, and crustal...
Authors
David Boore, Eric M. Thompson
The Landscape Evolution Observatory: a large-scale controllable infrastructure to study coupled Earth-surface processes The Landscape Evolution Observatory: a large-scale controllable infrastructure to study coupled Earth-surface processes
Zero-order drainage basins, and their constituent hillslopes, are the fundamental geomorphic unit comprising much of Earth's uplands. The convergent topography of these landscapes generates spatially variable substrate and moisture content, facilitating biological diversity and influencing how the landscape filters precipitation and sequesters atmospheric carbon dioxide. In light of...
Authors
Luke A. Pangle, Stephen B. DeLong, Nate Abramson, John Adams, Greg A. Barron-Gafford, David D. Breshears, Paul D. Brooks, Jon Chorover, William E. Dietrich, Katerina Dontsova, Matej Durcik, Javier Espeleta, T.P.A. Ferre, Regis Ferriere, Whitney Henderson, Edward A. Hunt, Travis E. Huxman, David Millar, Brendan Murphy, Guo-Yue Niu, Mitch Pavao-Zuckerman, Jon D. Pelletier, Craig Rasmussen, Joaquin Ruiz, Scott Saleska, Marcel Schaap, Michael Sibayan, Peter A. Troch, Markus Tuller, Joost van Haren, Xubin Zeng
Coping with earthquakes induced by fluid injection Coping with earthquakes induced by fluid injection
Large areas of the United States long considered geologically stable with little or no detected seismicity have recently become seismically active. The increase in earthquake activity began in the mid-continent starting in 2001 (1) and has continued to rise. In 2014, the rate of occurrence of earthquakes with magnitudes (M) of 3 and greater in Oklahoma exceeded that in California (see...
Authors
Arthur F. McGarr, Barbara Bekins, Nina Burkardt, James W. Dewey, Paul S. Earle, William L. Ellsworth, Shemin Ge, Stephen H. Hickman, Austin F. Holland, Ernest Majer, Justin L. Rubinstein, Anne Sheehan
The 21 May 2014 Mw 5.9 Bay of Bengal earthquake: macroseismic data suggest a high‐stress‐drop event The 21 May 2014 Mw 5.9 Bay of Bengal earthquake: macroseismic data suggest a high‐stress‐drop event
A modest but noteworthy Mw 5.9 earthquake occurred in the Bay of Bengal beneath the central Bengal fan at 21:51 Indian Standard Time (16:21 UTC) on 21 May 2014. Centered over 300 km from the eastern coastline of India (Fig. 1), it caused modest damage by virtue of its location and magnitude. However, shaking was very widely felt in parts of eastern India where earthquakes are uncommon...
Authors
Stacey Martin, Susan E. Hough
Strike-parallel and strike-normal coordinate system around geometrically complicated rupture traces: use by NGA-West2 and further improvements Strike-parallel and strike-normal coordinate system around geometrically complicated rupture traces: use by NGA-West2 and further improvements
We present a two-dimensional system of generalized coordinates for use with geometrically complex fault ruptures that are neither straight nor continuous. The coordinates are a generalization of the conventional strike-normal and strike-parallel coordinates of a single straight fault. The presented conventions and formulations are applicable to a single curved trace, as well as multiple...
Authors
Paul A. Spudich, Brian Chiou
Simulation of acceleration field of the Lushan earthquake (Ms7.0, April 20, 2013, China) Simulation of acceleration field of the Lushan earthquake (Ms7.0, April 20, 2013, China)
The acceleration field of the Lushan earthquake (Ms7.0, April 20, 2013, China) is simulated using a new modified version of the stochastic finite-fault method (EXSIM) based on a dynamic corner frequency approach. To incorporate the effect of heterogeneous slip distribution on the variation of source spectrum, we adopt an empirical source spectral model and derive the corresponding...
Authors
Wang Guoxin, Ding Yang, Roger D. Borcherdt
Update of the Graizer-Kalkan ground-motion prediction equations for shallow crustal continental earthquakes Update of the Graizer-Kalkan ground-motion prediction equations for shallow crustal continental earthquakes
A ground-motion prediction equation (GMPE) for computing medians and standard deviations of peak ground acceleration and 5-percent damped pseudo spectral acceleration response ordinates of maximum horizontal component of randomly oriented ground motions was developed by Graizer and Kalkan (2007, 2009) to be used for seismic hazard analyses and engineering applications. This GMPE was...
Authors
Vladimir Graizer, Erol Kalkan
Comment on “Models of stochastic, spatially varying stress in the crust compatible with focal‐mechanism data, and how stress inversions can be biased toward the stress rate” by Deborah Elaine Smith and Thomas H. Heaton Comment on “Models of stochastic, spatially varying stress in the crust compatible with focal‐mechanism data, and how stress inversions can be biased toward the stress rate” by Deborah Elaine Smith and Thomas H. Heaton
Smith and Heaton (2011) propose a model in which stress in the crust is fractal‐like and highly variable on a range of length scales, including short length‐scales of ~1 km. Smith and Heaton (2011) motivate the need for stress heterogeneity on short length‐scales by citing observations such as short length‐scale changes in stress directions inferred from borehole breakouts, short length...
Authors
Jeanne L. Hardebeck
Ground motion observations of the 2014 South Napa earthquake Ground motion observations of the 2014 South Napa earthquake
Ground motions of the South Napa earthquake (24 August 2014; M 6.0) were recorded at 19 stations within 20 km and 292 stations within 100 km of the rupture surface trace, generating peak ground motions in excess of 50%g and 50 cm/s in and near Napa Valley. This large dataset allows us to compare the ground motion from the earthquake to existing ground‐motion prediction equations (GMPEs)...
Authors
Annemarie S. Baltay Sundstrom, John Boatwright