Publications
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ShakeAlert—An earthquake early warning system for the United States west coast
Earthquake early warning systems use earthquake science and the technology of monitoring systems to alert devices and people when shaking waves generated by an earthquake are expected to arrive at their location. The seconds to minutes of advance warning can allow people and systems to take actions to protect life and property from destructive shaking. The U.S. Geological Survey (USGS), in collabo
Authors
Erin R. Burkett, Douglas D. Given, Lucile M. Jones
Grain-scale imaging and compositional characterization of cryo-preserved India NGHP 01 gas-hydrate-bearing cores
We report on grain-scale characteristics and gas analyses of gas-hydrate-bearing samples retrieved by NGHP Expedition 01 as part of a large-scale effort to study gas hydrate occurrences off the eastern-Indian Peninsula and along the Andaman convergent margin. Using cryogenic scanning electron microscopy, X-ray spectroscopy, and gas chromatography, we investigated gas hydrate grain morphology and d
Authors
Laura A. Stern, T.D. Lorenson
Seismicity, faulting, and structure of the Koyna-Warna seismic region, Western India from local earthquake tomography and hypocenter locations
Although seismicity near Koyna Reservoir (India) has persisted for ~50 years and includes the largest induced earthquake (M 6.3) reported worldwide, the seismotectonic framework of the area is not well understood. We recorded ~1800 earthquakes from 6 January 2010 to 28 May 2010 and located a subset of 343 of the highest-quality earthquakes using the tomoDD code of Zhang and Thurber (2003) to bette
Authors
Madan M. Dixit, Sanjay Kumar, Rufus D. Catchings, K. Suman, Dipankar Sarkar, M.K. Sen
Bayesian historical earthquake relocation: an example from the 1909 Taipei earthquake
Locating earthquakes from the beginning of the modern instrumental period is complicated by the fact that there are few good-quality seismograms and what traveltimes do exist may be corrupted by both large phase-pick errors and clock errors. Here, we outline a Bayesian approach to simultaneous inference of not only the hypocentre location but also the clock errors at each station and the origin ti
Authors
Sarah E. Minson, William H.K. Lee
Path durations for use in the stochastic‐method simulation of ground motions
The stochastic method of ground‐motion simulation assumes that the energy in a target spectrum is spread over a duration DT. DT is generally decomposed into the duration due to source effects (DS) and to path effects (DP). For the most commonly used source, seismological theory directly relates DS to the source corner frequency, accounting for the magnitude scaling of DT. In contrast, DP is relate
Authors
David M. Boore, Eric M. Thompson
Pulverization provides a mechanism for the nucleation of earthquakes at low stress on strong faults
An earthquake occurs when rock that has been deformed under stress rebounds elastically along a fault plane (Gilbert, 1884; Reid, 1911), radiating seismic waves through the surrounding earth. Rupture along the entire fault surface does not spontaneously occur at the same time, however. Rather the rupture starts in one tiny area, the rupture nucleation zone, and spreads sequentially along the fault
Authors
Karen R. Felzer
Drift issues of tall buildings during the March 11, 2011 M9.0 Tohoku earthquake, Japan - Implications
One of the most significant effects of the M9.0 Tohoku, Japan earthquake of March 11, 2011 is the now well-known long duration (>10 minutes) shaking of buildings in Japan – particularly those in Tokyo (~350-375 km from the epicenter) and in places as far as Osaka (~770 km from the epicenter). Although none collapsed, the strong shaking caused many tall buildings not to be functional for days and
Authors
Mehmet Çelebi, Izuru Okawa
Comparison of NGA-West2 directivity models
Five directivity models have been developed based on data from the NGA-West2 database and based on numerical simulations of large strike-slip and reverse-slip earthquakes. All models avoid the use of normalized rupture dimension, enabling them to scale up to the largest earthquakes in a physically reasonable way. Four of the five models are explicitly “narrow-band” (in which the effect of directiv
Authors
Paul A. Spudich, Badie Rowshandel, Shrey Shahi, Jack W. Baker, Brian S-J Chiou
Adding fling effects to processed ground‐motion time histories
Fling is the engineering term for the effects of the permanent tectonic offset, caused by a rupturing fault in the recorded ground motions near the fault. It is expressed by a one‐sided pulse in ground velocity and a nonzero final displacement at the end of shaking. Standard processing of earthquake time histories removes some of the fling effects that may be required for engineering applications.
Authors
Ronnie Kamai, Norman A. Abrahamson, Robert Graves
NGA-West2 Research Project
The NGA-West2 project is a large multidisciplinary, multi-year research program on the Next Generation Attenuation (NGA) models for shallow crustal earthquakes in active tectonic regions. The research project has been coordinated by the Pacific Earthquake Engineering Research Center (PEER), with extensive technical interactions among many individuals and organizations. NGA-West2 addresses several
Authors
Yousef Bozorgnia, Norman A. Abrahamson, Linda Al Atik, Timothy D. Ancheta, Gail M. Atkinson, Jack W. Baker, Annemarie S. Baltay, David M. Boore, Kenneth W. Campbell, Brian S.J. Chiou, Robert B. Darragh, Steve Day, Jennifer Donahue, Robert W. Graves, Nick Gregor, Thomas C. Hanks, I. M. Idriss, Ronnie Kamai, Tadahiro Kishida, Albert Kottke, Stephen A. Mahin, Sanaz Rezaeian, Badie Rowshandel, Emel Seyhan, Shrey Shahi, Tom Shantz, Walter Silva, Paul A. Spudich, Jonathan P. Stewart, Jennie Watson-Lamprey, Kathryn Wooddell, Robert Youngs
Imaging P and S attenuation in the Sacramento-San Joaquin Delta region, northern California
We obtain 3-D Qp and Qs models for the Delta region of the Sacramento and San Joaquin Rivers, a large fluvial-agricultural portion of the Great Valley located between the Sierra Nevada batholith and the San Francisco Bay - Coast Ranges region of active faulting. Path attenuation t* values have been obtained for P and S data from 124 distributed earthquakes, with a longer variable window for S base
Authors
Donna Eberhart-Phillips, Clifford Thurber, Jon Peter B. Fletcher
Geologic logs of geotechnical cores from the subsurface Sacramento-San Joaquin Delta, California
This report presents and summarizes descriptive geologic logs of geotechnical cores collected from 2009–12 in the Sacramento–San Joaquin Delta, California, by the California Department of Water Resources. Graphic logs are presented for 1,785.7 ft of retained cores from 56 borehole sites throughout the Sacramento-San Joaquin Delta. Most core sections are from a depth of ~100–200 feet. Cores primari
Authors
Katherine L. Maier, Daniel J. Ponti, John C. Tinsley, Emma Gatti, Mark Pagenkopp