Publications
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Lessons from Mexico’s earthquake early warning system Lessons from Mexico’s earthquake early warning system
The devastating 2017 Puebla quake provides an opportunity to assess how citizens perceive and use the Mexico City earthquake early warning system.
Authors
Richard M. Allen, Elizabeth S. Cochran, Thomas J. Huggins, Scott Miles, Diego Otegui
Quantifying uncertainty in cumulative surface slip along the Cucamonga Fault, a crustal thrust fault in southern California Quantifying uncertainty in cumulative surface slip along the Cucamonga Fault, a crustal thrust fault in southern California
Studies of historic earthquake ground surface ruptures show that displacements along strike are spatially variable. As a result, latest Quaternary slip rates developed from a spatially restricted set of cumulative displacement measurements may not accurately represent fault velocity. Here we examine the uncertainties associated with slip on the Cucamonga Fault, which is part of a network...
Authors
Devin McPhillips, Katherine M. Scharer
The 1952 Kern County, California earthquake: A case study of issues in the analysis of historical intensity data for estimation of source parameters The 1952 Kern County, California earthquake: A case study of issues in the analysis of historical intensity data for estimation of source parameters
Seismic intensity data based on first-hand accounts of shaking give valuable insight into historical and early instrumental earthquakes. Comparing an observed intensity distribution to intensity-prediction models based on modern calibration events allows the magnitude to be estimated for many historic earthquakes. Magnitude estimates can also potentially be refined for earthquakes for...
Authors
Leah Salditch, Susan E. Hough, Seth Stein, Bruce Spencer, Edward Brooks, James S. Neely, Madeleine C. Lucas
The 19 September 2017 M 7.1 Puebla‐Morelos earthquake: Spectral ratios confirm Mexico City zoning The 19 September 2017 M 7.1 Puebla‐Morelos earthquake: Spectral ratios confirm Mexico City zoning
One important element of understanding basin response to strong shaking is the analysis of spectral ratios, which may provide information about the dominant frequency of ground motion at specific locations. Spectral ratios computed from accelerations recorded by strong‐motion stations in Mexico City during the mainshock of the 19 September 2017 MM 7.1 Puebla‐Morelos earthquake reveal...
Authors
Mehmet Celebi, Valerie Jean Sahakian, Diego Melgar, Luis Quintanar
KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite - Part 1: measurements, pressure dependence and pore-fluid effects KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite - Part 1: measurements, pressure dependence and pore-fluid effects
Measuring the permeability of tight rocks remains a challenging task. In addition to the traditional sources of errors that affect more permeable formations (e.g. sample selection, non-representative specimens, disturbance introduced during sample acquisition and preparation), tight rocks can be particularly prone to solid–fluid interactions and thus more sensitive to the methods...
Authors
Christian David, J. Wasserman, F. Amann, David A. Lockner, E.H. Rutter, T Vanorio, A. Amann Hildenbrand, J. Billiotte, T. Reuschle, D. Lasseux, J. Fortin, R. Lenormand, A.P.S. Selvadurai, P.G. Meredith, J. Browning, T.M. Mitchell, D. Loggia, F. Nono, J. Sarout, L. Esteban, C. Davy, L. Louis, G. Boitnott, C. Madonna, E. Jahns, Fleury. M., G. Berthe, P. Delage, P. Braun, D. Gregoire, L. Perrier, P. Polito, Y. Jannot, A. Sommier, B. Krooss, R. Fink, Q. Hu, J.M. Klaver, A. Clark
Induced earthquake families reveal distinctive evolutionary patterns near disposal wells Induced earthquake families reveal distinctive evolutionary patterns near disposal wells
The timing of events in seismic sequences can provide insights into the physical processes controlling fault slip. In southern Kansas, the rate of earthquakes rose rapidly starting in 2013 following expansion of energy production into the area, demanding the disposal of large volumes of wastewater into deep wells. Seismicity catalogs that are complete to low magnitudes can provide...
Authors
Elizabeth S. Cochran, Zachary E. Ross, Rebecca M. Harrington, Sara L. Dougherty, Justin L. Rubinstein
Research to improve ShakeAlert earthquake early warning products and their utility Research to improve ShakeAlert earthquake early warning products and their utility
Earthquake early warning (EEW) is the rapid detection of an earthquake and issuance of an alert or notification to people and vulnerable systems likely to experience potentially damaging ground shaking. The level of ground shaking that is considered damaging is defined by the specific application; for example, manufacturing equipment may experience damage at a lower intensity ground...
Authors
Elizabeth S. Cochran, Brad T. Aagaard, Richard M. Allen, Jennifer Andrews, Annemarie S. Baltay Sundstrom, Andrew J. Barbour, Paul Bodin, Benjamin A. Brooks, Angela Chung, Brendan W. Crowell, Douglas D. Given, Thomas C. Hanks, J. Renate Hartog, Egill Hauksson, Thomas H. Heaton, Sara K. McBride, Men-Andrin Meier, Diego Melgar, Sarah E. Minson, Jessica R. Murray, Jennifer A. Strauss, Douglas Toomey
The Hayward Fault—Is it due for a repeat of the powerful 1868 earthquake? The Hayward Fault—Is it due for a repeat of the powerful 1868 earthquake?
On October 21, 1868, a magnitude 6.8 earthquake struck the San Francisco Bay area. Although the region was sparsely populated, the quake on the Hayward Fault was one of the most destructive in California’s history. U.S. Geological Survey (USGS) studies show that similar Hayward Fault quakes have repeatedly jolted the region in the past and that the fault may be ready to produce another...
Authors
Thomas M. Brocher, Jack Boatwright, James J. Lienkaemper, Carol S. Prentice, David P. Schwartz, Howard Bundock
Intensities, aftershock sequences, and the location of the 1936 Milton‐Freewater earthquake near the Oregon–Washington border, U.S.A. Intensities, aftershock sequences, and the location of the 1936 Milton‐Freewater earthquake near the Oregon–Washington border, U.S.A.
The epicenter of the 16 July 1936 MM 6 Milton‐Freewater earthquake, also known as the State Line earthquake and the largest historical earthquake in northeastern Oregon or southeastern Washington, is uncertain. Various studies place the epicenter of the earthquake, which was widely felt in eastern Washington, northeastern Oregon, and northern Idaho, within 30 km of the intersection of...
Authors
Thomas M. Brocher, Brian L. Sherrod
Pressure core analysis of geomechanical and fluid flow properties of seals associated with gas hydrate-bearing reservoirs in the Krishna-Godavari Basin, offshore India Pressure core analysis of geomechanical and fluid flow properties of seals associated with gas hydrate-bearing reservoirs in the Krishna-Godavari Basin, offshore India
Physical properties of the sediment directly overlying a gas hydrate reservoir provide important controls on the effectiveness of depressurizing that reservoir to extract methane from gas hydrate as an energy resource. The permeability of overlying sediment determines if a gas hydrate reservoir’s upper contact will provide an effective seal that enables efficient reservoir...
Authors
Junbong Jang, Sheng Dai, J. Yoneda, William F. Waite, Laura A. Stern, Lee-Gray Boze, Timothy S. Collett, Pushpendra Kumar
Shear failure of a granite pin traversing a sawcut fault Shear failure of a granite pin traversing a sawcut fault
Fault heterogeneities such as bumps, bends, and stepovers are commonly observed on natural faults, but are challenging to recreate under controlled laboratory conditions. We study deformation and microseismicity of a 76 mm-diameter Westerly granite cylinder with a sawcut fault with known frictional properties. An idealized asperity is added by emplacing a precision-ground 21 mm-diameter...
Authors
Gregory C. McLaskey, David A. Lockner
Broadband synthetic seismograms for magnitude 9 earthquakes on the Cascadia megathrust based on 3D simulations and stochastic synthetics, part 1: Methodology and overall results Broadband synthetic seismograms for magnitude 9 earthquakes on the Cascadia megathrust based on 3D simulations and stochastic synthetics, part 1: Methodology and overall results
We have produced a large set of broadband (0–10 Hz) synthetic seismograms for Mw 9.0 earthquakes on the Cascadia megathrust by combining synthetic seismograms derived from 3D finite‐difference simulations (≤1 Hz) with finite‐source, stochastic synthetics (≥1 Hz). We used a compound rupture model consisting of high stress drop Mw 8 subevents superimposed on large, shallower slip...
Authors
Arthur D. Frankel, Erin A. Wirth, Nasser A. Marafi, John Vidale, William J. Stephenson