Publications
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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
Broadband synthetic seismograms for magnitude 9 earthquakes on the Cascadia Megathrust based on 3D simulations and stochastic synthetics, Part 2: Rupture parameters and variability Broadband synthetic seismograms for magnitude 9 earthquakes on the Cascadia Megathrust based on 3D simulations and stochastic synthetics, Part 2: Rupture parameters and variability
We used a combination of 3D finite‐difference simulations (>1 Hz) to generate broadband (0–10 Hz) synthetic seismograms for numerous Mw 9 earthquake rupture scenarios on the Cascadia megathrust. Slip consists of multiple high‐stress‐drop subevents (Mw 8) with short rise times on the deeper portions of the fault, superimposed on a background slip distribution with longer rise times. We...
Authors
Erin A. Wirth, Arthur D. Frankel, Nasser A. Marafi, John E. Vidale, William J. Stephenson
Granite IP network default route disappearance—Diagnosis and solution Granite IP network default route disappearance—Diagnosis and solution
The U.S. Geological Survey (USGS) National Strong Motion Project (NSMP) operates numerous strong-motion seismographs to monitor ground shaking and structural response caused by large, nearby earthquakes. This report describes a problem NSMP scientists encountered communicating over the Internet with several Kinemetrics, Inc., Granite strong-motion recorders. The Granite strong-motion...
Authors
Lawrence M. Baker
Seismic sensors record a hurricane’s roar Seismic sensors record a hurricane’s roar
The instruments installed at Global Seismographic Network (GSN) stations were designed to record Earth’s vibrations, but they sometimes pick up sound waves from unexpected sources. For example, newly installed infrasound sensors at a station on Puerto Rico recorded the passage of Hurricane Maria on 20 September 2017.
Authors
David C. Wilson, Peter Davis, Carl Ebeling, Charles R. Hutt, Katrin Hafner
Complex bedding geometry in the upper portion of Aeolis Mons, Gale crater, Mars Complex bedding geometry in the upper portion of Aeolis Mons, Gale crater, Mars
The Upper formation of Aeolis Mons in Gale crater exhibits curvilinear bedding patterns on the surfaces of several erosional benches that have been interpreted as cross-bedding. We use High Resolution Imaging Science Experiment (HiRISE) stereo topography to test this hypothesis by measuring the bedding geometry within these benches. The bedding geometry is consistent with aeolian cross...
Authors
Ryan B. Anderson, Lauren A. Edgar, David M. Rubin, Kevin W. Lewis, Claire Newman
High resolution measurement of levee subsidence related to energy infrastructure in the Sacramento-San Joaquin Delta High resolution measurement of levee subsidence related to energy infrastructure in the Sacramento-San Joaquin Delta
We assess flood overtopping potential (when flood water elevation exceeds levee elevation) to the levees surrounding the islands in the interior of California's Sacramento-San Joaquin Delta. Because critical natural gas infrastructure is susceptible to overtopping-related disruption, we focus our analysis on regions that are crossed by the network of the state's natural gas pipelines. We...
Authors
Benjamin A. Brooks, Jennifer Telling, Todd Leroy Ericksen, Craig L. Glennie, Noah Knowles, Daniel Cayan, Darren L. Hauser, Adam LeWinter
Characterizing the Los Angeles Aqueduct crossing of the San Andreas Fault for improved earthquake resilience Characterizing the Los Angeles Aqueduct crossing of the San Andreas Fault for improved earthquake resilience
The five-mile-long Elizabeth Tunnel, which crosses the San Andreas fault (SAF) zone near Lake Hughes, California, is part of the Los Angeles Aqueduct (LAA) that delivers water from Owens Valley to the City of Los Angeles. Geologic characterization of the Elizabeth Tunnel alignment is focused on developing a better understanding of fault displacement hazards at the SAF crossing to support...
Authors
Scott Lindvall, Scott Kerwin, Chris Heron, Craig A. Davis, Jeff Tyson, Jim Chestnut, Kevin Mass, Mike Farr, Katherine M. Scharer, Devin McPhillips
Tilt Trivia: A free multiplayer app to learn geoscience concepts and definitions Tilt Trivia: A free multiplayer app to learn geoscience concepts and definitions
Today’s technology is opening up new ways to learn. Here, we introduce Tilt Trivia, a suite of quiz‐style, multiplayer games for use on mobile devices and tablets (Android or Apple) to help students learn simple definitions and facts. This mobile device game was built using the Unity engine and has a multiplayer functionality that runs seamlessly, all day, every day. A single game...
Authors
Debi Kilb, Alan Yang, Nathan Garrett, Kristine L. Pankow, Justin L. Rubinstein, Lisa Linville
KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite - Part 2: modeling, microstructures and complementary data KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite - Part 2: modeling, microstructures and complementary data
Measuring and modelling 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...
Authors
Christian David, J. Wassermann, F. Amann, J.M. Klaver, C. Davy, J. Sarout, L. Esteban, E.H. Rutter, Q. Hu, L. Louis, P. Delage, David A. Lockner, A.P.S. Selvadurai, T Vanorio, A. Amann Hildenbrand, P.G. Meredith, J. Browning, T.M. Mitchell, C. Madonna, J. Billiotte, T. Reuschle, D. Lasseux, J. Fortin, R. Lenormand, D. Loggia, F. Nono, G. Boitnott, E. Jahns, Fleury. M., G. Berthe, P. Braun, D. Gregoire, L. Perrier, P. Polito, Y. Jannot, A. Sommier, B. Krooss, R. Fink, A. Clark
Decomposing leftovers: Event, path, and site residuals for a small magnitude ANZA region GMPE Decomposing leftovers: Event, path, and site residuals for a small magnitude ANZA region GMPE
Ground‐motion prediction equations (GMPEs) are critical elements of probabilistic seismic hazard analysis (PSHA), as well as for other applications of ground motions. To isolate the path component for the purpose of building nonergodic GMPEs, we compute a regional GMPE using a large dataset of peak ground accelerations (PGAs) from small‐magnitude earthquakes (0.5 ≤ M ≤ 4.5 with > 10,000...
Authors
Valerie Jean Sahakian, Annemarie S. Baltay Sundstrom, Thomas C. Hanks, Janine S. Buehler, Frank L. Vernon, Deborah L. Kilb
Geoelectric hazard maps for the Pacific Northwest Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with historical 1‐min (2‐min Nyquist) geomagnetic...
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian
Controls on submarine canyon head evolution: Monterey Canyon, offshore central California Controls on submarine canyon head evolution: Monterey Canyon, offshore central California
The Monterey submarine canyon, incised across the continental shelf in Monterey Bay, California, provides a record of the link between onshore tectonism, fluvial transport, and deep-marine deposition. High-resolution seismic-reflection imaging in Monterey Bay reveals an extensive paleocanyon unit buried below the seafloor of the continental shelf around Monterey and Soquel canyon heads
Authors
Katherine L. Maier, Samuel Y. Johnson, Patrick E. Hart