Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 7221

Modeling the Holocene slip history of the Wasatch fault (Utah): Coseismic and postseismic Coulomb stress changes and implications for paleoseismicity and seismic hazard

The Wasatch fault zone defines the eastern boundary of the actively extending Basin and Range Province (Utah, western United States) and poses a significant seismic hazard to the metropolitan areas along the Wasatch Range. A wealth of paleoseismological data documents ∼24 surface-rupturing Mw ≥ 7 earthquakes along the Wasatch fault during the past 6400 yr. Here, we simulated the Holocene earthquak
Authors
Meike Bagge, Hampel andrea, Ryan D. Gold

Slab2, a comprehensive subduction zone geometry model

Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interfaces of subduction zones host our largest earthquakes and are likely the only faults capable of magnitude 9+ ruptures. Despite these facts, our knowledge of subduction zone geometry—which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone ear
Authors
Gavin P. Hayes, Ginevra Moore, Daniel E. Portner, Mike Hearne, Hanna E. Flamme, Maria Furtney, Gregory M. Smoczyk

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 solid gran
Authors
Gregory C. McLaskey, David A. Lockner

The case for mean rupture distance in ground‐motion estimation

This article advocates for the use of mean rupture distances that we contend are more physically representative of the distance to an earthquake and are simpler than minimum distances. Many current ground‐motion models (GMMs) rely on numerous modifications of minimum rupture distances to accurately model near‐source ground motions. These modifications, that include additional distance definitions
Authors
Eric M. Thompson, Annemarie S. Baltay

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) and 1D stochastic synthetics (>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
Authors
Erin A. Wirth, Arthur Frankel, Nasser A. Marafi, John E. Vidale, William J. Stephenson

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 recorders (“Gr
Authors
Lawrence M. Baker

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

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-beds: measu
Authors
Ryan Anderson, Lauren A. Edgar, David M. Rubin, Kevin W. Lewis, Claire Newman

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 design of
Authors
Scott Lindvall, Scott Kerwin, Chris Heron, Craig A. Davis, Jeff Tyson, Jim Chestnut, Kevin Mass, Mike Farr, Katherine Scharer, Devin McPhillips

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 consists of 6–10
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

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 methods, pr
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. Grégoire, L. Perrier, P. Polito, Y. Jannot, A. Sommier, B. Krooss, R. Fink, A. Clark

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 variation time
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian