Publications
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GPS velocity field of the Western United States for the 2023 National Seismic Hazard Model update GPS velocity field of the Western United States for the 2023 National Seismic Hazard Model update
Global Positioning System (GPS) velocity solutions of the western United States (WUS) are compiled from several sources of field networks and data processing centers for the 2023 U.S. Geological Survey National Seismic Hazard Model (NSHM). These solutions include both survey and continuous‐mode GPS velocity measurements. I follow the data processing procedure of Parsons et al. (2013) for...
Authors
Yuehua Zeng
Western U.S. geologic deformation model for use in the U.S. National Seismic Hazard Model 2023 Western U.S. geologic deformation model for use in the U.S. National Seismic Hazard Model 2023
Fault geometry and slip rates are key input data for geologic deformation models, which are a fundamental component of probabilistic seismic hazard analyses (PSHAs). However, geologic sources for PSHA have traditionally been limited to faults with field‐based slip rate constraints, which results in underrepresentation of known, but partially characterized, active faults. Here, we...
Authors
Alexandra Elise Hatem, Nadine G. Reitman, Richard W. Briggs, Ryan D. Gold, Jessica Ann Thompson Jobe, Reed J. Burgette
The Geodetic Centroid (gCent) Catalog: Global earthquake monitoring with satellite imaging geodesy The Geodetic Centroid (gCent) Catalog: Global earthquake monitoring with satellite imaging geodesy
Remote sensing geodetic observations (Interferometric Synthetic Aperture Radar [InSAR] and optical correlation [“pixel tracking”]) serve an increasingly diverse and important role in earthquake monitoring and response. This study introduces the Geodetic Centroid (gCent) catalog—an earthquake catalog derived solely from space‐based geodetic observations—and analysis of 74 earthquakes (...
Authors
William D. Barnhart, Hannah N. Shea
Mars Science Laboratory CheMin data from the Glen Torridon region and the significance of lake-groundwater interactions in interpreting mineralogy and sedimentary history Mars Science Laboratory CheMin data from the Glen Torridon region and the significance of lake-groundwater interactions in interpreting mineralogy and sedimentary history
The Glen Torridon (GT) region is positioned in terrains with strong clay mineral signatures, as inferred from orbital spectroscopy. The GT campaign confirmed orbital distinctions with in situ measurements by the Mars Science Laboratory rover, Curiosity, and the CheMin X-ray diffraction instrument with of some of the highest clay mineral abundances to date. Additionally, GT is unique...
Authors
Michael T. Thorpe, T. F. Bristow, E. Rampe, Nicholas Tosca, John P. Grotzinger, Kristen A. Bennett, C. N. Achilles, D. F. Blake, S. J. Chipera, G. Downs, R. T. Downs, S. M. Morrison, V. Tu, N. Castle, P. Craig, D. J. Des Marais, R. M. Hazen, D. W. Ming, R. V. Morris, A. H. Treiman, D. T. Vaniman, A. S. Yen, A. R. Vasavada, Erwin Dehouck, J. Bridges, J.O. Berger, Amy McAdam, T. Peretyazhko, K. Siebach, A. B. Bryk, V. F. Fox, Christopher M. Fedo
Viscoelastic fault-based model of crustal deformation for the 2023 update to the U.S. National Seismic Hazard Model Viscoelastic fault-based model of crustal deformation for the 2023 update to the U.S. National Seismic Hazard Model
The 2023 update to the National Seismic Hazard (NSHM) model is informed by several deformation models that furnish geodetically estimated fault slip rates. Here I describe a fault‐based model that permits estimation of long‐term slip rates on discrete faults and the distribution of off‐fault moment release. It is based on quantification of the earthquake cycle on a viscoelastic model of...
Authors
Frederick Pollitz
Sedimentary organics in Glen Torridon, Gale Crater, Mars: Results from the SAM instrument suite and supporting laboratory analyses Sedimentary organics in Glen Torridon, Gale Crater, Mars: Results from the SAM instrument suite and supporting laboratory analyses
The Sample Analysis at Mars (SAM) suite instrument on board NASA's Curiosity rover has characterized the inorganic and organic chemical composition of seven samples from the Glen Torridon (GT) clay-bearing unit. A variety of organic molecules were detected with SAM using pyrolysis (up to ∼850°C) and wet chemistry experiments coupled with evolved gas analysis (EGA) and gas chromatography...
Authors
Maeva Millan, Amy Williams, Amy McAdam, Jennifer Eigenbrode, A. Steele, C Freissinet, D. P. Glavin, C. Szopa, A. Buch, Roger E. Summons, J. M. T. Lewis, G. M. Wong, C. H. House, B. Sutter, O. McIntosh, A. B. Bryk, H. B. Franz, C. Pozarycki, J. C. Stern, R. Navarro-Gonzalez, R. H. Williams, D. P. Archer, V. Fox, Kristen A. Bennett, S. Teinturier, C. Malespin, S. S. Johnson, P. R. Mahaffy
Geology and stratigraphic correlation of the Murray and Carolyn Shoemaker formations across the Glen Torridon region, Gale crater, Mars Geology and stratigraphic correlation of the Murray and Carolyn Shoemaker formations across the Glen Torridon region, Gale crater, Mars
The Glen Torridon (GT) region within Gale crater, Mars, occurs in contact with the southern side of Vera Rubin ridge (VRR), a well-defined geomorphic feature that is comparatively resistant to erosion. Prior to detailed ground-based investigation of GT, its geologic relationship with VRR was unknown. Distinct lithologic subunits within the Jura member (Murray formation), which forms the...
Authors
Christopher M. Fedo, Alexander Bryk, Lauren A. Edgar, Kristen A. Bennett, Valerie K. Fox, William E. Dietrich, Steve G. Banham, Sanjeev Gupta, Kathryn M. Stack, Rebecca Williams, John P. Grotzinger, Nathan Stein, Dave Rubin, Gwenael Caravaca, Ray E. Arvidson, Madison N Hughes, Abigail A. Fraeman, Ashwin R. Vasavada, Juergen Schieber, Brad Sutter
Earthquakes in the shadows: Why aftershocks occur at surprising locations Earthquakes in the shadows: Why aftershocks occur at surprising locations
For decades there has been a debate about the relative effects of dynamic versus static stress triggering of aftershocks. According to the static Coulomb stress change hypothesis, aftershocks should not occur in stress shadows—regions where static Coulomb stress has been reduced. We show that static stress shadows substantially influence aftershock occurrence following three M ≥ 7...
Authors
Jeanne L. Hardebeck, Ruth A. Harris
Using machine learning techniques with incomplete polarity datasets to improve earthquake focal mechanism determination Using machine learning techniques with incomplete polarity datasets to improve earthquake focal mechanism determination
Earthquake focal mechanisms are traditionally produced using P‐wave first‐motion polarities and commonly require well‐recorded seismicity. A recent approach that is less dependent on high signal‐to‐noise exploits similar waveforms to produce relative polarity measurements between earthquake pairs. Utilizing these relative polarity measurements, it is possible to produce composite focal...
Authors
Robert Skoumal, David R. Shelly, Jeanne L. Hardebeck
A late Cenozoic kinematic model for fault motion within greater Cascadia A late Cenozoic kinematic model for fault motion within greater Cascadia
Widely accepted tectonic reconstructions indicate at least 100 km of coast-parallel northwestward translation of the Sierra Nevada block of California and 15–20° clockwise rotation of most of Oregon since the current phase of Basin and Range extension began ∼17 Ma. These reconstructions require at least 100 km of convergence between the central Coast Range of Oregon and rigid North...
Authors
Douglas S. Wilson, Patricia A. McCrory
Comparing root cohesion estimates from three models at a shallow landslide in the Oregon Coast Range Comparing root cohesion estimates from three models at a shallow landslide in the Oregon Coast Range
Although accurate root cohesion model estimates are essential to quantify the effect of vegetation roots on shallow slope stability, few means exist to independently validate such model outputs. One validation approach for cohesion estimates is back-calculation of apparent root cohesion at a landslide site with well-documented failure conditions. The catchment named CB1, near Coos Bay...
Authors
Collin Cronkite-Ratcliff, Kevin M. Schmidt, Charlotte Wirion
Spaceborne InSAR mapping of landslides and subsidence in rapidly deglaciating terrain, Glacier Bay National Park and Preserve and vicinity, Alaska and British Columbia Spaceborne InSAR mapping of landslides and subsidence in rapidly deglaciating terrain, Glacier Bay National Park and Preserve and vicinity, Alaska and British Columbia
The Glacier Bay area in southeastern Alaska and British Columbia, encompassing Glacier Bay National Park and Preserve, has experienced rapid glacier retreat since the end of the Little Ice Age in the mid-1800s. The impact that rapid deglaciation has had on the slope stability of valley walls and on the sedimentation of fans and deltas adjacent to fjords and inlets is an ongoing research...
Authors
Jinwook Kim, Jeffrey A. Coe, Zhong Lu, Nikita N. Avdievitch, Chad Hults