Publications
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Geologic controls on submarine slope failure along the central U.S. Atlantic margin: Insights from the Currituck Slide Complex
Multiple styles of failure, ranging from densely spaced, mass transport driven canyons to the large, slab-type slope failure of the Currituck Slide, characterize adjacent sections of the central U.S. Atlantic margin that appear to be defined by variations in geologic framework. Here we use regionally extensive, deep penetration multichannel seismic (MCS) profiles to reconstruct the influence of th
Authors
Jenna C. Hill, Daniel S. Brothers, Bradley K. Craig, Uri S. ten Brink, Jason D. Chaytor, Claudia Flores
Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database
The ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity has obtained > 300,000 spectra of rock and soil analysis targets since landing at Gale Crater in 2012, and the spectra represent perhaps the largest publicly-available LIBS datasets. The compositions of the major elements, reported as oxides (SiO2, TiO2, Al2O3, FeOT, MgO, Ca
Authors
Samuel M. Clegg, Roger C. Wiens, Ryan Anderson, Olivier Forni, Jens Frydenvang, Jeremie Lasue, Agnès Cousin, Valerie Payre, Tommy Boucher, M. Darby Dyar, Scott M. McLennan, Richard V. Morris, Trevor G. Graff, Stanley A Mertzman, Bethany L. Ehlmann, Ines Belgacem, Horton E. Newsom, Ben C. Clark, Noureddine Melikechi, Alissa Mezzacappa, Rhonda E. McInroy, Ronald Martinez, Patrick J. Gasda, Olivier Gasnault, Sylvestre Maurice
Evidence for coseismic subsidence events in a southern California coastal saltmarsh
Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter, grain size, and magnetic susceptibility. Microfossi
Authors
Robert Leeper, Brady P. Rhodes, Matthew E. Kirby, Katherine M. Scharer, Joseph A. Carlin, Eileen Hemphill-Haley, Simona Avnaim-Katav, Glen M. MacDonald, Scott W. Starratt, Angela Aranda
Systematic comparisons between PRISM version 1.0.0, BAP, and CSMIP ground-motion processing
A series of benchmark tests was run by comparing results of the Processing and Review Interface for Strong Motion data (PRISM) software version 1.0.0 to Basic Strong-Motion Accelerogram Processing Software (BAP; Converse and Brady, 1992), and to California Strong Motion Instrumentation Program (CSMIP) processing (Shakal and others, 2003, 2004). These tests were performed by using the MatLAB implem
Authors
Erol Kalkan, Christopher Stephens
Processing and review interface for strong motion data (PRISM) software, version 1.0.0—Methodology and automated processing
A continually increasing number of high-quality digital strong-motion records from stations of the National Strong-Motion Project (NSMP) of the U.S. Geological Survey (USGS), as well as data from regional seismic networks within the United States, call for automated processing of strong-motion records with human review limited to selected significant or flagged records. The NSMP has developed the
Authors
Jeanne Jones, Erol Kalkan, Christopher Stephens
Landslide kinematics and their potential controls from hourly to decadal timescales: Insights from integrating ground-based InSAR measurements with structural maps and long-term monitoring data
Knowledge of kinematics is rudimentary for understanding landslide controls and is increasingly valuable with greater spatiotemporal coverage. However, characterizing landslide-wide kinematics is rare, especially at broadly ranging timescales. We used highly detailed kinematic data obtained using photogrammetry and field mapping during the 1980s and 1990s and our 4.3-day ground-based InSAR survey
Authors
William Schulz, Jeffrey A. Coe, P.P Ricci, Gregory M. Smoczyk, Brett L Shurtleff, J Panosky
Tsunamis: Bayesian probabilistic hazard analysis
No abstract available.
Authors
Anita Grezio, Stefano Lorito, Tom Parsons, Jacopo Selva
Gravitational body forces focus North American intraplate earthquakes
Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such intraplate earthquake localization, with both natural and induced seismicity generally clustered in discrete zones. Here we use seismic velocity, gravity and topography to generate a 3D lithospheric density model of the re
Authors
William Brower Levandowski, Mark Zellman, Richard W. Briggs
Lithospheric density structure beneath the Tarim basin and surroundings, northwestern China, from the joint inversion of gravity and topography
Intraplate strain generally focuses in discrete zones, but despite the profound impact of this partitioning on global tectonics, geodynamics, and seismic hazard, the processes by which deformation becomes localized are not well understood. Such heterogeneous intraplate strain is exemplified in central Asia, where the Indo-Eurasian collision has caused widespread deformation while the Tarim block h
Authors
Yangfan Deng, William Brower Levandowski, Tim Kusky
Source modeling of the 2015 Mw 7.8 Nepal (Gorkha) earthquake sequence: Implications for geodynamics and earthquake hazards
The Gorkha earthquake on April 25th, 2015 was a long anticipated, low-angle thrust-faulting event on the shallow décollement between the India and Eurasia plates. We present a detailed multiple-event hypocenter relocation analysis of the Mw 7.8 Gorkha Nepal earthquake sequence, constrained by local seismic stations, and a geodetic rupture model based on InSAR and GPS data. We integrate these obser
Authors
Daniel E. McNamara, William L. Yeck, William D. Barnhart, V. Schulte-Pelkum, E. Bergman, L. B. Adhikari, Amod Dixit, S. E. Hough, Harley M. Benz, Paul S. Earle
Improved accuracy in quantitative laser-induced breakdown spectroscopy using sub-models
Accurate quantitative analysis of diverse geologic materials is one of the primary challenges faced by the Laser-Induced Breakdown Spectroscopy (LIBS)-based ChemCam instrument on the Mars Science Laboratory (MSL) rover. The SuperCam instrument on the Mars 2020 rover, as well as other LIBS instruments developed for geochemical analysis on Earth or other planets, will face the same challenge. Conseq
Authors
Ryan Anderson, Samuel M. Clegg, Jens Frydenvang, Roger C. Wiens, Scott M. McLennan, Richard V. Morris, Bethany L. Ehlmann, M. Darby Dyar
Chemistry of diagenetic features analyzed by ChemCam at Pahrump Hills, Gale crater, Mars
The Curiosity rover's campaign at Pahrump Hills provides the first analyses of lower Mount Sharp strata. Here we report ChemCam elemental composition of a diverse assemblage of post-depositional features embedded in, or cross-cutting, the host rock. ChemCam results demonstrate their compositional diversity, especially compared to the surrounding host rock: (i) Dendritic aggregates and relief enhan
Authors
Marion Nachon, Nicolas Mangold, Olivier Forni, Linda C. Kah, Agnès Cousin, Roger C. Wiens, Ryan Anderson, Diana L. Blaney, Jen G. Blank, Fred J. Calef, Samuel M. Clegg, Cecile Fabre, Martin R. Fisk, Olivier Gasnault, John P. Grotzinger, Rachel Kronyak, Nina L. Lanza, Jeremie Lasue, Laetitia Le Deit, Stephane Le Mouelic, Sylvestre Maurice, Pierre-Yves Meslin, D. Z. Oehler, Valerie Payre, William Rapin, Susanne Schroder, Katherine M. Stack, Dawn Sumner