Publications
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Electrical properties of carbon dioxide hydrate: Implications for monitoring CO2 in the gas hydrate stability zone Electrical properties of carbon dioxide hydrate: Implications for monitoring CO2 in the gas hydrate stability zone
CO2 and CH4 clathrate hydrates are of keen interest for energy and carbon cycle considerations. While both typically form on Earth as cubic structure I (sI), we find that pure CO2 hydrate exhibits over an order of magnitude higher electrical conductivity (σ) than pure CH4 hydrate at geologically relevant temperatures. The conductivity was obtained from frequency-dependent impedance (Z)
Authors
Laura A. Stern, S. Constable, Ryan Lu, Wyatt L. Du Frane, J. Murray Roberts
Influence of invasive submerged aquatic vegetation (E. densa) on currents and sediment transport in a freshwater tidal system Influence of invasive submerged aquatic vegetation (E. densa) on currents and sediment transport in a freshwater tidal system
We present a field study combining measurements of vegetation density, vegetative drag, and reduction of suspended-sediment concentration (SSC) within patches of the invasive submerged aquatic plant Egeria densa. Our study was motivated by concern that sediment trapping by E. densa, which has proliferated in the Sacramento–San Joaquin Delta, is impacting marsh accretion and reducing...
Authors
Jessica R. Lacy, Madeline R. Foster-Martinez, Rachel M. Allen, Judith Z. Drexler
Seismic monitoring during crises at the NEIC in support of the ANSS Seismic monitoring during crises at the NEIC in support of the ANSS
Over the past two decades, the U.S. Geological Survey (USGS) National Earthquake Information Center (NEIC) has overcome many operational challenges. These range from minor disruptions, such as power outages, to significant operational changes, including system reconfiguration to handle unique earthquake sequences and the need to handle distributed work during a pandemic. Our ability to...
Authors
Paul S. Earle, Harley M. Benz, William L. Yeck, Gavin P. Hayes, Michelle M. Guy, John Patton, David Kragness, David B. Mason, Brian Shiro, Emily Wolin, John Bellini, Jana Pursley, Robert Lorne Sanders
Seismic and geodetic analysis of rupture characteristics of the 2020 Mw 6.5 Monte Cristo Range, Nevada, earthquake Seismic and geodetic analysis of rupture characteristics of the 2020 Mw 6.5 Monte Cristo Range, Nevada, earthquake
The largest earthquake since 1954 to strike the state of Nevada, United States, ruptured on 15 May 2020 along the Monte Cristo range of west‐central Nevada. The Mw 6.5 event involved predominantly left‐lateral strike‐slip faulting with minor normal components on three aligned east–west‐trending faults that vary in strike by 23°. The kinematic rupture process is determined by joint...
Authors
Chengli Liu, Thorne Lay, Frederick Pollitz, Jiao Xu, Xiong Xiong
NGA-East Ground-Motion Characterization model part I: Summary of products and model development NGA-East Ground-Motion Characterization model part I: Summary of products and model development
In this article, we present an overview of the research project NGA-East, Next Generation Attenuation for Central and Eastern North America (CENA), and summarize the key methodology and products. The project was tasked with developing a new ground motion characterization (GMC) model for CENA. The final NGA-East GMC model includes a set of 17 median ground motion models (GMMs) for peak...
Authors
Christine A. Goulet, Yousef Bozorgnia, Nicolas Kuehn, Linda Al Atik, Robert Youngs, Robert Graves, Gail M. Atkinson
Selection of random vibration theory procedures for the NGA-East project and ground-motion modeling Selection of random vibration theory procedures for the NGA-East project and ground-motion modeling
Traditional ground-motion models (GMMs) are used to compute pseudo-spectral acceleration (PSA) from future earthquakes and are generally developed by regression of PSA using a physics-based functional form. PSA is a relatively simple metric that correlates well with the response of several engineering systems and is a metric commonly used in engineering evaluations; however...
Authors
Albert R. Kottke, Norman A. Abrahamson, David Boore, Yousef Bozorgina, Christine A. Goulet, Justin Hollenback, Tadahiro Kishida, Olga-Joan Ktenidou, Ellen Rathje, Walt Silva, Eric M. Thompson, Xiaoyue Wang
Brine-driven destruction of clay minerals in Gale crater, Mars Brine-driven destruction of clay minerals in Gale crater, Mars
Mars’ sedimentary rock record preserves information on geological (and potential astrobiological) processes that occurred on the planet billions of years ago. The Curiosity rover is exploring the lower reaches of Mount Sharp, in Gale crater on Mars. A traverse from Vera Rubin ridge to Glen Torridon has allowed Curiosity to examine a lateral transect of rock strata laid down in a martian...
Authors
T. F. Bristow, John P. Grotzinger, E. Rampe, J. Cuadros, S. J. Chipera, G. Downs, Christopher M. Fedo, Jens Frydenvang, A. C. McAdam, R. V. Morris, C. N. Achilles, D. F. Blake, N. Castle, P. Craig, D. J. Des Marais, R. T. Downs, R. M. Hazen, D. W. Ming, S. M. Morrison, M. T. Thorpe, A. H. Treiman, V. Tu, D. T. Vaniman, A. S. Yen, R. Gellert, P. R. Mahaffy, Roger C. Wiens, A. B. Bryk, Kristen A. Bennett, V. K. Fox, R. E. Milliken, Abigail A. Fraeman, A. R. Vasavada
Preliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska Preliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska
We simulated the concurrent rapid motion of landslides on an unstable slope at Barry Arm, Alaska. Movement of landslides into the adjacent fjord displaced fjord water and generated a tsunami, which propagated out of Barry Arm. Rather than assuming an initial sea surface height, velocity, and location for the tsunami, we generated the tsunami directly using a model capable of simulating...
Authors
Katherine R. Barnhart, Ryan P. Jones, David L. George, Jeffrey A. Coe, Dennis M. Staley
Robust earthquake early warning at a fraction of the cost: ASTUTI Costa Rica Robust earthquake early warning at a fraction of the cost: ASTUTI Costa Rica
We show that a fixed smartphone network can provide robust Earthquake Early Warning for at least two orders of magnitude less cost than scientific-grade networks. Our software and cloud-based data architecture that we have constructed for the Alerta Sismica Temprana Utilizando Teléfonos Inteligentes (ASTUTI; Earthquake Early Warning Utilizing Smartphones) network in Costa Rica is easily...
Authors
Benjamin A. Brooks, Marino Protti, Todd Ericksen, Julian Bunn, Floribeth Vega, Elizabeth S. Cochran, Chris Duncan, Jonathan Avery, Sarah E. Minson, Esteban J. Chaves, Juan Carlos Baez, James H. Foster, Craig L. Glennie
Wastewater disposal has not significantly altered the regional stress state in southern Kansas Wastewater disposal has not significantly altered the regional stress state in southern Kansas
Wastewater disposal is primarily responsible for the increased seismicity rate since ~2013 in southern Kansas. Previous work that used shear wave splitting (SWS) in southern Kansas interpreted a ~90º temporal rotation in the fast polarization direction and attributed it to increased pore pressures resulting from fluid injection. However, this interpreted rotation coincided with a change...
Authors
Robert Skoumal, Elizabeth S. Cochran
Twenty-first-century projections of shoreline change along inlet-interrupted coastlines Twenty-first-century projections of shoreline change along inlet-interrupted coastlines
Sandy coastlines adjacent to tidal inlets are highly dynamic and widespread landforms, where large changes are expected due to climatic and anthropogenic influences. To adequately assess these important changes, both oceanic (e.g., sea-level rise) and terrestrial (e.g., fluvial sediment supply) processes that govern the local sediment budget must be considered. Here, we present novel...
Authors
Janaka Bamunawala, Roshanka Ranasinghe, Ali Dastgheib, Robert .J. Nichols, A. Brad Murray, Patrick L. Barnard, T. A. J. G. Sirisena, Trang Minh Duong, Suzanne J. M. H. Hulscher, Ad van der Spek
Coastal Tree-Ring Records for Paleoclimate and Paleoenvironmental Applications in North America Coastal Tree-Ring Records for Paleoclimate and Paleoenvironmental Applications in North America
For more than a century, tree-ring research has identified relationships between climatic and ecological conditions and tree growth to describe past environments and constrain future ecosystem vulnerabilities. Tree-ring records are frequently used as environmental proxies that extend knowledge of past climate and ecology on millennial scales. Many of the most pressing global change...
Authors
Clay Tucker, Jessie K. Pearl