Publications
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Global-scale changes to extreme ocean wave events due to anthropogenic warming
Extreme surface ocean waves are often primary drivers of coastal flooding and erosion over various time scales. Hence, understanding future changes in extreme wave events owing to global warming is of socio-economic and environmental significance. However, our current knowledge of potential changes in high-frequency (defined here as having return periods of less than 1 year) extreme wave events ar
Authors
Joao Morim, Sean Vitousek, Mark Hemer, Borja Reguero, Li H. Erikson, Merce Casas-Prat, Xiaolan L. Wang, Alvaro Semedo, Nobuhito Mori, Tomoya Shimura, Lorenzo Mentaschi, Ben Timmerman
A numerical model for the cooling of a lava sill with heat pipe effects
Understanding the cooling process of volcanic intrusions into wet sediments is a difficult but important problem, given the presence of extremely large temperature gradients and potentially complex water-magma interactions. This report presents a numerical model to study such interactions, including the effect of heat pipes on the cooling of volcanic intrusions. Udell (1985) has shown that heat pi
Authors
Kaj E. Williams, Colin M. Dundas, Laszlo P. Kestay
Timing of iceberg scours and massive ice-rafting events in the subtropical North Atlantic
High resolution seafloor mapping shows extraordinary evidence that massive (>300 m thick) icebergs once drifted >5,000 km south along the eastern United States, with >700 iceberg scours now identified south of Cape Hatteras. Here we report on sediment cores collected from several buried scours that show multiple plow marks align with Heinrich Event 3 (H3), ~31,000 years ago. Numerical glacial iceb
Authors
Alan Condron, Jenna C. Hill
Down to Earth with nuclear electromagnetic pulse: Realistic surface impedance affects mapping of the E3 geoelectric hazard
An analysis is made of Earth-surface geoelectric fields and voltages on electricity transmission power-grids induced by a late-phase E3 nuclear electromagnetic pulse (EMP). A hypothetical scenario is considered of an explosion of several hundred kilotons set several hundred kilometers above the eastern-midcontinental United States. Ground-level E3 geoelectric fields are estimated by convolving a s
Authors
Jeffrey J. Love, Greg M. Lucas, Benjamin Scott Murphy, Paul A. Bedrosian, E. Joshua Rigler, Anna Kelbert
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) measurement
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
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 turbidity. In
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
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 overcome cr
Authors
Paul S. Earle, Harley M. Benz, William L. Yeck, Gavin P. Hayes, Michelle 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
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 inversion of Glo
Authors
Chengli Liu, Thorne Lay, Fred Pollitz, Jiao Xu, Xiong Xiong
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 ground accel
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
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, characteristics of the
Authors
Albert R. Kottke, Norman A. Abrahamson, David Boore, Yousef Bozorgina, Christine A. Goulet, Justin Hollenback, Tadahiro Kishida, Olga-Joan Ktenidou, Ellen M. Rathje, Walt Silva, Eric M. Thompson, Xiaoyue Wang
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 lake ~3.5
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
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 the dynamic
Authors
Katherine R. Barnhart, Ryan P. Jones, David L. George, Jeffrey A. Coe, Dennis M. Staley