Publications
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Examining the role of elevated and sustained strain in dynamically triggering earthquakes on the Anza section of the San Jacinto fault
Microearthquakes can be dynamically triggered in southern California by remote earthquakes. However, directly connecting dynamic triggering mechanisms with observational data remains challenging. One proposed failure mechanism suggests that both the amplitude and duration of cyclic fatigue caused by the passing seismic wave contribute to triggering occurrence. Here, we measure dynamic...
Authors
Nicolas DeSalvio, Andrew J Barbour, Wenyuan Fan
Long-term trends in microseismicity during operational shut-ins at the Coso Geothermal Field, California
Pausing injection and production can lead to induced seismicity in a variety of settings, with some of the largest events occurring during these so-called shut-ins. In geothermal fields, shut-ins are periodically conducted for maintenance on wells and surface infrastructure, thereby offering recurring means of estimating stress changes in the subsurface that lead to increased seismicity...
Authors
Joanna Holmgren, Joern Ole Kaven, Volker Oye
ShakeAlert® version 3: Expected performance in large earthquakes
The ShakeAlert earthquake early warning (EEW) system partners along with U.S. Geological Survey (USGS) licensed operators deliver EEW alerts to the public and trigger automated systems when a significant earthquake is expected to impact California, Oregon, or Washington. ShakeAlert’s primary goal is to provide usable warning times before the arrival of damaging shaking. EEW is most...
Authors
Jeffrey J. McGuire, Carl W. Ulberg, Angela I. Lux, Maren Böse, J.R. Andrews, Deborah E. Smith, B. Crowell, Jessica R. Murray, I. Henson, R. Hartog, C. Felizardo, Minh Huynh, Mario Aranha, Grace Alexandra Parker, Annemarie S. Baltay Sundstrom, Mark Hunter Murray, Glenn Biasi, Stephen Guiwits, J.K. Saunders, Andrew D. Good, V. Marcelo Santillan, C.W. Scrivener, Walter M. Szeliga, Timothy I. Melbourne, Victor Kress, Robert Michael deGroot, Sara K. McBride, Douglas D. Given, Richard M. Allen, Thomas H. Heaton, Allen L. Husker, Valerie I. Thomas, Harold Tobin, Sumant Jha, Julian J Bunn
Refined mapping of subsurface water ice on Mars to support future missions
Mars has an extensive yet poorly understood cryosphere. Nevertheless, both direct and indirect evidence indicates extensive buried ice across the midlatitudes, including locations where it is presently unstable. While much progress has been made in exploring the processes responsible for ice deposition and preservation during recent climatic fluctuations, a global assessment of the...
Authors
Gareth A. Morgan, Nathaniel E. Putzig, David W. Baker, Asmin E. Pathare, Colin M. Dundas, Megan Russell, Matthew Perry, Matthew Chojnacki, Hanna G. Sizemore, Ali M. Bramson, Eric I. Petersen, Stefano Nerozzi, Rachel H. Hoover, Zachary M. Bain
Mapping bedrock outcrops in the Sierra Nevada Mountains (California, USA) using machine learning
Accurate, high-resolution maps of bedrock outcrops can be valuable for applications such as models of land–atmosphere interactions, mineral assessments, ecosystem mapping, and hazard mapping. The increasing availability of high-resolution imagery can be coupled with machine learning techniques to improve regional bedrock outcrop maps. In the United States, the existing 30 m U.S...
Authors
Apoorva Ramesh Shastry, Corina Cerovski-Darriau, Brian Coltin, Jonathan D. Stock
3D viscoelastic models of slip-deficit rate along the Cascadia subduction zone
Interseismic deformation in the Pacific Northwest is constrained by the horizontal crustal velocity field derived from the Global Positioning System (GPS) in addition to vertical rates derived from GPS, leveling, and tide gauge measurements. Such measurements were folded in to deformation models of fault slip rates as part of the 2023 National Seismic Hazard Model (NSHM) update. Here I...
Authors
Frederick Pollitz
Haunted Summerville: Ghostly lights or earthquake lights?
Among the colorful local lore in the Charleston, South Carolina, area, are a number of ghost stories, shared not only over campfires but also in published books. Among the most well-known of the stories is the tale of the Summerville Light. Local lore holds that a strange light sometimes seen in a remote area is a lantern carried by the ghost of a local woman who once waited hours for...
Authors
Susan E. Hough
Slow slip detectability in seafloor pressure records offshore Alaska
In subduction zones worldwide, seafloor pressure data are used to observe tectonic deformation, particularly from megathrust earthquakes and slow slip events (SSEs). However, such measurements are also sensitive to oceanographic circulation-generated pressures over a range of frequencies that conflate with tectonic signals of interest. Using seafloor pressure and temperature data from...
Authors
Erik Fredrickson, Joan S. Gomberg, William Wilcock, Susan Hautala, Albert Hermann, H. Paul Johnson
Simulating human behavior under earthquake early warning
Earthquakes are a rapid-onset hazard where advance planning and learning plays a key role in mitigating injuries and death to individuals. Recent advances in earthquake detection have resulted in the development of earthquake early warning (EEW) systems. These systems can provide advance warning to predetermined geographic regions that an earthquake is in progress, which may result in...
Authors
Matthew Wood, Sara K. McBride, Xilei Zhao, Dare Baldwin, Elizabeth S. Cochran, Xiaojian Zhang, Nico Luco, Ruggiero Lovreglio, Tom Cova
Wave ripples formed in ancient, ice-free lakes in Gale crater, Mars
Symmetrical wave ripples identified with NASA’s Curiosity rover in ancient lake deposits at Gale crater provide a key paleoclimate constraint for early Mars: At the time of ripple formation, climate conditions must have supported ice-free liquid water on the surface of Mars. These features are the most definitive examples of wave ripples on another planet. The ripples occur in two...
Authors
C.A. Mondro, C.M. Fedo, JP Grotzinger, Michael P. Lamb, S. Gupta, W.E. Dietrich, S.G. Banham, C.M. Weitz, P. Gasda, Lauren A. Edgar, D. M. Rubin, A.B. Bryk, E.S. Kite, Gwenael Caravaca, J. Schieber, A.R. Vasavada
Reply to, “Comment on ‘The 1886 Charleston, South Carolina, earthquake: Relic railroad offset reveals rupture,’ by Roger Bilham and Susan E. Hough”
We welcome this opportunity to respond to Pratt et al. (2024) (hereinafter P24). Bilham and Hough (2023) proposed a “first-cut” elastic deformation model for the 1886 earthquake, a quantitative source model constrained by identified coseismic constraints. A key observation was the measurement of a lateral offset of a railroad line south of Summerville, leading to a model with...
Authors
Roger G. Bilham, Susan E. Hough
Thicknesses of lava flows in satellite images: Comparison of layered mare units with terrestrial analogs
Recent advances in satellite imaging technology have greatly improved our observations of planetary surfaces. The Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) records images with resolutions on average of 0.5 m per pixel, resolving meter scale features on the surface of the Moon. NAC images have revealed layered deposits, interpreted to be sequences of mare basalt flows...
Authors
M. Elise Rumpf, Heidi Needham, Sarah A. Fagents