Publications
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Revisiting California’s past great earthquakes and long-term earthquake rate
In this study, we revisit the three largest historical earthquakes in California—the 1857 Fort Tejon, 1872 Owens Valley, and 1906 San Francisco earthquakes—to review their published moment magnitudes, and compare their estimated shaking distributions with predictions using modern ground‐motion models (GMMs) and ground‐motion intensity conversion equations. Currently accepted moment magnitude estim
Authors
Susan E. Hough, Morgan T. Page, Leah Salditch, Molly M. Gallahue, Madeleine C. Lucas, James S. Neely, Seth Stein
Site response, basin amplification, and earthquake stress drops in the Portland, Oregon area
Site response, sedimentary basin amplification, and earthquake stress drops for the Portland, Oregon area were determined using accelerometer recordings at 16 sites of 10 local earthquakes with MDMD 2.6–4.0. A nonlinear inversion was applied to calculate site response (0.5–10 Hz), corner frequencies, and seismic moments from the Fourier spectra of the earthquakes. Site amplifications at lower freq
Authors
Arthur Frankel, Alex R. R. Grant
The 2018 update of the US National Seismic Hazard Model: Additional period and site class data
As part of the update of the 2018 National Seismic Hazard Model (NSHM) for the conterminous United States (CONUS), new ground motion and site effect models for the central and eastern United States were incorporated, as well as basin depths from local seismic velocity models in four western US (WUS) urban areas. These additions allow us, for the first time, to calculate probabilistic seismic hazar
Authors
Allison Shumway, Mark D. Petersen, Peter M. Powers, Sanaz Rezaeian, Kenneth S. Rukstales, Brandon Clayton
The Alaska convergent margin backstop splay fault zone, a potential large tsunami generator between the frontal prism and continental framework
The giant tsunami that swept the Pacific from Alaska to Antarctica in 1946 was generated along one of three Alaska Trench instrumentally recorded aftershock areas following great and giant earthquakes. Aftershock areas were investigated during the past decade with multibeam bathymetry, ocean bottom seismograph wide‐angle seismic, reprocessed legacy, and new seismic reflection images. Summarized an
Authors
Roland von Huene, John J. Miller, Anne Krabbenhoeft
Characteristics of frequent dynamic triggering of microearthquakes in Southern California
Dynamic triggering of earthquakes has been reported at various fault systems. The triggered earthquakes are thought to be caused either directly by dynamic stress changes due to the passing seismic waves, or indirectly by other nonlinear processes that are initiated by the passing waves. Distinguishing these physical mechanisms is difficult because of the general lack of high‐resolution earthquake
Authors
Wenyuan Fan, Andrew Barbour, Elizabeth S. Cochran, Guoqing Lin
Characterizing strain between rigid crustal blocks in the southern Cascadia forearc: Quaternary faults and folds of the northern Sacramento Valley, California
Topographic profiles across late Quaternary surfaces in the northern Sacramento Valley (California, USA) show offset and progressive folding on series of active east- and northeast—trending faults and folds. Optically stimulated luminescence ages on deposits draping a warped late Pleistocene river terrace yielded differential incision rates along the Sacramento River and indicate tectonic uplift e
Authors
Stephen J. Angster, Steven G. Wesnousky, Paula Figueiredo, Lewis A. Owen, Thomas Sawyer
Holocene paleoseismology of the Steamboat Mountain Site: Evidence for full‐Llngth rupture of the Teton Fault, Wyoming
The 72‐km‐long Teton fault in northwestern Wyoming is an ideal candidate for reconstructing the lateral extent of surface‐rupturing earthquakes and testing models of normal‐fault segmentation. To explore the history of earthquakes on the northern Teton fault, we hand‐excavated two trenches at the Steamboat Mountain site, where the east‐dipping Teton fault has vertically displaced west‐sloping allu
Authors
Christopher DuRoss, Mark S. Zellman, Glenn D. Thackray, Richard W. Briggs, Ryan D. Gold, Shannon A. Mahan
The induced Mw 5.0 March 2020 west Texas seismic sequence
On March 26, 2020, a M 5.0 earthquake occurred in the Delaware Basin, Texas, near the border between Reeves and Culberson Counties. This was the third largest earthquake recorded in Texas and the largest earthquake in the Central and Eastern United States since the three M 5.0–5.8 induced events in Oklahoma during 2016. Using multistation waveform template matching, we detect 3,940 earthquakes in
Authors
Robert Skoumal, Joern Kaven, Andrew Barbour, Charles Wicks, Michael R. Brudzinski, Elizabeth S. Cochran, Justin Rubinstein
Ocean floor manganese deposits
Much of the dissolved Mn delivered to the oceans is slowly oxidized and precipitated alongside varying amounts of Fe into Mn and ferromanganese (FeMn) mineral deposits that occur extensively in the deep ocean wherever sediment accumulation is low and substrate is available. FeMn crusts grow as pavements on rock outcrops throughout the global ocean whereas nodules form as individual FeMn-encrusted
Authors
Kira Mizell, James R. Hein
Planetary cave exploration progresses
Planetary caves have been identified on the Moon and on Mars, and are likely to occur across the Solar System. They present a new frontier for planetary science, subsurface astrobiology, geology and human exploration. The fourth in a series of scientific meetings focusing on the science and exploration of planetary caves brought together 55 terrestrial and planetary scientists, robotics and instru
Authors
Timothy N. Titus, C. M. Phillips-Lander, P. J. Boston, J. J. Wynne, L. Kerber
Sphalerite oxidation in seawater with covellite: Implications for seafloor massive sulfide deposits and mine waste
Metal sulfide minerals exist in several marine environments and are in thermodynamic disequilibrium with oxygenated seawater from the time of their formation. Oxidation is both ubiquitous and heterogeneous, as observational and experimental evidence demonstrates that sulfide minerals may oxidize completely on decadal timescales (hydrothermal plumes) or incompletely in billions of years (mineral de
Authors
Amy Gartman, Samantha P. Whisman, James R. Hein
Systematic characterization of morphotectonic variability along the Cascadia convergent margin: Implications for shallow megathrust behavior and tsunami hazards
Studies of recent destructive megathrust earthquakes and tsunamis along subduction margins in Japan, Sumatra, and Chile have linked forearc morphology and structure to megathrust behavior. This connection is based on the idea that spatial variations in the frictional behavior of the megathrust influence the tectono-morphological evolution of the upper plate. Here we present a comprehensive exa
Authors
Janet Watt, Daniel S. Brothers