Publications
Filter Total Items: 7619
Relationships among seismic velocity, metamorphism, and seismic and aseismic fault slip in the Salton Sea Geothermal Field region Relationships among seismic velocity, metamorphism, and seismic and aseismic fault slip in the Salton Sea Geothermal Field region
The Salton Sea Geothermal Field is one of the most geothermally and seismically active areas in California and presents an opportunity to study the effect of high-temperature metamorphism on the properties of seismogenic faults. The area includes numerous active tectonic faults that have recently been imaged with active source seismic reflection and refraction. We utilize the active...
Authors
Jeffrey J. McGuire, Rowena B. Lohman, Rufus D. Catchings, Michael J. Rymer, Mark R. Goldman
Micrometer-scale U–Pb age domains in eucrite zircons, impact re-setting, and the thermal history of the HED parent body Micrometer-scale U–Pb age domains in eucrite zircons, impact re-setting, and the thermal history of the HED parent body
Meteoritic zircons are rare, but some are documented to occur in asteroidal meteorites, including those of the howardite–eucrite–diogenite (HED) achondrite clan (Rubin, A. [1997]. Meteorit. Planet. Sci. 32, 231–247). The HEDs are widely considered to originate from the Asteroid 4 Vesta. Vesta and the other large main belt asteroids record an early bombardment history. To explore this...
Authors
M.D. Hopkins, S.J. Mojzsis, W.F. Bottke, Oleg Abramov
Chronology and ecology of late Pleistocene megafauna in the northern Willamette Valley, Oregon Chronology and ecology of late Pleistocene megafauna in the northern Willamette Valley, Oregon
Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic and isotopic analyses in conjunction with updated evaluations of stratigraphic context provide substantial new information on the species present, timing of losses, and...
Authors
Daniel M. Gilmour, Virginia L. Butler, James E. O'Connor, Edward Byrd Davis, Brendan J. Culleton, Douglas J. Kennett, Gregory W. L. Hodgins
Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data
Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water–rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument...
Authors
Nina L. Lanza, Ann M. Ollila, Agnes Cousin, Roger C. Wiens, Samuel M. Clegg, Nicolas Mangold, Nathan Bridges, Daniel Cooper, Mariek E. Schmidt, Jeffrey Berger, Raymond E. Arvidson, Noureddine Melikechi, Horton E. Newsom, Robert Tokar, Craig Hardgrove, Alissa Mezzacappa, Ryan S. Jackson, Benton C. Clark, Olivier Forni, Sylvestre Maurice, Marion Nachon, Ryan B. Anderson, Jennifer Blank, Matthew Deans, Dorothea Delapp, Richard Léveillé, Rhonda McInroy, Ronald Martinez, Pierre-Yves Meslin, Patrick Pinet
The use of wavenumber normalization in computing spatially averaged coherencies (KRSPAC) of microtremor data from asymmetric arrays The use of wavenumber normalization in computing spatially averaged coherencies (KRSPAC) of microtremor data from asymmetric arrays
The SPAC method of processing microtremor noise observations for estimation of Vs profiles has a limitation that the array has circular or triangular symmetry in order to allow spatial (azimuthal) averaging of inter-station coherencies over a constant station separation. Common processing methods allow for station separations to vary by typically ±10% in the azimuthal averaging before...
Authors
M.W. Asten, William J. Stephenson, Stephen H. Hartzell
How to build and teach with QuakeCaster: an earthquake demonstration and exploration tool How to build and teach with QuakeCaster: an earthquake demonstration and exploration tool
QuakeCaster is an interactive, hands-on teaching model that simulates earthquakes and their interactions along a plate-boundary fault. QuakeCaster contains the minimum number of physical processes needed to demonstrate most observable earthquake features. A winch to steadily reel in a line simulates the steady plate tectonic motions far from the plate boundaries. A granite slider in...
Authors
Kelsey Linton, Ross S. Stein
Paleoseismology of the Denali fault system at the Schist Creek site, central Alaska Paleoseismology of the Denali fault system at the Schist Creek site, central Alaska
Two hand-dug trenches at the Schist Creek site on the Denali fault system in central Alaska exposed evidence of four surface-rupturing earthquakes on the basis of upward terminations of fault strands and at least one buried, scarp-derived colluvial wedge. Limited radiocarbon ages provide some constraints on times of the ruptures. The youngest rupture (PE1) likely occurred about 200–400...
Authors
Stephen F. Personius, Anthony J. Crone, Patricia A.C. Burns, Ned Rozell
Context of ancient aqueous environments on Mars from in situ geologic mapping at Endeavour Crater Context of ancient aqueous environments on Mars from in situ geologic mapping at Endeavour Crater
Using the Mars Exploration Rover Opportunity, we have compiled one of the first field geologic maps on Mars while traversing the Noachian terrain along the rim of the 22 km diameter Endeavour Crater (Latitude −2°16′33″, Longitude −5°10′51″). In situ mapping of the petrographic, elemental, structural, and stratigraphic characteristics of outcrops and rocks distinguishes four mappable...
Authors
L.S. Crumpler, R. E. Arvidson, J. Bell, B. C. Clark, B. A. Cohen, W. H. Farrand, Ralf Gellert, M. Golombek, J. A. Grant, E. Guinness, Kenneth E. Herkenhoff, J. R. Johnson, B. Jolliff, D. W. Ming, D. W. Mittlefehldt, T. Parker, J. W. Rice, S. W. Squyres, R. Sullivan, A. S. Yen
U.S. States and Territories National Tsunami Hazard Assessment: Historical record and sources for waves – Update U.S. States and Territories National Tsunami Hazard Assessment: Historical record and sources for waves – Update
The first U.S. Tsunami Hazard Assessment (Dunbar and Weaver, 2008) was prepared at the request of the National Tsunami Hazard Mitigation Program (NTHMP). The NTHMP is a partnership formed between federal and state agencies to reduce the impact of tsunamis through hazard assessment, warning guidance, and mitigation. The assessment was conducted in response to a 2005 joint report by the...
Authors
Paula K. Dunbar, Craig S. Weaver
Rapid damage mapping for the 2015 M7.8 Gorkha earthquake using synthetic aperture radar data from COSMO-SkyMed and ALOS-2 satellites Rapid damage mapping for the 2015 M7.8 Gorkha earthquake using synthetic aperture radar data from COSMO-SkyMed and ALOS-2 satellites
The 25 April 2015 Mw 7.8 Gorkha earthquake caused more than 8000 fatalities and widespread building damage in central Nepal. The Italian Space Agency’s COSMO–SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area four days after the earthquake and the Japan Aerospace Exploration Agency’s Advanced Land Observing Satellite-2 SAR satellite for larger area nine...
Authors
Sang-Ho Yun, Kenneth W. Hudnut, Susan Owen, Frank Webb, Mark Simons, Patrizia Sacco, Eric Gurrola, Gerald Manipon, Cunren Liang, Eric Fielding, Pietro Milillo, Hook Hua, Alessandro Coletta
Micro-seismicity and seismic moment release within the Coso Geothermal Field, California Micro-seismicity and seismic moment release within the Coso Geothermal Field, California
We relocate 16 years of seismicity in the Coso Geothermal Field (CGF) using differential travel times and simultaneously invert for seismic velocities to improve our knowledge of the subsurface geologic and hydrologic structure. We expand on our previous results by doubling the number of relocated events from April 1996 through May 2012 using a new field-wide 3-D velocity model...
Authors
J. Ole Kaven, Stephen H. Hickman, Nicholas C. Davatzes
Seismic monitoring at the Decatur, Ill., CO2 sequestration demonstration site Seismic monitoring at the Decatur, Ill., CO2 sequestration demonstration site
The viability of carbon capture and storage (CCS) to reduce emissions of greenhouse gases depends on the ability to safely sequester large quantities of CO2 over geologic time scales. One concern with CCS is the potential of induced seismicity. We report on ongoing seismic monitoring by the U.S. Geological Survey (USGS) at a CCS demonstration site in Decatur, IL, in an effort to...
Authors
J. Ole Kaven, Stephen H. Hickman, Arthur F. McGarr, Steve R. Walter, William L. Ellsworth