Publications
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The influence of vegetation cover on debris-flow density during an extreme rainfall in the northern Colorado Front Range The influence of vegetation cover on debris-flow density during an extreme rainfall in the northern Colorado Front Range
We explored regional influences on debris-flow initiation throughout the Colorado Front Range (Colorado, USA) by exploiting a unique data set of more than 1100 debris flows that initiated during a 5 day rainstorm in 2013. Using geospatial data, we examined the influence of rain, hillslope angle, hillslope aspect, and vegetation density on debris-flow initiation. In particular we used a...
Authors
Francis K. Rengers, Luke McGuire, Jeffrey A. Coe, Jason W. Kean, Rex L. Baum, Dennis M. Staley, Jonathan W. Godt
Complex explosive volcanic activity on the Moon within Oppenheimer crater Complex explosive volcanic activity on the Moon within Oppenheimer crater
Oppenheimer Crater is a floor-fractured crater located within the South Pole-Aitken basin on the Moon, and exhibits more than a dozen localized pyroclastic deposits associated with the fractures. Localized pyroclastic volcanism on the Moon is thought to form as a result of intermittently explosive Vulcanian eruptions under low effusion rates, in contrast to the higher-effusion rate...
Authors
Kristen A Bennett, Briony H. N. Horgan, Lisa R. Gaddis, Benjamin T Greenhagen, Carlton C. Allen, Paul O. Hayne, James F. Bell, David A. Paige
ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars
At Gale crater, Mars, ChemCam acquired its first laser-induced breakdown spectroscopy (LIBS) target on Sol 13 of the landed portion of the mission (a Sol is a Mars day). Up to Sol 800, more than 188 000 LIBS spectra were acquired on more than 5800 points distributed over about 650 individual targets. We present a comprehensive review of ChemCam scientific accomplishments during that...
Authors
Sylvestre Maurice, Samuel M. Clegg, Roger C. Wiens, O. Gasnault, W. Rapin, O. Forni, Agnes Cousin, V. Sautter, Nicolas Mangold, L. Le Deit, Marion Nachon, Ryan B. Anderson, Nina Lanza, Cecile Fabre, Valerie Payre, Jeremie Lasue, Pierre-Yves Meslin, Richard A. LeVeille, Bruce Barraclough, Pierre Beck, Steven C. Bender, Gilles Berger, John C. Bridges, Nathan Bridges, Gilles Dromert, M. Darby Dyar, Raymond Francis, Jens Frydenvang, B. Gondet, Bethany L. Ehlmann, Kenneth E. Herkenhoff, Jeffrey R. Johnson, Yves Langevin, Madsen Morten B., N. Melikechi, J.-L. Lacour, Stephane Le Mouelic, Eric Lewin, Horton E. Newsom, Ann M. Ollila, Patrick Pinet, S. Schroder, Jean-Baptiste Sirven, Robert L. Tokar, M.J. Toplis, Claude d’Uston, David Vaniman, Ashwin R. Vasavada
Granitic boulder erosion caused by chaparral wildfire: Implications for cosmogenic radionuclide dating of bedrock surfaces Granitic boulder erosion caused by chaparral wildfire: Implications for cosmogenic radionuclide dating of bedrock surfaces
Rock surface erosion by wildfire is significant and widespread but has not been quantified in southern California or for chaparral ecosystems. Quantifying the surface erosion of bedrock outcrops and boulders is critical for determination of age using cosmogenic radionuclide techniques, as even modest surface erosion removes the accumulation of the cosmogenic radionuclides and causes...
Authors
Katherine J. Kendrick, Camille Partin, Robert C. Graham
The missing large impact craters on Ceres The missing large impact craters on Ceres
Asteroids provide fundamental clues to the formation and evolution of planetesimals. Collisional models based on the depletion of the primordial main belt of asteroids predict 10–15 craters >400 km should have formed on Ceres, the largest object between Mars and Jupiter, over the last 4.55 Gyr. Likewise, an extrapolation from the asteroid Vesta would require at least 6–7 such basins...
Authors
S. Marchi, A. Ermakov, C.A. Raymond, R.R. Fu, D.P. O’Brien, Michael T. Bland, E. Ammannito, De Sanctis, Tim Bowling, P. Schenk, J.E.C. Scully, D.L. Buczkowski, D.A. Williams, H. Hiesinger, C.T. Russell
Subsidence rates at the southern Salton Sea consistent with reservoir depletion Subsidence rates at the southern Salton Sea consistent with reservoir depletion
Space geodetic measurements from the Envisat satellite between 2003 and 2010 show that subsidence rates near the southeastern shoreline of the Salton Sea in Southern California are up to 52mmyr−1 greater than the far-field background rate. By comparing these measurements with model predictions, we find that this subsidence appears to be dominated by poroelastic contraction associated...
Authors
Andrew J. Barbour, Eileen Evans, Stephen H. Hickman, Mariana Eneva
U.S. Geological Survey Volcano Hazards Program—Assess, forecast, prepare, engage U.S. Geological Survey Volcano Hazards Program—Assess, forecast, prepare, engage
At least 170 volcanoes in 12 States and 2 territories have erupted in the past 12,000 years and have the potential to erupt again. Consequences of eruptions from U.S. volcanoes can extend far beyond the volcano’s immediate area. Many aspects of our daily life are vulnerable to volcano hazards, including air travel, regional power generation and transmission infrastructure, interstate
Authors
Wendy K. Stovall, Aleeza M. Wilkins, Charlie Mandeville, Carolyn L. Driedger
Structure of the 1906 near-surface rupture zone of the San Andreas Fault, San Francisco Peninsula segment, near Woodside, California Structure of the 1906 near-surface rupture zone of the San Andreas Fault, San Francisco Peninsula segment, near Woodside, California
High-resolution seismic-reflection and refraction images of the 1906 surface rupture zone of the San Andreas Fault near Woodside, California reveal evidence for one or more additional near-surface (within about 3 meters [m] depth) fault strands within about 25 m of the 1906 surface rupture. The 1906 surface rupture above the groundwater table (vadose zone) has been observed in...
Authors
C.M. Rosa, R. D. Catchings, M. J. Rymer, Karen Grove, M. R. Goldman
Geologic context of recurring slope lineae in Melas and Coprates Chasmata, Mars Geologic context of recurring slope lineae in Melas and Coprates Chasmata, Mars
One of the major Mars discoveries of recent years is the existence of recurring slope lineae (RSL), which suggests that liquid water occurs on or near the surface of Mars today. These dark and narrow features emerge from steep, rocky exposures and incrementally grow, fade, and reform on a seasonal basis and are detected in images from the High Resolution Imaging Science Experiment camera...
Authors
Matthew Chojnacki, Alfred McEwen, Colin M. Dundas, Lujendra Ojha, Anna Urso, Sarah Sutton
Composition and structure of the shallow subsurface of Ceres revealed by crater morphology Composition and structure of the shallow subsurface of Ceres revealed by crater morphology
Before NASA’s Dawn mission, the dwarf planet Ceres was widely believed to contain a substantial ice-rich layer below its rocky surface. The existence of such a layer has significant implications for Ceres’s formation, evolution, and astrobiological potential. Ceres is warmer than icy worlds in the outer Solar System and, if its shallow subsurface is ice-rich, large impact craters are...
Authors
Michael T. Bland, Carol A. Raymond, Paul M. Schenk, Roger R. Fu, Thomas Kneisl, Jan Hendrick Pasckert, Harald Hiesinger, Frank Preusker, Ryan S. Park, Simone Marchi, Scott King, Julie C. Castillo-Rogez, Christopher T. Russell
Spectral nature of CO2 adsorption onto meteorites Spectral nature of CO2 adsorption onto meteorites
Previous studies have identified carbon dioxide (CO2) on the surfaces of Jovian and Galilean satellites in regions of non-ice material that are too warm for CO2 ice to exist. CO2 ice would quickly sublimate if not retained by a less-volatile material. To ascertain what non-ice species may be responsible for stabilizing this CO2, we performed CO2 gas adsorption experiments on thirteen...
Authors
Genesis Berlanga, Charles A Hibbitts, Driss Takir, Draby M Dyar, Elizabeth Sklute
Assessing landslide potential on coastal bluffs near Mukilteo, Washington—Geologic site characterization for hydrologic monitoring Assessing landslide potential on coastal bluffs near Mukilteo, Washington—Geologic site characterization for hydrologic monitoring
During the summer 2015, the U.S. Geological Survey collected geologic and geotechnical data for two sites on coastal bluffs along the eastern shore of Puget Sound, Washington. The U.S. Geological Survey also installed hydrologic instrumentation at the sites and collected specimens for laboratory testing. The two sites are located on City of Mukilteo open-space land and are about 0.6...
Authors
Benjamin B. Mirus, Joel B. Smith, Benjamin Stark, York Lewis, Abigail Michel, Rex L. Baum