Publications
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The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam Onboard Curiosity The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam Onboard Curiosity
The Mars Science Laboratory rover Curiosity encountered potassium-rich clastic sedimentary rocks at two sites in Gale Crater, the waypoints Cooperstown and Kimberley. These rocks include several distinct meters thick sedimentary outcrops ranging from fine sandstone to conglomerate, interpreted to record an ancient fluvial or fluvio-deltaic depositional system. From ChemCam Laser-Induced...
Authors
Laetitia Le Deit, Nicolas Mangold, Olivier Forni, Agnes Cousin, Jeremie Lasue, Susanne Schröder, Roger C. Wiens, Dawn Y. Sumner, Cecile Fabre, Katherine M. Stack, Ryan B. Anderson, Diana L. Blaney, Samuel M. Clegg, Gilles Dromart, Martin Fisk, Olivier Gasnault, John P. Grotzinger, Sanjeev Gupta, Nina Lanza, Stephane Le Mouelic, Sylvestre Maurice, Scott M. McLennan, Pierre-Yves Meslin, Marion Nachon, Horton E. Newsom, Valerie Payre, William Rapin, Melissa Rice, Violaine Sautter, Allan H. Treiman
Lithospheric flexure under the Hawaiian volcanic load: Internal stresses and a broken plate revealed by earthquakes Lithospheric flexure under the Hawaiian volcanic load: Internal stresses and a broken plate revealed by earthquakes
Several lines of earthquake evidence indicate that the lithospheric plate is broken under the load of the island of Hawai`i, where the geometry of the lithosphere is circular with a central depression. The plate bends concave downward surrounding a stress-free hole, rather than bending concave upward as with past assumptions. Earthquake focal mechanisms show that the center of load...
Authors
Fred W. Klein
Fluvial erosion as a mechanism for crater modification on Titan Fluvial erosion as a mechanism for crater modification on Titan
There are few identifiable impact craters on Titan, especially in the polar regions. One explanation for this observation is that the craters are being destroyed through fluvial processes, such as weathering, mass wasting, fluvial incision and deposition. In this work, we use a landscape evolution model to determine whether or not this is a viable mechanism for crater destruction on...
Authors
Catherine D. Neish, J. L. Molaro, J. M. Lora, A.D. Howard, Randolph L. Kirk, P. Schenk, V.J. Bray, R. D. Lorenz
The tectonics of Titan: Global structural mapping from Cassini RADAR The tectonics of Titan: Global structural mapping from Cassini RADAR
The Cassini RADAR mapper has imaged elevated mountain ridge belts on Titan with a linear-to-arcuate morphology indicative of a tectonic origin. Systematic geomorphologic mapping of the ridges in Synthetic Aperture RADAR (SAR) images reveals that the orientation of ridges is globally E–W and the ridges are more common near the equator than the poles. Comparison with a global topographic...
Authors
Zac Yung-Chun Liu, Jani Radebaugh, Ron A. Harris, Eric H. Christiansen, Catherine D. Neish, Randolph L. Kirk, Ralph D. Lorenz
Nature, distribution, and origin of Titan’s Undifferentiated Plains Nature, distribution, and origin of Titan’s Undifferentiated Plains
The Undifferentiated Plains on Titan, first mapped by Lopes et al. (Lopes, R.M.C. et al., 2010. Icarus, 205, 540–588), are vast expanses of terrains that appear radar-dark and fairly uniform in Cassini Synthetic Aperture Radar (SAR) images. As a result, these terrains are often referred to as “blandlands”. While the interpretation of several other geologic units on Titan – such as dunes...
Authors
Rosaly Lopes, M. J. Malaska, A. Solomonidou, Gall A. Le, M.A. Janssen, Catherine D. Neish, E. P. Turtle, S. P. D. Birch, A. G. Hayes, J. Radebaugh, A. Coustenis, A. Schoenfeld, B.W. Stiles, Randolph L. Kirk, K. L. Mitchell, E. R. Stofan, K. J. Lawrence
Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide
In order to provide surface geodetic measurements with “landslide-wide” spatial coverage, we develop and validate a method for the characterization of 3-D surface deformation using the unique capabilities of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne repeat-pass radar interferometry system. We apply our method at the well-studied Slumgullion Landslide...
Authors
Brent G. Delbridge, Roland Burgmann, Eric Fielding, Scott Hensley, William H. Schulz
Extracting accurate and precise topography from LROC narrow angle camera stereo observations Extracting accurate and precise topography from LROC narrow angle camera stereo observations
The Lunar Reconnaissance Orbiter Camera (LROC) includes two identical Narrow Angle Cameras (NAC) that each provide 0.5 to 2.0 m scale images of the lunar surface. Although not designed as a stereo system, LROC can acquire NAC stereo observations over two or more orbits using at least one off-nadir slew. Digital terrain models (DTMs) are generated from sets of stereo images and registered...
Authors
M. R. Henriksen, M. R. Manheim, K. N. Burns, P. Seymour, E. J. Speyerer, A. Deran, A. K. Boyd, Elpitha Howington-Kraus PR, Mark R. Rosiek, Brent A. Archinal, M. S. Robinson
A study of the 2015 Mw 8.3 Illapel earthquake and tsunami: Numerical and analytical approaches A study of the 2015 Mw 8.3 Illapel earthquake and tsunami: Numerical and analytical approaches
The September 16, 2015 Illapel, Chile earthquake triggered a large tsunami, causing both economic losses and fatalities. To study the coastal effects of this earthquake, and to understand how such hazards might be accurately modeled in the future, different finite fault models of the Illapel rupture are used to define the initial condition for tsunami simulation. The numerical code Non...
Authors
Mauricio Fuentes, Sebastian Riquelme, Gavin P. Hayes, Miguel Medina, Diego Melgar, Gabriel Vargas, Jose Gonzalez, Angelo Villalobos
Likelihood testing of seismicity-based rate forecasts of induced earthquakes in Oklahoma and Kansas Likelihood testing of seismicity-based rate forecasts of induced earthquakes in Oklahoma and Kansas
Likelihood testing of induced earthquakes in Oklahoma and Kansas has identified the parameters that optimize the forecasting ability of smoothed seismicity models and quantified the recent temporal stability of the spatial seismicity patterns. Use of the most recent 1-year period of earthquake data and use of 10–20-km smoothing distances produced the greatest likelihood. The likelihood...
Authors
Morgan P. Moschetti, Susan M. Hoover, Charles Mueller
NGA-West2 equations for predicting vertical-component PGA, PGV, and 5%-damped PSA from shallow crustal earthquakes NGA-West2 equations for predicting vertical-component PGA, PGV, and 5%-damped PSA from shallow crustal earthquakes
We present ground motion prediction equations (GMPEs) for computing natural log means and standard deviations of vertical-component intensity measures (IMs) for shallow crustal earthquakes in active tectonic regions. The equations were derived from a global database with M 3.0–7.9 events. The functions are similar to those for our horizontal GMPEs. We derive equations for the primary M-...
Authors
Jonathan P. Stewart, David M. Boore, Emel Seyhan, Gail M. Atkinson
Summary of the GK15 ground‐motion prediction equation for horizontal PGA and 5% damped PSA from shallow crustal continental earthquakes Summary of the GK15 ground‐motion prediction equation for horizontal PGA and 5% damped PSA from shallow crustal continental earthquakes
We present a revised ground‐motion prediction equation (GMPE) for computing medians and standard deviations of peak ground acceleration (PGA) and 5% damped pseudospectral acceleration (PSA) response ordinates of the horizontal component of randomly oriented ground motions to be used for seismic‐hazard analyses and engineering applications. This GMPE is derived from the expanded Next...
Authors
Vladimir; Graizer, Erol Kalkan
Earthquake forecast for the Wasatch Front region of the Intermountain West Earthquake forecast for the Wasatch Front region of the Intermountain West
The Working Group on Utah Earthquake Probabilities has assessed the probability of large earthquakes in the Wasatch Front region. There is a 43 percent probability of one or more magnitude 6.75 or greater earthquakes and a 57 percent probability of one or more magnitude 6.0 or greater earthquakes in the region in the next 50 years. These results highlight the threat of large earthquakes...
Authors
Christopher B. DuRoss