Publications
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Martian fluvial conglomerates at Gale Crater Martian fluvial conglomerates at Gale Crater
Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic...
Authors
Rebecca M.E. Williams, J.P. Grotzinger, W. E. Dietrich, S. Gupta, D.Y. Sumner, R. C. Wiens, N. Mangold, M. C. Malin, K.S. Edgett, S. Maurice, O. Forni, O. Gasnault, A. Ollila, Horton E. Newsom, G. Dromart, M.C. Palucis, R.A. Yingst, Ryan B. Anderson, Kenneth E. Herkenhoff, S. Le Mouélic, W. Goetz, M.B. Madsen, A. Koefoed, J.K. Jensen, J.C. Bridges, S.P. Schwenzer, K.W. Lewis, K.M. Stack, D. Rubin, L.C. Kah, J.F. Bell, J.D. Farmer, R. Sullivan, T. Van Beek, D.L. Blaney, O. Pariser, R.G. Deen
The SCEC geodetic transient detection validation exercise The SCEC geodetic transient detection validation exercise
Over the past decade the number and size of continuously operating Global Positioning System (GPS) networks has grown substantially worldwide. A steadily increasing volume of freely available GPS measurements, combined with the application of new approaches for mining these data for signals of interest, has led to the identification of a large and diverse collection of time‐varying Earth...
Authors
Rowena B. Lohman, Jessica R. Murray
Chemical controls on fault behavior: weakening of serpentinite sheared against quartz-bearing rocks and its significance for fault creep in the San Andreas system Chemical controls on fault behavior: weakening of serpentinite sheared against quartz-bearing rocks and its significance for fault creep in the San Andreas system
The serpentinized ultramafic rocks found in many plate-tectonic settings commonly are juxtaposed against crustal rocks along faults, and the chemical contrast between the rock types potentially could influence the mechanical behavior of such faults. To investigate this possibility, we conducted triaxial experiments under hydrothermal conditions (200-350°C), shearing serpentinite gouge...
Authors
Diane E. Moore, David A. Lockner
Rupture history of the 2011 M 9 Tohoku Japan earthquake determined from strong‐motion and high‐rate GPS recordings: Subevents radiating energy in different frequency bands Rupture history of the 2011 M 9 Tohoku Japan earthquake determined from strong‐motion and high‐rate GPS recordings: Subevents radiating energy in different frequency bands
Strong‐motion records from KiK‐net and K‐NET, along with 1 sample/s Global Positioning System (GPS) records from GEONET, were analyzed to determine the location, timing, and slip of subevents of the M 9 2011 Tohoku earthquake. Timing of arrivals on stations along the coast shows that the first subevent was located closer to the coast than subevent (2), which produced the largest slip. A...
Authors
Arthur D. Frankel
Annual modulation of non-volcanic tremor in northern Cascadia Annual modulation of non-volcanic tremor in northern Cascadia
Two catalogs of episodic tremor events in northern Cascadia, one from 2006 to 2012 and the other from 1997 to 2011, reveal two systematic patterns of tremor occurrence in southern Vancouver Island: (1) most individual events tend to occur in the third quarter of the year; (2) the number of events in prolonged episodes (i.e., episodic tremor and slip events), which generally propagate to...
Authors
Frederick Pollitz, Aaron G. Wech, Honn Kao, Roland Burgmann
Structural evolution of the east Sierra Valley system (Owens Valley and vicinity), California: a geologic and geophysical synthesis Structural evolution of the east Sierra Valley system (Owens Valley and vicinity), California: a geologic and geophysical synthesis
The tectonically active East Sierra Valley System (ESVS), which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm), which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension
Authors
Calvin H. Stevens, Paul Stone, Richard J. Blakely
Crater topography on Titan: implications for landscape evolution Crater topography on Titan: implications for landscape evolution
We present a comprehensive review of available crater topography measurements for Saturn’s moon Titan. In general, the depths of Titan’s craters are within the range of depths observed for similarly sized fresh craters on Ganymede, but several hundreds of meters shallower than Ganymede’s average depth vs. diameter trend. Depth-to-diameter ratios are between 0.0012 ± 0.0003 (for the...
Authors
Catherine D. Neish, R. L. Kirk, R. D. Lorenz, V.J. Bray, P. Schenk, B.W. Stiles, E. Turtle, Ken Mitchell, A. Hayes
SLAMMER: Seismic LAndslide Movement Modeled using Earthquake Records SLAMMER: Seismic LAndslide Movement Modeled using Earthquake Records
This program is designed to facilitate conducting sliding-block analysis (also called permanent-deformation analysis) of slopes in order to estimate slope behavior during earthquakes. The program allows selection from among more than 2,100 strong-motion records from 28 earthquakes and allows users to add their own records to the collection. Any number of earthquake records can be...
Authors
Randall W. Jibson, Ellen M. Rathje, Matthew W. Jibson, Yong W. Lee
Enriquillo–Plantain Garden fault zone in Jamaica: paleoseismology and seismic hazard Enriquillo–Plantain Garden fault zone in Jamaica: paleoseismology and seismic hazard
The countries of Jamaica, Haiti, and the Dominican Republic all straddle the Enriquillo–Plantain Garden fault zone ( EPGFZ), a major left-lateral, strike-slip fault system bounding the Caribbean and North American plates. Past large earthquakes that destroyed the capital cities of Kingston, Jamaica (1692, 1907), and Port-au-Prince, Haiti (1751, 1770), as well as the 2010 Haiti earthquake...
Authors
R.D. Koehler, P. Mann, Carol S. Prentice, L. Brown, B. Benford, M. Grandison-Wiggins
Variability of displacement at a point: Implications for earthquake‐size distribution and rupture hazard on faults Variability of displacement at a point: Implications for earthquake‐size distribution and rupture hazard on faults
To investigate the nature of earthquake‐magnitude distributions on faults, we compare the interevent variability of surface displacement at a point on a fault from a composite global data set of paleoseismic observations with the variability expected from two prevailing magnitude–frequency distributions: the truncated‐exponential model and the characteristic‐earthquake model. We use...
Authors
Suzanne Hecker, N. A. Abrahamson, Kathryn Wooddell
Missing great earthquakes Missing great earthquakes
The occurrence of three earthquakes with moment magnitude (Mw) greater than 8.8 and six earthquakes larger than Mw 8.5, since 2004, has raised interest in the long-term global rate of great earthquakes. Past studies have focused on the analysis of earthquakes since 1900, which roughly marks the start of the instrumental era in seismology. Before this time, the catalog is less complete...
Authors
Susan E. Hough
Seismicity of the Earth 1900–2010 Himalaya and vicinity Seismicity of the Earth 1900–2010 Himalaya and vicinity
Seismicity in the Himalaya region predominantly results from the collision of the India and Eurasia continental plates, which are converging at a relative rate of 40–50 mm/yr. Northward underthrusting of India beneath Eurasia generates numerous earthquakes and consequently makes this area one of the most seismically hazardous regions on Earth. The surface expression of the plate boundary...
Authors
Bethan Turner, Jennifer Jenkins, Rebecca Turner, Amy Parker, Alison Sinclair, Sian Davies, Gavin P. Hayes, Antonio Villaseñor, Rirchard L. Dart, Arthur C. Tarr, Kevin P. Furlong, Harley M. Benz