Publications
Filter Total Items: 7487
Bounce Rock-A shergottite-like basalt encountered at Meridiani Planum, Mars Bounce Rock-A shergottite-like basalt encountered at Meridiani Planum, Mars
The Opportunity rover of the Mars Exploration Rover mission encountered an isolated rock fragment with textural, mineralogical, and chemical properties similar to basaltic shergottites. This finding was confirmed by all rover instruments, and a comprehensive study of these results is reported here. Spectra from the miniature thermal emission spectrometer and the Panoramic Camera reveal a...
Authors
J. Zipfel, C. Schroder, B.L. Jolliff, Ralf Gellert, K. E. Herkenhoff, R. Rieder, R. Anderson, J.F. Bell, J. Bruckner, J.A. Crisp, P. R. Christensen, B. C. Clark, P.A. de Souza, G. Dreibus, C. D'uston, T. Economou, S.P. Gorevan, B.C. Hahn, G. Klingelhofer, T.J. McCoy, H.Y. McSween, D. W. Ming, R.V. Morris, D.S. Rodionov, S. W. Squyres, H. Wanke, S.P. Wright, M.B. Wyatt, A. S. Yen
Earthquake rupture at focal depth, part II: mechanics of the 2004 M2.2 earthquake along the Pretorius Fault, TauTona Mine, South Africa Earthquake rupture at focal depth, part II: mechanics of the 2004 M2.2 earthquake along the Pretorius Fault, TauTona Mine, South Africa
We analyze here the rupture mechanics of the 2004, M2.2 earthquake based on our observations and measurements at focal depth (Part I). This event ruptured the Archean Pretorius fault that has been inactive for at least 2 Ga, and was reactivated due to mining operations down to a depth of 3.6 km depth. Thus, it was expected that the Pretorius fault zone will fail similarly to an intact...
Authors
V. Heesakkers, S. Murphy, D.A. Lockner, Z. Reches
Understanding the amplitudes of noise correlation measurements Understanding the amplitudes of noise correlation measurements
Cross correlation of ambient seismic noise is known to result in time series from which station-station travel-time measurements can be made. Part of the reason that these cross-correlation travel-time measurements are reliable is that there exists a theoretical framework that quantifies how these travel times depend on the features of the ambient noise. However, corresponding...
Authors
Victor C. Tsai
An empirical model of the quiet daily geomagnetic field variation An empirical model of the quiet daily geomagnetic field variation
An empirical model of the quiet daily geomagnetic field variation has been constructed based on geomagnetic data obtained from 21 stations along the 210 Magnetic Meridian of the Circum‐pan Pacific Magnetometer Network (CPMN) from 1996 to 2007. Using the least squares fitting method for geomagnetically quiet days (Kp ≤ 2+), the quiet daily geomagnetic field variation at each station was...
Authors
Y. Yamazaki, K. Yumoto, M.G. Cardinal, B.J. Fraser, P. Hattori, Y. Kakinami, J.Y. Liu, K.J.W. Lynn, R. Marshall, D. McNamara, T. Nagatsuma, V.M. Nikiforov, R.E. Otadoy, M. Ruhimat, B.M. Shevtsov, K. Shiokawa, S. Abe, T. Uozumi, A. Yoshikawa
Evaluation of TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis)'s predictive skill for hurricane-triggered landslides: A case study in Macon County, North Carolina Evaluation of TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis)'s predictive skill for hurricane-triggered landslides: A case study in Macon County, North Carolina
The key to advancing the predictability of rainfall-triggered landslides is to use physically based slope-stability models that simulate the transient dynamical response of the subsurface moisture to spatiotemporal variability of rainfall in complex terrains. TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis) is a USGS landslide prediction model...
Authors
Z. Liao, Y. Hong, D. Kirschbaum, R.F. Adler, J.J. Gourley, R. Wooten
Specifying initial stress for dynamic heterogeneous earthquake source models Specifying initial stress for dynamic heterogeneous earthquake source models
Dynamic rupture calculations using heterogeneous stress drop that is random and self-similar with a power-law spatial spectrum have great promise of producing realistic ground-motion predictions. We present procedures to specify initial stress for random events with a target rupture length and target magnitude. The stress function is modified in the depth dimension to account for the...
Authors
D.J. Andrews, M. Barall
The ShakeOut scenario: A hypothetical Mw7.8 earthquake on the Southern San Andreas Fault The ShakeOut scenario: A hypothetical Mw7.8 earthquake on the Southern San Andreas Fault
In 2008, an earthquake-planning scenario document was released by the U.S. Geological Survey (USGS) and California Geological Survey that hypothesizes the occurrence and effects of a Mw7.8 earthquake on the southern San Andreas Fault. It was created by more than 300 scientists and engineers. Fault offsets reach 13 m and up to 8 m at lifeline crossings. Physics-based modeling was used to...
Authors
K. Porter, L. Jones, D. Cox, J. Goltz, K. Hudnut, D. Mileti, S. Perry, D. Ponti, M. Reichle, A.Z. Rose, C.R. Scawthorn, H.A. Seligson, K.I. Shoaf, J. Treiman, A. Wein
Comment on "A model of earthquake triggering probabilities and application to dynamic deformations constrained by ground motion observations" by Joan Gomberg and Karen Felzer Comment on "A model of earthquake triggering probabilities and application to dynamic deformations constrained by ground motion observations" by Joan Gomberg and Karen Felzer
No abstract available.
Authors
R.S. Stein
Hyperspectral analysis of rocky surfaces on the Earth and other planetary systems: Chapter 27 Hyperspectral analysis of rocky surfaces on the Earth and other planetary systems: Chapter 27
This book is focused on studies of vegetation on Earth using hyperspectral remote sensing methods. However, it is appropriate to extend the application of these methods out to other rocky bodies in our Solar System for a variety of reasons. First, minerals, soils, and rocks form the substrate on which vegetation grows on Earth. Compositional analyses of these components with...
Authors
R. Greg Vaughan, Timothy N. Titus, Jeffery R Johnson, Justin Hagerty, Lisa R. Gaddis, Laurence A. Soderblom, Paul E. Geissler
The indication of Martian gully formation processes by slope-area analysis The indication of Martian gully formation processes by slope-area analysis
The formation process of recent gullies on Mars is currently under debate. This study aims to discriminate between the proposed formation processes - pure water flow, debris flow and dry mass wasting - through the application of geomorphological indices commonly used in terrestrial geomorphology. High-resolution digital elevation models (DEMs) of Earth and Mars were used to evaluate the...
Authors
Susan J. Conway, Matthew R. Balme, John B. Murray, Martin C. Towner, Chris Okubo, Peter M. Grindrod
Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater
Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of the atmosphere, soils, and rocks. This paper provides an overview of key discoveries between sols 511 and 2300, complementing earlier papers covering results from the initial phases of the mission. Key new results include (1) atmospheric argon measurements that...
Authors
R. E. Arvidson, James W. Ashley, J.F. Bell, M. Chojnacki, J. Cohen, T.E. Economou, W. H. Farrand, Robin L. Fergason, I. Fleischer, Paul E. Geissler, Ralf Gellert, M.P. Golombek, J.P. Grotzinger, E.A. Guinness, R.M. Haberle, Kenneth E. Herkenhoff, J.A. Herman, K.D. Iagnemma, B.L. Jolliff, J. R. Johnson, G. Klingelhofer, A.H. Knoll, A.T. Knudson, R. Li, S. M. McLennan, D. W. Mittlefehldt, R.V. Morris, T. J. Parker, M.S. Rice, C. Schroder, Laurence A. Soderblom, S. W. Squyres, R.J. Sullivan, M.J. Wolff
Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum
The weathering of meteorites found on Mars involves chemical and physical processes that can provide clues to climate conditions at the location of their discovery. Beginning on sol 1961, the Opportunity rover encountered three large iron meteorites within a few hundred meters of each other. In order of discovery, these rocks have been assigned the unofficial names Block Island, Shelter...
Authors
James W. Ashley, M.P. Golombek, P. R. Christensen, S. W. Squyres, T.J. McCoy, C. Schroder, I. Fleischer, J. R. Johnson, Kenneth E. Herkenhoff, T. J. Parker