Publications
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Meteorites on Mars observed with Mars Exploration Rovers
Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity's traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron meteorite and has been officially recognized a
Authors
C. Schroder, D.S. Rodionov, T.J. McCoy, B.L. Jolliff, Ralf Gellert, L.R. Nittler, W. H. Farrand, J. R. Johnson, S. W. Ruff, James W. Ashley, D. W. Mittlefehldt, Kenneth E. Herkenhoff, I. Fleischer, A. F. C. Haldemann, G. Klingelhofer, D. W. Ming, R.V. Morris, P.A. de Souza, S. W. Squyres, C. Weitz, A. S. Yen, J. Zipfel, T. Economou
Iron isotope fractionation during magmatic differentiation in Kilauea Iki lava lake
Magmatic differentiation helps produce the chemical and petrographic diversity of terrestrial rocks. The extent to which magmatic differentiation fractionates nonradiogenic isotopes is uncertain for some elements. We report analyses of iron isotopes in basalts from Kilauea Iki lava lake, Hawaii. The iron isotopic compositions (56Fe/54Fe) of late-stagemeltveins are 0.2 permil (per thousand) greater
Authors
F.-Z. Teng, N. Dauphas, Rosalind Tuthill Helz
MGS-TES thermal inertia study of the Arsia Mons Caldera
Temperatures of the Arsia Mons caldera floor and two nearby control areas were obtained by the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES). These observations revealed that the Arsia Mons caldera floor exhibits thermal behavior different from the surrounding Tharsis region when compared with thermal models. Our technique compares modeled and observed data to determine best fit v
Authors
Glen E. Cushing, Timothy N. Titus
Veneers, rinds, and fracture fills: Relatively late alteration of sedimentary rocks at Meridiani Planum, Mars
Veneers and thicker rinds that coat outcrop surfaces and partially cemented fracture fills formed perpendicular to bedding document relatively late stage alteration of ancient sedimentary rocks at Meridiani Planum, Mars. The chemistry of submillimeter thick, buff-colored veneers reflects multiple processes at work since the establishment of the current plains surface. Veneer composition is dominat
Authors
A.H. Knoll, B.L. Jolliff, W. H. Farrand, J.F. Bell, B. C. Clark, Ralf Gellert, M.P. Golombek, J.P. Grotzinger, Kenneth E. Herkenhoff, J.R. Johson, S.M. McLennam, Robert Morris, S. W. Squyres, R. Sullivan, N.J. Tosca, A. Yen, Z. Learner
Wind-driven particle mobility on Mars: Insights from Mars Exploration Rover observations at "El Dorado" and surroundings at Gusev Crater
The ripple field known as 'El Dorado' was a unique stop on Spirit's traverse where dust-raising, active mafic sand ripples and larger inactive coarse-grained ripples interact, illuminating several long-standing issues of Martian dust mobility, sand mobility, and the origin of transverse aeolian ridges. Strong regional wind events endured by Spirit caused perceptible migration of ripple crests in d
Authors
R. Sullivan, R. Arvidson, J.F. Bell, Ralf Gellert, M. Golombek, R. Greeley, Kenneth E. Herkenhoff, J. Johnson, S. Thompson, P. Whelley, J. Wray
Compositional stratigraphy of clay-bearing layered deposits at Mawrth Vallis, Mars
Phyllosilicates have previously been detected in layered outcrops in and around the Martian outflow channel Mawrth Vallis. CRISM spectra of these outcrops exhibit features diagnostic of kaolinite, montmorillonite, and Fe/Mg-rich smectites, along with crystalline ferric oxide minerals such as hematite. These minerals occur in distinct stratigraphic horizons, implying changing environmental conditio
Authors
J.J. Wray, B.L. Ehlmann, S. W. Squyres, J.F. Mustard, Randolph L. Kirk
Documentation for the 2008 update of the United States National Seismic Hazard Maps
The 2008 U.S. Geological Survey (USGS) National Seismic Hazard Maps display earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. This update of the maps incorporates new findings on earthquake ground shaking, faults, seismicity, and geodesy. Th
Authors
Mark D. Petersen, Arthur D. Frankel, Stephen C. Harmsen, Charles S. Mueller, Kathleen M. Haller, Russell L. Wheeler, Robert L. Wesson, Yuehua Zeng, Oliver S. Boyd, David M. Perkins, Nicolas Luco, Edward H. Field, Chris J. Wills, Kenneth S. Rukstales
Converting HAZUS capacity curves to seismic hazard-compatible building fragility functions: effect of hysteretic models
A methodology was recently proposed for the development of hazard-compatible building fragility models using parameters of capacity curves and damage state thresholds from HAZUS (Karaca and Luco, 2008). In the methodology, HAZUS curvilinear capacity curves were used to define nonlinear dynamic SDOF models that were subjected to the nonlinear time history analysis instead of the capacity spectrum m
Authors
Hyeuk Ryu, Nicolas Luco, Jack W. Baker, Erdem Karaca
Finite-fault analysis of the 2004 Parkfield, California, earthquake using Pnl waveforms
We apply a kinematic finite-fault inversion scheme to Pnl displacement waveforms recorded at 14 regional stations (Δ<2°) to recover the distribution of coseismic slip for the 2004 Parkfield earthquake using both synthetic Green’s functions (SGFs) calculated for one-dimensional (1D) crustal-velocity models and empirical Green’s functions (EGFs) based on the recordings of a single Mw 5.0 aftershock.
Authors
C. Mendoza, S. Hartzell
Trans-Alaska Crustal Transect and continental evolution involving subduction underplating and synchronous foreland thrusting
We investigate the crustal structure and tectonic evolution of the North American continent in Alaska, where the continent has grown through magmatism, accretion, and tectonic underplating. In the 1980s and early 1990s, we conducted a geological and geophysical investigation, known as the Trans-Alaska Crustal Transect (TACT), along a 1350-km-long corridor from the Aleutian Trench to the Arctic coa
Authors
Gary S. Fuis, Thomas E. Moore, G. Plafker, T. M. Brocher, M. A. Fisher, Walter D. Mooney, W. J. Nokleberg, R.A. Page, B. C. Beaudoin, N.I. Christensen, A. R. Levander, W. J. Lutter, R. W. Saltus, N.A. Ruppert
Collision tectonics of the Central Indian Suture zone as inferred from a deep seismic sounding study
The Central Indian Suture (CIS) is a mega-shear zone extending for hundreds of kilometers across central India. Reprocessing of deep seismic reflection data acquired across the CIS was carried out using workstation-based commercial software. The data distinctly indicate different reflectivity characteristics northwest and southeast of the CIS. Reflections northwest of the CIS predominantly dip sou
Authors
D.M. Mall, P.R. Reddy, Walter D. Mooney
Assessing methane release from the colossal Storegga submarine landslide
Marine slope failure involving methane-gas-hydrate-bearing sediments is one mechanism for releasing enormous quantities of methane to the ocean and atmosphere. The Storegga Slide, on the Norwegian margin, is the largest known Holocene-aged continental margin slope failure complex and is believed to have occurred in sediments that may have initially contained gas hydrate. Here, we report pore water
Authors
C. K. Paull, W. Ussler, W.S. Holbrook