Publications
Filter Total Items: 7494
Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: Several contiguous but discrete systems Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: Several contiguous but discrete systems
The volcanic history of the Long Valley region is examined within a framework of six successive (spatially discrete) foci of silicic magmatism, each driven by locally concentrated basaltic intrusion of the deep crust in response to extensional unloading and decompression melting of the upper mantle. A precaldera dacite field (3.5–2.5 Ma) northwest of the later site of Long Valley and the...
Authors
W. Hildreth
Basaltic rocks analyzed by the Spirit rover in Gusev crater Basaltic rocks analyzed by the Spirit rover in Gusev crater
The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini–Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain ≤25%...
Authors
H.Y. McSween, R. E. Arvidson, J.F. Bell, D. Blaney, N.A. Cabrol, P. R. Christensen, B. C. Clark, J.A. Crisp, L.S. Crumpler, D.J. Des Marias, J.D. Farmer, Ralf Gellert, A. Ghosh, S. Gorevan, T. Graff, J. Grant, L.A. Haskin, Kenneth E. Herkenhoff, J. R. Johnson, B.L. Jolliff, G. Klingelhoefer, A.T. Knudson, S. McLennan, K.A. Milam, J.E. Moersch, R.V. Morris, R. Rieder, S. W. Ruff, P.A. De Souza, S. W. Squyres, H. Wanke, A. Wang, M.B. Wyatt, A. Yen, J. Zipfel
Probabilistic seismic hazard analysis for Sumatra, Indonesia and across the Southern Malaysian Peninsula Probabilistic seismic hazard analysis for Sumatra, Indonesia and across the Southern Malaysian Peninsula
The ground motion hazard for Sumatra and the Malaysian peninsula is calculated in a probabilistic framework, using procedures developed for the US National Seismic Hazard Maps. We constructed regional earthquake source models and used standard published and modified attenuation equations to calculate peak ground acceleration at 2% and 10% probability of exceedance in 50 years for rock...
Authors
M.D. Petersen, J. Dewey, S. Hartzell, C. Mueller, S. Harmsen, A.D. Frankel, K. Rukstales
Quantifying probabilities of volcanic events: The example of volcanic hazard at Mount Vesuvius Quantifying probabilities of volcanic events: The example of volcanic hazard at Mount Vesuvius
We describe an event tree scheme to quantitatively estimate both long- and short-term volcanic hazard. The procedure is based on a Bayesian approach that produces a probability estimation of any possible event in which we are interested and can make use of all available information including theoretical models, historical and geological data, and monitoring observations. The main steps...
Authors
W. Marzocchi, L. Sandri, P. Gasparini, C. Newhall, Enzo Boschi
In situ evidence for an ancient aqueous environment at Meridiani Planum, Mars In situ evidence for an ancient aqueous environment at Meridiani Planum, Mars
Sedimentary rocks at Eagle crater in Meridiani Planum are composed of fine-grained siliciclastic materials derived from weathering of basaltic rocks, sulfate minerals (including magnesium sulfate and jarosite) that constitute several tens of percent of the rock by weight, and hematite. Cross-stratification observed in rock outcrops indicates eolian and aqueous transport. Diagenetic...
Authors
S. W. Squyres, J.P. Grotzinger, R. E. Arvidson, J.F. Bell, W. Calvin, P. R. Christensen, B. C. Clark, J.A. Crisp, W. H. Farrand, Kenneth E. Herkenhoff, J. R. Johnson, G. Klingelhofer, A.H. Knoll, S. M. McLennan, H.Y. McSween, R.V. Morris, J. W. Rice, R. Rieder, Laurence A. Soderblom
Seismic velocity models for the Denali fault zone along the Richardson Highway, Alaska Seismic velocity models for the Denali fault zone along the Richardson Highway, Alaska
Crustal-scale seismic-velocity models across the Denali fault zone along the Richardson Highway show a 50-km-thick crust, a near vertical fault trace, and a 5-km-wide damage zone associated with the fault near Trans-Alaska Pipeline Pump Station 10, which provided the closest strong ground motion recordings of the 2002 Denali fault earthquake. We compare models, derived from seismic...
Authors
T.M. Brocher, G. S. Fuis, W. J. Lutter, N.I. Christensen, N. A. Ratchkovski
Ground motion in Anchorage, Alaska, from the 2002 Denali fault earthquake: Site response and displacement pulses Ground motion in Anchorage, Alaska, from the 2002 Denali fault earthquake: Site response and displacement pulses
Data from the 2002 Denali fault earthquake recorded at 26 sites in and near Anchorage, Alaska, show a number of systematic features important in studies of site response and in constructing long-period spectra for use in earthquake engineering. The data demonstrate that National Earthquake Hazards Reduction Program (NEHRP) site classes are a useful way of grouping stations according to...
Authors
D.M. Boore
Time-series photographs of the sea floor in western Massachusetts Bay: June 1997 to June 1998 Time-series photographs of the sea floor in western Massachusetts Bay: June 1997 to June 1998
This report presents time-series photographs of the sea floor obtained from an instrumented tripod deployed at Site A in western Massachusetts Bay (42° 22.6' N., 70? 47.0' W., 30 m water depth, from June 1997 through June 1998. Site A is approximately 1 km south of an ocean outfall that began discharging treated sewage effluent from the Boston metropolitan area into Massachusetts Bay in...
Authors
Bradford Butman, P. Soupy Alexander, Michael H. Bothner
Coastal vulnerability assessment of Cumberland Island National Seashore (CUIS) to sea-level rise Coastal vulnerability assessment of Cumberland Island National Seashore (CUIS) to sea-level rise
A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise within Cumberland Island National Seashore in Georgia. The CVI ranks the following in terms of their physical contribution to sea-level rise-related coastal change: geomorphology, regional coastal slope, rate of relative sea-level rise, historical shoreline change rates...
Authors
Elizabeth A. Pendleton, E. Robert Thieler, S. Jeffress Williams
Holocene reef accretion: southwest Molokai, Hawaii, U.S.A. Holocene reef accretion: southwest Molokai, Hawaii, U.S.A.
Two reef systems off south Molokai, Hale O Lono and Hikauhi (separated by only 10 km), show strong and fundamental differences in modern ecosystem structure and Holocene accretion history that reflect the influence of wave-induced near-bed shear stresses on reef development in Hawaii. Both sites are exposed to similar impacts from south, Kona, and trade-wind swell. However, the Hale O...
Authors
Mary S. Engels, Charles H. Fletcher, Michael E. Field, Curt D. Storlazzi, Eric E. Grossman, John J.B. Rooney, Christopher L. Conger, Craig Glenn
Shear- and compressional- wave velocity measurements from two 150-m-deep boreholes in Seattle, Washington, USA Shear- and compressional- wave velocity measurements from two 150-m-deep boreholes in Seattle, Washington, USA
No abstract available.
Authors
Jack K. Odum, William J. Stephenson, Kathy Goetz-Troost, David M. Worley, Arthur D. Frankel, Robert A. Williams, Jake Fryer
Comparison of USGS and DLR topographic models of Comet Borrelly and photometric applications Comparison of USGS and DLR topographic models of Comet Borrelly and photometric applications
Stereo analysis of images obtained during the 2001 flyby of Comet Borrelly by NASA's Deep Space 1 (DS1) probe allows us to quantify the shape and photometric behavior of the nucleus. The shape is complex, with planar facets corresponding to the dark, mottled regions of the surface whereas the bright, smooth regions are convexly curved. The photometric as well as textural differences...
Authors
Randolph L. Kirk, Elpitha Howington-Kraus, Laurence A. Soderblom, Bernd Giese, Jurgen Oberst