Publications
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Strain accumulation across the Coast Ranges at the latitude of San Francisco, 1994-2000 Strain accumulation across the Coast Ranges at the latitude of San Francisco, 1994-2000
A 66-monument geodetic array spanning the Coast Ranges near San Francisco has been surveyed more than eight times by GIPS between late 1993 and early 2001. The measured horizontal velocities of the monuments are well represented by uniform, right-lateral, simple shear parallel to N29°W. (The local strike of the San Andreas Fault is ∼N34°W.) The observed areal dilatation rate of 6.9 ± 10...
Authors
J.C. Savage, Weijun Gan, W.H. Prescott, J. L. Svarc
The opportunity Rover's Athena science investigation at Meridiani Planum, Mars The opportunity Rover's Athena science investigation at Meridiani Planum, Mars
The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat...
Authors
S. W. Squyres, R. E. Arvidson, J.F. Bell, J. Bruckner, N.A. Cabrol, W. Calvin, M. H. Carr, P. R. Christensen, B.C. Clark, L. Crumpler, D.J. Des Marais, C. D'Uston, T. Economou, J. Farmer, W. Farrand, W. Folkner, M. Golombek, S. Gorevan, J. A. Grant, R. Greeley, J. Grotzinger, L. Haskin, Kenneth E. Herkenhoff, S. Hviid, J. Johnson, G. Klingelhofer, A.H. Knoll, G. Landis, M. Lemmon, R. Li, M.B. Madsen, M. C. Malin, S. M. McLennan, H.Y. McSween, D. W. Ming, J. Moersch, R.V. Morris, T. Parker, J. W. Rice, L. Richter, R. Rieder, M. Sims, M. Smith, P. Smith, Laurence A. Soderblom, R. Sullivan, H. Wanke, T. Wdowiak, M. Wolff, A. Yen
Shear wave velocity, seismic attenuation, and thermal structure of the continental upper mantle Shear wave velocity, seismic attenuation, and thermal structure of the continental upper mantle
Seismic velocity and attenuation anomalies in the mantle are commonly interpreted in terms of temperature variations on the basis of laboratory studies of elastic and anelastic properties of rocks. In order to evaluate the relative contributions of thermal and non-thermal effects on anomalies of attenuation of seismic shear waves, Q−1s, and seismic velocity, Vs, we compare global maps of...
Authors
I.M. Artemieva, M. Billien, J.-J. Leveque, Walter D. Mooney
Growth and collapse of Waianae volcano, Hawaii, as revealed by exploration of its submarine flanks Growth and collapse of Waianae volcano, Hawaii, as revealed by exploration of its submarine flanks
Wai‘anae Volcano comprises the western half of O‘ahu Island, but until recently little was known about the submarine portion of this volcano. Seven new submersible dives, conducted in 2001 and 2002, and multibeam bathymetry offshore of Wai‘anae provide evidence pertaining to the overall growth of the volcano's edifice as well as the timing of collapses that formed the Wai‘anae slump...
Authors
Michelle L. Coombs, David A. Clague, Gregory F. Moore, Brian L. Cousens
Coastal vulnerability assessment of Assateague Island National Seashore (ASIS) to sea-level rise Coastal vulnerability assessment of Assateague Island National Seashore (ASIS) to sea-level rise
A coastal vulnerability index (CVI, http://pubs.usgs.gov/of/2004/1020/html/cvi.htm) was used to map relative vulnerability of the coast to future sea-level rise within Assateague Island National Seashore (ASIS) in Maryland and Virginia. The CVI ranks the following in terms of their physical contribution to sea-level rise-related coastal change: geomorphology, regional coastal slope, rate...
Authors
Elizabeth A. Pendleton, S. Jeffress Williams, E. Robert Thieler
Late Quaternary evolution of channel and lobe complexes of Monterey Fan Late Quaternary evolution of channel and lobe complexes of Monterey Fan
The modern Monterey submarine fan, one of the largest deep-water deposits off the western US, is composed of two major turbidite systems: the Neogene Lower Turbidite System (LTS) and the late Quarternary Upper Turbidite System (UTS). The areally extensive LTS is a distal deposit with low-relief, poorly defined channels, overbank, and lower-fan elements. The younger UTS comprises almost...
Authors
Andrea Fildani, William R. Normark
The Spirit Rover's Athena science investigation at Gusev crater, Mars The Spirit Rover's Athena science investigation at Gusev crater, Mars
The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former take, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks...
Authors
S. W. Squyres, R. E. Arvidson, J.F. Bell, J. Bruckner, N.A. Cabrol, W. Calvin, M. H. Carr, P. R. Christensen, B.C. Clark, L. Crumpler, D.J. Des Marais, C. D'Uston, T. Economou, J. Farmer, W. Farrand, W. Folkner, M. Golombek, S. Gorevan, J. A. Grant, R. Greeley, J. Grotzinger, L. Haskin, Kenneth E. Herkenhoff, S. Hviid, J. Johnson, G. Klingelhofer, A. Knoll, G. Landis, M. Lemmon, R. Li, M.B. Madsen, M. C. Malin, S. M. McLennan, H.Y. McSween, D. W. Ming, J. Moersch, R.V. Morris, T. Parker, J. W. Rice, L. Richter, R. Rieder, M. Sims, M. Smith, P. Smith, Laurence A. Soderblom, R. Sullivan, H. Wanke, T. Wdowiak, M. Wolff, A. Yen
The Rock Elm meteorite impact structure, Wisconsin: Geology and shock-metamorphic effects in quartz The Rock Elm meteorite impact structure, Wisconsin: Geology and shock-metamorphic effects in quartz
The Rock Elm structure in southwest Wisconsin is an anomalous circular area of highly deformed rocks, ∼6.5 km in diameter, located in a region of virtually horizontal undeformed sedimentary rocks. Shock-produced planar microstructures (PMs) have been identified in quartz grains in several lithologies associated with the structure: sandstones, quartzite pebbles, and breccia. Two distinct...
Authors
B.M. French, W.S. Cordua, J. B. Plescia
Magmatic precursors to the 18 May 1980 eruption of Mount St. Helens, USA Magmatic precursors to the 18 May 1980 eruption of Mount St. Helens, USA
Perhaps the most difficult task facing volcanologists today is that of distinguishing between low-level volcanic restlessness and activity that presages a full-scale eruption. We illustrate these difficulties by reexamining the sequence of events that led to the 18 May 1980 eruption of Mount St. Helens, activity that is often presented as a classic example of early phreatic explosions...
Authors
K. V. Cashman, R. Hoblitt
Mapping of the Culann-Tohil region of Io from Galileo imaging data Mapping of the Culann-Tohil region of Io from Galileo imaging data
We have used Galileo spacecraft data to produce a geomorphologic map of the Culann–Tohil region of Io's antijovian hemisphere. This region includes a newly discovered shield volcano, Tsũi Goab Tholus and a neighboring bright flow field, Tsũi Goab Fluctus, the active Culann Patera and the enigmatic Tohil Mons-Radegast Patera–Tohil Patera complex. Analysis of Voyager global color and...
Authors
D.A. Williams, Paul M. Schenk, Jeffrey M. Moore, Laszlo P. Keszthelyi, Elizabeth P. Turtle, Windy L. Jaeger, Jani Radebaugh, Moses P. Milazzo, Rosaly Lopes, Ronald Greeley
Decompression experiments identify kinetic controls on explosive silicic eruptions Decompression experiments identify kinetic controls on explosive silicic eruptions
Eruption intensity is largely controlled by decompression‐induced release of water‐rich gas dissolved in magma. It is not simply the amount of gas that dictates how forcefully magma is propelled upwards during an eruption, but also the rate of degassing, which is partly a function of the supersaturation pressure (ΔPcritical) triggering gas bubble nucleation. High temperature and pressure
Authors
M. T. Mangan, T. W. Sisson, W.B. Hankins
Crustal structure along the geosciences transect from Altay to Altun Tagh Crustal structure along the geosciences transect from Altay to Altun Tagh
No abstract available.
Authors
Y.-X. Wang, G.-H. Han, M. Jiang, X.-C. Yuan, Walter D. Mooney, R. G. Coleman