Publications
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Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge
High-resolution multibeam bathymetry and a digital elevation model of the Hawaiian Islands are used to calculate the volumes of individual shield volcanoes and island complexes (Niihau, Kauai, Oahu, the Maui Nui complex, and Hawaii), taking into account subsidence of the Pacific plate under the load of the Hawaiian Ridge. Our calculated volume for the Island of Hawaii and its submarine...
Authors
Joel E. Robinson, Barry W. Eakins
A plastic flow model for the Acquara - Vadoncello landslide in Senerchia, Southern Italy A plastic flow model for the Acquara - Vadoncello landslide in Senerchia, Southern Italy
A previously developed model for stress and velocity fields in two-dimensional Coulomb plastic materials under self-weight and pore pressure predicts that long, shallow landslides develop slip surfaces that manifest themselves as normal faults and normal fault scarps at the surface in areas of extending flow and as thrust faults and thrust fault scarps at the surface in areas of...
Authors
W. Savage, J. Wasowski
Continuous borehole strain and pore pressure in the near field of the 28 September 2004 M 6.0 Parkfield, California, earthquake: Implications for nucleation, fault response, earthquake prediction and tremor Continuous borehole strain and pore pressure in the near field of the 28 September 2004 M 6.0 Parkfield, California, earthquake: Implications for nucleation, fault response, earthquake prediction and tremor
Near-field observations of high-precision borehole strain and pore pressure, show no indication of coherent accelerating strain or pore pressure during the weeks to seconds before the 28 September 2004 M 6.0 Parkfield earthquake. Minor changes in strain rate did occur at a few sites during the last 24 hr before the earthquake but these changes are neither significant nor have the form...
Authors
M.J.S. Johnston, R. D. Borcherdt, A. T. Linde, M. T. Gladwin
Cosmogenic 3He production rates revisited from evidences of grain size dependent release of matrix-sited helium Cosmogenic 3He production rates revisited from evidences of grain size dependent release of matrix-sited helium
Measurements of the cosmogenic 3He (3Hec) content of various size aliquots of exposed olivines show that the fine fraction (
Authors
P.-H. Blard, R. Pik, J. Lave, D. Bourles, P.G. Burnard, R. Yokochi, B. Marty, F. Trusdell
Eruptive history and geochronology of Mount Mazama and the Crater Lake region, Oregon Eruptive history and geochronology of Mount Mazama and the Crater Lake region, Oregon
Geologic mapping, K-Ar, and 40Ar/39Ar age determinations, supplemented by paleomagnetic measurements and geochemical data, are used to quantify the Quaternary volcanic history of the Crater Lake region in order to define processes and conditions that led to voluminous explosive eruptions. The Cascade arc volcano known as Mount Mazama collapsed during its climactic eruption of ∼50 km3 of...
Authors
Charles R. Bacon, Marvin A. Lanphere
Sedimentary textures formed by aqueous processes, Erebus crater Meridiani Planum, Mars Sedimentary textures formed by aqueous processes, Erebus crater Meridiani Planum, Mars
New observations at Erebus crater (Olympia outcrop) by the Mars Exploration Rover Opportunity between sols 671 and 735 (a sol is a martian day) indicate that a diverse suite of primary and penecontemporaneous sedimentary structures is preserved in sulfate-rich bedrock. Centimeter-scale trough (festoon) cross-lamination is abundant, and is better expressed and thicker than previously...
Authors
J. Grotzinger, J. Bell, Kenneth E. Herkenhoff, J. Johnson, A. Knoll, E. McCartney, S. McLennan, J. Metz, Jeff Moore, S. Squyres, R. Sullivan, O. Ahronson, R. Arvidson, B. Joliff, M. Golombek, K. Lewis, T. Parker, J. Soderblom
Titan Radar Mapper observations from Cassini's T3 fly-by Titan Radar Mapper observations from Cassini's T3 fly-by
Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be...
Authors
C. Elachi, S. Wall, M. Janssen, E. Stofan, R. Lopes, Randolph L. Kirk, R. Lorenz, J. Lunine, F. Paganelli, Laurence A. Soderblom, C. Wood, L. Wye, H. Zebker, Y. Anderson, S. Ostro, M. Allison, R. Boehmer, P. Callahan, P. Encrenaz, E. Flamini, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, W. Johnson, K. Kelleher, D. Muhleman, G. Picardi, F. Posa, L. Roth, R. Seu, S. Shaffer, B. Stiles, S. Vetrella, R. West
Perspectives on basaltic magma crystallization and differentiation: Lava-lake blocks erupted at Mauna Loa volcano summit, Hawaii Perspectives on basaltic magma crystallization and differentiation: Lava-lake blocks erupted at Mauna Loa volcano summit, Hawaii
Explosive eruptions at Mauna Loa summit ejected coarse-grained blocks (free of lava coatings) from Moku'aweoweo caldera. Most are gabbronorites and gabbros that have 0–26 vol.% olivine and 1–29 vol.% oikocrystic orthopyroxene. Some blocks are ferrogabbros and diorites with micrographic matrices, and diorite veins (≤2 cm) cross-cut some gabbronorites and gabbros. One block is an open...
Authors
Renee L. McCarter, R.V. Fodor, Frank A. Trusdell
CO2 jets formed by sublimation beneath translucent slab ice in Mars' seasonal south polar ice cap CO2 jets formed by sublimation beneath translucent slab ice in Mars' seasonal south polar ice cap
The martian polar caps are among the most dynamic regions on Mars, growing substantially in winter as a significant fraction of the atmosphere freezes out in the form of CO2 ice. Unusual dark spots, fans and blotches form as the south-polar seasonal CO2 ice cap retreats during spring and summer. Small radial channel networks are often associated with the location of spots once the ice...
Authors
Hugh H. Kieffer, Phillip R. Christensen, Timothy N. Titus
Two years at Meridiani Planum: Results from the Opportunity Rover Two years at Meridiani Planum: Results from the Opportunity Rover
The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling ∼8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict...
Authors
S. W. Squyres, A.H. Knoll, R. E. Arvidson, B. C. Clark, J.P. Grotzinger, B.L. Jolliff, S. M. McLennan, N. Tosca, J.F. Bell, W. M. Calvin, W. H. Farrand, T.D. Glotch, M.P. Golombek, Kenneth E. Herkenhoff, J. R. Johnson, G. Klingelhofer, H.Y. McSween, A. S. Yen
The heartbeat of the volcano: The discovery of episodic activity at Prometheus on Io The heartbeat of the volcano: The discovery of episodic activity at Prometheus on Io
The temporal signature of thermal emission from a volcano is a valuable clue to the processes taking place both at and beneath the surface. The Galileo Near Infrared Mapping Spectrometer (NIMS) observed the volcano Prometheus, on the jovian moon Io, on multiple occasions between 1996 and 2002. The 5 micron (μm) brightness of this volcano shows considerable variation from orbit to orbit...
Authors
Ashley G. Davies, Lionel Wilson, Dennis Matson, Giovanni Leone, Laszlo P. Keszthelyi, Windy L. Jaeger
Abrupt transitions during sustained explosive eruptions: Examples from the 1912 eruption of Novarupta, Alaska Abrupt transitions during sustained explosive eruptions: Examples from the 1912 eruption of Novarupta, Alaska
Plinian/ignimbrite activity stopped briefly and abruptly 16 and 45 h after commencement of the 1912 Novarupta eruption defining three episodes of explosive volcanism before finally giving way after 60 h to effusion of lava domes. We focus here on the processes leading to the termination of the second and third of these three episodes. Early erupted pumice from both episodes show a very...
Authors
N.K. Adams, Bruce F. Houghton, W. Hildreth