Publications
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Danger lurks deep: The human impact of volcanoes Danger lurks deep: The human impact of volcanoes
Near midnight of March 28, 1982, El Chichón — an obscure, little-studied volcano in Chiapas State, southern Mexico — violently erupted, terrifying local villagers and prompting a confused, poorly executed evacuation. For the next five days, the volcano remained intermittently but only weakly active, so many evacuees were allowed to return to their homes. Then, on April 3 and 4, two...
Authors
J. Feldman, Robert I. Tilling
Subaqueous geology and a filling model for Crater Lake, Oregon Subaqueous geology and a filling model for Crater Lake, Oregon
Results of a detailed bathymetric survey of Crater Lake conducted in 2000, combined with previous results of submersible and dredge sampling, form the basis for a geologic map of the lake floor and a model for the filling of Crater Lake with water. The most prominent landforms beneath the surface of Crater Lake are andesite volcanoes that were active as the lake was filling with water...
Authors
M. Nathenson, C. R. Bacon, D.W. Ramsey
Relationships between reef fish communities and remotely sensed rugosity measurements in Biscayne National Park, Florida, USA Relationships between reef fish communities and remotely sensed rugosity measurements in Biscayne National Park, Florida, USA
The realization that coral reef ecosystem management must occur across multiple spatial scales and habitat types has led scientists and resource managers to seek variables that are easily measured over large areas and correlate well with reef resources. Here we investigate the utility of new technology in airborne laser surveying (NASA Experimental Advanced Airborne Research Lidar (EAARL...
Authors
Ilsa B. Kuffner, John Brock, Rikki Grober-Dunsmore, Victor E. Bonito, T. Donald Hickey, C. Wayne Wright
A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley
The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry...
Authors
E. Robert Thieler, Bradford Butman, William C. Schwab, Mead A. Allison, Neal W. Driscoll, John P. Donnelly, Elazar Uchupi
Coastal-change impacts during hurricane katrina: an overview Coastal-change impacts during hurricane katrina: an overview
As part of an ongoing cooperative effort between USGS, NASA and USACE, the barrier islands within the right-front quadrant of Hurricane Katrina were surveyed with airborne lidar both before and after landfall. Dauphin Island, AL was located the farthest from landfall and wave runup intermittently overtopped its central and western sections. The Gulf-side of the island experienced severe...
Authors
Asbury Sallenger, C. Wayne Wright, Jeff Lillycrop
A three-dimensional geophysical model of the crust in the Barents Sea region: Model construction and basement characterization A three-dimensional geophysical model of the crust in the Barents Sea region: Model construction and basement characterization
BARENTS50, a new 3-D geophysical model of the crust in the Barents Sea Region has been developed by the University of Oslo, NORSAR and the U.S. Geological Survey. The target region comprises northern Norway and Finland, parts of the Kola Peninsula and the East European lowlands. Novaya Zemlya, the Kara Sea and Franz-Josef Land terminate the region to the east, while the Norwegian...
Authors
O. Ritzmann, N. Maercklin, Faleide J. Inge, H. Bungum, Walter D. Mooney, Shane T. Detweiler
New K-Ar ages for calculating end-of-shield extrusion rates at West Maui volcano, Hawaiian island chain New K-Ar ages for calculating end-of-shield extrusion rates at West Maui volcano, Hawaiian island chain
Thirty-seven new K–Ar ages from West Maui volcano, Hawai‘i, are used to define the waning stages of shield growth and a brief episode of postshield volcanism. All but two samples from shield-stage strata have reversed polarity magnetization, so conceivably the exposed shield is not much older than the Olduvai Normal-Polarity subchron, or about 1.8 Ma. The oldest ages obtained are in the...
Authors
David R. Sherrod, T. Murai, Takahiro Tagami
Methane gas hydrate effect on sediment acoustic and strength properties Methane gas hydrate effect on sediment acoustic and strength properties
To improve our understanding of the interaction of methane gas hydrate with host sediment, we studied: (1) the effects of gas hydrate and ice on acoustic velocity in different sediment types, (2) effect of different hydrate formation mechanisms on measured acoustic properties (3) dependence of shear strength on pore space contents, and (4) pore pressure effects during undrained shear. A...
Authors
W.J. Winters, W.F. Waite, D.H. Mason, L.Y. Gilbert, I.A. Pecher
Seasonal variations on the residence times and partitioning of short-lived radionuclides (234Th, 7Be and 210Pb) and depositional fluxes of 7Be and 210Pb in Tampa Bay, Florida Seasonal variations on the residence times and partitioning of short-lived radionuclides (234Th, 7Be and 210Pb) and depositional fluxes of 7Be and 210Pb in Tampa Bay, Florida
Historically, Tampa Bay has been impacted heavily by a wide range of anthropogenic perturbations that may include, agricultural-, shipping-, phosphate mining/distribution-related activities, as well as a burgeoning coastal population. Due to the presence of U-rich underlying sediments, elevated activities of U- and Th-series daughter products may be naturally released into this system...
Authors
M. Baskaran, P.W. Swarzenski
Drag-out effect of piezomagnetic signals due to a borehole: The Mogi source as an example Drag-out effect of piezomagnetic signals due to a borehole: The Mogi source as an example
We show that using borehole measurements in tectonomagnetic experiments allows enhancement of the observed signals. New magnetic dipoles, which vary with stress changes from mechanical sources, are produced on the walls of the borehole. We evaluate such an effect quantitatively. First we formulate a general expression for the borehole effect due to any arbitrary source models. This is...
Authors
Y. Sasai, M.J.S. Johnston, Y. Tanaka, R. Mueller, T. Hashimoto, M. Utsugi, S. Sakanaka, M. Uyeshima, J. Zlotnicki, P. Yvetot
Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens Probe Landing Site Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens Probe Landing Site
Titan's vast equatorial fields of RADAR-dark longitudinal dunes seen in Cassini RADAR synthetic aperture images correlate with one of two dark surface units discriminated as “brown” and “blue” in Visible and Infrared Mapping Spectrometer (VIMS) color composites of short-wavelength infrared spectral cubes (RGB as 2.0, 1.6, 1.3 μm). In such composites bluer materials exhibit higher...
Authors
Laurence A. Soderblom, Randolph L. Kirk, Jonathan I. Lunine, Jeffrey A. Anderson, Kevin H. Baines, Jason W. Barnes, Janet M. Barrett, Robert H. Brown, Bonnie J. Buratti, Roger N. Clark, Dale P. Cruikshank, Charles Elachi, Michael A. Janssen, Ralf Jaumann, Erich Karkoschka, Stéphane Le Mouélic, Rosaly Lopes, Ralph D. Lorenz, Thomas B. McCord, Philip D. Nicholson, Jani Radebaugh, Bashar Rizk, Christophe Sotin, Ellen R. Stofan, Tracie L. Sucharski, Martin G. Tomasko, Stephen D. Wall
Modeling barrier island response to sea-level rise in the Outer Banks, North Carolina Modeling barrier island response to sea-level rise in the Outer Banks, North Carolina
An 8500-year Holocene simulation developed in GEOMBEST provides a possible scenario to explain the evolution of barrier coast between Rodanthe and Cape Hatteras, NC. Sensitivity analyses suggest that in the Outer Banks, the rate of sea-level rise is the most important factor in determining how barrier islands evolve. The Holocene simulation provides a basis for future simulations, which...
Authors
Laura J. Moore, Jeffrey H. List, S. Jeffress Williams, David Stolper