Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 7225

Geodetic and seismic constraints on some seismogenic zone processes in Costa Rica

New seismic and geodetic data from Costa Rica provide insight into seismogenic zone processes in Central America, where the Cocos and Caribbean plates converge. Seismic data are from combined land and ocean bottom deployments in the Nicoya peninsula in northern Costa Rica and near the Osa peninsula in southern Costa Rica. In Nicoya, inversion of GPS data suggests two locked patches centered at 14
Authors
E. Norabuena, Timothy Dixon, Susan Schwartz, Heather DeShon, Andrew Newman, Marino Protti, Victor Gonzalez, LeRoy Dorman, Ernst Flueh, Paul Lundgren, Fred Pollitz, Dan Sampson

RADAR: The Cassini Titan Radar Mapper

The Cassini RADAR instrument is a multimode 13.8 GHz multiple-beam sensor that can operate as a synthetic-aperture radar (SAR) imager, altimeter, scatterometer, and radiometer. The principal objective of the RADAR is to map the surface of Titan. This will be done in the imaging, scatterometer, and radiometer modes. The RADAR altimeter data will provide information on relative elevations in selecte
Authors
C. Elachi, M.D. Allison, L. Borgarelli, P. Encrenaz, E. Im, M.A. Janssen, W.T.K. Johnson, Randolph L. Kirk, R. D. Lorenz, J. I. Lunine, D.O. Muhleman, S.J. Ostro, G. Picardi, F. Posa, C.G. Rapley, L.E. Roth, R. Seu, Laurence A. Soderblom, S. Vetrella, S. D. Wall, C. A. Wood, H. A. Zebker

Exploring Martian polar atmospheric circulation and surface interactions

The northern and southern seasonal polar caps of Mars are formed in the polar night, during their respective autumn and winter seasons, by the condensation of atmospheric CO2directly to the solid phase as ice, snow, and possibly frost. During spring and summer, the seasonal ice sublimes, returning CO2 to the atmosphere. The caps advance and recede in response to seasonal variations in solar insola
Authors
Thomas H. Prettyman, Timothy N. Titus

Ecosystem history of southern and central Biscayne Bay: Summary report on sediment core analyses - year two

The Comprehensive Everglades Restoration Plan (CERP) lists restoration of the timing, quantity, and quality of the natural flow of freshwater as one its primary goals. Before restoration can occur, however, the baseline conditions of the environment prior to significant human alteration must be established and the range of variation within the natural system must be determined. In addition, the
Authors
G. Lynn Wingard, Thomas M. Cronin, Charles W. Holmes, Debra A. Willard, Gary S. Dwyer, Scott E. Ishman, William Orem, Christopher P. Williams, Jessica Albietz, Christopher E. Bernhardt, Carlos A. Budet, Bryan Landacre, Terry Lerch, Marci Marot, Ruth E. Ortiz

The Loma Prieta, California, Earthquake of October 17, 1989 - Geologic setting and crustal structure

Although some scientists considered the Ms=7.1 Loma Prieta, Calif., earthquake of 1989 to be an anticipated event, some aspects of the earthquake were surprising. It occurred 17 km beneath the Santa Cruz Mountains along a left-stepping restraining bend in the San Andreas fault system. Rupture on the southwest-dipping fault plane consisted of subequal amounts of right-lateral and reverse motion but
Authors
Ray E. Wells

The world's largest floods, past and present: Their causes and magnitudes

Floods are among the most powerful forces on earth. Human societies worldwide have lived and died with floods from the very beginning, spawning a prominent role for floods within legends, religions, and history. Inspired by such accounts, geologists, hydrologists, and historians have studied the role of floods on humanity and its supporting ecosystems, resulting in new appreciation for the many-fa
Authors
Jim E. O'Connor, John E. Costa

Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2003

The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at historically active volcanoes in Alaska since 1988. The primary objectives of this program are the near real time seismic monitoring of
Authors
James P. Dixon, Scott D. Stihler, John A. Power, Guy Tytgat, Seth C. Moran, John J. Sanchez, Stephen R. McNutt, Steve Estes, John Paskievitch

New seafloor map of the Puerto Rico Trench helps assess earthquake and tsunami hazards

The Puerto Rico Trench, the deepest part of the Atlantic Ocean, is located where the North American (NOAM) plate is subducting under the Caribbean plate (Figure l). The trench region may pose significant seismic and tsunami hazards to Puerto Rico and the U.S.Virgin Islands, where 4 million U.S. citizens reside. Widespread damage in Puerto Rico and Hispaniola from an earthquake in 1787 was estimate
Authors
Uri S. ten Brink, William Danforth, Christopher Polloni, Brian D. Andrews, Pilar Llanes Estrada, Shepard Smith, Eugene Parker, Toshihiko Uozumi