Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 7221

Provisional geologic map of Augustine Volcano, Alaska

No abstract available.
Authors
R. B. Waitt, J. E. Beget, Juergen Kienle

Geothermal resources in the Crater Lake area, Oregon

No abstract available.
Authors
Charles R. Bacon, Manuel Nathenson

Database of potential sources for earthquakes larger than magnitude 6 in Northern California

The Northern California Earthquake Potential (NCEP) working group, composed of many contributors and reviewers in industry, academia and government, has pooled its collective expertise and knowledge of regional tectonics to identify potential sources of large earthquakes in northern California. We have created a map and database of active faults, both surficial and buried, that forms the basis for
Authors

The Loma Prieta, California, Earthquake of October 17, 1989: Main shock characteristics

The October 17, 1989, Loma Prieta, Calif., earthquake (0004:15.2 G.m.t. October 18; lat 37.036º N., long 121.883º W.; 19-km depth) had a local magnitude (ML) of about 6.7, a surface-wave magnitude (MS) of 7.1, a seismic moment of 2.2x1019 N-m to 3.5x1019 N-m, a source duration of 6 to 15 s, and an average stress drop of at least 50 bars. Slip occurred on a dipping fault surface about 35 km long an
Authors
Paul A. Spudich, Gregory C. Beroza, George Choy, John Boatwright, Stephen H. Hartzell, Gordon L. Stewart, Carlos Mendoza, Stephen Horton, John G. Anderson, Andres J. Mendez, Hiroo Kanamori, Kenji Satake, Michael Lisowski, Mark Hunter Murray, Jerry L. Svarc, Grant Marshall, Ross S. Stein, Karen McNally, Gerald W. Simila, Judy G. Brown, J.L. Nabelek, Ze'ev Reches, Mark D. Zoback, Jamison Steidl, Ralph J. Archuleta, Aaron A. Velasco, Thorne Lay, Jiajun Zhang, David J. Wald, Donald V. Helmberger, Thomas H. Heaton, Chesley R. Williams, Paul Segall, Francis T. Wu, Mingdong Wu, J.W. Rudnicki

Origin of high mountains in the continents: The Southern Sierra Nevada

Active and passive seismic experiments show that the southern Sierra, despite standing 1.8 to 2.8 kilometers above its surroundings, is underlain by crust of similar seismic thickness, about 30 to 40 kilometers. Thermobarometry of xenolith suites and magnetotelluric profiles indicate that the upper mantle is eclogitic to depths of 60 kilometers beneath the western and central parts of the range, b
Authors
B. Wernicke, R. Clayton, Mihai N. Ducea, C.H. Jones, S. Park, S. Ruppert, J. Saleeby, J.K. Snow, L. Squires, M. Fliedner, G. Jiracek, Rebecca Hylton Keller, S. Klemperer, J. Luetgert, P. Malin, K. Miller, Walter D. Mooney, H. Oliver, R. Phinney

Three-dimensional crustal structure of the southern Sierra Nevada from seismic fan profiles and gravity modeling

Traveltime data from the 1993 Southern Sierra Nevada Continental Dynamics seismic refraction experiment reveal low crustal velocities in the southern Sierra Nevada and Basin and Range province of California (6.0 to 6.6 km/s), as well as low upper mantle velocities (7.6 to 7.8 km/s). The crust thickens from southeast to northwest along the axis of the Sierra Nevada from 27 km in the Mojave Desert t
Authors
M.M. Fliedner, S. Ruppert, P.E. Malin, S. K. Park, G. Jiracek, R. A. Phinney, J.B. Saleeby, B. Wernicke, R. Clayton, Rebecca Hylton Keller, K. Miller, C. Jones, J. H. Luetgert, Walter D. Mooney, H. Oliver, S.L. Klemperer, G. A. Thompson

Transition from slab to slabless: Results from the 1993 Mendocino triple junction seismic experiment

Three seismic refraction-reflection profiles, part of the Mendocino triple junction seismic experiment, allow us to compare and contrast crust and upper mantle of the North American margin before and after it is modified by passage of the Mendocino triple junction. Upper crustal velocity models reveal an asymmetric Great Valley basin overlying Sierran or ophiolitic rocks at the latitude of Fort Br
Authors
B. C. Beaudoin, N. J. Godfrey, S.L. Klemperer, C. Lendl, A.M. Trehu, T.J. Henstock, A. Levander, J.E. Holl, A.S. Meltzer, James H. Luetgert, Walter D. Mooney

The 40Ar/39Ar and K/Ar dating of lavas from the Hilo 1-km core hole, Hawaii Scientific Drilling Project

Mauna Kea lava flows cored in the Hilo hole range in age from <200 ka to about 400 ka based on 40Ar/39Ar incremental heating and K‐Ar analyses of 16 groundmass samples and one coexisting plagioclase. The lavas, all subaerially deposited, include a lower section consisting only of tholeiitic basalts and an upper section of interbedded alkalic, transitional tholeiitic, and tholeiitic basalts. The lo
Authors
W.D. Sharp, B.D. Turrin, P.R. Renne, M. A. Lanphere

Seismic anisotropy of the crystalline crust: What does it tell us?

The study of the directional dependence of seismic velocities (seismic anisotropy) promises more refined insight into mineral composition and physical properties of the crystalline crust than conventional deep seismic refraction or reflection profiles providing average values of P-and S-wave velocities. The alignment of specific minerals by ductile rock deformation, for instance, causes specific t
Authors
Wolfgang Rabbel, Walter D. Mooney

U.S. East Coast EEZ: Part II

No abstract available.
Authors
James M. Robb, William P. Dillon, Dennis W. O'Leary, Peter Popenoe