Publications
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Argon geochronology of late Pleistocene to Holocene Westdahl volcano, Unimak Island, Alaska
High-precision 40Ar/39Ar geochronology of selected lavas from Westdahl Volcano places time constraints on several key prehistoric eruptive phases of this large active volcano. A dike cutting old pyroclastic-flow and associated lahar deposits from a precursor volcano yields an age of 1,654+/-11 k.y., dating this precursor volcano as older than early Pleistocene. A total of 11 geographically distrib
Authors
Andrew T. Calvert, Richard B. Moore, Robert G. McGimsey
Log of Trench 04A across the Hayward Fault at Tyson's Lagoon (Tule Pond), Fremont, Alameda County, California
This publication makes available a detailed trench log (sheets 1 and 2) of a 110-m trench we excavated in 2004 across a tectonic sag pond in the Hayward fault zone. Also included are revised stratigraphic unit descriptions from this fifth field season of subsurface investigation of the Hayward fault at Tyson's Lagoon (Tule Pond). Preliminary findings based on fieldwork done in 2000 have been publi
Authors
James J. Lienkaemper, Patrick L. Williams, Robert R. Sickler, Thomas E. Fumal
2003 volcanic activity in Alaska and Kamchatka: Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) monitors the more than 40 historically active volcanoes of the Aleutian Arc. Of these, 24 were considered monitored in real time with short-period seismic instrument networks as of the end of 2003. The AVO core monitoring program also includes daily analysis of satellite imagery, observation over flights, and compilation of pilot reports and reports from local
Authors
Robert G. McGimsey, Christina A. Neal, Olga Girina
Bulk sediment Qp and Qs in the Mississippi embayment, central United States
We have estimated P-wave and S-wave anelastic attenuation coefficients for the thick, unconsolidated sediments of the Mississippi embayment, central United States, using the spectral distance decay of explosion P and Rayleigh waves. The sediment-trapped P wave, Psed, is observed to ranges of 80 km at 10 Hz, and 1-Hz Rayleigh waves are observed out to 130 km from a 5000-lb borehole explosion in the
Authors
C.A. Langston, P. Bodin, C. Powell, M. Withers, S. Horton, Walter D. Mooney
Magma generation at a large, hyperactive silicic volcano (Taupo, New Zealand) revealed by U-Th and U-Pb systematics in zircons
Young (<∼65 ka) explosive silicic volcanism at Taupo volcano, New Zealand, has involved the development and evacuation of several crustal magmatic systems. Up to and including the 26·5 ka 530 km3 Oruanui eruption, magmatic systems were contemporaneous but geographically separated. Subsequently they have been separated in time and have vented from geographically overlapping areas. Single-crystal (s
Authors
B. L. A. Charlier, C. J. N. Wilson, J. B. Lowenstern, S. Blake, P.W. van Calsteren, J.P. Davidson
An updated global earthquake catalogue for stable continental regions: Reassessing the correlation with ancient rifts
We present an updated global earthquake catalogue for stable continental regions (SCRs; i.e. intraplate earthquakes) that is available on the Internet. Our database contains information on location, magnitude, seismic moment and focal mechanisms for over 1300 M (moment magnitude) ≥ 4.5 historic and instrumentally recorded crustal events. Using this updated earthquake database in combination with a
Authors
S.M. Schulte, Walter D. Mooney
The legacy of contaminated sediments in Boston Harbor
Scientists at the U.S. Geological Survey (USGS) have assembled a significant body of data that is now in a usable form. The USGS adopted an interdisciplinary approach to begin the pioneering effort at data rescue. This work involved collaboration with the Environmental Protection Agency (EPA), the U.S. Army Corps of Engineers (USACE), the Massachusetts Water Resources Authority (MWRA), Massachuset
Authors
Frank T. Manheim
Book review: Earth’s magnetism in the age of sail
For many centuries, the source, behavior, and even the essential nature of geomagnetism were enigmatic. Despite this, the effect of geomagnetism was familiar, by imparting a directional preference on the magnetized needle of the compass and providing a useful, if somewhat annoyingly complicated, reference for navigators. Although the compass seems to have first been invented in China, it was the E
Authors
Jeffrey J. Love
Evidence from Opportunity’s Microscopic Imager for water on Meridiani Planum
The Microscopic Imager on the Opportunity rover analyzed textures of soils and rocks at Meridiani Planum at a scale of 31 micrometers per pixel. The uppermost millimeter of some soils is weakly cemented, whereas other soils show little evidence of cohesion. Rock outcrops are laminated on a millimeter scale; image mosaics of cross-stratification suggest that some sediments were deposited by flowing
Authors
Kenneth E. Herkenhoff, S. W. Squyres, R. Arvidson, D.S. Bass, J. F. III Bell, P. Bertelsen, B. L. Ehlmann, W. Farrand, Lisa R. Gaddis, R. Greeley, J. Grotzinger, A. G. Hayes, S.F. Hviid, J. R. Johnson, B. Jolliff, K.M. Kinch, A. H. Knoll, M.B. Madsen, J.N. Maki, S. M. McLennan, H.Y. McSween, D. W. Ming, J. W. Rice, L. Richter, M. Sims, P. H. Smith, Laurence A. Soderblom, Nicole Spanovich, R. Sullivan, S. Thompson, T. Wdowiak, C. Weitz, P. Whelley
The ongoing Pu'u 'O'o-Kupaianaha eruption of Kilauea Volcano, Hawai'i
No abstract available.
Authors
Christina Heliker, Steven R. Brantley
Comments on potential geologic and seismic hazards affecting coastal Ventura County, California
This report examines the regional seismic and geologic hazards that could affect proposed liquefied natural gas (LNG) facilities in coastal Ventura County, California. Faults throughout this area are thought to be capable of producing earthquakes of magnitude 6.5 to 7.5, which could produce surface fault offsets of as much as 15 feet. Many of these faults are sufficiently well understood to be inc
Authors
Stephanie L. Ross, David M. Boore, Michael A. Fisher, Arthur D. Frankel, Eric L. Geist, Kenneth W. Hudnut, Robert E. Kayen, Homa J. Lee, William R. Normark, Florence L. Wong
Icelandic analogs to Martian flood lavas
We report on new field observations from Icelandic lava flows that have the same surface morphology as many Martian flood lava flows. The Martian flood lavas are characterized by a platy‐ridged surface morphology whose formation is not well understood. The examples on Mars include some of the most pristine lava on the planet and flows >1500 km long. The surfaces of the flows are characterized by (
Authors
Laszlo P. Keszthelyi, Thorvaldur Thordarson, Alfred McEwen, Henning Haack, Marie-Noelle Guilbaud, Stephen Self, Matti J. Rossi