Publications
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Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California
The Geysers geothermal field in northern California,
with about 2000-MW electrical capacity, is the largest geothermal
field in the world. Despite its importance as a resource
and as an example of a vapor-dominated reservoir,
very few complete geochemical analyses of the steam have
been published (Allen and Day, 1927; Truesdell and others,
1987). This report presents data from 90 steam, gas,
Authors
Jacob B. Lowenstern, Cathy J. Janik, Lynne Fahlquist, Linda S. Johnson
Radioisotope tracer studies of inorganic carbon and Ca in microbially derived CaCO3
Microbial calcification significantly impacts the cycling and deposition of inorganic carbon. This research employs 45Ca and 14C techniques as radioisotopic tracers to examine the role of cellular cycling of Ca2+ and inorganic carbon in CaCO3 precipitation by the unicellular green alga Nannochloris atomus. Implications of the effects of these physiological aspects on CaCO3 precipitation and the ef
Authors
Kimberly K. Yates, Lisa L. Robbins
210Pb and 210Po, manganese and iron cycling across the O2/H2S interface of a permanently anoxic fjord: Framvaren, Norway
Vertical profiles of dissolved and particulate 201Po and 210Pb were measured across the redox transition zone at Station F1 in Framvaren Fjord, Norway. In this fjord, a sharp decrease in pH above the O2/H2S interface facilitates the aerobic dissolution of MnO2. In contrast, Fe(II) concentrations begin to increase only at the O2/H2S interface depth. Activity profiles reveal that dissolved 210Po an
Authors
Peter W. Swarzenski, Brent A. McKee, Kai Sorenson, James F. Todd
7Be as a tracer of flood sedimentation on the northern California continental margin
Sediment inventories of the cosmogenic radionuclide 7Be (t1/2=53 d) were measured on the Eel River shelf and slope (northern California continental margin) to investigate sedimentation processes associated with coastal river flooding. Seabed coring shortly after major riverflow events in 1995 and 1997 documented a shelf-wide flood deposit, and subsequent radionuclide studies determined 7Be to be a
Authors
C. K. Sommerfield, C. A. Nittrouer, C. R. Alexander
Airborne laser study quantifies El Niño-induced coastal change
Winter storms during the 1997–1998 El Niño caused extensive changes to the beaches and cliffs of the west coast of the United States, a NASA-NOAA-USGS investigation using a scanning airborne laser has found. For example, near Pacifica in central California, the cliff eroded locally as much as 10–13 m landward during the El Niño winter, at least 40 times the long term average erosion rate. However,
Authors
Asbury H. Sallenger, William Krabill, John H. Brock, Robert Swift, Mark Jansen, Serdar Manizade, Bruce Richmond, Monty Hampton, David Eslinger
Scaling winter storm impacts on Assateague Island, Maryland, Virginia
No abstract available.
Authors
Asbury H. Sallenger, Peter Howd, John H. Brock, W. B. Krabill, R. N. Swift, S. Manizade, M. Duffy
Great earthquakes, abundant sand, and high wave energy in the Columbia Cell, USA
No abstract available.
Authors
Curt D. Peterson, Guy R. Gelfenbaum, Harry M. Jol, Jim B. Phipps, Frank Reckendorf, Dave C. Twichell, Sandy Vanderberg, Lorraine Woxell
Climatic-eustatic control of Holocene nearshore parasequence development, southeastern Texas coast
Sediment cores, seismic profiles, radiocarbon dates, and faunal assemblages were used to interpret the depositional setting and geological evolution of the southeastern Texas coast during the last glacio-eustatic cycle. Discrete lithofacies and biofacies zones in the ebb-dominated Sabine Lake estuary and adjacent chenier plain record alternating periods of rapid marine flooding and gradual shoalin
Authors
Robert A. Morton, Jack L. Kindinger, James G. Flocks, Laura B. Stewart
Turbidite pathways in Cascadia Basin and Tufts abyssal plain, Part A, Astoria Channel, Blanco Valley, and Gorda Basin
This open-file report was prepared in support of the USGS Earthquake Hazards of Cascadia Project. The primary objective of this phase of the project is to determine recurrence intervals of turbidites in Cascadia basin-floor channel systems and evaluate implications of this event record for the paleoseismic history of the Cascadia subduction zone. The purpose of this study is to determine whether t
Authors
Stephen C. Wolf, Michael R. Hamer
Storm-related change of the northern San Mateo County Coast, California
No abstract available.
Authors
Monty A. Hampton, John R. Dingler, Asbury H Sallenger, Bruce M. Richmond
Seismic survey probes urban earthquake hazards in Pacific Northwest
A multidisciplinary seismic survey earlier this year in the Pacific Northwest is expected to reveal much new information about the earthquake threat to U.S. and Canadian urban areas there. A disastrous earthquake is a very real possibility in the region.
The survey, known as the Seismic Hazards Investigation in Puget Sound (SHIPS), engendered close cooperation among geologists, biologists, enviro
Authors
M. A. Fisher, T. M. Brocher, R.D. Hyndman, A.M. Trehu, C. S. Weaver, K. C. Creager, R. S. Crosson, T. Parsons, A. K. Cooper, D. Mosher, G. Spence, B.C. Zelt, P.T. Hammer, J.R. Childs, G.R. Cochrane, S. Chopra, R. Walia
Seismic reflections identify finite differences in gas hydrate resources
Gas hydrate is a gas-bearing, ice-like crystalline solid. The substance's build ing blocks consist of a gas molecule (generally methane) sur-rounded by a cage of water molecules. The total amount of methane in hydrate in the world is immense - the most recent speculative estimate centers on values of 21x1015 cu meters. Thus, it may represent a future energy resource. This estimate was presented by
Authors
William P. Dillon, M. Max