Paleohydrologic record of spring deposits in and around Pleistocene pluvial Lake Tecopa, southeastern California
Stephen T. Nelson, Haraldur R. Karlsson, James B. Paces, David G. Tingey, Stephen Ward, Mark T. Peters
2001, GSA Bulletin (113) 659-670
Tufa (spring) deposits in the Tecopa basin, California, reflect the response of arid groundwater regimes to wet climate episodes. Two types of tufa are represented, informally defined as (1) an easily disaggregated, fine-grained mixture of calcite and quartz (friable tufa) in the southwest Tecopa Valley, and (2) hard, vuggy micrite,...
Field trials of line transect methods applied to estimation of desert tortoise abundance
David R. Anderson, Kenneth P. Burnham, Bruce C. Lubow, L. E. N. Thomas, Paul Stephen Corn, Philip A. Medica, R.W. Marlow
2001, Journal of Wildlife Management (65) 583-597
We examine the degree to which field observers can meet the assumptions underlying line transect sampling to monitor populations of desert tortoises (Gopherus agassizii). We present the results of 2 field trials using artificial tortoise models in 3 size classes. The trials were conducted on 2 occasions on an area...
Evidence for the recovery of terrestrial ecosystems ahead of marine primary production following a biotic crisis at the Cretaceous-Tertiary boundary
D.J. Beerling, B.H. Lomax, G.R. Upchurch Jr., D. J. Nichols, C. L. Pillmore, L.L. Handley, C.M. Scrimgeour
2001, Journal of the Geological Society (158) 737-740
The fossil record demonstrates that mass extinction across the Cretaceous–Tertiary (K–T) boundary is more severe in the marine than the terrestrial realm. We hypothesize that terrestrial ecosystems were able to recover faster than their marine counterparts. To test this hypothesis, we measured sedimentary δ13C as a tracer for global carbon...
Fractionation of Fe isotopes by soil microbes and organic acids
Susan L. Brantley, Laura Liermann, Thomas D. Bullen
2001, Geology (29) 535-538
Small natural variations in Fe isotopes have been attributed to biological cycling. However, without understanding the mechanism of fractionation, it is impossible to interpret such variations. Here we show that the δ56Fe of Fe dissolved from a silicate soil mineral by siderophore-producing bacteria is as much as 0.8% lighter than...
Silent slip on the Cascadia subduction interface
Wayne Thatcher
2001, Science (292) 1495-1496
No abstract available....
Pop-up disaster
Wayne Thatcher
2001, Nature (410) 757-758
No abstract available....
Processes controlling the episodic streamwater transport of atrazine and other agrichemicals in an agricultural watershed
Kenneth Hyer, George M. Hornberger, Janet S. Herman
2001, Journal of Hydrology (254) 47-66
Episodic streamwater transport of atrazine (a common agricultural herbicide) and nutrients has been observed throughout agricultural watersheds in the United States and poses a serious threat to the quality of its water resources. Catchment-scale atrazine and nutrient transport processes after agricultural application are still poorly understood, and predicting episodic streamwater...
The erosion of the Grand Canyon
George Billingsley
2001, Book chapter, Earth: inside and out
No abstract available....
Elevations and distances in the United States
U.S. Geological Survey
2001, Report
The information in this booklet was compiled to answer inquiries received by the U.S. Geological Survey from students, teachers, writers, editors, publishers of encyclopedias, almanacs, and other reference books, and people in many other fields of work. The elevations of features and distances between points in the United States were determined...
Displacement rates on the Toroweap and Hurricane faults: Implications for Quaternary downcutting in the Grand Canyon, Arizona
Cassandra R. Fenton, Robert H. Webb, Philip A. Pearthree, Thure E. Cerling, Robert J. Poreda
2001, Geology (29) 1035-1038
The Toroweap and Hurricane faults, considered to be the most active in Arizona, cross the Uinkaret volcanic field in the western Grand Canyon. These normal faults are downthrown to the west, and the Colorado River crosses these faults as it flows west in the Grand Canyon. Cosmogenic 3He (3Hec) dates...
Planning for a crowded Pacific Rim
David G. Howell
2001, Geotimes (November)
No abstract available....
Climate change in the United States: Implications for fish and wildlife management
Virginia Burkett
2001, Conference Paper, Transactions of the sixty-sixth North American wildlife and natural resource conference : Changing climates of North America : Political, social, and ecological
No abstract available....
Fire and invasives in mediterranean-climate ecosystems of California
Jon E. Keeley
K. E. M. Galley, T.P. Wilson, editor(s)
2001, Book, Proceedings of the Invasive Species Workshop: The Role of Fire in the Control and Spread of Invasive Species. Fire Conference 2000: The First National Congress on Fire Ecology, Prevention, and Management
A framework for ecological decision support systems: Building the right systems and building the systems right
Frank D’Erchia, Carl E. Korschgen, M. Nyquist, Ralph Root, Richard S. Sojda, Peter Stine
2001, Information and Technology Report 2001-0002
Workshops in the late 1990's launched the commitment of the U.S. Geological Survey's Biological Resources Division (BRD) to develop and implement decision support systems (DSS) applications. One of the primary goals of this framework document is to provide sufficient background and information for Department of the Interior (DOI) bureau stakeholders...
Steep-dip seismic imaging of the shallow San Andreas Fault near Parkfield
J.A. Hole, R. D. Catchings, K.C. St. Clair, M. J. Rymer, D. A. Okaya, B.J. Carney
2001, Science (294) 1513-1515
Seismic reflection and refraction images illuminate the San Andreas Fault to a depth of 1 kilometer. The prestack depth-migrated reflection image contains near-vertical reflections aligned with the active fault trace. The fault is vertical in the upper 0.5 kilometer, then dips about 70° to the southwest to at least 1...
Report of the workshop on marine fossils and climate change
John A. Barron, Lloyd H. Burckle
Athena Economou-Amilli, editor(s)
2001, Conference Paper, Proceedings of the 16th International Diatom Symposium
No abstract available....
Size and mass of grit in gizzards of sandhill cranes, tundra swans, and mute swans
J. Christian Franson, Scott P. Hansen, Adam E. Duerr, Stephen DeStefano
2001, Waterbirds (24) 242-244
Because it has been suggested that waterbirds may ingest lost or discarded lead fishing weights as grit, we examined grit in the gizzards of Sandhill Cranes (Grus canadensis), Tundra Swans (Cygnus columbianus), and Mute Swans (Cygnus olor), three species where individuals have been poisoned by the ingestion of lead fishing...
Progress made in understanding Mount Rainier's hazards
T. W. Sisson, J.W. Vallance, P. T. Pringle
2001, Eos, Transactions, American Geophysical Union (82) 113-120
At 4392 m high, glacier-clad Mount Rainier dominates the skyline of the southern Puget Sound region and is the centerpiece of Mount Rainier National Park. About 2.5 million people of the greater Seattle-Tacoma metropolitan area can see Mount Rainier on clear days, and 150,000 live in areas swept by lahars...
Proceedings of the Ocean Drilling Program, scientific results: Fluid, mass, and thermal fluxes in the Pacific margin of Costa Rica: Covering Leg 170 of the cruises of the drilling vessel JOIDES Resolution: San Diego, California, to Balboa, Panama: Sites 1039-1043, 16 October-17 December 1996
E. A. Silver, Gaku Kimura, Peter Blum, Gerad Blanc, A. J. Bolton, M. B. Clennell, J. R. Griffin, Bernard Housen, Masako Ibaraki, Toshiya Kanamatsu, Miriam Kastner, Nancy Lindsley-Griffin, Andreas Lueckge, Kirk McIntosh, Martin Meschede, Julie Morris, J. P. Muza, Grey Myers, Marino Protti, Ola Saether, Saneatsu Saito, David Scholl, George Spence, Harold Tobin, Paola Vannucchi, L. D. White, T. H. Shipley
2001, Book
No abstract available....
Occurrence of Coliform bacteria in a karst aquifer, Berkeley County, West Virginia, USA
M.D. Kozar, M.V. Mathes
2001, Book, Geotechnical and Environmental Applications of Karst Geology and Hydrology: Proceedings of the Eighth Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karsts, Louisville, Kentucky, 1-4 April 2001
No abstract available....
Bringing young scientists to USGS
Rama K. Kotra, Bethany J. Girardi, P. Patrick Leahy
2001, Geotimes (46) 13-13
No abstract available....
Forearc-basin sedimentary response to rapid Late Cretaceous batholith emplacement in the Peninsular Ranges of southern and Baja California
D.L. Kimbrough, D.P. Smith, J. B. Mahoney, Thomas E. Moore, Marty Grove, R.G. Gastil, Amabel Ortega-Rivera, C.M. Fanning
2001, Geology (29) 491-494
No abstract available....
Interactions between fire and invasive plants in temperate grasslands of North America
James B. Grace, Melinda D. Smith, S.L. Grace, Scott L. Collins, Thomas J. Stohlgren
2001, Conference Paper, Proceedings of the Invasive Species Workshop : the role of fire in the control and spread of invasive species. Fire Conference 2000
A substantial number of invasive grasses, forbs and woody plants have invaded temperate grasslands in North America. Among the invading species are winter annuals, biennials, cool-season perennials, warm-season perennials, vines, shrubs, and trees. Many of these species have been deliberately introduced and widely planted; some are still used for range...
Bacterial respiration of arsenate and its significance in the environment
Ronald S. Oremland, Diane Newman, B.W. Kail, J.F. Stolz
W.T. Frankenberger, editor(s)
2001, Book chapter, Environmental chemistry of arsenic
No abstract available. ...
Ground-water flow and quality in the Atlantic City 800-foot sand, New Jersey
Steven D. McAuley, Julia L. Barringer, Gary N. Paulachok, Jeffrey S. Clark, Otto S. Zapecza
2001, New Jersey Geological Survey Report GSR 41
The regional, confined Atlantic City 800-foot sand is the principal source of water supply for coastal communities of southern New Jersey. In response to extensive use of the aquifer--nearly 21 million gallons per day in 1986--water levels have declined to about 100 feet below sea level near Atlantic City and...
