Suspended sediment transport on the continental shelf near Davenport, California
J. P. Xu, M. Noble, S.L. Eittreim
2002, Marine Geology (181) 171-193
Suspended sediment transport on the shelves off Santa Cruz and Davenport, California is studied using field measurements and bottom boundary layer modeling. Strong transport events mostly occur during storms in winter; the volume of winter sediment transport is at least one order of magnitude greater than that of summer/spring transport....
Detection, quantitation and identification of enteroviruses from surface waters and sponge tissue from the Florida Keys using real-time RT-PCR
K.A. Donaldson, Dale W. Griffin, J.H. Paul
2002, Water Research (36) 2505-2514
A method was developed for the quantitative detection of pathogenic human enteroviruses from surface waters in the Florida Keys using Taqman (R) one-step Reverse transcription (RT)-PCR with the Model 7700 ABI Prism (R) Sequence Detection System. Viruses were directly extracted from unconcentrated grab samples of seawater, from seawater concentrated by...
Recovery of severely compacted soils in the Mojave Desert, California, USA
R. H. Webb
2002, Arid Land Research and Management (16) 291-305
Often as a result of large-scale military maneuvers in the past, many soils in the Mojave Desert are highly vulnerable to soil compaction, particularly when wet. Previous studies indicate that natural recovery of severely compacted desert soils is extremely slow, and some researchers have suggested that subsurface compaction may not...
Variations in sediment texture on the northern Monterey Bay National Marine Sanctuary continental shelf
B. D. Edwards
2002, Marine Geology (181) 83-100
The storm-protected continental shelf of Monterey Bay, part of the Monterey Bay National Marine Sanctuary, north-central California, is subject to abundant, episodic sediment input from fluvial sources. North of Monterey Bay, conditions of reduced sediment supply combined with the exposed nature of the shelf provide an effective laboratory for studying...
Accumulation rate and mixing of shelf sediments in the Monterey Bay National Marine Sanctuary
R.C. Lewis, K.H. Coale, B. D. Edwards, M. Marot, J.N. Douglas, E.J. Burton
2002, Marine Geology (181) 157-169
The distribution of excess 210Pb in 31 sediment cores was used to determine modern (last 100 yr) mass accumulation rates and the depth of sediment mixing on the continental shelf between Pacifica and Monterey, California, USA. Apparent mass accumulation rates average 0.27 g cm-2 yr-1 and range from 0.42 g...
Binding of mercury(II) to dissolved organic matter: The role of the mercury-to-DOM concentration ratio
M. Haitzer, G. R. Aiken, J. N. Ryan
2002, Environmental Science & Technology (36) 3564-3570
The binding of Hg(II) to dissolved organic matter (DOM; hydrophobic acids isolated from the Florida Everglades by XAD-8 resin) was measured at a wide range of Hg-to-DOM concentration ratios using an equilibrium dialysis ligand exchange method. Conditional distribution coefficients (KDOM‘) determined...
Interpretation of K-Ar dates of illitic clays from sedimentary rocks aided by modeling
J. Srodon, Norbert Clauer, D.D.D. Eberl
2002, American Mineralogist (87) 1528-1535
K-Ar dates of illitic clays from sedimentary rocks may contain "mixed ages," i.e., may have ages that are intermediate between the ages of end-member events. Two phenomena that may cause mixed ages are: (1) long-lasting reaction during the burial illitization of smectite: and (2) physical mixing of detrital and diagenetic...
A multiisotope C and N modeling analysis of soil organic matter turnover and transport as a function of soil depth in a California annual grassland soil chronosequence
W.T. Baisden, Ronald Amundson, D.L. Brenner, A.C. Cook, C. Kendall, J.W. Harden
2002, Global Biogeochemical Cycles (16) 82-1-82-26
We examine soil organic matter (SOM) turnover and transport using C and N isotopes in soil profiles sampled circa 1949, 1978, and 1998 (a period spanning pulse thermonuclear 14C enrichment of the atmosphere) along a 3‐million‐year annual grassland soil chronosequence. Temporal differences in soil Δ14C profiles indicate that inputs of recently...
Conventional U-Pb dating versus SHRIMP of the Santa Barbara Granite Massif, Rondonia, Brazil
I. Sparrenberger, Jorge S. Bettencourt, R. M. Tosdal, J. L. Wooden
2002, Geologia USP - Serie Cientifica (2) 79-94
The Santa Ba??rbara Granite Massif is part of the Younger Granites of Rondo??nia (998 - 974 Ma) and is included in the Rondo??nia Tin Province (SW Amazonian Craton). It comprises three highly fractionated metaluminous to peraluminous within-plate A-type granite units emplaced in older medium-grade metamorphic rocks. Sn-mineralization is closely associated...
Comparison of subyearling fall chinook salmon's use of riprap revetments and unaltered habitats in Lake Wallula of the Columbia river
R.D. Garland, K.F. Tiffan, D.W. Rondorf, L.O. Clark
2002, North American Journal of Fisheries Management (22) 1283-1289
Subyearling fall chinook salmon's Oncorhynchus tshawytscha use of unaltered and riprap habitats in Lake Wallula of the Columbia River was determined with point abundance data collected by electrofishing in May 1994 and 1995. We documented the presence or absence of subyearlings at 277 sample sites and collected physical habitat information...
Rocky Mountain futures: An ecological perspective
Jill Baron, editor(s)
2002, Book
The Rocky Mountain West is largely arid and steep, with ecological scars from past human use visible for hundreds of years. Just how damaging were the past 150 years of activity? How do current rates of disturbance compare with past mining, grazing, and water diversion activities? In the face of...
Nearly frictionless faulting by unclamping in long-term interaction models
T. Parsons
2002, Geology (30) 1063-1066
In defiance of direct rock-friction observations, some transform faults appear to slide with little resistance. In this paper finite element models are used to show how strain energy is minimized by interacting faults that can cause long-term reduction in fault-normal stresses (unclamping). A model fault contained within a sheared elastic...
Seismic-reflection profiles of the central part of the Clarendon-Linden fault system of western New York in relation to regional seismicity
R.H. Fakundiny, P.W. Pomeroy
2002, Tectonophysics (353) 173-213
Geological and geophysical research in upstate New York, with few exceptions, has not definitively associated seismicity with specific Proterozoic basement or Paleozoic bedrock structures. The central part of the Clarendon-Linden fault system (CLFS) between Batavia and Dale, NY is one of those exceptions where seismicity has been studied and has...
Status and opportunities for genomics research with rainbow trout
G.H. Thorgaard, G.S. Bailey, D. Williams, D. R. Buhler, S.L. Kaattari, S.S. Ristow, J.D. Hansen, J. R. Winton, J. L. Bartholomew, J.J. Nagler, P.J. Walsh, M.M. Vijayan, R.H. Devlin, R.W. Hardy, K.E. Overturf, W.P. Young, B.D. Robison, C. Rexroad, Y. Palti
2002, Conference Paper, Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
The rainbow trout (Oncorhynchus mykiss) is one of the most widely studied of model fish species. Extensive basic biological information has been collected for this species, which because of their large size relative to other model fish species are particularly suitable for studies requiring ample quantities of specific cells and...
Dynamics of the double-crested cormorant population on Lake Ontario
Bradley F. Blackwell, Martin A. Stapanian, D.V. Chip Weseloh
2002, Wildlife Society Bulletin (30) 345-353
After nearly 30 years of recolonization and expansion across North America, the double-crested cormorant (Phalacrocorax auritus) occupies the role of a perceived and, in some situations, realized threat to fish stocks and other resources. However, population data necessary to plan, defend, and implement management of this species are few....
Ancient impact structures on modern continental shelves: The Chesapeake Bay, Montagnais, and Toms Canyon craters, Atlantic margin of North America
C. Wylie Poag, J. B. Plescia, P.C. Molzer
2002, Deep-Sea Research Part II: Topical Studies in Oceanography (49) 1081-1102
Three ancient impact craters (Chesapeake Bay - 35.7 Ma; Toms Canyon - 35.7 Ma; Montagnais - 51 Ma) and one multiring impact basin (Chicxulub - 65 Ma) are currently known to be buried beneath modern continental shelves. All occur on the passive Atlantic margin of North America in regions extensively...
Subglacial volcanic features beneath the West Antarctic Ice Sheet interpreted from aeromagnetic and radar ice sounding
John C. Behrendt, D. D. Blankenship, D. L. Morse, C. A. Finn, R.E. Bell
2002, Geological Society Special Publication 337-355
The West Antarctic Ice Sheet (WAIS) flows through the volcanically active, late Cenozoic West Antarctic rift system. Active subglacial volcanism and a vast (>106 km3) extent of subglacial volcanic structures have been interpreted from aerogeophysical surveys over central West Antarctica in the past decade, combined with results from 1960s and...
Sea otter studies in Glacier Bay National Park and Preserve
James L. Bodkin, Kimberly A. Kloecker, George G. Esslinger, Daniel H. Monson, J.D. DeGroot, J. Doherty
2002, Report
Following translocations to the outer coast of Southeast Alaska in 1965, sea otters have been expanding their range and increasing in abundance. We began conducting surveys for sea otters in Cross Sound, Icy Strait, and Glacier Bay, Alaska in 1994, following initial reports (in 1993) of their presence in Glacier...
The utility of estimating net primary productivity over Alaska using baseline AVHRR data
C. J. Markon, Kim M. Peterson
2002, International Journal of Remote Sensing (23) 4571-4596
Net primary productivity (NPP) is a fundamental ecological variable that provides information about the health and status of vegetation communities. The Normalized Difference Vegetation Index, or NDVI, derived from the Advanced Very High Resolution Radiometer (AVHRR) is increasingly being used to model or predict NPP, especially over large remote areas....
Source properties of earthquakes near the Salton Sea triggered by the 16 October 1999 M 7.1 Hector Mine, California, earthquake
S. E. Hough, H. Kanamori
2002, Bulletin of the Seismological Society of America (92) 1281-1289
We analyze the source properties of a sequence of triggered earthquakes that occurred near the Salton Sea in southern California in the immediate aftermath of the M 7.1 Hector Mine earthquake of 16 October 1999. The sequence produced a number of early events that were not initially located by the...
Relating net nitrogen input in the Mississippi River Basin to nitrate flux in the Lower Mississippi River--A comparison of approaches
Gregory F. McIsaac, Mark B. David, George Z. Gertner, Donald A. Goolsby
2002, Journal of Environmental Quality (31) 1610-1622
A quantitative understanding of the relationship between terrestrial N inputs and riverine N flux can help guide conservation, policy, and adaptive management efforts aimed at preserving or restoring water quality. The objective of this study was to compare recently published approaches for relating terrestrial N inputs to the Mississippi River...
Methods to achieve accurate projection of regional and global raster databases
E. Lynn Usery, Jeong Chang Seong, Dan Steinwand
2002, Open-File Report 2001-181
Modeling regional and global activities of climatic and human-induced change requires accurate geographic data from which we can develop mathematical and statistical tabulations of attributes and properties of the environment. Many of these models depend on data formatted as raster cells or matrices of pixel values. Recently, it has been...
Geochemistry of surface and pore water at USGS coring sites in wetlands of South Florida, 1994 and 1995
William H. Orem, Harry E. Lerch, Peter Rawlik
2002, Open-File Report 97-454
In this report, we present preliminary data on surface and pore water geochemistry from 22 sites in south Florida sampled during 1994 and 1995. These results are part of a larger study designed to evaluate the role of biogeochemical processes in sediments in the cycling of carbon, nitrogen, phosphorus, and...
Documentation of Precipitation Runoff Modeling System modules for the Modular Modeling System modified for the Watershed and River Systems Management Program
Mark C. Mastin, J. J. Vaccaro
2002, Open-File Report 2002-362
A decision support system is being developed by the U.S. Geological Survey and the U.S. Bureau of Reclamation as part of a long-term project, the Watershed and River Systems Management Program. The goal of the program is to apply the decision support system to U.S. Bureau of Reclamation projects in...
MODFLOW-2000, the U.S. Geological Survey modular ground-water model -- Documentation of the Model-Layer Variable-Direction Horizontal Anisotropy (LVDA) capability of the Hydrogeologic-Unit Flow (HUF) package
Evan R. Anderman, K.L. Kipp, Mary C. Hill, Johan Valstar, R.M. Neupauer
2002, Open-File Report 2002-409
This report documents the model-layer variable-direction horizontal anisotropy (LVDA) capability of the Hydrogeologic-Unit Flow (HUF) Package of MODFLOW-2000. The LVDA capability allows the principal directions of horizontal anisotropy to be different than the model-grid row and column directions, and for the directions to vary on a cell-by-cell basis within model...
