A strategy for estimating the rates of recent United States land-cover changes
Thomas R. Loveland, Terry L. Sohl, S.V. Stehman, Alisa L. Gallant, K. L. Sayler, D.E. Napton
2002, Photogrammetric Engineering and Remote Sensing (68) 1091-1099
Information on the rates of land-use and land-cover change is important in addressing issues ranging from the health of aquatic resources to climate change. Unfortunately, there is a paucity of information on land-use and land-cover change except at very local levels. We describe a strategy for estimating land-cover change across...
δ13C values of soil organic matter in semiarid grassland with mesquite (Prosopis) encroachment in southeastern Arizona
Thomas H. Biggs, Jay Quade, Robert H. Webb
2002, Geoderma (110) 109-130
Over the past century, C3 woody plants and trees have increased in abundance in many semiarid ecosystems, displacing native C4 grasses. Livestock grazing, climatic fluctuations, and fire suppression are several reasons proposed for this shift. Soil carbon isotopic signatures are an ideal technique to evaluate carbon turnover rates in such...
Avian disease at the Salton Sea
Milton Friend
2002, Hydrobiologia (473) 293-306
A review of existing records and the scientific literature was conducted for occurrences of avian diseases affecting free-ranging avifauna within the Salton Sea ecosystem. The period for evaluation was 1907 through 1999. Records of the U.S. Department of Agriculture, Bureau of Biological Survey and the scientific literature were the data...
Association of methylmercury with dissolved humic acids
A. Amirbahman, A.L. Reid, T.A. Haines, J. S. Kahl, C. Arnold
2002, Environmental Science & Technology (36) 690-695
Sorption of methylmercury (MeHg) to three different humic acids was investigated as a function of pH and humic concentration. The extent of sorption did not show a strong pH dependence within the pH range of 5−9. Below pH 5, a decrease in adsorption for all humic samples was observed. The...
Satellite mapping of surface biophysical parameters at the biome scale over the North American grasslands: A case study
B.K. Wylie, D. J. Meyer, L.L. Tieszen, S. Mannel
2002, Remote Sensing of Environment (79) 266-278
Quantification of biophysical parameters is needed by terrestrial process modeling and other applications. A study testing the role of multispectral data for monitoring biophysical parameters was conducted over a network of grassland field sites in the Great Plains of North America. Grassland biophysical parameters [leaf area index (LAI), fraction of...
Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus)
S. J. Hamilton, K.M. Holley, K.J. Buhl
2002, Science of the Total Environment (291) 111-121
A hazard assessment was conducted based on information derived from two reproduction studies conducted with endangered razorback suckers (Xyrauchen texanus) at three sites near Grand Junction, CO, USA. Selenium contamination of the upper and lower Colorado River basin has been documented in water, sediment, and biota in studies by US...
Cycling of beryllium and carbon through hillslope soils in Iowa
J.W. Harden, T. L. Fries, M.J. Pavich
2002, Biogeochemistry (60) 317-336
Isotopes of Be and C were used to reconstruct loess accumulation, hillslope evolution, and agricultural modification in soils of western Iowa. While both elements are derived from additions by the atmosphere (via plants in the case of carbon), the differences in element cycling allow erosional and depositional processes to be...
Structure and physical characteristics of pumice from the climactic eruption of Mount Mazama (Crater Lake), Oregon
C. Klug, K. Cashman, Charles R. Bacon
2002, Bulletin of Volcanology (64) 486-501
The vesicularity, permeability, and structure of pumice clasts provide insight into conditions of vesiculation and fragmentation during Plinian fall and pyroclastic flow-producing phases of the ~7,700 cal. year B.P. climactic eruption of Mount Mazama (Crater Lake), Oregon. We show that bulk properties (vesicularity and permeability) can be correlated with internal textures...
Effect of flood-induced chemical load on filtrate quality at bank filtration sites
C. Ray, T.W. Soong, Y.Q. Lian, G.S. Roadcap
2002, Journal of Hydrology (266) 235-258
Riparian municipal wells, that are located on riverbanks, are specifically designed to capture a portion of the river water through induced infiltration. Runoff from agricultural watersheds is found to carry enormous amounts of pesticides and nitrate. While the risk of contamination for a vast majority of sites with small-capacity vertical...
Gravitational failure of sea cliffs in weakly lithified sediment
M. A. Hampton
2002, Environmental & Engineering Geoscience (8) 175-191
Gravitational failure of sea cliffs eroded into weakly lithified sediment at several sites in California involves episodic stress-release fracturing and cantilevered block falls. The principal variables that influence the gravitational stability are tensional stresses generated during the release of horizontal confining stress and weakening of the sediment with increased saturation...
Late quaternary evolution of the Orinoco Delta, Venezuela
A.G. Warne, E.H. Guevara, A. Aslan
2002, Journal of Coastal Research (18) 225-253
The modern Orinoco Delta is the latest of a series of stacked deltas that have infilled the Eastern Venezuelan Basin (EVB) since the Oligocene. During the late Pleistocene sea-level lowstand (20,000 to 16,000 yrs BP), bedrock control points at the position of the present delta apex prevented the river channel...
Timing of large earthquakes since A.D. 800 on the Mission Creek strand of the San Andreas fault zone at Thousand Palms Oasis, near Palm Springs, California
T. E. Fumal, M. J. Rymer, G. G. Seitz
2002, Bulletin of the Seismological Society of America (92) 2841-2860
Paleoseismic investigations across the Mission Creek strand of the San Andreas fault at Thousand Palms Oasis indicate that four and probably five surface-rupturing earthquakes occurred during the past 1200 years. Calendar age estimates for these earthquakes are based on a chronological model that incorporates radiocarbon dates from 18 in situ burn layers...
Geology and geochemistry of Carlin-type gold deposits in China
H. Rui-Zhong, S. Wen-Chao, B. Xian-Wu, T. Guang-Zhi, A. H. Hofstra
2002, Mineralium Deposita (37) 378-392
The Carlin-type gold deposits in China lie mostly near the margins of the Proterozoic Yangtze and Aba cratons. Submicron-sized gold in micron-sized arsenian pyrite is disseminated in fractured Cambrian through Triassic carbonaceous shale and carbonate rocks, and is associated with anomalous Hg, Sb, As, U, and Tl. Alteration typically includes...
Extracting low‐resolution river networks from high‐resolution digital elevation models
Francisco Olivera, Mary S. Lear, James S. Famiglietti, Kwabena Asante
2002, Water Resources Research (38) 13-1-13-8
Including a global river network in the land component of global climate models (GCMs) is necessary in order to provide a more complete representation of the hydrologic cycle. The process of creating these networks is called river network upscaling and consists of lowering the resolution of already available fine networks...
A record of large earthquakes on the southern Hayward fault for the past 500 years
J. J. Lienkaemper, T. E. Dawson, S. F. Personius, G. G. Seitz, L.M. Reidy, David P. Schwartz
2002, Bulletin of the Seismological Society of America (92) 2637-2658
The Hayward fault, a major branch of the right-lateral San Andreas fault system, traverses the densely populated eastern San Francisco Bay region, California. We conducted a paleoseismic investigation to better understand the Hayward fault's past earthquake behavior. The site is near the south end of Tyson's Lagoon, a sag pond...
Sequence stratigraphic and sedimentologic significance of biogenic structures from a late Paleozoic marginal- to open-marine reservoir, Morrow Sandstone, subsurface of southwest Kansas, USA
L.A. Buatois, M.G. Mangano, A. Alissa, T.R. Carr
2002, Sedimentary Geology (152) 99-132
Integrated ichnologic, sedimentologic, and stratigraphic studies of cores and well logs from Lower Pennsylvanian oil and gas reservoirs (lower Morrow Sandstone, southwest Kansas) allow distinction between fluvio-estuarine and open marine deposits in the Gentzler and Arroyo fields. The fluvio-estuarine facies assemblage is composed of both interfluve and valley-fill deposits, encompassing...
Magnitude estimates of two large aftershocks of the 16 December 1811 New Madrid earthquake
S. E. Hough, S. Martin
2002, Bulletin of the Seismological Society of America (92) 3259-3268
The three principal New Madrid mainshocks of 1811-1812 were followed by extensive aftershock sequences that included numerous felt events. Although no instrumental data are available for either the mainshocks or the aftershocks, available historical accounts do provide information that can be used to estimate magnitudes and locations for the large...
Rangeland health attributes and indicators for qualitative assessment
David A. Pyke, Jeffrey E. Herrick, Patrick Shaver, Mike Pellant
2002, Journal of Range Management (55) 584-597
Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a...
Seismic determination of saturation in fractured reservoirs
R.L. Brown, M.L. Wiggins, A. Gupta
2002, SPE Journal (7) 237-242
Detecting the saturation of a fractured reservoir using shear waves is possible when the fractures have a geometry that induces a component of movement perpendicular to the fractures. When such geometry is present, vertically traveling shear waves can be used to examine the saturation of the fractured reservoir. Tilted, corrugated,...
Paleoseismology at high latitudes: Seismic disturbance of upper Quaternary deposits along the Castle Mountain fault near Houston, Alaska
Peter J. Haeussler, Timothy C. Best, Christopher F. Waythomas
2002, Geological Society of America Bulletin (114) 1296-1310
Most paleoseismic studies are at low to moderate latitudes. Here we present results from a high-latitude (61°30′ N) trenching study of the Castle Mountain fault in south-central Alaska. This fault is the only one known in the greater Anchorage, Alaska, area with historical seismicity and a Holocene fault scarp. It...
Improved method for quantifying the avicide 3-chloro-p-toluidine hydrochloride in bird tissues using a deuterated surrogate/GC/MS method
Randal S. Stahl, Thomas W. Custer, P. A. Pochop, J. J. Johnston
2002, Journal of Agricultural and Food Chemistry (50) 732-738
A method using a deuterated surrogate of the avicide 3-chloro-p-toluidine hydrochloride (CPTH) was developed to quantify the CPTH residues in the gastrointestinal (GI) tract and breast muscle tissues in birds collected in CPTH-baited sunflower and rice fields. This method increased the range of a previous surrogate/gas chromatography/mass spectroscopy method...
Gonadotropin-dependent oocyte maturational competence requires activation of the protein kinase A pathway and synthesis of RNA and protein in ovarian follicles of Nibe, Nibea mitsukurii (Teleostei, Sciaenidae)
G. Yoshizaki, M. Shusa, T. Takeuchi, R. Patino
2002, Fish Physiology and Biochemistry (25) 201-208
Luteinizing hormone- (LH)-dependent ovarian follicle maturation has been recently described in two stages for teleost fishes. The oocyte's ability to respond to the steroidal maturation-inducing hormone (MIH), also known as oocyte maturational competence (OMC), is acquired during the first stage; whereas the MIH-dependent resumption of meiosis occurs during the second...
Modified Biot-Gassmann theory for calculating elastic velocities for unconsolidated and consolidated sediments
Myung W. Lee
2002, Marine Geophysical Research (23) 403-412
The classical Biot-Gassmann theory (BGT) generally overestimates shear-wave velocities of water-saturated sediments. To overcome this problem, a new theory is developed based on BGT and on the velocity ratio as a function of G(1−φ)n, where φ is porosity and n and G are constants. Based on laboratory data measured at ultrasonic frequencies, parameters for the...
Comparison of mitochondrial DNA control region sequence and microsatellite DNA analyses in estimating population structure and gene flow rates in Atlantic sturgeon Acipenser oxyrinchus
I. Wirgin, J. Waldman, J. Stabile, B. Lubinski, T. King
2002, Journal of Applied Ichthyology (18) 313-319
Atlantic sturgeon Acipenser oxyrinchus is large, long-lived, and anadromous with subspecies distributed along the Atlantic (A. oxyrinchus oxyrinchus) and Gulf of Mexico (A. o. desotoi) coasts of North America. Although it is not certain if extirpation of some population units has occurred, because of anthropogenic influences abundances of all populations...
Population dynamics of tule elk at point Reyes National Seashore, California
J. A. Howell, G. C. Brooks, M. Semenoff-Irving, C. Greene
2002, Journal of Wildlife Management (66) 478-490
The presence of locally abundant wildlife raises questions about natural regulation and ecological consequences of overpopulation. We sought to establish precise information about population size, structure, and productivity to examine the role of natural regulation in a closed tule elk (Cervus elaphus nannodes) population at Point Reyes National Seashore, California,...
