Long-term changes in the phosphorus loading to and trophic state of the Salton Sea, California
Dale M. Robertson, S.G. Schladow, G.C. Holdren
2008, Hydrobiologia (604) 21-36
The Salton Sea (Sea) is a eutrophic to hypereutrophic lake characterized by high nutrient concentrations, low water clarity, and high biological productivity. Based on dissolved phosphorus (P) and nitrogen (N) concentrations and N:P ratios, P is typically the limiting nutrient in the Sea and, therefore, should be the primary nutrient...
Containment of fluid samples in the hydrothermal diamond-anvil cell without the use of metal gaskets: Performance and advantages for in situ analysis
I.-M. Chou, William A. Bassett, Alan J. Anderson, Robert A. Mayanovic, L. Shang
2008, Review of Scientific Instruments (79)
Metal gaskets (Re, Ir, Inconel, or stainless steel) normally used to contain fluid samples in the hydrothermal diamond-anvil cell (HDAC) are sometimes undesirable due to possible contamination and to gasket deformation at high pressures and temperatures resulting in nonisochoric behavior. Furthermore, in x-ray spectroscopic experiments, metal gaskets may attenuate the...
Transient deterministic shallow landslide modeling: Requirements for susceptibility and hazard assessments in a GIS framework
J. W. Godt, R.L. Baum, W. Z. Savage, D. Salciarini, W.H. Schulz, E. L. Harp
2008, Engineering Geology (102) 214-226
Application of transient deterministic shallow landslide models over broad regions for hazard and susceptibility assessments requires information on rainfall, topography and the distribution and properties of hillside materials. We survey techniques for generating the spatial and temporal input data for such models and present an example using a transient deterministic...
Water-quality monitoring and process understanding in support of environmental policy and management
N.E. Peters
2008, Conference Paper, IAHS-AISH Publication
The quantity and quality of freshwater at any point on the landscape reflect the combined effects of many processes operating along hydrological pathways within a drainage basin/watershed/catchment. Primary drivers for the availability of water are landscape changes and patterns, and the processes affecting the timing, magnitude, and intensity of precipitation,...
Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes
B.F. Jones, J.S. Herman
2008, Conference Paper, Mineralogical Magazine
Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and...
Joint variability of global runoff and global sea surface temperatures
G.J. McCabe, D.M. Wolock
2008, Journal of Hydrometeorology (9) 816-824
Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the...
Micropaleontologic record of late Pliocene and Quaternary paleoenvironments in the northern Albemarle Embayment, North Carolina, U.S.A.
S.J. Culver, K.M. Farrell, D. J. Mallinson, B. P. Horton, Debra A. Willard, E.R. Thieler, S.R. Riggs, S.W. Snyder, J.F. Wehmiller, C.E. Bernhardt, C. Hillier
2008, Palaeogeography, Palaeoclimatology, Palaeoecology (264) 54-77
Micropaleontological data provide a strong actualistic basis for detailed interpretations of Quaternary paleoenvironmental change. The 90 m-thick Quaternary record of the Albemarle Embayment in the mid-Atlantic coastal plain of the USA provides an excellent opportunity to use such an approach in a region where the details of Quaternary environmental change are...
Estimating watershed level nonagricultural pesticide use from golf courses using geospatial methods
G.A. Fox, G.P. Thelin, G.J. Sabbagh, J.W. Fuchs, I.D. Kelly
2008, Journal of the American Water Resources Association (44) 1363-1372
Limited information exists on pesticide use for nonagricultural purposes, making it difficult to estimate pesticide loadings from nonagricultural sources to surface water and to conduct environmental risk assessments. A method was developed to estimate the amount of pesticide use on recreational turf grasses, specifically golf course turf grasses, for watersheds...
Improvements in the use of aquatic herbicides and establishment of future research directions
K.D. Getsinger, M.D. Netherland, C.E. Grue, T.J. Koschnick
2008, Conference Paper, Journal of Aquatic Plant Management
Peer-reviewed literature over the past 20 years identifies significant changes and improvements in chemical control strategies used to manage nuisance submersed vegetation. The invasive exotic plants hydrilla (Hydrilla verticillata L.f. Royle) and Eurasian watermilfoil (Myriophyllum spicatum L.) continue to spread and remain the plant species of greatest concern for aquatic...
Removal of phosphorus from wastewater using ferroxysorb sorption media produced from amd sludge
P.L. Sibrell, T.W. Tucker, T. Kehler, J.W. Fletcher
2008, Conference Paper, Hydrometallurgy 2008: Proceedings of the 6th International Symposium
Treatment of acid mine drainage (AMD), whether with lime, limestone, caustic or simple aeration, nearly always results in generation of a metal hydroxide sludge. Disposal of the sludge often constitutes a significant fraction of the operating cost for the AMD treatment plant. Research at the USGS - Leetown Science Center...
Northeast storms ranked by wind stress and wave-generated bottom stress observed in Massachusetts Bay, 1990-2006
B. Butman, C. R. Sherwood, P.S. Dalyander
2008, Continental Shelf Research (28) 1231-1245
Along the coast of the northeastern United States, strong winds blowing from the northeast are often associated with storms called northeasters, coastal storms that strongly influence weather. In addition to effects caused by wind stress, the sea floor is affected by bottom stress associated with these storms. Bottom stress caused...
Hydrodynamic implications of textural trends in sand deposits of the 2004 tsunami in Sri Lanka
R.A. Morton, J.R. Goff, S.L. Nichol
2008, Sedimentary Geology (207) 56-64
Field observations and sediment samples at a coastal-plain setting in southeastern Sri Lanka were used to document the erosional and depositional impacts of the 2004 Indian Ocean tsunami and to interpret the hydrodynamic processes that produced an extensive sand-sheet deposit. Tsunami deposit thicknesses ranged from 6 to 22??cm with thickness...
Western juniper and ponderosa pine ecotonal climate-growth relationships across landscape gradients in southern Oregon
K.C. Knutson, D.A. Pyke
2008, Canadian Journal of Forest Research (38) 3021-3032
Forecasts of climate change for the Pacific northwestern United States predict warmer temperatures, increased winter precipitation, and drier summers. Prediction of forest growth responses to these climate fluctuations requires identification of climatic variables limiting tree growth, particularly at limits of free species distributions. We addressed this problem at the pine-woodland...
Evidence for ponding and catastrophic floods in central Valles Marineris, Mars
K.P. Harrison, M. G. Chapman
2008, Icarus (198) 351-364
The Valles Marineris canyon system of Mars is closely related to large flood channels, some of which emerge full born from chaotic terrain in canyon floors. Coprates Chasma, one of the largest Valles Marineris canyons, is connected at its west end to Melas Chasma and on its east end to...
Aquatic macroinvertebrates associated with Schoenoplectus litter in a constructed wetland in California (USA)
S. M. Nelson, J.S. Thullen
2008, Ecological Engineering (33) 91-101
Culm processing characteristics were associated with differences in invertebrate density in a study of invertebrates and senesced culm packs in a constructed treatment wetland. Invertebrate abundance differed by location within the wetland and there were differences between the two study years that appeared to be related to water quality and...
Predators of Dusky Canada Goose goslings and the effect of transmitters on gosling survival
T.F. Fondell, J.B. Grand, David A. Miller, R. Michael Anthony
2008, Journal of Field Ornithology (79) 399-407
The population of Dusky Canada Geese (Branta canadensis occidentalis) has been in long-term decline, likely due to reduced breeding productivity. To identify causes of mortality, we monitored goslings marked with radio transmitters on the western Copper River Delta, Alaska, from 1997 to 1999. Almost all gosling mortality (96%; 81 of...
Trends and spatial distribution of annual and seasonal rainfall in Ethiopia
W.H. Cheung, G.B. Senay, A. Singh
2008, International Journal of Climatology (28) 1723-1734
As a country whose economy is heavily dependent on low-productivity rainfed agriculture, rainfall trends are often cited as one of the more important factors in explaining various socio-economic problems such as food insecurity. Therefore, in order to help policymakers and developers make more informed decisions, this study investigated the temporal...
A fully distributed implementation of mean annual streamflow regional regression equations
K.L. Verdin, B. Worstell
2008, Journal of the American Water Resources Association (44) 1537-1547
Estimates of mean annual streamflow are needed for a variety of hydrologic assessments. Away from gage locations, regional regression equations that are a function of upstream area, precipitation, and temperature are commonly used. Geographic information systems technology has facilitated their use for projects, but traditional approaches using the polygon overlay...
Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing
M. Kusakabe, T. Ohba, Issa, Y. Yoshida, H. Satake, T. Ohizumi, William C. Evans, G. Tanyileke, G.W. Kling
2008, Geochemical Journal (42) 93-118
Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986,...
Prevalence of Influenza A viruses in wild migratory birds in Alaska: Patterns of variation in detection at a crossroads of intercontinental flyways
S. Ip, Paul L. Flint, J. Christian Franson, Robert J. Dusek, Dirk V. Derksen, Robert E. Gill Jr., Craig R. Ely, John M. Pearce, Richard B. Lanctot, Steven M. Matsuoka, D.B. Irons, J.B. Fischer, R.M. Oates, Margaret R. Petersen, T.F. Fondell, D.A. Rocque, J.C. Pedersen, T.C. Rothe
2008, Virology Journal (5)
Background. The global spread of the highly pathogenic avian influenza H5N1 virus has stimulated interest in a better understanding of the mechanisms of H5N1 dispersal, including the potential role of migratory birds as carriers. Although wild birds have been found dead during H5N1 outbreaks, evidence suggests that others have survived...
Characteristics of mangrove swamps managed for mosquito control in eastern Florida, USA
B. Middleton, D. Devlin, E. Proffitt, Karen McKee, K.F. Cretini
2008, Marine Ecology Progress Series (371) 117-129
Manipulations of the vegetation and hydrology of wetlands for mosquito control are common worldwide, but these modifications may affect vital ecosystem processes. To control mosquitoes in mangrove swamps in eastern Florida, managers have used rotational impoundment management (RIM) as an alternative to the worldwide practice of mosquito ditching. Levees surround...
Orbital identification of carbonate-bearing rocks on Mars
B.L. Ehlmann, J.F. Mustard, S.L. Murchie, F. Poulet, J.L. Bishop, A.J. Brown, W. M. Calvin, R. N. Clark, D.J. Des Marais, R.E. Milliken, L.H. Roach, T. L. Roush, G.A. Swayze, J.J. Wray
2008, Science (322) 1828-1832
Geochemical models for Mars predict carbonate formation during aqueous alteration. Carbonate-bearing rocks had not previously been detected on Mars' surface, but Mars Reconnaissance Orbiter mapping reveals a regional rock layer with near-infrared spectral characteristics that are consistent with the presence of magnesium carbonate in the Nili Fossae region. The carbonate...
An hydrothermal experimental study of the cobalt-cobalt oxide redox buffer
K.H. Lemke, R.J. Rosenbauer, J. L. Bischoff, D.K. Bird
2008, Chemical Geology (252) 136-144
Equilibrium aqueous hydrogen concentration and corresponding energies of reaction, ??Grxno(T, P), for the reaction Co(s) + H2O(l) = CoO(s) + H2(aq) have been determined at temperatures between 256 and 355 ??C and at 400 bar. Steady-state concentrations of hydrogen were approached in experiments under conditions of both H2 excess and...
Influence of summer water-level variability on St. Lawrence River-wetland fish assemblages
J.E. McKenna Jr., J.L. Barkley, J. H. Johnson
2008, Journal of Freshwater Ecology (23) 513-517
Water-level and associated variability are substantial influences on wetland and shallow aquatic communities. The Akwesasne Wetland Complex is an extensive St. Lawrence River system affected by water regulation. The responses of fish assemblages to short-term summer water-level variation were examined throughout this section of the St. Lawrence River and its...
Field-based evaluations of horizontal flat-plate fish screens
B.P. Rose, M.G. Mesa, G. Barbin-Zydlewski
2008, North American Journal of Fisheries Management (28) 1702-1713
Diversions from streams are often screened to prevent the loss of or injury to fish. Hydraulic criteria meant to protect fish that encounter screens have been developed, but primarily for screens that are vertical to the water flow rather than horizontal. For this reason, we measured selected hydraulic variables and...
