Evasion of added isotopic mercury from a northern temperate lake
G. Southworth, S. Lindberg, H. Hintelmann, M. Amyot, A. Poulain, M. Bogle, M. Peterson, J. Rudd, R. Harris, K. Sandilands, David P. Krabbenhoft, Mark L. Olsen
2007, Environmental Toxicology and Chemistry (26) 53-60
Isotopically enriched Hg (90% 202Hg) was added to a small lake in Ontario, Canada, at a rate equivalent to approximately threefold the annual direct atmospheric deposition rate that is typical of the northeastern United States. The Hg spike was thoroughly mixed into the epilimnion in nine separate events at two-week...
Diel mercury-concentration variations in streams affected by mining and geothermal discharge
David A. Nimick, R. Blaine McCleskey, C.H. Gammons, Tom Cleasby, S.R. Parker
2007, Science of the Total Environment (373) 344-355
Diel variations of concentrations of unfiltered and filtered total Hg and filtered methyl Hg were documented during 24-h sampling episodes in water from Silver Creek, which drains a historical gold-mining district near Helena, Montana, and the Madison River, which drains the geothermal system of Yellowstone National Park. The concentrations of...
Prioritizing bottomland hardwood forest sites for protection and augmentation
J. Carter, J. Biagas
2007, Natural Areas Journal (27) 72-82
Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these...
Modelingevapotranspirationina sub-tropical climate
M.R. Savabi, T.A. Cochrane, E. German, C. Ikiz, N. Cockshutt
2007, Journal of Environmental Hydrology (15) 1-15
Evapotranspiration (ET) loss is estimated at about 80-85% of annual precipitation in South Florida. Accurate prediction of ET is important during and beyond the implementation of the Comprehensive Everglades Restoration Plan (CERP). In the USDA's Everglades Agro-Hydrology Model (EAHM) the soil water intake is linked with the soil water redistribution,...
Habitat connectivity and ecosystem productivity: implications from a simple model.
James E. Cloern
2007, American Naturalist (169) E22-E33
The import of resources (food, nutrients) sustains biological production and food webs in resource-limited habitats. Resource export from donor habitats subsidizes production in recipient habitats, but the ecosystem-scale consequences of resource translocation are generally unknown. Here, I use a nutrient-phytoplankton-zooplankton model to show how dispersive connectivity between a shallow autotrophic...
Alpine debris flows triggered by a 28 July 1999 thunderstorm in the central Front Range, Colorado
J. W. Godt, J. A. Coe
2007, Geomorphology (84) 80-97
On 28 July 1999, about 480 alpine debris flows were triggered by an afternoon thunderstorm along the Continental Divide in Clear Creek and Summit counties in the central Front Range of Colorado. The thunderstorm produced about 43??mm of rain in 4??h, 35??mm of which fell in the first 2??h. Several...
Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA
Stephen R. Hinkle, John Karl Bohlke, John H. Duff, David S. Morgan, Rodney J. Weick
2007, Journal of Hydrology (333) 486-503
Geochemical and isotopic tools were applied at aquifer, transect, and subtransect scales to provide a framework for understanding sources, transport, and fate of dissolved inorganic N in a sandy aquifer near La Pine, Oregon. NO3 is a common contaminant in shallow ground water in this area, whereas high concentrations of...
Profiling refined hydrocarbon fuels using polar components
Colleen E. Rostad, Frances D. Hostettler
2007, Environmental Forensics (8) 129-137
Identification of a fuel released into the environment can be difficult due to biodegradation or weathering. Negative electrospray ionization/mass spectrometry was used to screen for unique polar components in a wide variety of commercial hydrocarbon products and mixtures. These fuels produced unique and relatively simple spectra. When applied to hydrocarbon...
Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change
M. Person, P. Roy, H. Wright, W. Gutowski Jr., E. Ito, T. Winter, D. Rosenberry, D. Cohen
2007, Geological Society of America Bulletin (119) 363-376
In this study, we have integrated a suite of Holocene paleoclimatic proxies with mathematical modeling in an attempt to obtain a comprehensive picture of how watersheds respond to past climate change. A three-dimensional surface-water-groundwater model was developed to assess the effects of mid-Holocene climate change on water resources within the...
Heat transport in the Red Lake Bog, Glacial Lake Agassiz Peatlands
J.M. McKenzie, D. I. Siegel, Donald O. Rosenberry, P.H. Glaser, Clifford I. Voss
2007, Hydrological Processes (21) 369-378
We report the results of an investigation on the processes controlling heat transport in peat under a large bog in the Glacial Lake Agassiz Peatlands. For 2 years, starting in July 1998, we recorded temperature at 12 depth intervals from 0 to 400 cm within a vertical peat profile at...
Space geodetic observation of expansion of the San Gabriel Valley, California, aquifer system, during heavy rainfall in winter 2004-2005
N.E. King, D. Argus, J. Langbein, D.C. Agnew, G. Bawden, R.S. Dollar, Z. Liu, D. Galloway, E. Reichard, A. Yong, F.H. Webb, Y. Bock, K. Stark, D. Barseghian
2007, Journal of Geophysical Research B: Solid Earth (112)
[1] Starting early in 2005, the positions of GPS stations in the San Gabriel valley region of southern California showed statistically significant departures from their previous behavior. Station LONG moved up by about 47 mm, and nearby stations moved away from LONG by about 10 mm....
Factors influencing ground-water recharge in the eastern United States
B. T. Nolan, R. W. Healy, P.E. Taber, K. Perkins, K.J. Hitt, D.M. Wolock
2007, Journal of Hydrology (332) 187-205
Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1...
Cytherellid species (Ostracoda) and their significance to the Late Quaternary events in the Santos Basin, Brazil
C.T. Bergue, J.C. Coimbra, T. M. Cronin
2007, Senckenbergiana Maritima (37) 5-12
Four autochthonous cytherellid species (Cytherella serratula (BRADY, 1880), C. hermargentina WHATLEY et al. 1998, C. pleistocenica sp. nov. and C. santosensis sp. nov.) have been identified from two offshore cores (44 samples) within the Santos Basin. The distribution of these ostracodes is controlled by local hydrological conditions such as the...
The role of headwater streams in downstream water quality
R. B. Alexander, E.W. Boyer, R. A. Smith, G. E. Schwarz, R. B. Moore
2007, Journal of the American Water Resources Association (43) 41-59
Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current...
Effects of surface-water irrigation on sources, fluxes, and residence times of water, nitrate, and uranium in an alluvial aquifer
John Karl Bohlke, Ingrid M. Verstraeten, Thomas F. Kraemer
2007, Applied Geochemistry (22) 152-174
Effects of surface-water irrigation on an alluvial aquifer were evaluated using chemical and isotopic data including δ2H, δ18O, 3H, δ3He, Ar, Ne, N2, δ15N, and 234U/238U activity ratios in a transect of nested wells in the North Platte River valley in western Nebraska, USA. The data were used to evaluate sources and fluxes of H2O, <span...
Past and future changes in climate and hydrological indicators in the US Northeast
K. Hayhoe, C.P. Wake, T.G. Huntington, L. Luo, M.D. Schwartz, J. Sheffield, E. Wood, B. Anderson, J. Bradbury, A. DeGaetano, T.J. Troy, D. Wolfe
2007, Climate Dynamics (28) 381-407
To assess the influence of global climate change at the regional scale, we examine past and future changes in key climate, hydrological, and biophysical indicators across the US Northeast (NE). We first consider the extent to which simulations of twentieth century climate from nine atmosphere-ocean general circulation models (AOGCMs) are...
Ecological linkages between headwaters and downstream ecosystems: Transport of organic matter, invertebrates, and wood down headwater channels
M.S. Wipfli, J.S. Richardson, R.J. Naiman
2007, Journal of the American Water Resources Association (43) 72-85
Headwater streams make up a large proportion of the total length and watershed area of fluvial networks, and are partially characterized by the large volume of organic matter (large wood, detritus, and dissolved organic matter) and invertebrate inputs from the riparian forest, relative to stream size. Much of those inputs...
Annual modulation of seismicity along the San Andreas Fault near Parkfield, CA
L.B. Christiansen, Shaul Hurwitz, Steven E. Ingebritsen
2007, Geophysical Research Letters (34)
We analyze seismic data from the San Andreas Fault (SAF) near Parkfield, California, to test for annual modulation in seismicity rates. We use statistical analyses to show that seismicity is modulated with an annual period in the creeping section of the fault and a semiannual period in the locked section...
Paleoecology of the Late Pennsylvanian-age Calhoun coal bed and implications for long-term dynamics of wetland ecosystems
Debra A. Willard, T.L. Phillips, Alicia D. Lesnikowska, William A. DiMichele
2007, International Journal of Coal Geology (69) 21-54
Quantitative plant assemblage data from coal balls, miospores, megaspores, and compression floras from the Calhoun coal bed (Missourian) of the Illinois Basin (USA) are used to interpret spatial and temporal changes in plant communities in the paleo-peat swamp. Coal-ball and miospore floras from the Calhoun coal bed are dominated strongly...
DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River
F.J. Triska, J.H. Duff, R.W. Sheibley, A. P. Jackman, R.J. Avanzino
2007, Journal of the American Water Resources Association (43) 60-71
Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial...
Forensic fingerprinting of oil-spill hydrocarbons in a methanogenic environment-Mandan, ND and Bemidji, MN
Frances D. Hostettler, Y. Wang, Y. Huang, W. Cao, Barbara A. Bekins, Colleen E. Rostad, C. F. Kulpa, Andrew E. Laursen
2007, Environmental Forensics (8) 139-153
In recent decades forensic fingerprinting of oil-spill hydrocarbons has emerged as an important tool for correlating oils and for evaluating their source and character. Two long-term hydrocarbon spills, an off-road diesel spill (Mandan, ND) and a crude oil spill (Bemidji, MN) experiencing methanogenic biodegradation were previously shown to be undergoing...
Persistence of pharmaceuticals and other organic compounds in chlorinated drinking water as a function of time
Jacob Gibs, Paul E. Stackelberg, Edward T. Furlong, Michael T. Meyer, Steven D. Zaugg, R.L. Lippincott
2007, Science of the Total Environment (373) 240-249
Ninety eight pharmaceuticals and other organic compounds (POOCs) that were amended to samples of chlorinated drinking-water were extracted and analyzed 1, 3, 6, 8, and 10 days after amendment to determine whether the total chlorine residual reacted with the amended POOCs in drinking water in a time frame similar to...
Responses of hydrochemical inorganic ions in the rainfall-runoff processes of the experimental catchments and its significance for tracing
W.-Z. Gu, J.-J. Lu, X. Zhao, N.E. Peters
2007, Shuikexue Jinzhan/Advances in Water Science (18) 1-7
Aimed at the rainfall-runoff tracing using inorganic ions, the experimental study is conducted in the Chuzhou Hydrology Laboratory with special designed experimental catchments, lysimeters, etc. The various runoff components including the surface runoff, interflow from the unsaturated zone and the groundwater flow from saturated zone were monitored hydrometrically. Hydrochemical inorganic...
A field investigation of phreatophyte‐induced fluctuations in the water table
James J. Butler Jr., Gerard J. Kluitenberg, Donald O. Whittemore, Steven P. Loheide II, Wei Jin, Mark A. Billinger, Xiaoyong Zhan
2007, Water Resources Research (43)
Hydrographs from shallow wells in vegetated riparian zones frequently display a distinctive pattern of diurnal water table fluctuations produced by variations in plant water use. A multisite investigation assessed the major controls on these fluctuations and the ecohydrologic insights that can be gleaned from them. Spatial and temporal variations in...
The lakes of Titan
Ellen R. Stofan, Charles Elachi, Jonathan I. Lunine, Ralf D. Lorenz, B. Stiles, K. L. Mitchell, S. Ostro, Laurence A. Soderblom, C. Wood, H. Zebker, S. Wall, Michael A. Janssen, Randolph L. Kirk, Rosaly Lopes, F. Paganelli, Jani Radebaugh, L. Wye, Y. Anderson, M. Allison, R. Boehmer, P. Callahan, P. Encrenaz, E. Flamini, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, W.T.K. Johnson, K. Kelleher, D. Muhleman, Philipe Paillou, G. Picardi, F. Posa, L. Roth, R. Seu, S. Shaffer, S. Vetrella, R. West
2007, Nature (445) 61-64
The surface of Saturn’s haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface1,2. Initial visible3 and radar4,5 imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on...
