Methyl t-Butyl Ether Mineralization in Surface-Water Sediment Microcosms under Denitrifying Conditions
P. M. Bradley, F. H. Chapelle, J. E. Landmeyer
2001, Applied and Environmental Microbiology (67) 1975-1978
Mineralization of [U-14C] methyl t-butyl ether (MTBE) to 14CO2 without accumulation of t-butyl alcohol (TBA) was observed in surface-water sediment microcosms under denitrifying conditions. Methanogenic activity and limited transformation of MTBE to TBA were observed in the absence of denitrification. Results indicate that bed sediment microorganisms can effectively degrade MTBE...
Contribution of base flow to nonpoint source pollution loads in an agricultural watershed
K. E. Schilling, C.F. Wolter
2001, Ground Water (39) 49-58
Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source pollution from base flow ground water was estimated in the Walnut Creek watershed by measuring chemical loads of atrazine, nitrate, chloride, and sulfate...
Trends in evaporation and surface cooling in the Mississippi River basin
P. C. D. Milly, K.A. Dunne
2001, Geophysical Research Letters (28) 1219-1222
A synthesis of available data for the Mississippi River basin (area 3 ?? 106 km2) reveals an upward trend in evaporation during recent decades, driven primarily by increases in precipitation and secondarily by human water use. A cloud-related decrease in surface net radiation appears to have accompanied the precipitation trend....
Anomalous preservation of pure methane hydrate at 1 atm
L.A. Stern, S. Circone, S. H. Kirby, W.B. Durham
2001, Journal of Physical Chemistry B (105) 1756-1762
Direct measurement of decomposition rates of pure, polycrystalline methane hydrate reveals a thermal regime where methane hydrate metastably `preserves' in bulk by as much as 75 K above its nominal equilibrium temperature (193 K at 1 atm). Rapid release of the sample pore pressure at isothermal conditions between 242 and...
InSAR analysis of natural recharge to define structure of a ground-water basin, San Bernardino, California
Z. Lu, W.R. Danskin
2001, Geophysical Research Letters (28) 2661-2664
Using interferometric synthetic aperture radar (InSAR) analysis of ERS-1 and ERS-2 images, we detect several centimeters of uplift during the first half of 1993 in two areas of the San Bernardino ground-water basin of southern California. This uplift correlates with unusually high runoff from the surrounding mountains and increased ground-water...
No enhancement in bioconcentration of organic contaminants by low levels of DOM
M. Haitzer, J. Akkanen, C. Steinberg, J.V.K. Kukkonen
2001, Chemosphere (44) 165-171
The aim of the present work was to systematically study the effect of low concentrations of dissolved organic matter (DOM) on the bioconcentration of organic contaminants, in order to show whether the phenomenon of enhanced bioconcentration factors (BCFs), that has been reported in the literature, is generally found at low...
Ruffed grouse (Bonasa umbellus) drumming log and habitat use in Grand Teton National Park, Wyoming
M.L. Buhler, S.H. Anderson
2001, Western North American Naturalist (61) 236-240
We described 15 Ruffed Grouse (Bonasa umbellus) drumming logs and adjacent habitat within Grand Teton National Park, Wyoming. Drumming logs and adjacent habitat differed from 30 random non-drumming sites. Drumming logs had fewer limbs (8; P = 0.003) and a smaller percentage of bark remaining (12%; P = 0.0001). These...
Long-term changes in consentrations and flux fo nitrogen in the Mississippi River Basin, USA
D. A. Goolsby, W.A. Battaglin
2001, Hydrological Processes (15) 1209-1226
Current and historical data show that nitrogen concentrations and flux in the Mississippi River Basin have increased significantly during the past 100 years. Most of the increase observed in the lower Mississippi River has occurred since the early 1970s and is due almost entirely to an increase in nitrate. The...
Water Resources Data, Alaska, Water Year 2000
D. F. Meyer, D.L. Hess, M.F. Schellekens, C. W. Smith, E.F. Snyder, G. L. Solin
2001, Water Data Report AK-00-1
Water-resources data for the 2000 water year for Alaska consists of records of stage, discharge, and water quality of streams; stages of lakes; and water levels and water quality of ground-water wells. This volume contains records for water discharge at 106 gaging stations; stage or contents only at 4 gaging...
Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 1. Biochemical oxygen demand and dissolved oxygen in receiving streams
S.R. Corsi, N.L. Booth, D. W. Hall
2001, Environmental Toxicology and Chemistry (20) 1474-1482
Aircraft and runway deicers are used during cold weather at many of the world's airports to facilitate safe air travel. Propylene glycol-, ethylene glycol-, and urea-based deicers are known to have very high biochemical oxygen demand. At General Mitchell International Airport (GMIA) in Milwaukee, Wisconsin, USA, deicer application, water chemistry,...
Wisconsin Glaciation of the Sierra Nevada (79,000-15,000 yr B.P.) as recorded by rock flour in sediments of Owens Lake, California
J. L. Bischoff, K. Cummins
2001, Quaternary Research (55) 14-24
Chemical analyses of the clay-sized fractions of 564 continuous sediment samples (200-yr resolution) from composite core OL90/92 allow quantification of an abundance of glacial rock flour. Rock flour produced during glacier advances is represented by clay-sized plagioclase, K-feldspar, and biotite in homogeneous internal composition. The abundance of rock flour is...
Regional variations in provenance and abundance of ice-rafted clasts in Arctic Ocean sediments: Implications for the configuration of late Quaternary oceanic and atmospheric circulation in the Arctic
R. L. Phillips, A. Grantz
2001, Marine Geology (172) 91-115
The composition and distribution of ice-rafted glacial erratics in late Quaternary sediments define the major current systems of the Arctic Ocean and identify two distinct continental sources for the erratics. In the southern Amerasia basin up to 70% of the erratics are dolostones and limestones (the Amerasia suite) that originated...
Elastic properties of gas hydrate-bearing sediments
Myung W. Lee, T. S. Collett
2001, Geophysics (66) 763-771
Downhole-measured compressional- and shear-wave velocities acquired in the Mallik 2L-38 gas hydrate research well, northwestern Canada, reveal that the dominant effect of gas hydrate on the elastic properties of gas hydrate-bearing sediments is as a pore-filling constituent. As opposed to high elastic velocities predicted from a cementation theory, whereby a...
Stepped-combustion 14C dating of sediment: A comparison with established techniques
J. McGeehin, G. S. Burr, A.J.T. Juli, D. Reines, J. Gosse, P.T. Davis, D. Muhs, J. R. Southon
2001, Radiocarbon (43) 255-261
Radiocarbon dating of bulk sediment has long been used as a method of last resort when reliable wood, charcoal, or plant macrofossils are not available for analysis. Accurate dating of sediment is complicated by the presence of multiple organic carbon fractions, each with a potentially different 14C activity. Additionally, the...
Pyrite discs in coal: evidence for fossilized bacterial colonies
G. Southam, R. Donald, A. Rostad, C. Brock
2001, Geology (29) 47-50
Discs of pyrite from 1 to 3 mm in diameter and ∼100 μm thick were observed within fracture planes in coal from the Black Mesa coal deposit in northeastern Arizona. The pyrite discs were composed of aggregates of crystals, which suggested that sulfide mineral diagenesis had initiated at multiple nucleation...
Sperm-cell ultrastructure of North American sturgeons. IV. The pallid sturgeon (Scaphirhynchus albus Forbes and Richardson, 1905)
M. N. DiLauro, R.A. Walsh, M. Peiffer, R. M. Bennett
2001, Canadian Journal of Zoology (79) 802-808
Sperm-cell morphology and ultrastructure in the pallid sturgeon (Scaphirhynchus albus) were examined using transmission and scanning electron microscopy. Metrics and structure were compared with similar metrics obtained from other published descriptions of sturgeon sperm cells. General morphology was found to be similar to that of sperm cells of the white...
Global occurrences of gas hydrate
K.A. Kvenvolden, T.D. Lorenson
2001, Conference Paper, Proceedings of the International Offshore and Polar Engineering Conference
Natural gas hydrate is found worldwide in sediments of outer continental margins of all oceans and in polar areas with continuous permafrost. There are currently 77 localities identified globally where geophysical, geochemical and/or geological evidence indicates the presence of gas hydrate. Details concerning individual gas-hydrate occurrences are compiled at a...
Characterization of dispersion, attenuation, and anisotropy at the Buena Vista Hills field, California
C.L. Hackert, J.O. Parra, R.L. Brown, H.A. Collier
2001, Geophysics (66) 90-96
We create a log of intrinsic dispersion and attenuation for the Antelope Shale formation of the Buena Vista Hills field, San Joaquin Valley, California. High dispersion (or low Q) values correlate with thin sand and carbonate beds within the Antelope Shale. These beds are at least ten times as permeable as...
Cytochrome P450 1A expression in midwater fishes: Potential effects of chemical contaminants in remote oceanic zones
John J. Stegeman, Jennifer J. Schlezinger, James E. Craddock, Donald E. Tillitt
2001, Environmental Science & Technology (35) 54-62
Cytochrome P450 1A (CYP1A) induction is a robust marker for exposure to polynuclear aromatic hydrocarbons and planar halogenated aromatic hydrocarbons that are aryl hydrocarbon receptor agonists. We examined CYP1A expression in mesopelagic fishes from the western North Atlantic. Individuals in 22 species were obtained from slope water and the Sargasso...
Performance of a proposed determinative method for p-TSA in rainbow trout fillet tissue and bridging the proposed method with a method for total chloramine-T residues in rainbow trout fillet tissue
J.R. Meinertz, G. R. Stehly, W.H. Gingerich, Shari L. Greseth
2001, Journal of AOAC International (84) 1332-1336
Chloramine-T is an effective drug for controlling fish mortality caused by bacterial gill disease. As part of the data required for approval of chloramine-T use in aquaculture, depletion of the chloramine-T marker residue (para-toluenesulfonamide; p-TSA) from edible fillet tissue of fish must be characterized. Declaration of p-TSA as the marker...
International collaboration: The cornerstone of satellite land remote sensing in the 21st century
G. Bryan Bailey, Donald T. Lauer, David M. Carneggie
2001, Space Policy (17) 161-169
Satellite land remotely sensed data are used by scientists and resource managers world-wide to study similar multidisciplinary earth science problems. Most of their information requirements can be met by a small number of satellite sensor types. Moderate-resolution resource satellites and low-resolution environmental satellites are the most prominent of these, and...
Demonstration of significant abiotic iron isotope fractionation in nature
T.D. Bullen, A. F. White, C.W. Childs, D.V. Vivit, M.S. Schultz
2001, Geology (29) 699-702
Field and laboratory studies reveal that the mineral ferrihydrite, formed as a result of abiotic oxidation of aqueous ferrous to ferric Fe, contains Fe that is isotopically heavy relative to coexisting aqueous Fe. Because the electron transfer step of the oxidation process at pH >5 is essentially irreversible and should...
Dynamics of individual growth in a recovering population of lake trout (Salvelinus namaycush)
Mary C. Fabrizio, Robert M. Dorazio, Stephen T. Schram
2001, Canadian Journal of Fisheries and Aquatic Sciences (58) 262-272
In 1976, the Wisconsin Department of Natural Resources established a refuge for a nearly depleted population of lake trout (Salvelinus namaycush) at Gull Island Shoal, Lake Superior. The refuge was intended to reduce fishing mortality by protecting adult lake trout. We examined the growth dynamics of these lake...
Chemical anesthesia of Northern sea otters (Enhydra lutris): Results of past field studies
Daniel H. Monson, C. McCormick, Brenda E. Ballachey
2001, Journal of Zoo and Wildlife Medicine (32) 181-189
Between 1987 and 1997, we chemically immobilized 597 wild sea otters (Enhydra lutris) in Alaska for the collection of biological samples or for surgical instrumentation. One drug-related sea otter fatality occurred during this time. Fentanyl in combination with diazepam produced consistent, smooth inductions with minimal need for supplemental anesthetics during...
Choosing the "correct" bat detector - A reply
Chris Corben, Gary M. Fellers
2001, Acta Chiropterologica (3) 253-256
No abstract available at this time...
