Complex response of a midcontinent north America drainage system to late Wisconsinan sedimentation
E. Arthur Bettis III, W.J. Autin
1997, Journal of Sedimentary Research (67) 740-748
The geomorphic evolution of Mud Creek basin in eastern Iowa, U.S.A. serves to illustrate how geomorphic influences such as sediment supply, valley gradient, climate, and vegetation are recorded in the alluvial stratigraphic record. Sediment supply to the fluvial system increased significantly during the...
Aquatic invertebrate ecology during a simulated botulism epizootic in a Sacramento Valley wetland
Jane M. Hicks, Ned H. Euliss Jr., Stanley W. Harris
1997, Wetlands (17) 157-162
We investigated the effect of decomposing duck carcasses on aquatic invertebrate numbers, biomass, and taxonomic composition in a seasonally flooded, impounded wetland in the Sacramento Valley, California during August–November 1988 and 1989. Major invertebrate taxa were copepods (Cyclopoida, occurred in 8.3% of samples), water fleas (Daphnidae, 8.9%), water boatmen (<i...
Herbicides and their metabolites in rainfall: Origin, transport, and deposition patterns across the midwestern and northeastern United States, 1990-1991
D. A. Goolsby, E.M. Thurman, M.L. Pomes, M. T. Meyer, W.A. Battaglin
1997, Environmental Science & Technology (31) 1325-1333
Herbicides were detected in rainfall throughout the midwestern and northeastern United States during late spring and summer of 1990 and 1991. Herbicide concentrations exhibited distinct geographic and seasonal patterns. The highest concentrations occurred in midwestern cornbelt states following herbicide application to cropland. Volume-weighted concentrations of 0.2−0.4 μg/L...
Moss and soil contributions to the annual net carbon flux of a maturing boreal forest
J.W. Harden, K. P. O’Neill, S.E. Trumbore, H. Veldhuis, B.J. Stocks
1997, Journal of Geophysical Research D: Atmospheres (102) 28805-28816
We used input and decomposition data from 14C studies of soils to determine rates of vertical accumulation of moss combined with carbon storage inventories on a sequence of burns to model how carbon accumulates in soils and moss after a stand-killing fire. We used soil drainage—moss associations and soil drainage maps...
Bimodal basalt-rhyolite magmatism in the central and western Snake River Plain, Idaho and Oregon
M. McCurry, B. Bonnichsen, C. White, M.M. Godchaux, S.S. Hughes
1997, Brigham Young University Geology Studies (42) 381-422
The purpose of this trip is to examine Miocene to Pleistocene basalt and rhyolite flows, ignimbrites and hypabyssal intrusions in a transect from the western Snake River Plain graben across the older part of the Snake River Plain "hot-spot-track." The earlier, dominantly explosive rhyolitic phase of volcanism will be examined...
Does vegetation structure limit the distribution of Northern Goshawks in the Oregon Coast ranges?
S. DeStefano, J. Mccloskey
1997, Journal of Raptor Research (31) 34-39
Northern Goshawks (Accipiter gentilis) breed in a variety of forested areas throughout the Pacific Northwest. Nevertheless, they were only first found breeding in the Coast Ranges of Oregon in 1995, despite apparently suitable habitat and abundant prey. We document the rarity of goshawks in the Coast Ranges by reviewing previous...
Experimental manipulations of snow-depth: Effects on nutrient content of caribou forage
Noreen E. Walsh, Thomas R. McCabe, J.M. Welker, A.N. Parsons
1997, Global Change Biology (3) 158-164
We investigated the potential effects of global climate change on arctic tundra vegetation used as caribou forage. A total of 96 experimental plots was established at six sites on the coastal plain of the Arctic National Wildlife Refuge, Alaska, in 1993 and 1994. We erected snow-fences to increase the amount...
Climatic controls of western U.S. glaciers at the last glacial maximum
S. W. Hostetler, P.U. Clark
1997, Quaternary Science Reviews (16) 505-511
We use a nested atmospheric modeling strategy to simulate precipitation and temperature of the western United States 18,000 years ago (18 ka). The high resolution of the nested model allows us to isolate the regional structure of summer temperature and winter precipitation that is crucial to determination of the net...
Onset of thermally induced gas convection in mine wastes
N. Lu, Y. Zhang
1997, International Journal of Heat and Mass Transfer (40) 2621-2636
A mine waste dump in which active oxidation of pyritic materials occurs can generate a large amount of heat to form convection cells. We analyze the onset of thermal convection in a two-dimensional, infinite horizontal layer of waste rock filled with moist gas, with the top surface of the waste...
Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994
P.T. Squillace, J.S. Zogorski, W. G. Wilber, C. V. Price
1997, ACS Division of Environmental Chemistry, Preprints (37) 372-374
The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE), is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60...
Comparison of three qualitative habitat indices and their applicability to prairie streams
J. C. Stauffer, R. M. Goldstein
1997, North American Journal of Fisheries Management (17) 348-361
Qualitative stream habitat indices are important tools in classifying, interpreting, and assessing the conditions of stream ecosystems. Habitat indices are numerical values produced from scoring various features of a stream. Three commonly used habitat indices are the qualitative habitat evaluation index (QHEI), the rapid bioassessment protocols (RBP), and the riparian,...
Risk of nitrate in groundwaters of the United States - A national perspective
B. T. Nolan, B. C. Ruddy, K.J. Hitt, D.R. Helsel
1997, Environmental Science & Technology (31) 2229-2236
Nitrate contamination of groundwater occurs in predictable patterns, based on findings of the U.S. Geological Survey's (USGS) National Water Quality Assessment (NAWQA) Program. The NAWQA Program was begun in 1991 to describe the quality of the Nation's water resources, using nationally consistent methods. Variables affecting nitrate concentration in groundwater were...
Geologic hazards in the region of the Hurricane fault
W.R. Lund
1997, Brigham Young University Geology Studies (42) 235-277
Complex geology and variable topography along the 250-kilometer-long Hurricane fault in northwestern Arizona and southwestern Utah combine to create natural conditions that can present a potential danger to life and property. Geologic hazards are of particular concern in southwestern Utah, where the St. George Basin and Interstate-15 corridor north to...
Changes in breeding bird populations in North Dakota: 1967 to 1992-93
L.D. Igl, Douglas H. Johnson
1997, The Auk (114) 74-92
We compared breeding bird populations in North Dakota using surveys conducted in 1967 and 1992-93. In decreasing order, the five most frequently occurring species were Horned Lark (Eremophila alpestris), Brown-headed Cowbird (Molothrus ater), Western Meadowlark (Sturnella neglecta), Red-winged Blackbird (Agelaius phoeniceus), and Eastern Kingbird (Tyrannus tyrannus). The five most abundant...
A numerical model of sediment transport applied to San Francisco Bay, California
E.T. Mcdonald, R. T. Cheng
1997, Journal of Marine Environmental Engineering (4) 1-41
A two dimensional depth-averaged sediment transport model is used to simulate field measurements of suspended sediment concentrations in northern San Francisco Bay. The model uses a semi-implicit finite difference method to solve the shallow water equations and incorporates standard empirical expressions for erosion and deposition of sediments into the transport...
Strengths of serpentinite gouges at elevated temperatures
Diane E. Moore, D.A. Lockner, S. Ma, R. Summers, J.D. Byerlee
1997, Journal of Geophysical Research B: Solid Earth (102) 14787-14801
Serpentinite has been proposed as a cause of both low strength and aseismic creep of fault zones. To test these hypotheses, we have measured the strength of chrysotile-, lizardite-, and antigorite-rich serpentinite gouges under hydrothermal conditions, with emphasis on chrysotile, which has thus far received little attention. At 25°C, the...
Importance of analytically verifying chemical treatments
J.J. Rach, M.P. Gaikowski, J.J. Olson
1997, Progressive Fish-Culturist (59) 222-228
Hydrogen peroxide is considered a low regμLatory priority compound by the U.S. Food and Drug Administration. It is used to control fungal infections on fish eggs. We studied the treatment profiles of hydrogen peroxide in Heath, McDonald egg jar, and Clark–Williamson incubators during treatments intended to deliver an effective regimen...
A dynamic balance between magma supply and eruption rate at Kilauea volcano, Hawaii
R.P. Denlinger
1997, Journal of Geophysical Research B: Solid Earth (102) 18091-18100
The dynamic balance between magma supply and vent output at Kilauea volcano is used to estimate both the volume of magma stored within Kilauea volcano and its magma supply rate. Throughout most of 1991 a linear decline in volume flux from the Kupaianaha vent on Kilauea's east rift zone was...
Late Holocene eolian activity in the mineralogically mature Nebraska Sand Hills
D.R. Muhs, Thomas W. Stafford Jr., J. B. Swinehart, S.D. Cowherd, S. A. Mahan, C. A. Bush, R.F. Madole, P.B. Maat
1997, Quaternary Research (48) 162-176
The age of sand dunes in the Nebraska Sand Hills has been controversial, with some investigators suggesting a full-glacial age and others suggesting that they were last active in the late Holocene. New accelerator mass spectrometry radiocarbon ages of unaltered bison bones and organic-rich sediments suggest that eolian sand deposition...
Molecular markers and environmental organic geochemistry: An overview
Robert P. Eganhouse
1997, ACS Symposium Series (671) 1-20
No abstract available....
Unnatural isotopic composition of lithium reagents
H. P. Qi, Tyler B. Coplen, Q. Zh Wang, Y. #NAME? Wang
1997, Analytical Chemistry (69) 4076-4078
Isotopic analysis of 39 lithium reagents from several manufacturers indicates that seven were artificially depleted in 6Li significantly in excess of the variation found in terrestrial materials. The atomic weight of lithium in analyzed reagents ranged from 6.939 to 6.996, and δ7Li, reported relative to L-SVEC lithium carbonate, ranged from −11...
Practical considerations for measuring hydrogen concentrations in groundwater
F. H. Chapelle, D.A. Vroblesky, J.C. Woodward, Derek R. Lovley
1997, Environmental Science & Technology (31) 2873-2877
Several practical considerations for measuring concentrations of dissolved molecular hydrogen (H2) in groundwater including 1 sampling methods 2 pumping methods and (3) effects of well casing materials were evaluated. Three different sampling methodologies (a downhole sampler, a gas- stripping method, and a diffusion sampler) were compared. The downhole sampler and...
Watershed responses to climate change at Glacier National Park
D.B. Fagre, P.L. Comanor, J.D. White, F. Richard Hauer, S. W. Running
1997, Journal of the American Water Resources Association (33) 755-765
We have developed an approach which examines ecosystem function and the potential effects of climatic shifts. The Lake McDonald watershed of Glacier National Park was the focus for two linked research activities: acquisition of baseline data on hydrologic, chemical and aquatic organism attributes that characterize this pristine northern rocky mountain...
Hydraulic modeling for lahar hazards at cascades volcanoes
J. E. Costa
1997, Environmental & Engineering Geoscience (3) 21-30
The National Weather Service flood routing model DAMBRK is able to closely replicate field-documented stages of historic and prehistoric lahars from Mt. Rainier, Washington, and Mt. Hood, Oregon. Modeled time-of-travel of flow waves are generally consistent with documented lahar travel-times from other volcanoes around the world. The model adequately replicates...
GSLIB-style programs for discriminant analysis and regionalized classification
Geoffrey C. Bohling
1997, Computers & Geosciences (23) 739-761
Discriminant analysis is a statistical technique used to predict the group membership of a set of multivariate observations, each of which is assumed to arise from one of a set of distinct classes or groups. Each group is characterized by a certain distribution in multivariate space, and group allocations are...
