Sieve efficiency in benthic sampling as related to chironomid head capsule width
Patrick L. Hudson, Jean V. Adams
1998, Journal of the Kansas Entomological Society (71) 456-468
The width of the head capsule in chironomid larvae is the most important morphometric character controlling retention of specimens in sieving devices. Knowledge of the range in size of these widths within any chironomid community is fundamental to sampling and interpreting the resulting data. We present the head capsule widths...
Aquatic ecosystems
Jill Baron, J.T. Turk
1998, General Technical Report RMRS-GTR-4
No abstract available....
Estimation of the depth to the fresh-water/salt-water interface from vertical head gradients in wells in coastal and island aquifers
S. K. Izuka, S. B. Gingerich
1998, Hydrogeology Journal (6) 365-373
An accurate estimate of the depth to the theoretical interface between fresh, water and salt water is critical to estimates of well yields in coastal and island aquifers. The Ghyben–Herzberg relation, which is commonly used to estimate interface depth, can greatly underestimate or overestimate the fresh-water...
Winter and early spring CO2 efflux from tundra communities of northern Alaska
J. T. Fahnestock, M.H. Jones, P. D. Brooks, D.A. Walker, J.M. Welker
1998, Journal of Geophysical Research D: Atmospheres (103) 29023-29027
Carbon dioxide concentrations through snow were measured in different arctic tundra communities on the North Slope of Alaska during winter and early spring of 1996. Subnivean CO2 concentrations were always higher than atmospheric CO2. A steady state diffusion model was used to generate conservative estimates of CO2 flux to the atmosphere. The...
Soft shell clams Mya arenaria with disseminated neoplasia demonstrate reverse transcriptase activity
M.L. House, C.H. Kim, P.W. Reno
1998, Diseases of Aquatic Organisms (34) 187-192
Disseminated neoplasia (DN), a proliferative cell disorder of the circulatory system of bivalves, was first reported in oysters in 1969. Since that time, the disease has been determined to be transmissible through water-borne exposure, but the etiological agent has not been unequivocally identified. In order to determine if a viral...
Sources of crustal deformation associated with the Krafla, Iceland, eruption of September 1984
T. Arnadottir, F. Sigmundsson, P.T. Delaney
1998, Geophysical Research Letters (25) 1043-1046
A decade-long plate-boundary rifting episode in northern Iceland ended with the September 1984 fissure eruption of Krafla volcano. We apply a nonlinear inversion method to geodetic data collected before and after the eruption to infer the location, geometry, and strengths of deformation sources associated with the...
Thunder on the Yellowstone revisited: An assessment of management of native ungulates by natural regulation, 1968-1993
F. J. Singer, D.M. Swift, M.B. Coughenour, J.D. Varley
1998, Wildlife Society Bulletin (26) 375-390
Natural regulation of native ungulates was initiated in 1968 in Yellowstone National Park (YNP) based on the premise that ungulates would reach an equilibrium with their plant resources. The natural-regulation management model stated: density dependence will regulate ungulates (i.e., a dynamic equilibrium will result between ungulates and their food supply,...
Isotopic composition of ice cores and meltwater from upper fremont glacier and Galena Creek rock glacier, Wyoming
L. DeWayne Cecil, J.R. Green, S. Vogt, R. Michel, G. Cottrell
1998, Geografiska Annaler, Series A: Physical Geography (80) 287-292
Meltwater runoff from glaciers can result from various sources, including recent precipitation and melted glacial ice. Determining the origin of the meltwater from glaciers through isotopic analysis can provide information about such things as the character and distribution of ablation on glaciers.A 9.4 m ice core and meltwater were collected...
Three-dimensional P-wave velocity structure of Mt. Etna, Italy
A. Villasenor, H.M. Benz, L. Filippi, G. De Luca, R. Scarpa, G. Patane, S. Vinciguerra
1998, Geophysical Research Letters (25) 1975-1978
The three-dimensional P-wave velocity structure of Mt. Etna is determined to depths of 15 km by tomographic inversion of first arrival times from local earthquakes recorded by a network of 29 permanent and temporary seismographs. Results show a near-vertical low-velocity zone that extends from beneath the central...
Comparison of two stable hydrogen isotope-ratio measurement techniques on Antarctic surface-water and ice samples
J.A. Hopple, J.E. Hannon, T.B. Coplen
1998, Chemical Geology (152) 321-323
A comparison of the new hydrogen isotope-ratio technique of Vaughn et al. ([Vaughn, B.H., White, J.W.C., Delmotte, M., Trolier, M., Cattani, O., Stievenard, M., 1998. An automated system for hydrogen isotope analysis of water. Chem. Geol. (Isot. Geosci. Sect.), 152, 309-319]; the article immediately preceding this article) for the analysis...
Relative importance of physical and economic factors in Appalachian coalbed gas assessment
E. D. Attanasi
1998, International Journal of Coal Geology (38) 47-59
In the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey, only 20% of the assessed technically recoverable Appalachian Province coalbed gas resources were economic. Physical and economic variables are examined to explain the disparity between economic and technically recoverable coalbed gas. The Anticline and...
Stable carbon and oxygen isotope record of central Lake Erie sediments
M.J.S. Tevesz, A.L. Spongberg, J. A. Fuller
1998, Journal of Paleolimnology (20) 295-305
Stable carbon and oxygen isotope data from mollusc aragonite extracted from sediment cores provide new information on the origin and history of sedimentation in the southwestern area of the central basin of Lake Erie. Sediments infilling the Sandusky subbasin consist of three lithologic units overlying glacial deposits. The lowest of...
New U-Pb zircon ages and the duration and division of Devonian time
R. D. Tucker, D. C. Bradley, C. A. Ver Straeten, A. G. Harris, J.R. Ebert, S.R. McCutcheon
1998, Earth and Planetary Science Letters (158) 175-186
Newly determined U-Pb zircon ages of volcanic ashes closely tied to biostratigraphic zones are used to revise the Devonian time-scale. They are: 1) 417.6 ?? 1.0 Ma for an ash within the conodont zone of Icriodus woschmidti/I. w. hesperius Lochkovian); 2) 408.3 ?? 1.9 Ma for an ash of early...
The interplinian activity at Somma-Vesuvius in the last 3500 years
G. Rolandi, P. Petrosino, Geehin J. Mc
1998, Journal of Volcanology and Geothermal Research (82) 19-52
Between 1884 B.C. and A.D. 472, eruptive activity at Somma-Vesuvius was dominated by the three plinian eruptions of Avellino (3550 yr B.P.), Pompei (A.D. 79) and A.D. 472 and, as a result, little attention has been given to the intervening interplinian activity. The interplinian events are here reconstructed using new...
Generation of coastal marsh topography with radar and ground-based measurements
Elijah W. Ramsey III, G.A. Nelson, S.C. Laine, R.G. Kirkman, W. Topham
1998, Journal of Coastal Research (14) 1158-1164
A topographic surface of a low lying coastal marsh was created by using three flood extent vectors digitized from ERS-1 SAR images and two elevation contours from U.S. Geological Survey topographic quadrangles. Point measurement of water depth at the times of the SAR collections allowed conversion of the radar measured...
Geochemical evidence for a comet shower in the late Eocene
K.A. Farley, A. Montanari, E.M. Shoemaker, C.S. Shoemaker
1998, Science (280) 1250-1253
Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began ~1 My before and ended ~1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters ~36...
Hermit crabs in the diet of Pigeon Guillemots at Kachemak Bay, Alaska
Michael A. Litzow, John F. Piatt, Jared D. Figurski
1998, Colonial Waterbirds (21) 242-244
Guillemots (Cepphus spp.) feed their chicks a diet that is almost exclusively fish. We observed Pigeon Guillemots (C. columba) at two colonies in Alaska where hermit crabs (Crustacea: Anomura) were a major part of the diet for some nestlings. Hermit crabs were delivered to three of five observed nests at...
Organic carbon accumulation and preservation in surface sediments on the Peru margin
M.A. Arthur, W.E. Dean, K. Laarkamp
1998, Chemical Geology (152) 273-286
Concentrations and characteristics of organic matter in surface sediments deposited under an intense oxygen-minimum zone on the Peru margin were studied in samples from deck-deployed box cores and push cores acquired by submersible on two transects spanning depths of 75 to 1000 m at 12??and 13.5??S. The source of organic...
Earth data for the future
Bruce K. Quirk, Ronald E. Beck
1998, Geotimes (43) 21-23
No abstract available....
The captive environment and reintroduction: the black-footed ferret as a case study with comments on other taxa
B. J. Miller, D. E. Biggins, Astrid Vargas, M. Hutchins, L. Hanebury, J. L. Godbey, Gerardo Ceballos, S. Anderson, J. L. Oldemeyer, F. L. Knopf
1998, Book chapter, Second nature: Environmental enrichment for captive animals
No abstract available. ...
Considerations in As analysis and speciation
M. Edwards, S. Patel, L. McNeil, H.W. Chen, M. Frey, A.D. Eaton, Ronald C. Antweiler, Howard E. Taylor
1998, Journal of the American Water Works Association (43) 1378-1383
This article summarizes recent experiences in arsenic (As) quantification, preservation, and speciation developed during AWWA Research Foundation (AWWARF) and Water Industry Technical Action Fund (WITAF) projects. The goal of this article is to alert analysts and decision-makers to potential problems in As analysis and speciation, because there appear to be...
Biodegradation of crude oil into nonvolatile organic acids in a contaminated aquifer near Bemidji, Minnesota
K. A. Thorn, G. R. Aiken
1998, Organic Geochemistry (29) 909-931
As the result of a pipeline burst, a body of light aliphatic crude oil floats atop the groundwater in a shallow sand and gravel aquifer in a remote area outside Bemidji, Minnesota. Biodegradation has resulted in the formation of a plume of DOC downgradient from the oil body. Groundwater has...
Brief notes on habitat geology and clay pipe habitat on Stellwagen Bank
Page C. Valentine
Eleanor M. Dorsey, Judith Pederson, editor(s)
1998, Book chapter, Effects of fishing gear on the sea floor of New England
In our studies of sea floor habitats, my colleagues and I use both biological and geological approaches. We call our studies “habitat geology,” a term coined by a biologist friend of mine. We view it as the study of sea floor materials and biological and geological processes that influence where...
Grizzly bears and calving caribou: What is the relation with river corridors?
Donald D. Young Jr., Thomas R. McCabe
1998, Journal of Wildlife Management (62) 255-261
Researchers have debated the effect of the Trans-Alaska Pipeline (TAP) and associated developments to caribou (Rangifer tarandus) of the central Arctic herd (CAH) since the 1970s. Several studies have demonstrated that cows and calves of the CAH avoided the TAP corridor because of disturbance associated with the pipeline, whereas others...
Identifying and mitigating errors in satellite telemetry of polar bears
Stephen M. Arthur, Gerald W. Garner, Tamara L. Olson
1998, Ursus (10) 413-419
Satellite radiotelemetry is a useful method of tracking movements of animals that travel long distances or inhabit remote areas. However, the logistical constraints that encourage the use of satellite telemetry also inhibit efforts to assess accuracy of the resulting data. To investigate effectiveness of methods that might be used to...
