Regional propagation characteristics and source parameters of earthquakes in northeastern North America
John Boatwright
1994, Bulletin of the Seismological Society of America (84) 1-15
The vertical components of the S wave trains recorded on the Eastern Canadian Telemetered Network (ECTN) from 1980 through 1990 have been spectrally analyzed for source, site, and propagation characteristics. The data set comprises some 1033 recordings of 97 earthquakes whose magnitudes range from M ≈ 3 to 6....
Geochemical evidence for enhanced preservation of organic matter in the oxygen minimum zone of the continental margin of northern California during the Late Pleistocene
Walter E. Dean, James V. Gardner, Roger Y. Anderson
1994, Paleoceanography (9) 47-61
The present upper water mass of the northeastern Pacific Ocean off California has a well-developed oxygen minimum zone between 600 and 1200 m wherein concentrations of dissolved oxygen are less than 0.5 mL/L. Even at such low concentrations of dissolved oxygen, benthic burrowing organisms are abundant enough to thoroughly bioturbate...
The use of simulation and multiple environmental tracers to quantify groundwater flow in a shallow aquifer
Thomas E. Reilly, Niel Plummer, Patrick J. Phillips, Eurybiades Busenberg
1994, Water Resources Research (30) 421-433
Measurements of the concentrations of chlorofluorocarbons (CFCs), tritium, and other environmental tracers can be used to calculate recharge ages of shallow groundwater and estimate rates of groundwater movement. Numerical simulation also provides quantitative estimates of flow rates, flow paths, and mixing properties of the groundwater system. The environmental tracer techniques...
Instream flows to assist the recovery of endangered fishes of the upper Colorado River basin
J. A. Stanford
1994, Biological Report (24) 47-47
The riverine landscape of the upper Colorado River basin has been extensively modified by dams, diversions, revetments, and water abstractions. These changes, probably coupled with the introduction of many nonnative fishes, have compromised the existence of four of the native fishes (Colorado River squawfish Ptychocheilus lucius, humpback chub Gila cypha,...
Habitat use by an endangered riverine fish and implications for species protection
B. J. Freeman, Mary Freeman
1994, Ecology of Freshwater Fish (3) 49-58
We investigated habitat specificity of the amber darter (Percina antesella Williams & Etnier 1977), an imperiled fish from restricted portions of 2 rivers in the southeastern United States. Foraging amber darters occupied a narrow range of riffle habitat, consistently avoiding areas < 20 cm deep and with velocity < 10 cm....
Body composition dynamics of ruddy ducks during wing moult
W.L. Hohman
1994, Canadian Journal of Zoology (71) 2224-2228
A method was developed for indexing moulting costs in waterfowl based on intensity of moult and proportional mass of feathers in seven feather regions (ADJMOLT). This method was then applied to an examination of relations between moulting costs and size-adjusted body mass and composition of postbreeding male and female ruddy...
Bed material and numerical modeling in a grand bed stream
R.T. Milhous
1994, Conference Paper, Hydraulic engineering '94 : Proceedings of the 1994 Conference
No abstract available. ...
Coupling of volatile transport and internal heat flow on Triton
Robert H. Brown, Randolph L. Kirk
1994, Journal of Geophysical Research E: Planets (99) 1965-1981
Recently Brown et al. (1991) showed that Triton's internal heat source could amount to 5–20% of the absorbed insolation on Triton, thus significantly affecting volatile transport and atmospheric pressure. Subsequently, Kirk and Brown (1991a) used simple analytical models of the effect of internal heat on the distribution of volatiles on...
40Ar/39Ar chronology and volcanology of silicic volcanism in the Davis Mountains, Trans-Pecos Texas
Christopher D. Henry, Michael J. Kunk, W. C. McIntosh
1994, GSA Bulletin (106) 1359-1376
Field studies and 40Ar/39Ar dating reveal that silicic volcanism in the Davis Mountains part of the Trans-Pecos Texas volcanic field occurred in six episodes at 0.3 m.y. intervals between 36.8 and 35.3 Ma. Additionally, two groups of silicic intrusions were emplaced at 34.6 and 32.8 Ma. This episodicity is similar to...
Fate and pathways of injection-well effluent in the Florida Keys
Eugene A. Shinn, Ronald S. Reese, Christopher D. Reich
1994, Open-File Report 94-276
Twenty-four wells (21 locations) were core drilled into the limestone beneath the Keys, reef tract, and outer reefs to determine if sewage effluents injected in Class V wells onshore are reaching offshore reef areas via underground flow. These wells were fitted with PVC casings and well screens and were...
Modeling fluid flow and heat transfer at Basin and Range faults: preliminary results for Leach hot springs, Nevada
Dina L. Lopez, Leslie Smith, Michael L. Storey
Dennis L. Nielson, editor(s)
1994, Restructuring the geothermal industry (18) 11-16
The hydrothermal systems of the Basin and Range Province are often located at or near major range bounding normal faults. The flow of fluid and energy at these faults is affected by the advective transfer of heat and fluid from an to the adjacent mountain ranges and valleys, This paper...
Nutrient additions by waterfowl to lakes and reservoirs: predicting their effects on productivity and water quality
Bruce A. Manny, W.C. Johnson, R.G. Wetzel
1994, Hydrobiologia (279/280) 121-132
Lakes and reservoirs provide water for human needs and habitat for aquatic birds. Managers of such waters may ask whether nutrients added by waterfowl degrade water quality. For lakes and reservoirs where primary productivity is limited by phosphorus (P), we developed a procedure that integrates annual P loads...
Elk carrying capacity on Yellowstone's Northern Elk Winter Range: preliminary modeling to integrate climate, landscape, and nutritional requirements
M. B. Coughenour
1994, Report, Plants and their environments: proceedings of the first biennial scientific conference on the Greater Yellowstone Ecosystem
No abstract available....
A program to maintain the endangered razorback suckers in a highly modified riverine habitat
G. Mueller, T. Burke, M. Horn
1994, Book, Environmental Enhancement of Water Projects, Proceedings of the 1993 seminar
No abstract available....
Analysis of nitrogen saturation potential in Rocky Mountain tundra and forest: implications for aquatic systems
Jill S. Baron, Dennis S. Ojima, Elisabeth A. Holland, William J. Parton
1994, Biogeochemistry (27) 61-82
We employed grass and forest versions of the CENTURY model under a range of N deposition values (0.02–1.60 g N m−2 y−1) to explore the possibility that high observed lake and stream N was due to terrestrial N saturation of alpine tundra and subalpine forest in Loch Vale Watershed, Rocky...
Evolution of instream flow habitat modelling
C. B. Stalnaker
1994, Book chapter, The Rivers Handbook: Hydrological and Ecological Principles
No abstract available....
Models, methods, and tools for regional models of the response of ecosystems to global change
Davis S. Schimel, Timothy G.F. Kittel, D. S. Ojima, F. Giorgi, A. Metherell, R. A. Pielke, C. V. Cole, J. G. Bromberg
1994, Book, Sustainable land management for the 21st century: proceedings of the International Workshop on Sustainable Land Management for the 21st Century
No abstract available....
Project snow leopard: a model for conserving central Asian biodiversity
Don O. Hunter
1994, Book, Seventh International Snow Leopard Symposium
No abstract available....
Modeling effects of flow alteration on riparian vegetation
Gregor T. Auble, M. L. Scott, J.M. Friedman, Lee S. Ischinger
1994, Report
No abstract available....
Mechanistic solutions to the opening of the Gulf of Mexico
Hans Schouten, Kim D. Klitgord
1994, Geology (22) 507-510
Two mechanistic models—which are unlike the traditional plate-tectonic landfill models used for most proposed Pangea reconstructions of the Yucatán block—relate the Mesozoic opening of the Gulf of Mexico directly to the movement of the North and South American plates: (1) a previous piggyback model in which Yucatán moves with South...
Field and modeling studies of multiphase fluid flow at the Bemidji, Minnesota crude-oil spill site
Hedeff I. Essaid, William N. Herkelrath, L.A. Dillard
A.R. Dutton, editor(s)
1994, Book chapter, Toxic substances and the hydrologic sciences
No abstract available....
Neural networks for river flow prediction
Nachimuthu Karunanithi, William J. Grenney, Darrell Whitley, Ken Bovee
1994, Journal of Computing in Civil Engineering (8) 201-203
The surface‐water hydrographs of rivers exhibit large variations due to many natural phenomena. One of the most commonly used approaches for interpolating and extending streamflow records is to fit observed data with an analytic power model. However, such analytic models may not adequately represent the flow process, because they are...
Hydrological controls on dissolved organic carbon during snowmelt in the Snake River near Montezuma, Colorado
G.M. Hornberger, Kenneth E. Bencala, D.M. McKnight
1994, Biogeochemistry (25) 147-165
A quantitative understanding of the factors controlling the variation of dissolved organic carbon (DOC) in headwater streams is of scientific concern for at least two reasons. First, quantifying the overall carbon budgets of lotic systems is needed for a fundamental understanding of these systems. Second, DOC interacts strongly with other...
Wilderness monitoring and data management
A. R. Riebau
1994, Environmental Software (9) 227-232
In the last decade, increased public interest in natural areas has resulted in increased monitoring activity by federal wilderness managers to assess the status of wilderness values. Wilderness values are those large-scale entities of wilderness which comprise, in sum, wilderness character. Data collected through wilderness monitoring must support the maintenance...
Map showing depth to bedrock of the Tacoma and part of the Centralia 30' x 60' quadrangles, Washington
Jane M. Buchanan-Banks, Donley S. Collins
1994, Miscellaneous Field Studies Map 2265
The heavily populated Puget Sound region in the State of Washington has experienced moderate to large earthquakes in the recent past (Nuttli, 1952; Mullineaux and others, 1967). Maps showing thickness of unconsolidated sedimentary deposits are useful aids in delineating areas where damage to engineered structures can result from increased shaking...
