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...
Spatial extent of a hydrothermal system at Kilauea Volcano, Hawaii, determined from array analyses of shallow long-period seismicity 1. Method
J. Almendros, B. Chouet, P. Dawson
2001, Journal of Geophysical Research B: Solid Earth (106) 13565-13580
We present a probabilistic method to locate the source of seismic events using seismic antennas. The method is based on a comparison of the event azimuths and slownesses derived from frequency-slowness analyses of array data, with a slowness vector model. Several slowness vector models are considered including both homogeneous and...
Seismic response of the katmai volcanoes to the 6 December 1999 magnitude 7.0 Karluk Lake earthquake, Alaska
J.A. Power, S.C. Moran, S.R. McNutt, S.D. Stihler, J.J. Sanchez
2001, Bulletin of the Seismological Society of America (91) 57-63
A sudden increase in earthquake activity was observed beneath volcanoes in the Katmai area on the Alaska Peninsula immediately following the 6 December 1999 magnitude (Mw) 7.0 Karluk Lake earthquake beneath southern Kodiak Island, Alaska. The observed increase in earthquake activity consisted of small (ML < 1.3), shallow (Z <...
Aeromagnetic expression of faults that offset basin fill, Albuquerque basin, New Mexico
V. J. S. Grauch, M.R. Hudson, S.A. Minor
2001, Geophysics (66) 707-720
High-resolution aeromagnetic data acquired over the Albuquerque basin show widespread expression of faults that offset basin fill and demonstrate that the aeromagnetic method can be an important hydrogeologic and surficial mapping tool in sediment-filled basins. Aeromagnetic expression of faults is recognized by the common correspondence of linear anomalies to surficial...
Trace metal suites in Antarctic pre-industrial ice are consistent with emissions from quiescent degassing of volcanoes worldwide
A. Matsumoto, T. K. Hinkley
2001, Earth and Planetary Science Letters (186) 33-43
Trace metals are more abundant in atmospheric load and deposition material than can be due to rock and soil dusts and ocean salt. In pre-industrial ice from coastal west Antarctica, dust and salt account for only a few percent of the lead, cadmium, and indium that is present in most...
Pollen-limited reproduction in blue oak: Implications for wind pollination in fragmented populations
E. E. Knapp, M.A. Goedde, K.J. Rice
2001, Oecologia (128) 48-55
Human activities are fragmenting forests and woodlands worldwide, but the impact of reduced tree population densities on pollen transfer in wind-pollinated trees is poorly understood. In a 4-year study, we evaluated relationships among stand density, pollen availability, and seed production in a thinned and fragmented population of blue oak (Quercus...
User interface for ground-water modeling: Arcview extension
Ming-shu Tsou, Donald O. Whittemore
2001, Journal of Hydrologic Engineering (6) 251-257
Numerical simulation for ground-water modeling often involves handling large input and output data sets. A geographic information system (GIS) provides an integrated platform to manage, analyze, and display disparate data and can greatly facilitate modeling efforts in data compilation, model calibration, and display of model parameters and results. Furthermore, GIS...
Unsuccessful initial search for a midmantle chemical boundary with seismic arrays
J.E. Vidale, G. Schubert, P.S. Earle
2001, Geophysical Research Letters (28) 859-862
Compositional layering of the midmantle has been proposed to account for seismic and geochemical patterns [van der Hilst and Karason, 1999], and inferred radiogenic heat source concentrations [Kellogg et al., 1999]. Compositional layering would require thermal boundary layers both above and below an interface. We construct a minimal 1-D model...
Applying the scientific method to small catchment studies: Areview of the Panola Mountain experience
R. P. Hooper
2001, Hydrological Processes (15) 2039-2050
A hallmark of the scientific method is its iterative application to a problem to increase and refine the understanding of the underlying processes controlling it. A successful iterative application of the scientific method to catchment science (including the fields of hillslope hydrology and biogeochemistry) has been hindered by two factors....
Streamflow forecasting using the modular modeling system and an object-user interface
A.E. Jeton
2001, Conference Paper, Proceedings of The Western Snow Conference
The U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation (BOR), developed a computer program to provide a general framework needed to couple disparate environmental resource models and to manage the necessary data. The Object-User Interface (OUI) is a map-based interface for models and modeling data. It provides...
Regression models for estimating herbicide concentrations in U.S. streams from watershed characteristics
S.J. Larson, R. J. Gilliom
2001, Journal of the American Water Resources Association (37) 1349-1367
Regression models were developed for estimating stream concentrations of the herbicides alachlor, atrazine, cyanazine, metolachlor, and trifluralin from use-intensity data and watershed characteristics. Concentrations were determined from samples collected from 45 streams throughout the United States during 1993 to 1995 as part of the U.S. Geological Survey's National Water-Quality Assessment...
Predictions of hydrothermal alteration within near-ridge oceanic crust from coordinated geochemical and fluid flow models
L.R. Wetzel, Jeff P. Raffensperger, E.L. Shock
2001, Journal of Volcanology and Geothermal Research (110) 319-342
Coordinated geochemical and hydrological calculations guide our understanding of the composition, fluid flow patterns, and thermal structure of near-ridge oceanic crust. The case study presented here illustrates geochemical and thermal changes taking place as oceanic crust ages from 0.2 to 1.0 Myr. Using a finite element code, we model fluid...
Impact of the Conservation Reserve Program on duck recruitment in the U.S. Prairie Pothole Region
Ronald E. Reynolds, Terry L. Shaffer, Randy W. Renner, Wesley E. Newton, Bruce D.J. Batt
2001, Journal of Wildlife Management (65) 765-780
The U.S. Department of Agriculture (USDA)'s Conservation Reserve Program (CRP) resulted in the conversion of about 1.9 million ha of cropland to perennial grass cover in the Prairie Pothole Region of North Dakota, South Dakota, and northeastern Montana by 1992. Many wildlife managers believed this cover would provide benefits to...
The fish community of a small impoundment in upstate New York
C. Mead McCoy III, Charles P. Madenjian, Jean V. Adams, Willard N. Harman
2001, Journal of Freshwater Ecology (16) 389-394
Moe Pond is a dimictic impoundment with surface area of 15.6 ha, a mean depth of 1.8 m, and an unexploited fish community of only two species: brown bullhead (Ameiurus nebulosus) and golden shiner (Notemigonus crysoleucas). The age-1 and older brown bullhead population was estimated to be 4,057 individuals, based...
Simulating the impact of human land use change on forest composition in the Great Plains agroecosystems with the Seedscape model
W.E. Easterling, J.R. Brandle, C.J. Hays, Q. Guo, D.S. Guertin
2001, Ecological Modelling (104) 163-176
The expansion and contraction of marginal cropland in the Great Plains often involves small forested strips of land that provide important ecological benefits. The effect of human disturbance on these forests is not well known. Because of their unique structure such forests are not well-represented by forest gap models. In...
Pleurochrysis pseudoroscoffensis (Prymnesiophyceae) blooms on the surface of the Salton Sea, California
Kristen M. Reifel, M. P. McCoy, M. A. Tiffany, Tonie E. Rocke, Charles Trees, S. B. Barlow, D. J. Faulkner, S. H. Hurlbert
2001, Hydrobiologia (466) 177-185
Dense populations of the coccolithophore Pleurochrysis pseudoroscoffensis were found in surface films at several locations around the Salton Sea in February–August, 1999. An unidentified coccolithophorid was also found in low densities in earlier studies of the lake (1955–1956). To our knowledge, this is the first record of this widespread marine species in...
Estimation of brood and nest survival: Comparative methods in the presence of heterogeneity
Bryan F.J. Manly, Joel A. Schmutz
2001, Journal of Wildlife Management (65) 258-270
The Mayfield method has been widely used for estimating survival of nests and young animals, especially when data are collected at irregular observation intervals. However, this method assumes survival is constant throughout the study period, which often ignores biologically relevant variation and may lead to biased survival estimates. We examined...
Colletotrichum as a model system for defining the genetic basis of fungal symbiotic lifestyles
R. J. Rodriguez, R. S. Redman
2001, Report, Host specificity, pathology and host pathogen interactions of Colletotrichum
Abstract not available ...
New approaches for sampling and modeling native and exotic plant species richness
G.W. Chong, R.M. Reich, M. A. Kalkhan, T.J. Stohlgren
2001, Western North American Naturalist (61) 328-335
Development and application of a spatial hydrology model of Okefenokee Swamp, Georgia
C.S. Loftin, W.M. Kitchens, N. Ansay
2001, Journal of the American Water Resources Association (37) 935-956
The model described herein was used to assess effects of the Suwannee River sill (a low earthen dam constructed to impound the Suwannee River within the Okefenokee National Wildlife Refuge to eliminate wildfires) on the hydrologic environment of Okefenokee Swamp, Georgia. Developed with Arc/Info Macro Language routines in the GRID...
Coastline complexity: A parameter for functional classification of coastal environments
J.D. Bartley, R. W. Buddemeier, D.A. Bennett
2001, Conference Paper, Journal of Sea Research
To understand the role of the world's coastal zone (CZ) in global biogeochemical fluxes (particularly those of carbon, nitrogen, phosphorus, and sediments) we must generalise from a limited number of observations associated with a few well-studied coastal systems to the global scale. Global generalisation must be based on globally available...
Flow of variably fluidized granular masses across three-dimensional terrain I. Coulomb mixture theory
R.M. Iverson, R.P. Denlinger
2001, Journal of Geophysical Research B: Solid Earth (106) 537-552
Rock avalanches, debris flows, and related phenomena consist of grain-fluid mixtures that move across three-dimensional terrain. In all these phenomena the same basic forces, govern motion, but differing mixture compositions, initial conditions, and boundary conditions yield varied dynamics and deposits. To predict motion of diverse grain-fluid masses from initiation to...
Watershed scaling effect on base flow nitrate, valley and ridge physiographic province
B.D. Lindsey, W.J. Gburek, G.J. Folmar
2001, Journal of the American Water Resources Association (37) 1103-1117
A study of stream base flow and NO3-N concentration was conducted simultaneously in 51 subwatersheds within the 116-square-kilometer watershed of East Mahantango Creek near Klingerstown, Pennsylvania. The study was designed to test whether measurable results of processes and observations within the smaller watersheds were similar to or transferable to a...
Formation and failure of volcanic debris dams in the Chakachatna River valley associated with eruptions of the Spurr volcanic complex, Alaska
C. F. Waythomas
2001, Geomorphology (39) 111-129
The formation of lahars and a debris avalanche during Holocene eruptions of the Spurr volcanic complex in south-central Alaska have led to the development of volcanic debris dams in the Chakachatna River valley. Debris dams composed of lahar and debris-avalanche deposits formed at least five times in the last 8000-10,000...
Geology, coal quality, and resources of the Antaramut-Kurtan-Dzoragukh coal field, north-central Armenia
B.S. Pierce, A. Martirosyan, G. Malkhasian, S. Harutunian, G. Harutunian
2001, International Journal of Coal Geology (45) 267-279
The Antaramut-Kurta-Dzoragukh (AKD) coal deposit is a previously unrecognized coal field in north-central Armenia. Coal has been known to exist in the general vicinity since the turn of the century, but coal was thought to be restricted to a small (1 km2) area only near the village of Antaramut. However,...
