Conference Papers
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Brown bear response to elevated viewing structures at Brooks River, Alaska
The increasing popularity of brown bear (Ursus arctos) viewing at Brooks River in Katmai National Park, Alaska has resulted in overcrowded facilities, increasing bear-human conflicts, displacement of bears from important habitats, and degradation of cultural resources. To partially address these issues, the National Park Service (NPS) constructed a 300-m-long elevated boardwalk with interconnected
Authors
T.D. DeBruyn, T. S. Smith, K. Proffitt, S. Partridge, T.D. Drummer
Calibration of specific conductance, water-temperature, and turbidity instruments
No abstract available.
Authors
H. R. Ramil, P.A. Buchanan, B. J. Sullivan, G. D. Brewster
Carbon dioxide transport over complex terrain
The nocturnal transport of carbon dioxide over complex terrain was investigated. The high carbon dioxide under very stable conditions flows to local low-ground. The regional drainage flow dominates the carbon dioxide transport at the 6 m above the ground and carbon dioxide was transported to the regional low ground. The results show that the local drainage flow was sensitive to turbulent mixing as
Authors
Jielun Sun, Sean P. Burns, A.C. Delany, S.P. Oncley, A. Turnipseed, B. Stephens, A. Guenther, D.E. Anderson, R. Monson
Carbon, sulfur, and mercury - A biogeochemical axis of evil
I welcome this opportunity to come and preach the gospel according to Aiken, which is that to really understand ecosystems we need to pay much more attention to reactions involving natural organic matter. It's taken me many years to convince my colleagues of the important role of dissolved organic matter (DOM) in the methylation of mercury. Methylmercury is a nasty player - it's a very efficient b
Authors
George R. Aiken
Changes in the substrate of rivers in historic mining districts
The restoration of rivers in watersheds with historic mining districts has become a topic of interest during the last decade. Rivers restoration in these areas is difficult because the mines and mills can be scattered over a wide area and often small. Many have also been abandoned. This paper presents two substrate related factors that are important in the evaluation of river restoration alternati
Authors
R.T. Milhous
Characteristics of urban-ecosystem atmosphere fluxes of CO2, CH4, N2O, and et over Denver, Colorado
The characteristics of urban ecosystems fluxes of carbon dioxide, methane, nitrous oxide, and evapotranspiration (ET) over Denver, Colorado were discussed. These atmospheric fluxes were measured using a methodology that included a combination of eddy covariance sensors at two levels on a tall tower and chamber measurements at 33 locations on the soil surface. There was both strong temporal and spa
Authors
D.E. Anderson, C. Alvarez, T. Thienelt
Characterization of single-walled carbon nanotubes for environmental implications
Adsorption capacities of N2 and various organic vapors (methyl-ethyl ketone (MEK), toluene, and cyclohexane) on select electric-arc and HiPco produced single walled carbon nanotubes (SWNT) were measured at 77 and 298 K, respectively. The amount of N2 adsorbed on a SWNT sample depended on the sample purity, methodology, and on the sample age. Adsorption capacities of organic vapors (100-1000 ppm vo
Authors
S. Agnihotri, M. Rostam-Abadi, M.J. Rood
Clearwater local scour experiments in a large flume
Local sediment scour experiments have been conducted with 0.114 m, 0.305 m and 0.914 m diameter circular piles in a 6.1 m (20 ft) wide by 6.4 m (21 ft) deep by 38.4 m (126 ft) long flume in the Hydraulics Laboratory at the USGS Conte Laboratory in Turners Falls, MA. All of the tests to date have been in the clearwater scour range of velocities and with two near uniform diameter sediments with medi
Authors
D.M. Sheppard, M. Odeh, A. Pritsivelis, T. Glasser
CO2 mitigation via accelerated limestone weathering
We evaluate accelerated weathering of limestone (AWL: CO2 + CaCO3 + H2O=> Ca2+ + 2HCO3-) as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology. With access to seawater and limestone being essential to this approach, significant limestone resources are close to most CO2-emitting power plants along the coastal US. Waste fines, representing more
Authors
Greg H. Rau, Kevin G. Knauss, William H. Langer, Caldeira
Coal systems - A gateway to predictive assessments of coal production
Current federal and State coal assessments estimate resources in the ground, resources available for mining, and economically recoverable resources. None of these assessments predict the amount of coal that may be produced from an assessed area in the near future (???20 years). Predictive assessments of coal production would be based on an understanding of the regional coal geology (coal systems),
Authors
R. Milici
Coastal wetlands of the Laurentian Great Lakes: Summary and future directions
[No abstract available]
Authors
T. Mayer, T. Edsall, M. Munawar
Comparison of AMSR-E and SSM/I snow parameter retrievals over the Ob river basin
Passive microwave observations from the Advanced Microwave Scanning Radiometer - EOS (AMSR-E) and from the Special Sensor Microwave Imager (SSM/I) are used to analyse the evolution of the snow pack in the Ob river basin during the snow season of 2002-03. The Ob river is the biggest Russian river with respect to its watershed area (2 975 000 km2). The Ob originates in the Altai mountains and flows
Authors
N. M. Mognard, M. Grippa, T. LeToan, R.E.J. Kelly, A.T.C. Chang, E.G. Josberger