Conference Papers
Science Quality and Integrity
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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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Net carbon exchange across the Arctic tundra-boreal forest transition in Alaska 1981-2000 Net carbon exchange across the Arctic tundra-boreal forest transition in Alaska 1981-2000
Shifts in the carbon balance of high-latitude ecosystems could result from differential responses of vegetation and soil processes to changing moisture and temperature regimes and to a lengthening of the growing season. Although shrub expansion and northward movement of treeline should increase carbon inputs, the effects of these vegetation changes on net carbon exchange have not been...
Authors
Catharine Copass Thompson, A. D. McGuire, Joy S. Clein, F. S. Chapin, J. Beringer
New ghost-node method for linking different models with varied grid refinement New ghost-node method for linking different models with varied grid refinement
A flexible, robust method for linking grids of locally refined ground-water flow models constructed with different numerical methods is needed to address a variety of hydrologic problems. This work outlines and tests a new ghost-node model-linking method for a refined "child" model that is contained within a larger and coarser "parent" model that is based on the iterative method of...
Authors
S.C. James, J.E. Dickinson, S.W. Mehl, M. C. Hill, S. A. Leake, G.A. Zyvoloski, A.-A. Eddebbarh
Numerical modeling of magnetic moments for UXO applications Numerical modeling of magnetic moments for UXO applications
The surface magnetic anomaly observed in UXO clearance is mainly dipolar and, consequently, the dipole is the only magnetic moment regularly recovered in UXO applications. The dipole moment contains information about intensity of magnetization but lacks information about shape. In contrast, higher-order moments, such as quadrupole and octupole, encode asymmetry properties of the...
Authors
V. Sanchez, Y. Li, M. Nabighian, D. Wright
Oil resources - Estimates and uncertainties Oil resources - Estimates and uncertainties
Oil reserves are reasonably well known, but they are not a reliable indicator of longterm supply. Future oil availability will depend upon reserve additions, which are highly uncertain. New reserves will come from three sources: 1) new field discoveries, 2) growth of reserves in existing fields, and 3) development of unconventional resources. U.S. Geological Survey estimates of global...
Authors
D. L. Gautier
Organic geochemistry - A retrospective of its first 70 years Organic geochemistry - A retrospective of its first 70 years
Organic geochemistry had its origin in the early part of the 20th century when organic chemists and geologists realized that detailed information on the organic materials in sediments and rocks was scientifically interesting and of practical importance. The generally acknowledged "father" of organic geochemistry is Alfred E. Treibs (1899-1983), who discovered and described, in 1936...
Authors
K.A. Kvenvolden
Overview of selected surrogate technologies for continuous suspended-sediment monitoring Overview of selected surrogate technologies for continuous suspended-sediment monitoring
Surrogate technologies for inferring selected characteristics of suspended sediments in surface waters are being tested by the U.S. Geological Survey and several partners with the ultimate goal of augmenting or replacing traditional monitoring methods. Optical properties of water such as turbidity and optical backscatter are the most commonly used surrogates for suspended-sediment...
Authors
J. R. Gray, J. W. Gartner
Panel: Eco-informatics and decision making managing our natural resources Panel: Eco-informatics and decision making managing our natural resources
This panel responds to the December 2004 workshop on Eco-Informatics and Decision Making [1], which addressed how informatics tools can help with better management of natural resources and policy making. The workshop was jointly sponsored by the NSF, NBII, NASA, and EPA. Workshop participants recommended that informatics research in four IT areas be funded: modeling and simulation, data...
Authors
J.B. Gushing, T. Wilson, F. Martin, J. Schnase, S. Spengler, L. Sugarbaker, T. Pardo
Planning and implementation of a seismic monitoring system for the bill emerson memorial bridge in cape Girardeau, MO Planning and implementation of a seismic monitoring system for the bill emerson memorial bridge in cape Girardeau, MO
[No abstract available]
Authors
B.A. Hartnagel, J. O'Connor, W.-H. Yen, P. Clogston, M. Çelebi
Polar bear research in Alaska Polar bear research in Alaska
Since the 13th Working Meeting of the Polar Bear Specialist Group the U.S. Geological Survey (USGS) has seen the completion of many research projects and the start of many new ones. Much has been accomplished and yet we have new challenges awaiting us. This report summarises our focal questions and progress in those areas.
Authors
George M. Durner, Steven C. Amstrup, Geoff S. York, Eric V. Regehr, Kristin S. Simac, Tom S. Smith, Steven T. Partridge, Torsten Bentzen, Kristin S. Amstrup, David C. Douglas
Postrelease movements and survival of adult and young black-footed ferrets Postrelease movements and survival of adult and young black-footed ferrets
A successful captive breeding program for highly endangered black-footed ferrets (Mustela nigripes) has resulted in surplus animals that have been released at multiple sites since 1991. Because reproductive output of captive ferrets declines after several years, many adult ferrets must be removed from captive breeding facilities annually to keep total production high. Adults are...
Authors
Dean E. Biggins, Jerry L. Godbey, Travis M. Livieri, Marc R. Matchett, Brent D. Bibles
Prediction and discovery of new geothermal resources in the Great Basin: Multiple evidence of a large undiscovered resource base Prediction and discovery of new geothermal resources in the Great Basin: Multiple evidence of a large undiscovered resource base
Geothermal potential maps by themselves cannot directly be used to estimate undiscovered resources. To address the undiscovered resource base in the Great Basin, a new and relatively quantitative methodology is presented. The methodology involves three steps, the first being the construction of a data-driven probabilistic model of the location of known geothermal systems using weights of...
Authors
M.F. Coolbaugh, G. L. Raines, R. E. Zehner, L. Shevenell, C.F. Williams