Climate change: Conflict of observational science, theory, and politics
L. C. Gerhard
2004, American Association of Petroleum Geologists Bulletin (88) 1211-1220
Debate over whether human activity causes Earth climate change obscures the immensity of the dynamic systems that create and maintain climate on the planet. Anthropocentric debate leads people to believe that they can alter these planetary dynamic systems to prevent that they perceive as negative climate impacts on human civilization....
Geochemical cycles in sediments deposited on the slopes of the Guaymas and Carmen Basins of the Gulf of California over the last 180 years
W. Dean, C. Pride, R. Thunell
2004, Quaternary Science Reviews (23) 1817-1833
Sediments deposited on the slopes of the Guaymas and Carmen Basins in the central Gulf of California were recovered in two box cores. Q-mode factor analyses identified detrital-clastic, carbonate, and redox associations in the elemental composition of these sediments. The detrital-clastic fraction appears to contain two source components, a more...
A review of models and micrometeorological methods used to estimate wetland evapotranspiration
J.Z. Drexler, R.L. Snyder, D. Spano, U.K.T. Paw
2004, Hydrological Processes (18) 2071-2101
Within the past decade or so, the accuracy of evapotranspiration (ET) estimates has improved due to new and increasingly sophisticated methods. Yet despite a plethora of choices concerning methods, estimation of wetland ET remains insufficiently characterized due to the complexity of surface characteristics and the diversity of wetland types. In...
The helium isotopic chemistry of Lake Bonney, Taylor Valley, Antarctica: Timing of late holocene climate change in Antarctica
R.J. Poreda, A.G. Hunt, Lyons W. Berry, K.A. Welch
2004, Aquatic Geochemistry (10) 353-371
To better understand the long-term climate history of Antarctica, we studied Lake Bonney in Taylor Valley, Southern Victoria Land (78?? S). Helium isotope ratios and He, Ne, Ar and N2 concentration data, obtained from hydrocasts in the East (ELB) and West (WLB) Lobesof Lake Bonney, provided important constraints on the...
Hydrochemical tracers in the middle Rio Grande Basin, USA: 2. Calibration of a groundwater-flow model
W. E. Sanford, Niel Plummer, D. P. McAda, L. M. Bexfield, S. K. Anderholm
2004, Hydrogeology Journal (12) 389-407
The calibration of a groundwater model with the aid of hydrochemical data has demonstrated that low recharge rates in the Middle Rio Grande Basin may be responsible for a groundwater trough in the center of the basin and for a substantial amount of Rio Grande water in the regional flow...
Divergent evolution in fluviokarst landscapes of central Kentucky
J. D. Phillips, L.L. Martin, V.G. Nordberg, W.A. Andrews Jr.
2004, Earth Surface Processes and Landforms (29) 799-819
Central Kentucky is characterized by a mixture of karst and fluvial features, typically manifested as mosaic of karst-rich/ channel-poor (KRCP) and channel-rich/karst-poor (CRKP) environments. At the regional scale the location and distribution of KRCP and CRKP areas are not always systematically related to structural, lithological, topographic, or other controls. This...
Alum amendment effects on phosphorus release and distribution in poultry litter-amended sandy soils
K.E. Staats, Y. Arai, D.L. Sparks
2004, Journal of Environmental Quality (33) 1904-1911
Increased poultry production has contributed to excess nutrient problems in Atlantic Coastal Plain soils due to land application of poultry litter (PL). Aluminum sulfate [alum, Al2(SO4)3·14H2O] amendment of PL effectively reduces soluble phosphorus (P) in the PL; however, the effects of these litters when added to acidic, sandy soils are...
Modeling the effects of human activity on Katmai brown bears (Ursus arctos) through the use of survival analysis
T. S. Smith, B.A. Johnson
2004, Arctic (57) 160-165
Brown bear-human interactions were observed in 1993, 1995, and 1997 at Kulik River in Katmai National Park and Preserve, Alaska. We analyzed these interactions using survival analysis, creating survival curves for the time that bears remained on the river in the presence, and absence, of human activity. Bear-only survival curves...
Massive sulfide deposition and trace element remobilization in the Middle Valley sediment-hosted hydrothermal system, northern Juan de Fuca Rdge
J.L. Houghton, Wayne C. Shanks III, W.E. Seyfried Jr.
2004, Geochimica et Cosmochimica Acta (68) 2863-2873
The Bent Hill massive sulfide deposit and ODP Mound deposit in Middle Valley at the northernmost end of the Juan de Fuca Ridge are two of the largest modern seafloor hydrothermal deposits yet explored. Trace metal concentrations of sulfide minerals, determined by laser-ablation ICP-MS, were used in conjunction with mineral...
Glacier ice mass fluctuations and fault instability in tectonically active Southern Alaska
J.M. Sauber, B. F. Molnia
2004, Conference Paper, Global and Planetary Change
Across the plate boundary zone in south central Alaska, tectonic strain rates are high in a region that includes large glaciers undergoing wastage (glacier retreat and thinning) and surges. For the coastal region between the Bering and Malaspina Glaciers, the average ice mass thickness changes between 1995 and 2000 range...
Stable foraging areas and variable chick diet in Cassin's auklets (Ptychoramphus aleuticus) off southern California
Josh Adams, John Y. Takekawa, Harry R. Carter
2004, Canadian Journal of Zoology (82) 1578-1595
Planktivorous seabirds readily respond to changes in marine ecosystems and have the ability to integrate information regarding variability in abundance, availability, and community composition of key prey resources. We studied the foraging and breeding ecology of the Cassin's auklet, Ptychoramphus aleuticus (Pallas, 1811), off southern California during three breeding seasons...
Ancient wet aeolian environments on Earth: Clues to presence of fossil/live microorganisms on Mars
W.C. Mahaney, M.W. Milner, D. I. Netoff, D. Malloch, J. M. Dohm, V.R. Baker, H. Miyamoto, T.M. Hare, G. Komatsu
2004, Icarus (171) 39-53
Ancient wet aeolian (wet-sabkha) environments on Earth, represented in the Entrada and Navajo sandstones of Utah, contain pipe structures considered to be the product of gas/water release under pressure. The sediments originally had considerable porosity allowing the ingress of living plant structures, microorganisms, clay minerals, and fine-grained primary minerals of...
Assessing the potential for fish predation to impact zebra mussels (Dreissena polymorpha): Insight from bioenergetics models
M.A. Eggleton, L.E. Miranda, J.P. Kirk
2004, Ecology of Freshwater Fish (13) 85-95
Rates of annual food consumption and biomass were modeled for several fish species across representative rivers and lakes in eastern North America. Results were combined to assess the relative potential of fish predation to impact zebra mussels (Dreissena polymorpha). Predicted annual food consumption by fishes in southern waters was over...
Approaches to surface complexation modeling of Uranium(VI) adsorption on aquifer sediments
J.A. Davis, D.E. Meece, M. Kohler, G.P. Curtis
2004, Geochimica et Cosmochimica Acta (68) 3621-3641
Uranium(VI) adsorption onto aquifer sediments was studied in batch experiments as a function of pH and U(VI) and dissolved carbonate concentrations in artificial groundwater solutions. The sediments were collected from an alluvial aquifer at a location upgradient of contamination from a former uranium mill...
Mechanisms of electron acceptor utilization: Implications for simulating anaerobic biodegradation
M.E. Schreiber, G.R. Carey, D. T. Feinstein, J.M. Bahr
2004, Journal of Contaminant Hydrology (73) 99-127
Simulation of biodegradation reactions within a reactive transport framework requires information on mechanisms of terminal electron acceptor processes (TEAPs). In initial modeling efforts, TEAPs were approximated as occurring sequentially, with the highest energy-yielding electron acceptors (e.g. oxygen) consumed before those that yield less energy (e.g., sulfate). Within this framework in...
Fish-habitat modeling for gap analysis to conserve the endangered Topeka shiner (Notropis topeka)
S.S. Wall, C. R. Berry Jr., C.M. Blausey, J.A. Jenks, C.J. Kopplin
2004, Canadian Journal of Fisheries and Aquatic Sciences (61) 954-973
Decision support tools that predict fish distribution over broad spatial scales are needed to assist in planning watershed management and endangered species recovery. We developed a geographical information system model with multivariate logistic regression to rank valley segments for probable occurrence of the endangered Topeka shiner (Notropis topeka) using stream...
Application of deterministic deconvolution of ground-penetrating radar data in a study of carbonate strata
J. Xia, E. K. Franseen, R. D. Miller, T.V. Weis
2004, Journal of Applied Geophysics (56) 213-229
We successfully applied deterministic deconvolution to real ground-penetrating radar (GPR) data by using the source wavelet that was generated in and transmitted through air as the operator. The GPR data were collected with 400-MHz antennas on a bench adjacent to a cleanly exposed quarry face. The quarry site is characterized...
Shear wave velocity variation across the Taupo Volcanic Zone, New Zealand, from receiver function inversion
S. Bannister, C.J. Bryan, H.M. Bibby
2004, Geophysical Journal International (159) 291-310
The Taupo Volcanic Zone (TVZ), New Zealand is a region characterized by very high magma eruption rates and extremely high heat flow, which is manifest in high-temperature geothermal waters. The shear wave velocity structure across the region is inferred using non-linear inversion of receiver functions, which were derived from teleseismic...
Timing of Precambrian melt depletion and Phanerozoic refertilization events in the lithospheric mantle of the Wyoming Craton and adjacent Central Plains Orogen
R. W. Carlson, A.J. Irving, D.J. Schulze, B. C. Hearn Jr.
2004, LITHOS (77) 453-472
Garnet peridotite xenoliths from the Sloan kimberlite (Colorado) are variably depleted in their major magmaphile (Ca, Al) element compositions with whole rock Re-depletion model ages generally consistent with this depletion occurring in the mid-Proterozoic. Unlike many lithospheric peridotites, the Sloan samples are also depleted in incompatible trace elements, as shown...
Multimodal approach to seismic pavement testing
N. Ryden, C.B. Park, P. Ulriksen, R. D. Miller
2004, Journal of Geotechnical and Geoenvironmental Engineering (130) 636-645
A multimodal approach to nondestructive seismic pavement testing is described. The presented approach is based on multichannel analysis of all types of seismic waves propagating along the surface of the pavement. The multichannel data acquisition method is replaced by multichannel simulation with one receiver. This method uses only one accelerometer-receiver...
Acoustic measurements of the 1999 basaltic eruption of Shishaldin volcano, Alaska 2. Precursor to the Subplinian phase
S. Vergniolle, J. Caplan-Auerbach
2004, Journal of Volcanology and Geothermal Research (137) 135-151
The 1999 eruption of Shishaldin volcano (Alaska, USA) displayed both Strombolian and Subplinian basaltic activity. The Subplinian phase was preceded by a signal of low amplitude and constant frequency (??? 2 Hz) lasting 13 h. This "humming signal" is interpreted as the coalescence of the very shallow part of a...
Similarities in acute phase protein response during hibernation in black bears and major depression in humans: A response to underlying metabolic depression?
J.A. Tsiouris, V.P.S. Chauhan, A.M. Sheikh, A. Chauhan, M. Malik, M.R. Vaughan
2004, Canadian Journal of Zoology (82) 1468-1476
This study investigated the effects of hibernation with mild hypothermia and the stress of captivity on levels of six acute-phase proteins (APPs) in serial samples of serum from 11 wild and 6 captive black bears (Ursus americanus Pallas, 1780) during active and hibernating states. We hypothesize that during hibernation with...
Habitat disturbance and the diversity and abundance of ants (Formicidae) in the Southeastern Fall-Line Sandhills
J.H. Graham, H.H. Hughie, S. Jones, K. Wrinn, A.J. Krzysik, J.J. Duda, D. Carl Freeman, J.M. Emlen, J.C. Zak, D.A. Kovacic, C. Chamberlin-Graham, H. Balbach
2004, Journal of Insect Science (4) 1-15
We examined habitat disturbance, species richness, equitability, and abundance of ants in the Fall-Line Sandhills, at Fort Benning, Georgia. We collected ants with pitfall traps, sweep nets, and by searching tree trunks. Disturbed areas were used for military training; tracked and wheeled vehicles damaged vegetation and soils. Highly disturbed sites...
Evaluation of multidimensional transport through a field-scale compacted soil liner
T.W. Willingham, C.J. Werth, A.J. Valocchi, I.G. Krapac, C. Toupiol, T.D. Stark, D.E. Daniel
2004, Journal of Geotechnical and Geoenvironmental Engineering (130) 887-895
A field-scale compacted soil liner was constructed at the University of Illinois at Urbana-Champaign by the U.S. Environmental Protection Agency (USEPA) and Illinois State Geological Survey in 1988 to investigate chemical transport rates through low permeability compacted clay liners (CCLs). Four tracers (bromide and three benzoic acid tracers) were each...
Enhanced marine productivity off western North America during warm climate intervals of the past 52 k.y
J.D. Ortiz, S. B. O’Connell, J. DelViscio, W. Dean, J.D. Carriquiry, T. Marchitto, Yen Zheng, A. VanGeen
2004, Geology (32) 521-524
Studies of the Santa Barbara Basin off the coast of California have linked changes in its bottom-water oxygen content to millennial-scale climate changes as recorded by the oxygen isotope composition of Greenland ice. Through the use of detailed records from a sediment core collected off the Magdalena Margin of Baja...
