Modeling decadal timescale interactions between surface water and ground water in the central Everglades, Florida, USA
J. W. Harvey, J.T. Newlin, S.L. Krupa
2006, Journal of Hydrology (320) 400-420
Surface-water and ground-water flow are coupled in the central Everglades, although the remoteness of this system has hindered many previous attempts to quantify interactions between surface water and ground water. We modeled flow through a 43,000 ha basin in the central Everglades called Water Conservation Area 2A. The purpose of...
The chlorinated AHR ligand 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) promotes reactive oxygen species (ROS) production during embryonic development in the killifish (Fundulus heteroclitus)
Xabier Arzuaga, Deena Wassenberg, Richard D. Giulio, Adria Elskus
2006, Aquatic Toxicology (76) 13-23
Exposure to dioxin-like chemicals that activate the aryl hydrocarbon receptor (AHR) can result in increased cellular and tissue production of reactive oxygen species (ROS). Little is known of these effects during early fish development. We used the fish model, Fundulus heteroclitus, to determine if the AHR ligand and pro-oxidant 3,3′,4,4′,5-pentachlorobiphenyl (PCB126)...
Spirit rover localization and topographic mapping at the landing site of Gusev crater, Mars
Rongxing Li, Brent A. Archinal, Raymond E. Arvidson, Jim Bell, Phillip R. Christensen, Larry S. Crumpler, David J. Des Marais, Kaichang Di, Tom Duxbury, Matthew P. Golombek, John Grant, Ronald Greeley, Joe Guinn, Aaron H. Johnson, Randolph L. Kirk, Mark Maimone, Larry H. Matthies, Michael Malin, Timothy Parker, Michael H. Sims, Shane D. Thompson, Steven W. Squyres, Laurence A. Soderblom
2006, Journal of Geophysical Research E: Planets (111)
By sol 440, the Spirit rover has traversed a distance of 3.76 km (actual distance traveled instead of odometry). Localization of the lander and the rover along the traverse has been successfully performed at the Gusev crater landing site. We localized the lander in the Gusev crater using two-way Doppler...
Dislocation pileup as a representation of strain accumulation on a strike-slip fault
J.C. Savage
2006, Journal of Geophysical Research B: Solid Earth (111)
The conventional model of strain accumulation on a vertical transform fault is a discrete screw dislocation in an elastic half-space with the Burgers vector of the dislocation increasing at the rate of relative plate motion. It would be more realistic to replace that discrete dislocation by a dislocation distribution, presumably...
The quest for the perfect gravity anomaly: Part 1 - New calculation standards
X. Li, T.G. Hildenbrand, W. J. Hinze, Gordon R. Keller, D. Ravat, M. Webring
2006, SEG Technical Program Expanded Abstracts (25) 859-863
The North American gravity database together with databases from Canada, Mexico, and the United States are being revised to improve their coverage, versatility, and accuracy. An important part of this effort is revision of procedures and standards for calculating gravity anomalies taking into account our enhanced computational power, modern satellite-based...
The study of ozone variations in the Las Vegas metropolitan area using remote sensing information and ground observations
G. Xian, M. Crane
2006, Conference Paper, 86th AMS Annual Meeting
Urban development in the Las Vegas Valley, Nevada, has grown rapidly in the past fifty years. Associated with this growth has been a change in landscape from natural cover types to developed urban land mixed with planned vegetation canopy throughout in the metropolitan area. Air quality in the Las Vegas...
Relative importance of magnetic moments in UXO clearance applications
V. Sanchez, Y. Li, M. Nabighian, D. Wright
2006, SEG Technical Program Expanded Abstracts (25) 1381-1385
Surface magnetic anomaly observed in UXO clearance is mainly dipolar and, as a result, the dipole is the only moment used regularly in UXO applications. The dipole moment contains intensity of magnetization information but lacks shape information. Unlike dipole, higher-order moments, such as quadrupole and octupole, encode asymmetry properties of...
Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates
N. M. Mahowald, D.R. Muhs, S. Levis, P.J. Rasch, M. Yoshioka, C.S. Zender, C. Luo
2006, Journal of Geophysical Research D: Atmospheres (111)
Desert dust simulations generated by the National Center for Atmospheric Research's Community Climate System Model for the current climate are shown to be consistent with present day satellite and deposition data. The response of the dust cycle to last glacial maximum, preindustrial, modern, and doubled-carbon dioxide climates is analyzed. Only...
Evaluation of kinetic uncertainty in numerical models of petroleum generation
K. E. Peters, C.C. Walters, P.J. Mankiewicz
2006, American Association of Petroleum Geologists Bulletin (90) 387-403
Oil-prone marine petroleum source rocks contain type I or type II kerogen having Rock-Eval pyrolysis hydrogen indices greater than 600 or 300-600 mg hydrocarbon/g total organic carbon (HI, mg HC/g TOC), respectively. Samples from 29 marine source rocks worldwide that contain mainly type II kerogen (HI = 230-786 mg HC/g...
Estimating crustal heterogeneity from double-difference tomography
J.-L. Got, V. Monteiller, J. Virieux, P. Okubo
2006, Pure and Applied Geophysics (163) 405-430
Seismic velocity parameters in limited, but heterogeneous volumes can be inferred using a double-difference tomographic algorithm, but to obtain meaningful results accuracy must be maintained at every step of the computation. MONTEILLER et al. (2005) have devised a double-difference tomographic algorithm that takes full advantage of the accuracy of cross-spectral...
Distribution of foraminifera in Pamlico Sound, North Carolina, over the past century
I.J. Abbene, S.J. Culver, D.R. Corbett, M.A. Buzas, L.S. Tully
2006, Journal of Foraminiferal Research (36) 135-151
Foraminiferal and radionuclide data have been used to investigate environmental change that has occurred within Pamlico Sound, North Carolina, over the last century. Environmental conditions were evaluated for three time slices; (1) the modern environment as determined by surficial (0-1 cm) sediments, (2) short-core intervals representing approximately 40 years BP,...
Sulfate deposition in subsurface regolith in Gusev crater, Mars
A. Wang, L.A. Haskin, S. W. Squyres, B.L. Jolliff, L. Crumpler, Ralf Gellert, C. Schroder, Kenneth E. Herkenhoff, J. Hurowitz, N.J. Tosca, W. H. Farrand, R. Anderson, A.T. Knudson
2006, Journal of Geophysical Research E: Planets (111)
Excavating into the shallow Martian subsurface has the potential to expose stratigraphic layers and mature regolith, which may hold a record of more ancient aqueous interactions than those expected under current Martian surface conditions. During the Spirit rover's exploration of Gusev crater, rover wheels were used to dig three trenches...
Scaling uncertainties in estimating canopy foliar maintenance respiration for black spruce ecosystems in Alaska
X. Zhang, A. D. McGuire, Roger W. Ruess
2006, Mitigation and Adaptation Strategies for Global Change (11) 147-174
A major challenge confronting the scientific community is to understand both patterns of and controls over spatial and temporal variability of carbon exchange between boreal forest ecosystems and the atmosphere. An understanding of the sources of variability of carbon processes at fine scales and how these contribute to uncertainties in...
Response of surface water chemistry to reduced levels of acid precipitation: Comparison of trends in two regions of New York, USA
Douglas A. Burns, M.R. McHale, C. T. Driscoll, K. M. Roy
2006, Hydrological Processes (20) 1611-1627
In light of recent reductions in sulphur (S) and nitrogen (N) emissions mandated by Title IV of the Clean Air Act Amendments of 1990, temporal trends and trend coherence in precipitation (1984-2001 and 1992-2001) and surface water chemistry (1992-2001) were determined in two of the most acid-sensitive regions of North...
A method for mapping corn using the US Geological Survey 1992 National Land Cover Dataset
S.K. Maxwell, J.R. Nuckols, M.H. Ward
2006, Computers and Electronics in Agriculture (51) 54-65
Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin's lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type....
Evaluation of the factors controlling the time-dependent inactivation rate coefficients of bacteriophage MS2 and PRD1
R. Anders, C.V. Chrysikopoulos
2006, Environmental Science & Technology (40) 3237-3242
Static and dynamic batch experiments were conducted to study the effects of temperature and the presence of sand on the inactivation of bacteriophage MS2 and PRD1. The experimental data suggested that the inactivation process can be satisfactorily represented by a pseudo-first-order expression with time-dependent rate coefficients. The time-dependent rate coefficients...
Time-lapse seismic study of levees in southern New Mexico
J. Ivanov, R. D. Miller, N. Stimac, R.F. Ballard Jr., J. Joseph Dunbar, S. Steve Smullen
2006, SEG Technical Program Expanded Abstracts (25) 3255-3259
The primary objective of this work was to measure changes in compressional- (Vp) and shear-wave (Vs) velocities in an earthen levee during a ponding experiment designed to simulate flood conditions on the Rio Grande in south New Mexico. Although similar to such experiment, performed an year earlier on the Rio...
Influence of landscape-scale factors in limiting brook trout populations in Pennsylvania streams
P.M. Kocovsky, R.F. Carline
2006, Transactions of the American Fisheries Society (135) 76-88
Landscapes influence the capacity of streams to produce trout through their effect on water chemistry and other factors at the reach scale. Trout abundance also fluctuates over time; thus, to thoroughly understand how spatial factors at landscape scales affect trout populations, one must assess the changes in populations over time...
A productivity model for parasitized, multibrooded songbirds
L.A. Powell, M. G. Knutson
2006, Condor (108) 292-300
We present an enhancement of a simulation model to predict annual productivity for Wood Thrushes (Hylocichla mustelina) and American Redstarts (Setophaga ruticilla); the model includes effects of Brown-headed Cowbird (Molothrus ater) parasitism. We used species-specific data from the Driftless Area Ecoregion of Wisconsin, Minnesota, and Iowa to parameterize the model...
Chemical evolution of Miocene wood: Example from the Belchatow brown coal deposit, central Poland
A. Drobniak, Maria Mastalerz
2006, International Journal of Coal Geology (66) 157-178
Miocene conifer wood samples from the Belchatow brown coal deposit in Poland were studied in order to discuss a range of chemical variations that occur as a result of biochemical coalification. Petrographic analysis, ultimate analysis, electron microprobe technique, and FTIR spectroscopy were used in this study. Our data show several...
Demography, genetics, and the value of mixed messages
John M. Pearce, Sandra L. Talbot
2006, Condor (108) 474-479
Iverson et al. (2004) used estimates of the homing rate for molting adult Harlequin Ducks (Histrionicus histrionicus) in Alaska to draw inferences about population structure. Homing rates, defined as one minus the ratio of birds recaptured elsewhere to those recaptured at the original banding site, were high (0.95–1.00) for males...
Mapping stream habitats with a global positioning system: Accuracy, precision, and comparison with traditional methods
D.C. Dauwalter, W.L. Fisher, K.C. Belt
2006, Environmental Management (37) 271-280
We tested the precision and accuracy of the Trimble GeoXT??? global positioning system (GPS) handheld receiver on point and area features and compared estimates of stream habitat dimensions (e.g., lengths and areas of riffles and pools) that were made in three different Oklahoma streams using the GPS receiver and a...
Crustal contamination and crystal entrapment during polybaric magma evolution at Mt. Somma-Vesuvius volcano, Italy: Geochemical and Sr isotope evidence
M. Piochi, R. A. Ayuso, B. de Vivo, R. Somma
2006, LITHOS (86) 303-329
New major and trace element analyses and Sr-isotope determinations of rocks from Mt. Somma-Vesuvius volcano produced from 25 ky BP to 1944 AD are part of an extensive database documenting the geochemical evolution of this classic region. Volcanic rocks include silica undersaturated, potassic and ultrapotassic lavas and tephras characterized by...
Nitrogen loads to estuaries from waste water plumes: Modeling and isotopic approaches
K.D. Kroeger, Marci L. Cole, J.K. York, I. Valiela
2006, Ground Water (44) 188-200
We developed, and applied in two sites, novel methods to measure ground water-borne nitrogen loads to receiving estuaries from plumes resulting from land disposal of waste water treatment plant (WWTP) effluent. In addition, we quantified nitrogen losses from WWTP effluent during transport through watersheds. WWTP load to receiving water was...
Numerical modeling of a long-term in situ chemical osmosis experiment in the Pierre Shale, South Dakota
A.M. Garavito, H. Kooi, C. E. Neuzil
2006, Advances in Water Resources (29) 481-492
We have numerically modeled evolving fluid pressures and concentrations from a nine-year in situ osmosis experiment in the Pierre Shale, South Dakota. These data were obtained and recently interpreted by one of us (C.E.N.) as indicating a potentially significant role for chemical osmosis in media like the Pierre Shale. That...
