Hydrochemical characterization of groundwater in the Akyem area, Ghana
B. Banoeng-Yakubo, S.M. Yidana, Y. Anku, T. Akabzaa, D. Asiedu
2008, Journal of Environmental Hydrology (16) 1-12
The Akyem area is a small farming community located in southeastern Ghana. Groundwater samples from wells in the area were analyzed for concentrations of the major ions, silica, electrical conductivity and pH. The objective was to determine the main controls on the hydrochemistry of ground-water. Mass balance modeling was used...
Fidelity and breeding probability related to population density and individual quality in black brent geese Branta bernicla nigricans
James S. Sedinger, N.D. Chelgren, David H. Ward, M. S. Lindberg
2008, Journal of Animal Ecology (77) 702-712
1. Patterns of temporary emigration (associated with non-breeding) are important components of variation in individual quality. Permanent emigration from the natal area has important implications for both individual fitness and local population dynamics. 2. We estimated both permanent and temporary emigration of black brent geese (Branta bernicla nigricans Lawrence) from...
The use of groundwater age as a calibration target
Leonard F. Konikow, G.Z. Hornberger, L.D. Putnam, A.M. Shapiro, B.A. Zinn
2008, Conference Paper, IAHS-AISH Publication
Groundwater age (or residence time), as estimated on the basis of concentrations of one or more environmental tracers, can provide a useful and independent calibration target for groundwater models. However, concentrations of environmental tracers are affected by the complexities and mixing inherent in groundwater flow through heterogeneous media, especially in...
Development and evaluation of geochemical methods for the sourcing of archaeological maize
L. V. Benson, Howard E. Taylor, K.A. Peterson, B.D. Shattuck, C.A. Ramotnik, J.R. Stein
2008, Journal of Archaeological Science (35) 912-921
Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths...
Aspen height, stem-girth and survivorship in an area of high ungulate use
R.B. Keigley, M.R. Frisina
2008, Northwest Science (82) 199-210
An increase in ungulate population size potentially exposes aspen suckers, saplings, and trees to increased use. This study examined how stem height and girth influenced the selection of stems by ungulates for browsing, rubbing, and gnawing, and reconstructed the history of ungulate use for the study area. Transects were run...
Thermal history of the unsaturated zone at Yucca Mountain, Nevada, USA
J. F. Whelan, L.A. Neymark, R.J. Moscati, B.D. Marshall, E. Roedder
2008, Applied Geochemistry (23) 1041-1075
Secondary calcite, silica and minor amounts of fluorite deposited in fractures and cavities record the chemistry, temperatures, and timing of past fluid movement in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a high-level radioactive waste repository. The distribution and geochemistry of these deposits are consistent with...
Tectonic and magmatic evolution of the northwestern Basin and Range and its transition to unextended volcanic plateaus: Black Rock Range, Nevada
D.W. Lerch, E. Miller, M. McWilliams, J. Colgan
2008, Geological Society of America Bulletin (120) 300-311
The seismically active eastern and western margins of the northern Basin and Range have been extensively studied, yet the northwestern margin of the province remains incompletely understood. The Black Rock Range of northwestern Nevada straddles the transition from the Basin and Range province to the south and east, and flat-lying...
Fate and transport of pesticides in the ground water systems of southwest Georgia, 1993-2005
M.S. Dalton, E. A. Frick
2008, Conference Paper, Journal of Environmental Quality
Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological...
Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts
M. A. Bowker, J. Belnap, Bala V. Chaudhary, N.C. Johnson
2008, Soil Biology and Biochemistry (40) 2309-2316
Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which...
Soil slip/debris flow localized by site attributes and wind-driven rain in the San Francisco Bay region storm of January 1982
R.J. Pike, S. Sobieszczyk
2008, Geomorphology (94) 290-313
GIS analysis at 30-m resolution reveals that effectiveness of slope-destabilizing processes in the San Francisco Bay area varies with compass direction. Nearly half the soil slip/debris flows mapped after the catastrophic rainstorm of 3-5 January 1982 occurred on slopes that face S to WSW, whereas fewer than one-quarter have a...
Seismic hazard in the Istanbul metropolitan area: A preliminary re-evaluation
E. Kalkan, Polat Gulkan, N.Y. Ozturk, M. Çelebi
2008, Journal of Earthquake Engineering (12) 151-164
In 1999, two destructive earthquakes (M7.4 Kocaeli and M7.2 Duzce) occurred in the north west of Turkey and resulted in major stress-drops on the western segment of the North Anatolian Fault system where it continues under the Marmara Sea. These undersea fault segments were recently explored using bathymetric and reflection...
Deformation and stress-change modeling at Sierra Negra volcano, Galapagos, from ENVISAT INSAR and GPS observations
Sigurjon Jonsson, W.W. Chadwick, Michael Poland, D. Geist
2008, Conference Paper, European Space Agency, (Special Publication) ESA SP
We use radar interferograms and GPS observations to constrain models of magma accumulation and faulting at Sierra Negra volcano, Galápagos, during the years before its 2005 eruption. The data have shown ~5 m of pre-eruption uplift and multiple trapdoor faulting events on an intra-caldera fault system. We find the...
Diverse deformation patterns of Aleutian volcanoes from InSAR
Z. Lu, D. Dzurisin, C. Wicks Jr., J. Power
2008, Conference Paper, European Space Agency, (Special Publication) ESA SP
Interferometric synthetic aperture radar (InSAR) is capable of measuring ground-surface deformation with centimeter-to-subcentimeter precision at a spatial resolution of tens of meters over an area of hundreds to thousands of square kilometers. With its global coverage and all-weather imaging capability, InSAR has become an increasingly important measurement technique for constraining...
Mineralogical and compositional characteristics of Late Permian coals from an area of high lung cancer rate in Xuan Wei, Yunnan, China: Occurrence and origin of quartz and chamosite
S. Dai, L. Tian, C. L. Chou, Y. Zhou, M. Zhang, L. Zhao, Jingyuan Wang, Z. Yang, H. Cao, D. Ren
2008, International Journal of Coal Geology (76) 318-327
Some townships in Xuan Wei County, Yunnan Province, have one of the highest lung cancer mortality rates in China and the epidemic disease in the area has generally been attributed to the polycyclic aromatic hydrocarbons (PAHs) released from domestic coal burning. However, the cancer-causing culprit is not settled as Tian...
100 Myr record of sequences, sedimentary facies and sea level change from Ocean Drilling Program onshore coreholes, US Mid-Atlantic coastal plain
J.V. Browning, K.G. Miller, P. J. Sugarman, M.A. Kominz, P.P. McLaughlin, A.A. Kulpecz, M.D. Feigenson
2008, Basin Research (20) 227-248
We analyzed the latest Early Cretaceous to Miocene sections (???110-7Ma) in 11 New Jersey and Delaware onshore coreholes (Ocean Drilling Program Legs 150X and 174AX). Fifteen to seventeen Late Cretaceous and 39-40 Cenozoic sequence boundaries were identified on the basis of physical and temporal breaks. Within-sequence changes follow predictable patterns...
Radiometric cross-calibration of the Terra MODIS and Landsat 7 ETM+ using an invariant desert site
T. Choi, A. Angal, G. Chander, X. Xiong
2008, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
A methodology for long-term radiometric cross-calibration between the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) sensors was developed. The approach involves calibration of near-simultaneous surface observations between 2000 and 2007. Fifty-seven cloud-free image pairs were carefully selected over the Libyan desert for...
Relationship of floodplain ichnocoenoses to paleopedology, paleohydrology, and paleoclimate in the Willwood Formation, Wyoming, during the Paleocene-Eocene Thermal Maximum
J.J. Smith, S.T. Hasiotis, M. J. Kraus, D.T. Woody
2008, Palaios (23) 683-699
Vertical changes in distribution, abundance, and ichnodiversity of ichnocoenoses in alluvial deposits of the Willwood Formation suggest significantly drier moisture regimes in the Bighorn Basin, Wyoming, during the Paleocene-Eocene Thermal Maximum (PETM), a transient period of global warming. The Willwood Formation at Polecat Bench contains an abundant assemblage of ichnofossils,...
Monitoring programs to assess reintroduction efforts: A critical component in recovery
E. Muths, V. Dreitz
2008, Animal Biodiversity and Conservation (31) 47-56
Reintroduction is a powerful tool in our conservation toolbox. However, the necessary follow-up, i.e. long-term monitoring, is not commonplace and if instituted may lack rigor. We contend that valid monitoring is possible, even with sparse data. We present a means to monitor based on demographic data and a projection model...
MODIS and SeaWIFS on-orbit lunar calibration
Jielun Sun, R.E. Eplee Jr., X. Xiong, T. Stone, G. Meister, C.R. McClain
2008, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
The Moon plays an important role in the radiometric stability monitoring of the NASA Earth Observing System's (EOS) remote sensors. The MODIS and SeaWIFS are two of the key instruments for NASA's EOS missions. The MODIS Protoflight Model (PFM) on-board the Terra spacecraft and the MODIS Flight Model 1 (FM1)...
Track of the Yellowstone hotspot: Young and ongoing geologic processes from the Snake River Plain to the Yellowstone Plateau and Tetons
Lisa A. Morgan, Kenneth L. Pierce, Pat Shanks
Robert G.H. Raynolds, editor(s)
2008, Book chapter, Roaming the Rocky Mountains and environs: Geological field trips
This field trip highlights various stages in the evolution of the Snake River Plain–Yellowstone Plateau bimodal volcanic province, and associated faulting and uplift, also known as the track of the Yellowstone hotspot. The 16 Ma Yellowstone hotspot track is one of the few places on Earth where time-transgressive processes on...
Hydrogeomorphic features mediate the effects of land use/cover on reservoir productivity and food webs
M.T. Bremigan, P.A. Soranno, M.J. Gonzalez, D.B. Bunnell, K.K. Arend, W. H. Renwick, R.A. Stein, M.J. Vanni
2008, Limnology and Oceanography (53) 1420-1433
Although effects of land use/cover on nutrient concentrations in aquatic systems are well known, half or more of the variation in nutrient concentration remains unexplained by land use/cover alone. Hydrogeomorphic (HGM) landscape features can explain much remaining variation and influence food web interactions. To explore complex linkages among land use/cover,...
Scaling hyporheic exchange and its influence on biogeochemical reactions in aquatic ecosystems
Ben L. O’Connor, Judson W. Harvey
2008, Water Resources Research (44)
Hyporheic exchange and biogeochemical reactions are difficult to quantify because of the range in fluid‐flow and sediment conditions inherent to streams, wetlands, and nearshore marine ecosystems. Field measurements of biogeochemical reactions in aquatic systems are impeded by the difficulty of measuring hyporheic flow simultaneously with chemical gradients in sediments. Simplified...
Nitrogen attenuation in the Connecticut River, northeastern USA; a comparison of mass balance and N2 production modeling approaches
T. E. Smith, A.E. Laursen, J. R. Deacon
2008, Biogeochemistry (87) 311-323
Two methods were used to measure in-stream nitrogen loss in the Connecticut River during studies conducted in April and August 2005. A mass balance on nitrogen inputs and output for two study reaches (55 and 66 km), at spring high flow and at summer low flow, was computed on the...
Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them
Richard A. Schultz, Roger Soliva, Haakon Fossen, Chris Okubo, Donald M. Reeves
2008, Journal of Structural Geology (30) 1405-1411
Displacement–length data from faults, joints, veins, igneous dikes, shear deformation bands, and compaction bands define two groups. The first group, having a power-law scaling relation with a slope of n = 1 and therefore a linear dependence of maximum displacement and discontinuity length (Dmax = γL), comprises faults and...
Historical and current environmental influences on an endemic great plains fish
John R. Fischer, C.P. Paukert
2008, American Midland Naturalist (159) 364-377
Native fishes of the Great Plains are at risk of decline due to disturbances to physical habitat caused by changes in land and water use, as well as shifts in species assemblages driven by the invasion of introduced species with the loss of natives. We used historical and current fish...
