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Page 1834, results 45826 - 45850

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Not all publications have extents, not all extents are completely accurate
Diverse, discrete, mantle-derived batches of basalt erupted along a short normal fault zone: The Poison Lake chain, southernmost Cascades
L.J.P. Muffler, M.A. Clynne, A.T. Calvert, D.E. Champion
2011, Geological Society of America Bulletin (123) 2177-2200
The Poison Lake chain consists of small, monogenetic, calc-alkaline basaltic volcanoes located east of the Cascade arc axis, 30 km ENE of Lassen Peak in northeastern California. This chain consists of 39 distinguishable units in a 14-km-long and 2-kmwide zone trending NNW, parallel to nearby Quaternary normal faults. The 39...
Investigating the spatial distribution of water levels in the Mackenzie Delta using airborne LiDAR
C. Hopkinson, N. Crasto, P. Marsh, D. Forbes, L. Lesack
2011, Hydrological Processes (25) 2995-3011
Airborne light detection and ranging (LiDAR) data were used to map water level (WL) and hydraulic gradients (δH/δx) in the Mackenzie Delta. The LiDAR WL data were validated against eight independent hydrometric gauge measurements and demonstrated mean offsets from − 0·22 to + 0·04 m (σ< 0·11). LiDAR‐based WL gradients...
Algal bioassessment metrics for wadeable streams and rivers of Maine, USA
Thomas J. Danielson, Cynthia S. Loftin, Leonidas Tsomides, Jeanne L. DiFranco, Beth Connors
2011, Freshwater Science (30) 1033-1048
Many state water-quality agencies use biological assessment methods based on lotic fish and macroinvertebrate communities, but relatively few states have incorporated algal multimetric indices into monitoring programs. Algae are good indicators for monitoring water quality because they are sensitive to many environmental stressors. We evaluated benthic algal community attributes along...
Eruption dynamics of Hawaiian-style fountains: The case study of episode 1 of the Kilauea Iki 1959 eruption
W.K. Stovall, Bruce F. Houghton, H. Gonnermann, S.A. Fagents, Don Swanson
2011, Bulletin of Volcanology (73) 511-529
Hawaiian eruptions are characterized by fountains of gas and ejecta, sustained for hours to days that reach tens to hundreds of meters in height. Quantitative analysis of the pyroclastic products from the 1959 eruption of Kīlauea Iki, Kīlauea volcano, Hawai‘i, provides insights into the processes occurring during typical Hawaiian fountaining...
Hydrogeomorphic processes of thermokarst lakes with grounded-ice and floating-ice regimes on the Arctic coastal plain, Alaska
C.D. Arp, Benjamin M. Jones, F.E. Urban, G. Grosse
2011, Hydrological Processes (25) 2422-2438
Thermokarst lakes cover > 20% of the landscape throughout much of the Alaskan Arctic Coastal Plain (ACP) with shallow lakes freezing solid (grounded ice) and deeper lakes maintaining perennial liquid water (floating ice). Thus, lake depth relative to maximum ice thickness (1·5–2·0 m) represents an important threshold that impacts permafrost,...
Source and site response study of the 2008 Mount Carmel, Illinois, earthquake
S. Hartzell, C. Mendoza
2011, Bulletin of the Seismological Society of America (101) 951-963
Two separate inversions are performed using the ground-motion data from the 2008 Mount Carmel, Illinois, earthquake. One uses aftershocks as empirical Green’s functions to determine a finite-fault slip distribution. The second uses mainshock ground-motion spectra to calculate source, path, and site response parameters. The slip inversion reveals a prominent asperity...
Efficiency of time-lapse intervals and simple baits for camera surveys of wild pigs
B.L. Williams, R.W. Holtfreter, S.S. Ditchkoff, J. Barry Grand
2011, Journal of Wildlife Management (75) 655-659
Growing concerns surrounding established and expanding populations of wild pigs (Sus scrofa) have created the need for rapid and accurate surveys of these populations. We conducted surveys of a portion of the wild pig population on Fort Benning, Georgia, to determine if a longer time‐lapse interval than had been previously...
Distribution and seasonal dynamics of arsenic in a shallow lake in northwestern New Jersey, USA
J. L. Barringer, Z. Szabo, T.P. Wilson, J.L. Bonin, T. Kratzer, K. Cenno, T. Romagna, M. Alebus, B. Hirst
2011, Environmental Geochemistry and Health (33) 1-22
Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions are addressed by alum and copper sulfate applications and aerators operating in the summer....
The use of historical imagery in the remediation of an urban hazardous waste site
E.T. Slonecker
2011, Conference Paper, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
The information derived from the interpretation of historical aerial photographs is perhaps the most basic multitemporal application of remote-sensing data. Aerial photographs dating back to the early 20th century can be extremely valuable sources of historical landscape activity. In this application, imagery from 1918 to 1927 provided a wealth of...
Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments
J. Stankiewicz, G. Munoz, O. Ritter, Paul A. Bedrosian, T. Ryberg, U. Weckmann, M. Weber
2011, Geochemistry, Geophysics, Geosystems (12)
In the framework of the DEad SEa Rift Transect (DESERT) project a 150 km magnetotelluric profile consisting of 154 sites was carried out across the Dead Sea Transform. The resistivity model presented shows conductive structures in the western section of the study area terminating abruptly at the Arava Fault. For...
Evaluation of ADCP apparent bed load velocity in a large sand-bed river: Moving versus stationary boat conditions
E. C. Jamieson, C. D. Rennie, R. B. Jacobson, R. D. Townsend
2011, Journal of Hydraulic Engineering (137) 1064-1071
Detailed mapping of bathymetry and apparent bed load velocity using a boat-mounted acoustic Doppler current profiler (ADCP) was carried out along a 388-m section of the lower Missouri River near Columbia, Missouri. Sampling transects (moving boat) were completed at 5- and 20-m spacing along the study section....
Functional profiles reveal unique ecological roles of various biological soil crust organisms
Matthew A. Bowker, R.L. Mau, F.T. Maestre, C. Escolar, A. P. Castillo-Monroy
2011, Functional Ecology (25) 787-795
 At the heart of the body of research on biodiversity effects on ecosystem function is the debate over whether different species tend to be functionally singular or redundant. When we consider ecosystem multi‐function, the provision of multiple ecosystem functions simultaneously, we may find that seemingly redundant species may in fact...
Random variability explains apparent global clustering of large earthquakes
A.J. Michael
2011, Geophysical Research Letters (38)
The occurrence of 5 Mw ≥ 8.5 earthquakes since 2004 has created a debate over whether or not we are in a global cluster of large earthquakes, temporarily raising risks above long-term levels. I use three classes of statistical tests to determine if the record of M ≥ 7 earthquakes...
Threshold responses of songbirds to long-term timber management on an active industrial forest
Douglas A. Becker, Petra Bohall Wood, Patrick D. Keyser, T. Bently Wigley, Rachel Dellinger, Cathy A. Weakland
2011, Forest Ecology and Management (262) 449-460
Forest managers often seek to balance economic benefits from timber harvesting with maintenance of habitat for wildlife, ecosystem function, and human uses. Most research on the relationship between avian abundance and active timber management has been short-term, lasting one to two years, creating the need to investigate long-term avian responses...
Black swans, wicked problems, and science during crises
G.E. Machlis, M.K. McNutt
2011, Oceanography (24) 318-320
Oceanic resources face challenges that are significant and widespread, including (but not limited to) overharvesting, climate change, selected stock collapse, coral reef decline, species extinction, pollution, and more. These challenges are the focus of much ocean science, which is helping to inform policy and guide management actions. The steady growth...
Changes in agricultural cropland areas between a water-surplus year and a water-deficit year impacting food security, determined using MODIS 250 m time-series data and spectral matching techniques, in the Krishna river basin (India)
Murali Krishna Gumma, Prasad S. Thenkabail, I.V. Muralikrishna, Naga Manohar Velpuri, P.T. Gangadhararao, V. Dheeravath, C.M. Biradar, S.A. Nalan, A. Gaur
2011, International Journal of Remote Sensing (32) 3495-3520
The objective of this study was to investigate the changes in cropland areas as a result of water availability using Moderate Resolution Imaging Spectroradiometer (MODIS) 250 m time-series data and spectral matching techniques (SMTs). The study was conducted in the Krishna River basin in India, a very large river basin...
High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry
J.L.L. Morgan, G.W. Gordon, R.C. Arrua, J.L. Skulan, A.D. Anbar, T.D. Bullen
2011, Analytical Chemistry (83) 6956-6962
We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity...
Trench infiltration for managed aquifer recharge to permeable bedrock
V.M. Heilweil, D.E. Watt
2011, Hydrological Processes (25) 141-151
Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge...
Role of water in hydrocarbon generation from Type-I kerogen in Mahogany oil shale of the Green River Formation
M. D. Lewan, S. Roy
2011, Organic Geochemistry (42) 31-41
Hydrous and anhydrous closed-system pyrolysis experiments were conducted on a sample of Mahogany oil shale (Eocene Green River Formation) containing Type-I kerogen to determine whether the role of water had the same effect on petroleum generation as reported for Type-II kerogen in the Woodford Shale. The experiments were conducted at...
Sulfate threshold target to control methylmercury levels in wetland ecosystems
J. Corrales, G.M. Naja, C. Dziuba, R.G. Rivero, W. Orem
2011, Science of the Total Environment (409) 2156-2162
Sulfate contamination has a significant environmental implication through the stimulation of toxic hydrogen sulfide and methylmercury (MeHg) production. High levels of MeHg are a serious problem in many wetland ecosystems worldwide. In the Florida Everglades, it has been demonstrated that increasing MeHg occurrence is due to a sulfate contamination problem....
Assessment of field-related influences on polychlorinated biphenyl exposures and sorbent amendment using polychaete bioassays and passive sampler measurements
E.M. Janssen, A.M. Oen, Samuel N. Luoma, R.G. Luthy
2011, Environmental Toxicology and Chemistry (30) 173-180
Field-related influences on polychlorinated biphenyl (PCB) exposure were evaluated by employing caged deposit-feeders, Neanthes arenaceodentata, along with polyoxymethylene (POM) samplers using parallel in situ and ex situ bioassays with homogenized untreated or activated carbon (AC) amended sediment. The AC amendment achieved a remedial efficiency in reducing bioaccumulation by 90% in...
Historical trends of hypoxia in Changjiang River estuary: Applications of chemical biomarkers and microfossils
X. Li, T.S. Bianchi, Z. Yang, L.E. Osterman, M. A. Allison, Steven F. DiMarco, G. Yang
2011, Journal of Marine Systems (86) 57-68
Over the past two decades China has become the largest global consumer of fertilizers, which has enhanced river nutrient fluxes and caused eutrophication and hypoxia in the Yangtze (Changjiang) large river delta-front estuary (LDE). In this study, we utilized plant pigments, lignin-phenols, stable isotopes (δ13C and δ15N) and foraminiferal microfossils...
Effectiveness of bowl trapping and netting for inventory of a bee community
R. Grundel, K.J. Frohnapple, R.P. Jean, N.B. Pavlovic
2011, Environmental Entomology (40) 374-380
Concern over the status of bees has increased the need to inventory bee communities and, consequently, has increased the need to understand effectiveness of different bee sampling methods. We sampled bees using bowl traps and netting at 25 northwest Indiana sites ranging from open grasslands to forests. Assemblages of bees...
Microstructure and crystallographic preferred orientation of polycrystalline microgarnet aggregates developed during progressive creep, recovery, and grain boundary sliding
M.A. Massey, D.J. Prior, D.P. Moecher
2011, Journal of Structural Geology (33) 713-730
Optical microscopy, electron probe microanalysis, and electron backscatter diffraction methods have been used to examine a broad range of garnet microstructures within a high strain zone that marks the western margin of a major transpression zone in the southern New England Appalachians. Garnet accommodated variable states of finite strain, expressed...