The Augustine magmatic system as revealed by seismic tomography and relocated earthquake hypocenters from 1994 through 2009
E.M. Syracuse, C.H. Thurber, John A. Power
2011, Journal of Geophysical Research B: Solid Earth (116)
We incorporate 14 years of earthquake data from the Alaska Volcano Observatory with data from a 1975 controlled‐source seismic experiment to obtain the three‐dimensional P and S wave velocity structure and the first high‐precision earthquake locations at Augustine Volcano to be calculated in a fully three‐dimensional velocity model. Velocity tomography...
Simulating adsorption of U(VI) under transient groundwater flow and hydrochemistry: Physical versus chemical nonequilibrium model
J. Greskowiak, M.B. Hay, H. Prommer, C. Liu, V.E.A. Post, R. Ma, J.A. Davis, C. Zheng, J.M. Zachara
2011, Water Resources Research (47)
Coupled intragrain diffusional mass transfer and nonlinear surface complexation processes play an important role in the transport behavior of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes were analyzed and compared: (1) the physical nonequilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface...
Evaluating the growth potential of sea lampreys (Petromyzon marinus) feeding on siscowet lake trout (Salvelinus namaycush) in Lake Superior
E.K. Moody, B.C. Weidel, T.D. Ahrenstorff, W.P. Mattes, J.F. Kitchell
2011, Journal of Great Lakes Research (37) 343-348
Differences in the preferred thermal habitat of Lake Superior lake trout morphotypes create alternative growth scenarios for parasitic sea lamprey (Petromyzon marinus) attached to lake trout hosts. Siscowet lake trout (Salvelinus namaycush) inhabit deep, consistently cold water (4–6 °C) and are more abundant than lean lake trout (Salvelinus namaycush) which...
A first look at the petroleum geology of the Lomonosov Ridge microcontinent, Arctic Ocean
Thomas E. Moore, Arthur Grantz, Janet K. Pitman, Philip J. Brown
2011, Geological Society Memoir (35) 751-769
The Lomonosov microcontinent is an elongated continental fragment that transects the Arctic Ocean between North America and Siberia via the North Pole. Although it lies beneath polar pack ice, the geological framework of the microcontinent is inferred from sparse seismic reflection data, a few cores, potential field data and the...
Regional magnetic domains of the Circum-Arctic: A framework for geodynamic interpretation
R. W. Saltus, E. L. Miller, C. Gaina, P. J. Brown
2011, Geological Society Memoir (35) 49-60
We identify and discuss 57 magnetic anomaly pattern domains spanning the Circum-Arctic. The domains are based on analysis of a new Circum-Arctic data compilation. The magnetic anomaly patterns can be broadly related to general geodynamic classification of the crust into stable, deformed (magnetic and nonmagnetic), deep magnetic high, oceanic and...
Radionuclides, trace elements, and radium residence in phosphogypsum of Jordan
R. A. Zielinski, M. S. Al-Hwaiti, J. R. Budahn, J. F. Ranville
2011, Environmental Geochemistry and Health (33) 149-165
Voluminous stockpiles of phosphogypsum (PG) generated during the wet process production of phosphoric acid are stored at many sites around the world and pose problems for their safe storage, disposal, or utilization. A major concern is the elevated concentration of long-lived 226Ra (half-life = 1,600 years) inherited from the processed...
Sparrow modeling to understand water-quality conditions in major regions of the United States: A featured collection introduction
S. D. Preston, R. B. Alexander, D.M. Wolock
2011, Journal of the American Water Resources Association (47) 887-890
No abstract available....
Nutrient loadings to streams of the Continental United States from municipal and industrial effluent
M.A. Maupin, T. Ivahnenko
2011, Journal of the American Water Resources Association (47) 950-964
Data from the United States Environmental Protection Agency Permit Compliance System national database were used to calculate annual total nitrogen (TN) and total phosphorus (TP) loads to surface waters from municipal and industrial facilities in six major regions of the United States for 1992, 1997, and 2002. Concentration and effluent...
Estimating phosphorus availability for microbial growth in an emerging landscape
S.K. Schmidt, C.C. Cleveland, D.R. Nemergut, S.C. Reed, A.J. King, P. Sowell
2011, Geoderma (163) 135-140
Estimating phosphorus (P) availability is difficult—particularly in infertile soils such as those exposed after glacial recession—because standard P extraction methods may not mimic biological acquisition pathways. We developed an approach, based on microbial CO2 production kinetics and conserved carbon:phosphorus (C:P) ratios, to estimate the amount of P available for microbial...
Use of waveform lidar and hyperspectral sensors to assess selected spatial and structural patterns associated with recent and repeat disturbance and the abundance of sugar maple (Acer saccharum Marsh.) in a temperate mixed hardwood and conifer forest
J.E. Anderson, Mark J. Ducey, A. Fast, M.E. Martin, L. Lepine, M.-L. Smith, T.D. Lee, R.O. Dubayah, M.A. Hofton, P. Hyde, Birgit Peterson, J.B. Blair
2011, Journal of Applied Remote Sensing (5)
Waveform lidar imagery was acquired on September 26, 1999 over the Bartlett Experimental Forest (BEF) in New Hampshire (USA) using NASA's Laser Vegetation Imaging Sensor (LVIS). This flight occurred 20 months after an ice storm damaged millions of hectares of forestland in northeastern North America. Lidar measurements of the amplitude...
Thermal structure and dynamics of Saturn's northern springtime disturbance
L.N. Fletcher, B.E. Hesman, P.G.J. Irwin, K. H. Baines, T.W. Momary, A. Sanchez-Lavega, F.M. Flasar, P.L. Read, G.S. Orton, A. Simon-Miller, R. Hueso, G.L. Bjoraker, A. Mamoutkine, Rio-Gaztelurrutia Del, J.M. Gomez, B. Buratti, R. N. Clark, P. D. Nicholson, Christophe Sotin
2011, Science (332) 1413-1417
Saturn’s slow seasonal evolution was disrupted in 2010–2011 by the eruption of a bright storm in its northern spring hemisphere. Thermal infrared spectroscopy showed that within a month, the resulting planetary-scale disturbance had generated intense perturbations of atmospheric temperatures, winds, and composition between 20° and 50°N over an entire hemisphere...
Active aeolian processes on Mars: A regional study in Arabia and Meridiani Terrae
S. Silvestro, D.A. Vaz, L.K. Fenton, Paul E. Geissler
2011, Geophysical Research Letters (38)
We present evidence of widespread aeolian activity in the Arabia Terra/Meridiani region (Mars), where different kinds of aeolian modifications have been detected and classified. Passing from the regional to the local scale, we describe one particular dune field in Meridiani Planum, where two ripple populations are distinguished by means of...
Scale-dependent factors affecting North American river otter distribution in the midwest
Mackenzie R. Jeffress, Craig P. Paukert, Joanna B. Whittier, B. K. Sandercock, P. S. Gipson
2011, American Midland Naturalist (166) 177-193
The North American river otter (Lontra canadensis) is recovering from near extirpation throughout much of its range. Although reintroductions, trapping regulations and habitat improvements have led to the reestablishment of river otters in the Midwest, little is known about how their distribution is influenced by local- and landscape-scale habitat....
Scented guide ropes as a method to enhance brown treesnake (Boiga irregularis) trap capture success on Guam
L.C. Mason, J. A. Savidge, G.H. Rodda, A. A. Yackel Adams
2011, Journal of Herpetology (45) 308-312
Current methods for controlling the invasive Brown Treesnake (Boiga irregularis) on Guam include a modified minnow trap with a live mouse lure. We investigated the effects on capture success of augmenting these traps with scented guide ropes leading to trap entrances. Initial screening of scent preferences was based on...
Potential misuse of avian density as a conservation metric
Susan K. Skagen, Amy A. Yackel Adams
2011, Conservation Biology (25) 48-55
: Effective conservation metrics are needed to evaluate the success of management in a rapidly changing world. Reproductive rates and densities of breeding birds (as a surrogate for reproductive rate) have been used to indicate the quality of avian breeding habitat, but the underlying assumptions of these metrics rarely have...
Pressure waves in a supersaturated bubbly magma
I. Kurzon, V. Lyakhovsky, O. Navon, B. Chouet
2011, Geophysical Journal International (187) 421-438
We study the interaction of acoustic pressure waves with an expanding bubbly magma. The expansion of magma is the result of bubble growth during or following magma decompression and leads to two competing processes that affect pressure waves. On the one hand, growth in vesicularity leads to increased damping and...
Sex effect on polychlorinated biphenyl concentrations in fish: a synthesis
C.P. Madenjian
2011, Fish and Fisheries (12) 451-460
Polychlorinated biphenyls (PCBs) accumulate in fish primarily via food intake, and therefore, PCBs serve as a chemical tracer for food consumption. Sex differences in PCB concentrations of fish have been attributed to the following three mechanisms: (i) females losing a substantial portion of their PCB body burden during spawning and...
Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity
K. Barrett, A. David McGuire, E.E. Hoy, E.S. Kasischke
2011, Ecological Applications (21) 2380-2396
Large fire years in which >1% of the landscape burns are becoming more frequent in the Alaskan (USA) interior, with four large fire years in the past 10 years, and 79 000 km2 (17% of the region) burned since 2000. We modeled fire severity conditions for the entire area burned in large...
A multi-agency nutrient dataset used to estimate loads, improve monitoring design, and calibrate regional nutrient SPARROW models
D. A. Saad, G. E. Schwarz, Dale M. Robertson, N.L. Booth
2011, Journal of the American Water Resources Association (47) 933-949
Stream‐loading information was compiled from federal, state, and local agencies, and selected universities as part of an effort to develop regional SPAtially Referenced Regressions On Watershed attributes (SPARROW) models to help describe the distribution, sources, and transport of nutrients in streams throughout much of the United States. After screening, 2,739...
Homogenization of large-scale movement models in ecology
M.J. Garlick, J. A. Powell, M.B. Hooten, L.R. McFarlane
2011, Bulletin of Mathematical Biology (73) 2088-2108
A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct...
Using multilevel spatial models to understand salamander site occupancy patterns after wildfire
Nathan Chelgren, M. J. Adams, Larissa L. Bailey, R. Bruce Bury
2011, Ecology (92) 408-421
Studies of the distribution of elusive forest wildlife have suffered from the confounding of true presence with the uncertainty of detection. Occupancy modeling, which incorporates probabilities of species detection conditional on presence, is an emerging approach for reducing observation bias. However, the current likelihood modeling framework is restrictive for handling...
Surface-water nutrient conditions and sources in the United States Pacific Northwest
D.R. Wise, H.M. Johnson
2011, Journal of the American Water Resources Association (47) 1110-1135
The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface-water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well...
Evaluation of groundwater discharge into small lakes based on the temporal distribution of radon-222
N. T. Dimova, W. C. Burnett
2011, Limnology and Oceanography (56) 486-494
In order to evaluate groundwater discharge into small lakes we constructed a model that is based on the budget of 222Rn (radon, t1/2=3.8 d) as a tracer. The main assumptions in our model are that the lake's waters are well‐mixed horizontally and vertically; the only significant 222Rn source is via groundwater discharge;...
A working environment for digital planetary data processing and mapping using ISIS and GRASS GIS
A. Frigeri, T. Hare, M. Neteler, A. Coradini, C. Federico, R. Orosei
2011, Conference Paper, Planetary and Space Science
Since the beginning of planetary exploration, mapping has been fundamental to summarize observations returned by scientific missions. Sensor-based mapping has been used to highlight specific features from the planetary surfaces by means of processing. Interpretative mapping makes use of instrumental observations to produce thematic maps that summarize observations of actual...
Titan's cloud seasonal activity from winter to spring with Cassini/VIMS
S. Rodriguez, S. Le Mouelic, P. Rannou, Christophe Sotin, R. H. Brown, J. W. Barnes, C.A. Griffith, J. Burgalat, K. H. Baines, B. J. Buratti, R. N. Clark, P. D. Nicholson
2011, Icarus (216) 89-110
Since Saturn orbital insertion in July 2004, the Cassini orbiter has been observing Titan throughout most of the northern winter season (October 2002–August 2009) and the beginning of spring, allowing a detailed monitoring of Titan’s cloud coverage at high spatial resolution with close flybys on a monthly basis. This...
