Nutrient sources and transport in the Missouri River Basin, with emphasis on the effects of irrigation and reservoirs
J.B. Brown, L.A. Sprague, J.A. Dupree
2011, Journal of the American Water Resources Association (47) 1034-1060
SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and...
Portrait of a small population of boreal toads (anaxyrus boreas)
E. Muths, R. D. Scherer
2011, Herpetologica (67) 369-377
Much attention has been given to the conservation of small populations, those that are small because of decline, and those that are naturally small. Small populations are of particular interest because ecological theory suggests that they are vulnerable to the deleterious effects of environmental, demographic, and genetic stochasticity as well...
Assessing historical rate changes in global tsunami occurrence
E.L. Geist, T. Parsons
2011, Geophysical Journal International (187) 497-509
The global catalogue of tsunami events is examined to determine if transient variations in tsunami rates are consistent with a Poisson process commonly assumed for tsunami hazard assessments. The primary data analyzed are tsunamis with maximum sizes >1m. The record of these tsunamis appears to be complete since approximately 1890....
δ15N constraints on long-term nitrogen balances in temperate forests
S.S. Perakis, E.R. Sinkhorn, J.E. Compton
2011, Oecologia (167) 793-807
Biogeochemical theory emphasizes nitrogen (N) limitation and the many factors that can restrict N accumulation in temperate forests, yet lacks a working model of conditions that can promote naturally high N accumulation. We used a dynamic simulation model of ecosystem N and δ15N to evaluate which combination of N input...
A trans-dimensional Bayesian Markov chain Monte Carlo algorithm for model assessment using frequency-domain electromagnetic data
B. J. Minsley
2011, Geophysical Journal International (187) 252-272
A meaningful interpretation of geophysical measurements requires an assessment of the space of models that are consistent with the data, rather than just a single, ‘best’ model which does not convey information about parameter uncertainty. For this purpose, a trans-dimensional Bayesian Markov chain Monte Carlo (MCMC) algorithm is developed for...
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...
Habitat suitability and nest survival of white-headed woodpeckers in unburned forests of Oregon
Jeff P. Hollenbeck, Victoria A. Saab, Richard W. Frenzel
2011, Journal of Wildlife Management (75) 1061-1071
We evaluated habitat suitability and nest survival of breeding white-headed woodpeckers (Picoides albolarvatus) in unburned forests of central Oregon, USA. Daily nest-survival rate was positively related to maximum daily temperature during the nest interval and to density of large-diameter trees surrounding the nest tree. We developed a niche-based habitat suitability...
An empirical model of the quiet daily geomagnetic field variation
Y. Yamazaki, K. Yumoto, M.G. Cardinal, B.J. Fraser, P. Hattori, Y. Kakinami, J.Y. Liu, K.J.W. Lynn, R. Marshall, D. McNamara, T. Nagatsuma, V.M. Nikiforov, R.E. Otadoy, M. Ruhimat, B.M. Shevtsov, K. Shiokawa, S. Abe, T. Uozumi, A. Yoshikawa
2011, Journal of Geophysical Research A: Space Physics (116)
An empirical model of the quiet daily geomagnetic field variation has been constructed based on geomagnetic data obtained from 21 stations along the 210 Magnetic Meridian of the Circum‐pan Pacific Magnetometer Network (CPMN) from 1996 to 2007. Using the least squares fitting method for geomagnetically quiet days (Kp ≤ 2+),...
Seismic and geodetic signatures of fault slip at the Slumgullion Landslide Natural Laboratory
J. Gomberg, W. Schulz, P. Bodin, J. Kean
2011, Journal of Geophysical Research B: Solid Earth (116)
We tested the hypothesis that the Slumgullion landslide is a useful natural laboratory for observing fault slip, specifically that slip along its basal surface and side-bounding strike-slip faults occurs with comparable richness of aseismic and seismic modes as along crustal- and plate-scale boundaries. Our study provides new constraints on models...
Landscape evolution in south-central Minnesota and the role of geomorphic history on modern erosional processes
K.B. Gran, P. Belmont, S.S. Day, N. Finnegan, C. Jennings, J.W. Lauer, P.R. Wilcock
2011, Conference Paper, GSA Today
The Minnesota River Valley was carved during catastrophic drainage of glacial Lake Agassiz at the end of the late Pleistocene. The ensuing base-level drop on tributaries created knickpoints that excavated deep valleys as they migrated upstream. A sediment budget compiled in one of these tributaries, the Le Sueur River, shows...
Shear-wave velocity characterization of the USGS Hawaiian strong-motion network on the Island of Hawaii and development of an NEHRP site-class map
Ivan G. Wong, Kenneth Stokoe, Brady R. Cox, Jiabei Yuan, Keith L. Knudsen, Fabia Terra, Paul G. Okubo, Yin-Cheng Lin
2011, Bulletin of the Seismological Society of America (101) 2252-2269
To assess the level and nature of ground shaking in Hawaii for the purposes of earthquake hazard mitigation and seismic design, empirical ground-motion prediction models are desired. To develop such empirical relationships, knowledge of the subsurface site conditions beneath strong-motion stations is critical. Thus, as a first step...
The Christiansen Effect in Saturn's narrow dusty rings and the spectral identification of clumps in the F ring
M.M. Hedman, P. D. Nicholson, M.R. Showalter, R. H. Brown, B. J. Buratti, R. N. Clark, K. Baines, Christophe Sotin
2011, Icarus (215) 695-711
Stellar occultations by Saturn’s rings observed with the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft reveal that dusty features such as the F ring and the ringlets in the Encke and the Laplace Gaps have distinctive infrared transmission spectra. These spectra show a narrow optical depth minimum...
Diffusion-driven magnesium and iron isotope fractionation in Hawaiian olivine
F.-Z. Teng, N. Dauphas, Rosalind Tuthill Helz, S. Gao, S. Huang
2011, Earth and Planetary Science Letters (308) 317-324
Diffusion plays an important role in Earth sciences to estimate the timescales of geological processes such as erosion, sediment burial, and magma cooling. In igneous systems, these diffusive processes are recorded in the form of crystal zoning. However, meaningful interpretation of these signatures is often hampered by the fact that...
Recent advances in the hydrostratigraphy of paleozoic bedrock in the midwestern united states
K. R. Bradbury, Anthony C. Runkel
2011, Conference Paper, GSA Today
Recent hydrostratigraphic researches have made it possible to acquire knowledge about the relatively undeformed Paleozoic bedrock that forms the most widely used aquifers in Minnesota and Wisconsin. Ongoing evaluation of the Cambrian Eau Claire Formation in southern Wisconsin has caused the formation to be considered a major regional aquitard. Subsurface...
Source and Delivery of Nutrients to Receiving Waters in the Northeastern and Mid-Atlantic Regions of the United States
R. B. Moore, C. M. Johnston, R. A. Smith, B. Milstead
2011, Journal of the American Water Resources Association (47) 965-990
This study investigates nutrient sources and transport to receiving waters, in order to provide spatially detailed information to aid water‐resources managers concerned with eutrophication and nutrient management strategies. SPAtially Referenced Regressions On Watershed attributes (SPARROW) nutrient models were developed for the Northeastern and Mid‐Atlantic (NE US) regions of the United...
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...
Time-lapse three-dimensional inversion of complex conductivity data using an active time constrained (ATC) approach
M. Karaoulis, A. Revil, D.D. Werkema, B. J. Minsley, W.F. Woodruff, A. Kemna
2011, Geophysical Journal International (187) 237-251
Induced polarization (more precisely the magnitude and phase of impedance of the subsurface) is measured using a network of electrodes located at the ground surface or in boreholes. This method yields important information related to the distribution of permeability and contaminants in the shallow subsurface. We propose a new time-lapse...
Transient electromagnetic study of basin fill sediments in the Upper San Pedro Basin, Mexico
M.W. Bultman, F. Gray
2011, Environmental Earth Sciences (64) 2091-2106
The Upper San Pedro River Basin in Mexico and the United States is an important riparian corridor that is coming under increasing pressure from growing populations and the associated increase in groundwater withdrawal. Several studies have produced three-dimensional maps of the basin fill sediments in the US portion of the...
Modeled sources, transport, and accumulation of dissolved solids in water resources of the southwestern United States
D.W. Anning
2011, Journal of the American Water Resources Association (47) 1087-1109
Information on important source areas for dissolved solids in streams of the southwestern United States, the relative share of deliveries of dissolved solids to streams from natural and human sources, and the potential for salt accumulation in soil or groundwater was developed using a SPAtially Referenced Regressions On Watershed attributes...
A multitracer approach for characterizing interactions between shallow groundwater and the hydrothermal system in the Norris Geyser Basin area, Yellowstone National Park
W.P. Gardner, David D. Susong, D. K. Solomon, H.P. Heasler
2011, Geochemistry, Geophysics, Geosystems (12)
Multiple environmental tracers are used to investigate age distribution, evolution, and mixing in local‐ to regional‐scale groundwater circulation around the Norris Geyser Basin area in Yellowstone National Park. Springs ranging in temperature from 3°C to 90°C in the Norris Geyser Basin area were sampled for stable isotopes of hydrogen and...
Modules based on the geochemical model PHREEQC for use in scripting and programming languages
S.R. Charlton, D.L. Parkhurst
2011, Computers & Geosciences (37) 1653-1663
The geochemical model PHREEQC is capable of simulating a wide range of equilibrium reactions between water and minerals, ion exchangers, surface complexes, solid solutions, and gases. It also has a general kinetic formulation that allows modeling of nonequilibrium mineral dissolution and precipitation,...
Modeling the height of young forests regenerating from recent disturbances in Mississippi using Landsat and ICESat data
Ainong Li, Chengquan Huang, Guoqing Sun, Hua Shi, Chris Toney, Zhiliang Zhu, Matthew G. Rollins, Samuel N. Goward, Jeffery G. Masek
2011, Remote Sensing of Environment (115) 1837-1849
Many forestry and earth science applications require spatially detailed forest height data sets. Among the various remote sensing technologies, lidar offers the most potential for obtaining reliable height measurement. However, existing and planned spaceborne lidar systems do not have the capability to produce spatially contiguous, fine resolution forest height maps...
Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program
R.B. Hunter, Timothy S. Collett, R. Boswell, B.J. Anderson, S.A. Digert, G. Pospisil, R. Baker, M. Weeks
2011, Marine and Petroleum Geology (28) 295-310
The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the...
Deep rock damage in the san andreas fault revealed by P- and S-type fault-zone-guided waves
William L. Ellsworth, Peter E. Malin
2011, Geological Society Special Publication (359) 39-53
Damage to fault-zone rocks during fault slip results in the formation of a channel of low seismic-wave velocities. Within such channels guided seismic waves, denoted by Fg, can propagate. Here we show with core samples, well logs and Fg-waves that such a channel is crossed by the SAFOD (San Andreas...
Estimating Hydraulic Parameters When Poroelastic Effects Are Significant
S.J. Berg, P. A. Hsieh, W.A. Illman
2011, Ground Water (49) 815-829
For almost 80 years, deformation-induced head changes caused by poroelastic effects have been observed during pumping tests in multilayered aquifer-aquitard systems. As water in the aquifer is released from compressive storage during pumping, the aquifer is deformed both in the horizontal and vertical directions. This deformation in the pumped aquifer...
