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...
Native and European haplotypes of Phragmites Australis (common reed) in the central Platte River, Nebraska
D.L. Larson, S.M. Galatowitsch, J.L. Larson
2011, Great Plains Research (21) 175-180
Phragmites australis (common reed) is known to have occurred along the Platte River historically, but recent rapid increases in both distribution and density have begun to impact habitat for migrating sandhill cranes and nesting piping plovers and least terns. Invasiveness in Phragmites has been associated with the incursion of a...
Islands at bay: Rising seas, eroding islands, and waterbird habitat loss in Chesapeake Bay (USA)
R. Michael Erwin, D.F. Brinker, B.D. Watts, G.R. Costanzo, D.D. Morton
2011, Journal of Coastal Conservation (15) 51-60
Like many resources in the Chesapeake Bay region of the U.S., many waterbird nesting populations have suffered over the past three to four decades. In this study, historic information for the entire Bay and recent results from the Tangier Sound region were evaluated to illustrate patterns of island erosion and...
Ground settlement monitoring based on temporarily coherent points between two SAR acquisitions
L. Zhang, X. Ding, Z. Lu
2011, ISPRS Journal of Photogrammetry and Remote Sensing (66) 146-152
An InSAR analysis approach for identifying and extracting the temporarily coherent points (TCP) that exist between two SAR acquisitions and for determining motions of the TCP is presented for applications such as ground settlement monitoring. TCP are identified based on the spatial characteristics of the range and azimuth offsets of...
Methane hydrate-bearing seeps as a source of aged dissolved organic carbon to the oceans
J. W. Pohlman, J.E. Bauer, W.F. Waite, C.L. Osburn, N.R. Chapman
2011, Nature Geoscience (4) 37-41
Marine sediments contain about 500-10,000 Gt of methane carbon, primarily in gas hydrate. This reservoir is comparable in size to the amount of organic carbon in land biota, terrestrial soils, the atmosphere and sea water combined, but it releases relatively little methane to the ocean and atmosphere. Sedimentary microbes convert...
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...
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...
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...
Waves and tides responsible for the intermittent closure of the entrance of a small, sheltered tidal wetland at San Francisco, CA
D.M. Hanes, K. Ward, L. H. Erikson
2011, Continental Shelf Research (31) 1682-1687
Crissy Field Marsh (CFM; http://www.nps.gov/prsf/planyourvisit/crissy-field-marsh-and-beach.htm) is a small, restored tidal wetland located in the entrance to San Francisco Bay just east of the Golden Gate. The marsh is small but otherwise fairly typical of many such restored wetlands worldwide. The marsh is hydraulically connected to the...
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...
Provenance of Des Moines lobe till records ice-stream catchment evolution during Laurentide deglaciation
B.A. Lusardi, C.E. Jennings, K.L. Harris
2011, Boreas (40) 585-597
Mapping and analysis of deposits of the Des Moines lobe of the Laurentide Ice Sheet, active after the Last Glacial Maximum (LGM), reveal several texturally and lithologically distinct tills within what had been considered to be a homogeneous deposit. Although the differences between tills are subtle, minor distinctions are predictable...
The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies
Z.M. Migaszewski, P. J. Lamothe, J.G. Crock, A. Galuszka, S. Dolegowska
2011, Environmental Chemistry Letters (9) 323-329
Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the...
U.S. Department of Energy's site screening, site selection, and initial characterization for storage of CO2 in deep geological formations
T.D. Rodosta, J.T. Litynski, S.I. Plasynski, S. Hickman, S. Frailey, L. Myer
2011, Conference Paper, Energy Procedia
The U.S. Department of Energy (DOE) is the lead Federal agency for the development and deployment of carbon sequestration technologies. As part of its mission to facilitate technology transfer and develop guidelines from lessons learned, DOE is developing a series of best practice manuals (BPMs) for carbon capture and storage...
Behavioral and physiological responses to male handicap in chick-rearing black-legged kittiwakes
S. Leclaire, V. Bourret, R.H. Wagner, Scott A. Hatch, F. Helfenstein, O. Chastel, E. Danchin
2011, Behavioral Ecology (22) 1156-1165
Parental investment entails a trade-off between the benefits of effort in current offspring and the costs to future reproduction. Long-lived species are predicted to be reluctant to increase parental effort to avoid affecting their survival. We tested this hypothesis in black-legged kittiwakes Rissa tridactyla by clipping flight feathers of experimental males at...
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...
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...
Stoichiometric relationship between suspension-feeding caddisfly (Trichoptera: Brachycentridae) and seston
J.A. Veldboom, R. J. Haro
2011, Hydrobiologia (675) 129-141
Organisms must acquire adequate amounts of carbon (C) and nutrients [i.e., nitrogen (N) and phosphorus (P)] from their food to support growth. The growth of organisms can be constrained by consumer-resource elemental imbalances in C:nutrient ratios, especially in aquatic ecosystems. Furthermore, the elemental composition of aquatic organisms can change through...
Soils and late-Quaternary landscape evolution in the Cottonwood River basin, east-central Kansas: Implications for archaeological research
J.M. Beeton, R.D. Mandel
2011, Geoarchaeology (26) 693-723
Temporal and spatial patterns of landscape evolution strongly influence the temporal and spatial patterns of the archaeological record in drainage systems. In this geoarchaeological investigation we took a basin‐wide approach in assessing the soil stratigraphy, lithostratigraphy, and geochronology of alluvial deposits and associated buried soils in the Cottonwood River basin...
Near-surface shear-wave velocity measurements in unlithified sediment
B.T. Richards, D. Steeples, R. Miller, J. Ivanov, S. Peterie, S.D. Sloan, J.R. McKenna
2011, SEG Technical Program Expanded Abstracts (30) 1416-1420
S-wave velocity can be directly correlated to material stiffness and lithology making it a valuable physical property that has found uses in construction, engineering, and environmental projects. This study compares different methods for measuring S-wave velocities, investigating and identifying the differences among the methods' results, and prioritizing the different methods...
Sewers as a source and sink of chlorinated-solvent groundwater contamination, Marine Corps Recruit Depot, Parris Island, South Carolina
D.A. Vroblesky, M.D. Petkewich, M.A. Lowery, J. E. Landmeyer
2011, Ground Water Monitoring and Remediation (31) 63-69
Groundwater contamination by tetrachloroethene and its dechlorination products is present in two partially intermingled plumes in the surficial aquifer near a former dry‐cleaning facility at Site 45, Marine Corps Recruit Depot, Parris Island, South Carolina. The northern plume originates from the vicinity of former above‐ground storage tanks. Free‐phase tetrachloroethene from...
Migration and wintering sites of Pelagic Cormorants determined by satellite telemetry
Scott A. Hatch, V.A. Gill, D.M. Mulcahy
2011, Journal of Field Ornithology (82) 269-278
Factors affecting winter survival may be key determinants of status and population trends of seabirds, but connections between breeding sites and wintering areas of most populations are poorly known. Pelagic Cormorants (Phalacrocorax pelagicus; N= 6) surgically implanted with satellite transmitters migrated from a breeding colony on Middleton Island, northern Gulf...
Species replacement by a nonnative salmonid alters ecosystem function by reducing prey subsidies that support riparian spiders
J.R. Benjamin, K.D. Fausch, C. V. Baxter
2011, Oecologia (167) 503-512
Replacement of a native species by a nonnative can have strong effects on ecosystem function, such as altering nutrient cycling or disturbance frequency. Replacements may cause shifts in ecosystem function because nonnatives establish at different biomass, or because they differ from native species in traits like foraging behavior. However, no...
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...
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...
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....
