Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem factors
J.G. Wiener, B.C. Knights, M.B. Sandheinrich, Jeffrey D. Jeremiason, M. E. Brigham, D.R. Engstrom, L. G. Woodruff, W.F. Cannon, S.J. Balogh
2006, Environmental Science & Technology (40) 6261-6268
Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercury to interior lakes and watersheds within the Park and identified ecosystem factors associated with...
Deep-water antipatharians: Proxies of environmental change
B. Williams, Michael J. Risk, Steve W. Ross, K. J. Sulak
2006, Geology (34) 773-776
Deep-water (307-697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of...
On the interpretation of energy and energy fluxes of nonlinear internal waves: An example from Massachusetts Bay
A. Scotti, R. Beardsley, B. Butman
2006, Journal of Fluid Mechanics (561) 103-112
A self-consistent formalism to estimate baroclinic energy densities and fluxes resulting from the propagation of internal waves of arbitrary amplitude is derived using the concept of available potential energy. The method can be applied to numerical, laboratory or field data. The total energy flux is shown to be the sum...
Population momentum across vertebrate life histories
D. N. Koons, J.B. Grand, J.M. Arnold
2006, Ecological Modelling (197) 418-430
Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally...
The global abundance and size distribution of lakes, ponds, and impoundments
J. A. Downing, Y.T. Prairie, J. J. Cole, C.M. Duarte, L.J. Tranvik, Robert G. Striegl, W. H. McDowell, Pirkko Kortelainen, N.F. Caraco, J.M. Melack, J.J. Middelburg
2006, Limnology and Oceanography (51) 2388-2397
One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance...
Spatial correlation of shear-wave velocity within San Francisco Bay Sediments
E.M. Thompson, L.G. Baise, R. E. Kayen
2006, Conference Paper, GeoCongress 2006: Geotechnical Engineering in the Information Technology Age
Sediment properties are spatially variable at all scales, and this variability at smaller scales influences high frequency ground motions. We show that surface shear-wave velocity is highly correlated within San Francisco Bay Area sediments using shear-wave velocity measurements from 210 seismic cone penetration tests. We use this correlation to estimate...
Hyporheic exchange and fulvic acid redox reactions in an alpine stream/wetland ecosystem, Colorado front range
Matthew P. Miller, Diane M. McKnight, R.M. Cory, Mark W. Williams, Robert L. Runkel
2006, Environmental Science & Technology (40) 5943-5949
The influence of hyporheic zone interactions on the redox state of fulvic acids and other redox active species was investigated in an alpine stream and adjacent wetland, which is a more reducing environment. A tracer injection experiment using bromide (Br-) was conducted in the stream system. Simulations...
Does body size affect a bird's sensitivity to patch size and landscape structure?
Maiken Winter, Douglas H. Johnson, Jill A. Shaffer
2006, Condor (108) 808-816
Larger birds are generally more strongly affected by habitat loss and fragmentation than are smaller ones because they require more resources and thus larger habitat patches. Consequently, conservation actions often favor the creation or protection of larger over smaller patches. However, in grassland systems the boundaries between a patch and...
Global synthesis of groundwater recharge in semiarid and arid regions
Bridget R. Scanlon, K.E. Keese, A. L. Flint, L. E. Flint, C.B. Gaye, W.M. Edmunds, I. Simmers
2006, Hydrological Processes (20) 3335-3370
Global synthesis of the findings from ∼140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many...
Protolith and metamorphic ages of the Haiyangsuo Complex, eastern China: A non-UHP exotic tectonic slab in the Sulu ultrahigh-pressure terrane
J. G. Liou, T. Tsujimori, W. Chu, R. Y. Zhang, J. L. Wooden
2006, Conference Paper, Mineralogy and Petrology
The Haiyangsuo Complex in the NE Sulu ultrahigh-pressure (UHP) terrane has discontinuous, coastal exposures of Late Archean gneiss with amphibolitized granulite, amphibolite, Paleoproterozoic metagabbroic intrusives, and Cretaceous granitic dikes over an area of about 15 km2. The U-Pb SHRIMP dating of zircons indicates that theprotolith age of a garnet-biotite gneiss...
Comparison of the effects and performance of four types of radiotransmitters for use with scoters
S. A. Iverson, W. S. Boyd, Daniel Esler, D.M. Mulcahy, Timothy D. Bowman
2006, Wildlife Society Bulletin (34) 656-663
Radiotransmitters are widely used in wildlife ecology, often providing data that cannot be collected using other methods. However, negative effects have been associated with the use of transmitters for some species. We evaluated the effects and performance of 4 radiotransmitter types for use with surf and white-winged scoters (Melanitta perspicillata...
Use of cotton gin trash to enhance denitrification in restored forested wetlands
S. Ullah, S.P. Faulkner
2006, Forest Ecology and Management (237) 557-563
Lower Mississippi Valley (LMV) has lost about 80% bottomland hardwood forests, mainly to agriculture. This landscape scale alteration of the LMV resulted in the loss of nitrate (NO3) removal capacity of the valley, contributing to nitrogen (N)-enhanced eutrophication and potentially hypoxia in the northern Gulf of Mexico. Restoration of hardwood...
The feasibility of well-logging measurements of arsenic levels using neutron-activation analysis
C.P. Oden, J.S. Schweitzer, G.M. McDowell
2006, Applied Radiation and Isotopes (64) 1074-1081
Arsenic is an extremely toxic metal, which poses a significant problem in many mining environments. Arsenic contamination is also a major problem in ground and surface waters. A feasibility study was conducted to determine if neutron-activation analysis is a practical method of measuring in situ arsenic levels. The response of...
Testing the use of aeromagnetic data for the determination of Curie depth in California
H.E. Ross, R.J. Blakely, Mark D. Zoback
2006, Geophysics (71)
Using California as a test region, we have examined the feasibility of using Curie-isotherm depths, estimated from magnetic anomalies, as a proxy for lithospheric thermal structure. Our method follows previous studies by dividing a regional aeromagnetic database into overlapping subregions and analyzing the power-density spectrum of each subregion, but we...
Reticulate melanism in western painted turtles (Chrysemys picta bellii): Exploring linkages with habitat and heating rates
W.K. Gronke, S. R. Chipps, S.J. Bandas, K.F. Higgins
2006, American Midland Naturalist (156) 289-298
In western painted turtles (Chrysemys picta bellii), males often exhibit one of two morphs: (1) a reticulated form, characterized by an intricate network of dark markings on the carapace or (2) a non-reticulated form. Although several hypotheses have been proposed to explain the adaptive significance of reticulate melanism (RM) on...
Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana
M.C. Woodin, T.C. Michot
2006, Conference Paper, Hydrobiologia
Redheads, Aythya americana, concentrate in large numbers annually in traditional wintering areas along the western and northern rim of the Gulf of Mexico. Two of these areas are the Laguna Madre of Texas and Chandeleur Sound of Louisiana. We collected data on 54,340 activities from 103 redhead flocks in Texas...
Incorporation of seawater into mid-ocean ridge lava flows during emplacement
S.A. Soule, D.J. Fornari, M.R. Perfit, W.I. Ridley, M.H. Reed, J.R. Cann
2006, Earth and Planetary Science Letters (252) 289-307
Evidence for the interaction between seawater and lava during emplacement on the deep seafloor can be observed in solidified flows at a variety of scales including rapid quenching of their outer crusts and the formation of lava pillars through the body of the flow. Recently, an additional interaction, incorporation of...
Secondary gas emissions during coal desorption, Marathon Grassim Oskolkoff-1 Well, Cook Inlet Basin, Alaska: Implications for resource assessment
C.E. Barker, T. Dallegge
2006, Bulletin of Canadian Petroleum Geology (54) 273-291
Cuttings samples of sub-bituminous humic coals from the Oligocene to Pliocene Tyonek Formation, Cook Inlet Basin, Alaska show secondary gas emissions whose geochemistry is consistent with renewed microbial methanogenesis during canister desorption. The renewed methanogenesis was noted after initial desorption measurements had ceased and a canister had an air and...
Seismic characteristics of central Brazil crust and upper mantle: A deep seismic refraction study
J.E. Soares, J. Berrocal, R.A. Fuck, Thomas Mooney, D.B.R. Ventura
2006, Journal of Geophysical Research B: Solid Earth (111)
[1] A two‐dimensional model of the Brazilian central crust and upper mantle was obtained from the traveltime interpretation of deep seismic refraction data from the Porangatu and Cavalcante lines, each approximately 300 km long. When the lines were deployed, they overlapped by 50 km, forming an E‐W...
Groundwater-transported dissolved organic nitrogen exports from coastal watersheds
K.D. Kroeger, Marci L. Cole, I. Valiela
2006, Limnology and Oceanography (51) 2248-2261
We analyzed groundwater-transported nitrogen (N) exports from 41 watershed segments that comprised 10 Cape Cod, Massachusetts watersheds to test the hypotheses that chemical form of N exports is related to land use and to length of flow paths through watersheds. In the absence of human habitation, these glacial outwash-plain watersheds...
Using models to manage systems subject to sustainability indicators
M. C. Hill
2006, Conference Paper, IAHS-AISH Publication
Mathematical and numerical models can provide insight into sustainability indicators using relevant simulated quantities, which are referred to here as predictions. To be useful, many concerns need to be considered. Four are discussed here: (a) mathematical and numerical accuracy of the model; (b) the accuracy of the data used in...
Use of the moon to support on-orbit sensor calibration for climate change measurements
T.C. Stone, H. H. Kieffer
2006, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
Production of reliable climate datasets from multiple observational measurements acquired by remote sensing satellite systems available now and in the future places stringent requirements on the stability of sensors and consistency among the instruments and platforms. Detecting trends in environmental parameters measured at solar reflectance wavelengths (0.3 to 2.5 microns)...
Alkaline volcanic rocks from the Columbia Hills, Gusev crater, Mars
H.Y. McSween, S. W. Ruff, R.V. Morris, J.F. Bell III, Kenneth E. Herkenhoff, Ralf Gellert, K.R. Stockstill, L.L. Tornabene, S. W. Squyres, J.A. Crisp, P. R. Christensen, T.J. McCoy, D. W. Mittlefehldt, M. Schmidt
2006, Journal of Geophysical Research E: Planets (111)
Irvine, Backstay, and Wishstone are the type specimens for three classes of fine-grained or fragmental, relatively unaltered rocks with distinctive thermal emission spectra, found as float on the flanks of the Columbia Hills. Chemical analyses indicate that these rocks are mildly alkaline basalt, trachybasalt, and tephrite, respectively. Their mineralogy consists...
Gimme shelter: The importance of crevices to some fish species inhabiting a deeper-water rocky outcrop in Southern California
M.S. Love, D.M. Schroeder, B. Lenarz, G.R. Cochrane
2006, California Cooperative Oceanic Fisheries Investigations Reports (47) 119-126
Federal law governing fisheries management recognizes the role habitat plays in structuring fish assemblages and achieving sustainable fisheries. However, in most instances it is not known which aspects of habitat are important to the lives of fish species. In 2004, we examined the importance of sheltering sites (crevices) to fishes...
Development of spatially diverse and complex dune-field patterns: Gran Desierto Dune Field, Sonora, Mexico
C. Beveridge, G. Kocurek, R.C. Ewing, N. Lancaster, P. Morthekai, A.K. Singhvi, S. A. Mahan
2006, Sedimentology (53) 1391-1409
The pattern of dunes within the Gran Desierto of Sonora, Mexico, is both spatially diverse and complex. Identification of the pattern components from remote-sensing images, combined with statistical analysis of their measured parameters demonstrate that the composite pattern consists of separate populations of simple dune patterns. Age-bracketing by optically stimulated...
