HiRISE observations of fractured mounds: Possible Martian pingos
Colin M. Dundas, Michael T. Mellon, Alfred S. McEwen, Alexandra Lefort, Laszlo P. Keszthelyi, Nicolas Thomas
2008, Geophysical Research Letters (35)
Early images from the High Resolution Imaging Science Experiment (HiRISE) camera have revealed small fractured mounds in the Martian mid‐latitudes. HiRISE resolves fractures on the mound surfaces, indicating uplift, and shows that the mound surface material resembles that of the surrounding landscape. Analysis of Mars Orbiter Camera (MOC) images shows...
A comparative analysis of simulated and observed landslide locations triggered by Hurricane Camille in Nelson County, Virginia
M.M. Morrissey, G. F. Wieczorek, B. A. Morgan
2008, Hydrological Processes (22) 524-531
In 1969, Nelson County, Virginia received up to 71 cm of rain within 12 h starting at 7 p.m. on August 19. The total rainfall from the storm exceeded the 1000-year return period in the region. Several thousands of landslides were induced by rainfall associated with Hurricane Camille causing fatalities...
Modeling variability and trends in pesticide concentrations in streams
A. V. Vecchia, Jeffrey D. Martin, R. J. Gilliom
2008, Journal of the American Water Resources Association (44) 1308-1324
A parametric regression model was developed for assessing the variability and long-term trends in pesticide concentrations in streams. The dependent variable is the logarithm of pesticide concentration and the explanatory variables are a seasonal wave, which represents the seasonal variability of concentration in response to seasonal application rates; a streamflow...
Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain
R.L. Bentzen, A.N. Powell, R.S. Suydam
2008, Journal of Wildlife Management (72) 1781-1789
King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2...
Thermal and energetic constraints on ectotherm abundance: A global test using lizards
L.B. Buckley, G.H. Rodda, W. Jetz
2008, Ecology (89) 48-55
Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population...
The role of shear and tensile failure in dynamically triggered landslides
T.L. Gipprich, R.K. Snieder, R.W. Jibson, W. Kimman
2008, Geophysical Journal International (172) 770-778
Dynamic stresses generated by earthquakes can trigger landslides. Current methods of landslide analysis such as pseudo-static analysis and Newmark's method focus on the effects of earthquake accelerations on the landslide mass to characterize dynamic landslide behaviour. One limitation of these methods is their use Mohr-Coulomb failure criteria, which only accounts...
Modeled tephra ages from lake sediments, base of Redoubt Volcano, Alaska
C.J. Schiff, D. S. Kaufman, K.L. Wallace, A. Werner, T.-L. Ku, T.A. Brown
2008, Quaternary Geochronology (3) 56-67
A 5.6-m-long lake sediment core from Bear Lake, Alaska, located 22 km southeast of Redoubt Volcano, contains 67 tephra layers deposited over the last 8750 cal yr, comprising 15% of the total thickness of recovered sediment. Using 12 AMS 14C ages, along with the 137Cs and 210Pb activities of recent...
Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China
Y. Zhao, Jiahua Zhang, C. L. Chou, Y. Li, Z. Wang, Y. Ge, C. Zheng
2008, International Journal of Coal Geology (73) 52-62
The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr,...
Variability of passive gas emissions, seismicity, and deformation during crater lake growth at White Island Volcano, New Zealand, 2002-2006
C. Werner, T. Hurst, B. Scott, S. Sherburn, B.W. Christenson, K. Britten, J. Cole-Baker, B. Mullan
2008, Journal of Geophysical Research B: Solid Earth (113)
We report on 4 years of airborne measurements of CO2, SO2, and H2S emission rates during a quiescent period at White Island volcano, New Zealand, beginning in 2003. During this time a significant crater lake emerged, allowing scrubbig processes to be investigated. CO2 emissions varied from a baseline of 250...
An exact solution for ideal dam-break floods on steep slopes
C. Ancey, Richard M. Iverson, M. Rentschler, Roger P. Denlinger
2008, Water Resources Research (44)
The shallow‐water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce...
Changes in consumption by alewives and lake whitefish after dreissenid mussel invasions in Lakes Michigan and Huron
S.A. Pothoven, C.P. Madenjian
2008, North American Journal of Fisheries Management (28) 308-320
Growth of alewives Alosa pseudoharengus and lake whitefish Coregonus clupeaformis has declined since the arrival and spread of dreissenid mussels in Lakes Michigan and Huron. Alewives are the main forage for the salmonids in Lake Michigan, and lake whitefish are the most important commercial species in both lakes. Bioenergetics modeling...
Factors controlling nitrogen release from two forested catchments with contrasting hydrochemical responses
S.F. Christopher, M.J. Mitchell, Michael McHale, E.W. Boyer, Douglas A. Burns, C. Kendall
2008, Hydrological Processes (22) 46-62
Quantifying biogeochemical cycles of nitrogen (N) and the associated fluxes to surface waters remains challenging, given the need to deal with spatial and temporal variability and to characterize complex and heterogeneous landscapes. We focused our study on catchments S14 and S15 located in the Adirondack Mountains...
Seasonal temperature responses to land-use change in the western United States
L.M. Kueppers, M.A. Snyder, L.C. Sloan, D. Cayan, J. Jin, H. Kanamaru, M. Kanamitsu, N.L. Miller, Mary Tyree, H. Du, B. Weare
2008, Global and Planetary Change (60) 250-264
In the western United States, more than 79 000??km2 has been converted to irrigated agriculture and urban areas. These changes have the potential to alter surface temperature by modifying the energy budget at the land-atmosphere interface. This study reports the seasonally varying temperature responses of four regional climate models (RCMs)...
Distinguishing black carbon from biogenic humic substances in soil clay fractions
D.A. Laird, M.A. Chappell, D.A. Martens, R.L. Wershaw, M. Thompson
2008, Geoderma (143) 115-122
Most models of soil humic substances include a substantial component of aromatic C either as the backbone of humic heteropolymers or as a significant component of supramolecular aggregates of degraded biopolymers. We physically separated coarse (0.2–2.0 μm e.s.d.), medium (0.02–0.2 μm e.s.d.), and fine (> 0.02 μm e.s.d.)...
Distribution, occupancy, and habitat correlates of American martens (Martes americana) in Rocky Mountain National Park, Colorado
R.A. Baldwin, Louis C. Bender
2008, Journal of Mammalogy (89) 419-427
A clear understanding of habitat associations of martens (Martes americana) is necessary to effectively manage and monitor populations. However, this information was lacking for martens in most of their southern range, particularly during the summer season. We studied the distribution and habitat correlates of martens from 2004 to 2006 in...
Inverse modeling of surface-water discharge to achieve restoration salinity performance measures in Florida Bay, Florida
E.D. Swain, D.E. James
2008, Journal of Hydrology (351) 188-202
The use of numerical modeling to evaluate regional water-management practices involves the simulation of various alternative water-delivery scenarios, which typically are designed intuitively rather than analytically. These scenario simulations are used to analyze how specific water-management practices affect factors such as water levels, flows, and salinities. In lieu of testing...
Influences of the unsaturated, saturated, and riparian zones on the transport of nitrate near the Merced River, California, USA
Joseph L. Domagalski, S.P. Phillips, E.R. Bayless, C. Zamora, C. Kendall, R.A. Wildman, J. G. Hering
2008, Hydrogeology Journal (16) 675-690
Transport and transformation of nitrate was evaluated along a 1-km groundwater transect from an almond orchard to the Merced River, California, USA, within an irrigated agricultural setting. As indicated by measurements of pore-water nitrate and modeling using the root zone water quality model, about 63% of the applied nitrogen was...
A test of the cross-scale resilience model: Functional richness in Mediterranean-climate ecosystems
D.A. Wardwell, Craig R. Allen, G.D. Peterson, A.J. Tyre
2008, Ecological Complexity (5) 165-182
Ecological resilience has been proposed to be generated, in part, in the discontinuous structure of complex systems. Environmental discontinuities are reflected in discontinuous, aggregated animal body mass distributions. Diversity of functional groups within body mass aggregations (scales) and redundancy of functional groups across body mass aggregations (scales) has been proposed...
Application of environmental groundwater tracers at the Sulphur Bank Mercury Mine, California, USA
M.A. Engle, F. Goff, D.G. Jewett, G.J. Reller, J.B. Bauman
2008, Hydrogeology Journal (16) 559-573
Boron, chloride, sulfate, ??D, ??18O, and 3H concentrations in surface water and groundwater samples from the Sulphur Bank Mercury Mine (SBMM), California, USA were used to examine geochemical processes and provide constraints on evaporation and groundwater flow. SBMM is an abandoned sulfur and mercury mine with an underlying hydrothermal system,...
Quantile regression applied to spectral distance decay
D. Rocchini, B.S. Cade
2008, IEEE Geoscience and Remote Sensing Letters (5) 640-643
Remotely sensed imagery has long been recognized as a powerful support for characterizing and estimating biodiversity. Spectral distance among sites has proven to be a powerful approach for detecting species composition variability. Regression analysis of species similarity versus spectral distance allows us to quantitatively estimate the amount of turnover in...
Mineral sources and transport pathways for arsenic release in a coastal watershed, USA
Nora K. Foley, Robert A. Ayuso
2008, Geochemistry: Exploration, Environment, Analysis (8) 59-75
Metasedimentary bedrock of coastal Maine contains a diverse suite of As-bearing minerals that act as significant sources of elements found in ground and surface waters in the region. Arsenic sources in the Penobscot Formation include, in order of decreasing As content by weight: löllingite and realgar (c.70%), arsenopyrite, cobaltite, glaucodot,...
Monitoring a supervolcano in repose: Heat and volatile flux at the yellostone caldera
J. B. Lowenstern, S. Hurwitz
2008, Elements (4) 35-40
Although giant calderas ("supervolcanoes") may slumber for tens of thousands of years between eruptions, their abundant earthquakes and crustal deformation reveal the potential for future upheaval. Any eventual supereruption could devastate global human populations, so these systems must be carefully scrutinized. Insight into dormant but restless calderas can be gained...
Simulating the impact of cholinesterase-inhibiting pesticides on non-target wildlife in irrigated crops
J.M. Pisani, W.E. Grant, M.A. Mora
2008, Ecological Modelling (210) 179-192
We present a simulation model for risk assessment of the impact of insecticide inhibitors of cholinesterase (ChE) applied in irrigated agricultural fields on non-target wildlife. The model, which we developed as a compartment model based on difference equations (??t = 1 h), consists of six submodels describing the dynamics of...
Numerical simulation of the paleohydrology of glacial Lake Oshkosh, eastern Wisconsin, USA
J.A. Clark, K.M. Befus, T.S. Hooyer, P.W. Stewart, T.D. Shipman, C.T. Gregory, D.J. Zylstra
2008, Quaternary Research (69) 117-129
Proglacial lakes, formed during retreat of the Laurentide ice sheet, evolved quickly as outlets became ice-free and the earth deformed through glacial isostatic adjustment. With high-resolution digital elevation models (DEMs) and GIS methods, it is possible to reconstruct the evolution of surface hydrology. When a DEM deforms through time as...
The evolution of volcano-hosted geothermal systems based on deep wells from Karaha-Telaga Bodas, Indonesia
J.N. Moore, R.G. Allis, M. Nemcok, T.S. Powell, C.J. Bruton, P.E. Wannamaker, I.B. Raharjo, D.I. Norman
2008, American Journal of Science (308) 1-48
Temperature and pressure surveys, fluid samples, and petrologic analyses of rock samples from deep drill holes at the Karaha - Telaga Bodas geothermal field on the volcanic ridge extending northward from Galunggung Volcano, West Java, have provided a unique opportunity to characterize the evolution of an active volcano-hosted geothermal system....
