Supergene destruction of a hydrothermal replacement alunite deposit at Big Rock Candy Mountain, Utah: Mineralogy, spectroscopic remote sensing, stable-isotope, and argon-age evidences
Charles G. Cunningham, Robert O. Rye, Barnaby W. Rockwell, Michael J. Kunk, Terry B. Councell
2005, Chemical Geology (215) 317-337
Big Rock Candy Mountain is a prominent center of variegated altered volcanic rocks in west-central Utah. It consists of the eroded remnants of a hypogene alunite deposit that, at ∼21 Ma, replaced intermediate-composition lava flows. The alunite formed in steam-heated conditions above the upwelling limb of a convection cell that...
Three decades of Martian surface changes
P.E. Geissler
2005, Journal of Geophysical Research E: Planets (110) 1-23
The surface of Mars has changed dramatically during the three decades spanned by spacecraft exploration. Comparisons of Mars Global Surveyor images with Viking and Mariner 9 pictures suggest that more than one third of Mars' surface area has brightened or darkened by at least 10%. Such albedo changes could produce...
The role of shoreland development and commercial cranberry farming in a lake in Wisconsin, USA
P.J. Garrison, S.A. Fitzgerald
2005, Journal of Paleolimnology (33) 169-188
Musky Bay in Lac Courte Oreilles, Wisconsin, USA, is currently eutrophic. This large, shallow bay of an oligotrophic lake possesses the densest aquatic plant growth and a floating algal mat. Paleoecological reconstructions encompassing the last 130 years, were based on multiproxy analyses of sediment cores from three coring sites, two...
Invertebrate eggs can fly: Evidence of waterfowl-mediated gene flow in aquatic invertebrates
J. Figuerola, A.J. Green, T.C. Michot
2005, American Naturalist (165) 274-280
Waterfowl often have been assumed to disperse freshwater aquatic organisms between isolated wetlands, but no one has analyzed the impact of this transport on the population structure of aquatic organisms. For three cladocerans (Daphnia ambigua, Daphnia laevis, and Sida crystallina) and one bryozoan (Cristatella mucedo), we estimated the genetic distances...
TREMOR: A wireless MEMS accelerograph for dense arrays
J.R. Evans, R.H. Hamstra Jr., C. Kundig, P. Camina, J. A. Rogers
2005, Earthquake Spectra (21) 91-124
The ability of a strong-motion network to resolve wavefields can be described on three axes: frequency, amplitude, and space. While the need for spatial resolution is apparent, for practical reasons that axis is often neglected. TREMOR is a MEMS-based accelerograph using wireless Internet to minimize lifecycle cost. TREMOR instruments can...
Bioeconomic analysis of selected conservation practices on soil erosion and freshwater fisheries
John Westra, J. K. H. Zimmerman, Bruce C. Vondracek
2005, Journal of the American Water Resources Association (41) 309-322
Farmers can generate environmental benefits (improved water quality and fisheries and wildlife habitat), but they may not be able to quantify them. Furthermore, farmers may reduce their incomes from managing lands to produce these positive externalities but receive little monetary compensation in return. This study simulated the relationship between agricultural...
Upstream migration of Pacific lampreys in the John Day River, Oregon: Behavior, timing, and habitat use
T. Craig Robinson, J.M. Bayer
2005, Northwest Science (79) 106-119
Adult Pacific lamprey migration and habitat preferences for over-winter holding and spawning, and larval rearing in tributaries to the Columbia River are not well understood. The John Day River is one such tributary where larval and adult stages of this species have been documented, and its free-flowing character provided the...
Survival of captive-reared Puerto Rican Parrots released in the Caribbean National Forest
Thomas H. White Jr., Jaime A. Collazo, Francisco Vilella
2005, Condor (107) 424-432
We report first-year survival for 34 captive-reared Puerto Rican Parrots (Amazona vittata) released in the Caribbean National Forest, Puerto Rico between 2000 and 2002. The purpose of the releases were to increase population size and the potential number of breeding individuals of the sole extant wild population, and to refine...
Investigating surface water-well interaction using stable isotope ratios of water
R. J. Hunt, T.B. Coplen, N.L. Haas, D. A. Saad, M. A. Borchardt
2005, Journal of Hydrology (302) 154-172
Because surface water can be a source of undesirable water quality in a drinking water well, an understanding of the amount of surface water and its travel time to the well is needed to assess a well's vulnerability. Stable <a title="Learn more about isotope ratios"...
Seasonal to interannual morphodynamics along a high-energy dissipative littoral cell
P. Ruggiero, G. M. Kaminsky, G. Gelfenbaum, B. Voigt
2005, Journal of Coastal Research (21) 553-578
A beach morphology monitoring program was initiated during summer 1997 along the Columbia River littoral cell (CRLC) on the coasts of northwest Oregon and southwest Washington, USA. This field program documents the seasonal through interannual morphological variability of these high-energy dissipative beaches over a variety of spatial scales. Following the...
Temporal variations and scaling of streamflow and baseflow and their nitrate-nitrogen concentrations and loads
Y.-K. Zhang, K. Schilling
2005, Advances in Water Resources (28) 701-710
The patterns of temporal variations of precipitation (P), streamflow (SF) and baseflow (BF) as well as their nitrate-nitrogen (nitrate) concentrations (C) and loads (L) from a long-term record (28 years) in the Raccoon River, Iowa, were analyzed using variogram and spectral analyses. The daily P is random but scaling may...
Long-term behavior of water content and density in an earthen liner
T.E. Frank, I.G. Krapac, T.D. Stark, G.D. Strack
2005, Journal of Geotechnical and Geoenvironmental Engineering (131) 800-803
An extensively instrumented compacted earthen liner was constructed at the Illinois State Geological Survey facility in Champaign, III. in 1987. A pond of water 0.31 m deep was maintained on top of the 7.3 m ?? 14.6 m ?? 0.9 m thick liner for 14 years. One of the goals...
CO2 dynamics in the Amargosa Desert: Fluxes and isotopic speciation in a deep unsaturated zone
Michelle Ann Walvoord, Robert G. Striegl, David E. Prudic, David A. Stonestrom
2005, Water Resources Research (41) 1-15
Natural unsaturated-zone gas profiles at the U.S. Geological Survey's Amargosa Desert Research Site, near Beatty, Nevada, reveal the presence of two physically and isotopically distinct CO2 sources, one shallow and one deep. The shallow source derives from seasonally variable autotrophic and heterotrophic respiration in the root zone. Scanning electron micrograph...
Paleoproterozoic high-sulfidation mineralization in the Tapajós gold province, Amazonian Craton, Brazil: geology, mineralogy, alunite argon age, and stable-isotope constraints
Caetano Juliani, Robert O. Rye, Carmen Nunes, Lawrence W. Snee, Rafael H. Correa, Lena V.S. Monteiro, Jorge S. Bettencourt, Rainer Neumann, Arnaldo A. Neto
2005, Chemical Geology (215) 95-125
The Brazilian Tapajós gold province contains the first evidence of high-sulfidation gold mineralization in the Amazonian Craton. The mineralization appears to be in large nested calderas. The Tapajós–Parima (or Ventuari–Tapajós) geological province consists of a metamorphic, igneous, and sedimentary sequence formed during a 2.10 to 1.87 Ga ocean−continent orogeny. The...
Home range and space use patterns of flathead catfish during the summer-fall period in two Missouri streams
Jason C. Vokoun, Charles F. Rabeni
2005, Transactions of the American Fisheries Society (134) 509-517
Flathead catfish Pylodictis olivaris were radio-tracked in the Grand River and Cuivre River, Missouri, from late July until they moved to overwintering habitats in late October. Fish moved within a definable area, and although occasional long-distance movements occurred, the fish typically returned to the previously occupied area. Seasonal...
Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah
N.C. Davatzes, P. Eichhubl, A. Aydin
2005, Geological Society of America Bulletin (117) 135-148
Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying...
New constraints on mechanisms of remotely triggered seismicity at Long Valley Caldera
E. E. Brodsky, S. G. Prejean
2005, Journal of Geophysical Research B: Solid Earth (110) 1-14
Regional-scale triggering of local earthquakes in the crust by seismic waves from distant main shocks has now been robustly documented for over a decade. Some of the most thoroughly recorded examples of repeated triggering of a single site from multiple, large earthquakes are measured in geothermal fields of the western...
Surface water acidification responses and critical loads of sulfur and nitrogen deposition in Loch Vale watershed, Colorado
T.J. Sullivan, B.J. Cosby, K.A. Tonnessen, D. W. Clow
2005, Water Resources Research (41)
We evaluated the sensitivity of The Loch, a subalpine lake in Rocky Mountain National Park in Colorado, to acidification in response to increased atmospheric loading of sulfur (S) and nitrogen (N) using the Model of Acidification of Groundwater in Catchments (MAGIC). Lake water acid‐base chemistry was moderately sensitive to changes...
Longer-term effects of selective thinning on microarthropod communities in a late-successional coniferous forest
Robert W. Peck, C. G. Niwa
2005, Environmental Entomology (34) 646-655
Microarthropod densities within late-successional coniferous forests thinned 16–41 yr before sampling were compared with adjacent unthinned stands to identify longer term effects of thinning on this community. Soil and forest floor layers were sampled separately on eight paired sites. Within the forest floor oribatid, mesostigmatid, and to a marginal extent,...
Ongoing hydrothermal heat loss from the 1912 ash-flow sheet, Valley of Ten Thousand Smokes, Alaska
N. Hogeweg, T. E. C. Keith, E.M. Colvard, S. E. Ingebritsen
2005, Journal of Volcanology and Geothermal Research (143) 279-291
The June 1912 eruption of Novarupta filled nearby glacial valleys on the Alaska Peninsula with ash-flow tuff (ignimbrite), and post-eruption observations of thousands of steaming fumaroles led to the name ‘Valley of Ten Thousand Smokes’ (VTTS). By the late 1980s most fumarolic activity had ceased, but the discovery of thermal...
A frictional population model of seismicity rate change
J. Gomberg, P. Reasenberg, M. Cocco, M.E. Belardinelli
2005, Journal of Geophysical Research B: Solid Earth (110) 1-10
We study models of seismicity rate changes caused by the application of a static stress perturbation to a population of faults and discuss our results with respect to the model proposed by Dieterich (1994). These models assume distribution of nucleation sites (e.g., faults) obeying rate-state frictional relations that fail at...
Compositional maps of Saturn's moon Phoebe from imaging spectroscopy
R. N. Clark, R. H. Brown, R. Jaumann, D. P. Cruikshank, R.M. Nelson, B. J. Buratti, T. B. McCord, J. Lunine, K. H. Baines, G. Bellucci, J.-P. Bibring, F. Capaccioni, P. Cerroni, A. Coradini, V. Formisano, Y. Langevin, D. L. Matson, V. Mennella, P. D. Nicholson, B. Sicardy, Christophe Sotin, T.M. Hoefen, J. M. Curchin, G. Hansen, K. Hibbits, K.-D. Matz
2005, Nature (435) 66-69
The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination,...
The distribution of phosphorus in Popes Creek, VA, and in the Pocomoke River, MD: Two watersheds with different land management practices in the Chesapeake Bay Basin
N.S. Simon, O.P. Bricker, W. Newell, J. McCoy, R. Morawe
2005, Water, Air, & Soil Pollution (164) 189-204
This paper compares phosphorus (P) concentrations in sediments from two watersheds, one with, and one without, intensive animal agriculture. The watersheds are in the coastal plain of the Chesapeake Bay and have similar physiographic characteristics. Agriculture in the Pocomoke River, MD, watershed supplied 2.7 percent of all broiler chickens produced...
Speciation and transport of newly deposited mercury in a boreal forest wetland: A stable mercury isotope approach
B.A. Branfireun, D. P. Krabbenhoft, H. Hintelmann, R. J. Hunt, J.P. Hurley, J.W.M. Rudd
2005, Water Resources Research (41)
As part of the Mercury Experiment to Assess Atmospheric Loadings in Canada and the United States (METAALICUS) the fate and transport of contemporary mercury (Hg) deposition in a boreal wetland was investigated using an experimentally applied stable mercury isotope. We applied high purity (99.2% ± 0.1) 202Hg(II) to a wetland plot...
Widespread detection of N, N-diethyl-m-toluamide in U.S. streams: Comparison with concentrations of pesticides, personal care products, and other organic wastewater compounds
Mark W. Sandstrom, D.W. Kolpin, E.M. Thurman, S.D. Zaugg
2005, Environmental Toxicology and Chemistry (24) 1029-1034
One of the most frequently detected organic chemicals in a nationwide study concerning the effects of wastewater on stream water quality conducted in the year 2000 was the widely used insect repellant N,N-diethyl-m-toluamide (DEET). It was detected at levels of 0.02 μg/L or greater in 73% of the stream sites...
