The Spar Lake strata-Bound Cu-Ag deposit formed across a mixing zone between trapped natural gas and metals-bearing brine
Timothy S. Hayes, Gary P. Landis, Joseph F. Whelan, Robert O. Rye, Richard J. Moscati
2012, Economic Geology (107) 1223-1249
Ore formation at the Spar Lake red bed-associated strata-bound Cu deposit took place across a mixing and reaction zone between a hot oxidized metals-transporting brine and a reservoir of “sour” (H2S-bearing) natural gas trapped in the host sandstones. Fluid inclusion volatile analyses have very high CH4 concentrations (≥1 mol %...
The effects of permafrost thaw on soil hydrologic, thermal, and carbon dynamics in an Alaskan peatland
Jonathan A. O’Donnell, M. Torre Jorgenson, Jennifer W. Harden, A. David McGuire, Mikhail Z. Kanevskiy, Kimberly P. Wickland
2012, Ecosystems (15) 213-229
Recent warming at high-latitudes has accelerated permafrost thaw in northern peatlands, and thaw can have profound effects on local hydrology and ecosystem carbon balance. To assess the impact of permafrost thaw on soil organic carbon (OC) dynamics, we measured soil hydrologic and thermal dynamics and soil OC stocks across a...
Selecting sagebrush seed sources for restoration in a variable climate: ecophysiological variation among genotypes
Matthew J. Germino
2012, Report, Great Basin Native Plant Selection and Increase Project 2011 Progress Report
Big sagebrush (Artemisia tridentata) communities dominate a large fraction of the United States and provide critical habitat for a number of wildlife species of concern. Loss of big sagebrush due to fire followed by poor restoration success continues to reduce ecological potential of this ecosystem type, particularly in the Great...
Ecological consequences of manipulative parasites
Kevin D. Lafferty, A. M. Kuris, Michel Loreau
2012, Book chapter, Host manipulation by parasites
This chapter considers the context in which manipulative parasites could have noticeable ecological effects. By this, we mean that a manipulation of a host that benefits a parasite can also indirectly affect other non-hosts in the system, sometimes in dramatic fashion. Such ecosystem-level changes could occur for manipulative parasites that...
On modeling weak sinks in MODPATH
Daniel B. Abrams, Henk Haitjema, Leon J. Kauffman
2012, Ground Water (51) 597-602
Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as...
Bacterial and enchytraeid abundance accelerate soil carbon turnover along a lowland vegetation gradient in interior Alaska
M. P. Waldrop, Jennifer W. Harden, M.R. Turetsky, D.G. Petersen, A. D. McGuire, M.J.I. Briones, A.C. Churchill, D.H. Doctor, L.E. Pruett
2012, Soil Biology and Biochemistry (50) 188-198
Boreal wetlands are characterized by a mosaic of plant communities, including forests, shrublands, grasslands, and fens, which are structured largely by changes in topography and water table position. The soil associated with these plant communities contain quantitatively and qualitatively different forms of soil organic matter (SOM) and nutrient availability that...
Root zone water quality model (RZWQM2): Model use, calibration and validation
Liwang Ma, Lajpat Ahuja, B. T. Nolan, Robert Malone, Thomas Trout, Z. Qi
2012, Transactions of the ASABE (55) 1425-1446
The Root Zone Water Quality Model (RZWQM2) has been used widely for simulating agricultural management effects on crop production and soil and water quality. Although it is a one-dimensional model, it has many desirable features for the modeling community. This article outlines the principles of calibrating the model component by...
Predation rates, timing, and predator composition for Scoters (Melanitta spp.) in marine habitats
Eric J. Anderson, Daniel Esler, Boyd W. Sean, Joseph Evenson, David R. Nysewander, David H. Ward, Rian D. Dickson, Brian D. Uher-Koch, C.S. Vanstratt, Jerry W. Hupp
2012, Canadian Journal of Zoology (90) 42-50
Studies of declining populations of sea ducks have focused mainly on bottom-up processes with little emphasis on the role of predation. We identified 11 potential predators of White-winged Scoters (Melanitta fusca (L., 1758)) and Surf Scoters (Melanitta perspicillata (L., 1758)) in North American marine habitats. However, of 596 Scoters marked...
California spotted owls
Suzanne C. Roberts, M. North
2012, General Technical Report PSW-GTR-237-5
California spotted owls (Strix occidentalis occidentalis) are habitat specialists that are strongly associated with late-successional forests. For nesting and roosting, they require large trees and snags embedded in a stand with a complex forest structure (Blakesley et al. 2005, Gutiérrez et al. 1992, Verner et al. 1992b). In mixed-conifer forests...
Soil-occupancy effects of invasive and native grassland plant species on composition and diversity of mycorrhizal associations
Nicholas R. Jordan, Laura Aldrich-Wolfe, Sheri C. Huerd, Diane L. Larson, Gary Muehlbauer
2012, Invasive Plant Science and Management (5) 494-505
Diversified grasslands that contain native plant species can produce biofuels, support sustainable grazing systems, and produce other ecosystem services. However, ecosystem service production can be disrupted by invasion of exotic perennial plants, and these plants can have soil-microbial “legacies” that may interfere with establishment and maintenance of diversified grasslands even...
Range overlap and individual movements during breeding season influence genetic relationships of caribou herds in south-central Alaska
Gretchen H. Roffler, Layne G. Adams, Sandra L. Talbot, George K. Sage, Bruce W. Dale
2012, Canadian Journal of Zoology (93) 1318-1330
North American caribou (Rangifer tarandus) herds commonly exhibit little nuclear genetic differentiation among adjacent herds, although available evidence supports strong demographic separation, even for herds with seasonal range overlap. During 1997–2003, we studied the Mentasta and Nelchina caribou herds in south-central Alaska using radiotelemetry to determine individual movements and range...
Erratum to Dynamic stresses, Coulomb failure, and remote triggering and to Surface wave potential for triggering tectonic (nonvolcanic) tremor
David P. Hill
2012, Bulletin of the Seismological Society of America (102) 2795-2795
Hill (2008) and Hill (2010) contain two technical errors: (1) a missing factor of 2 for computed Love‐wave amplitudes, and (2) a sign error in the off‐diagonal elements in the Euler rotation matrix....
Diversity of nitrogen isotopes and protein status in caribou: implications for monitoring northern ungulates
David D. Gustine, Perry S. Barboza, James P. Lawler, Layne G. Adams, Kathy L. Parker, Steve M. Arthur, Brad S. Shults
2012, Journal of Mammalogy (93) 778-790
Nutritional condition is an important determinant of productivity and survival in caribou (Rangifer tarandus). We used samples of excreta (n = 1,150) to estimate diet composition from microhistology and 2 isotopic proxies of protein status for 2 ecotypes of caribou in 4 herds in late winter (2006–2008). Isotopes of nitrogen...
The current state of modeling
Randall J. Hunt, Chunmiao Zheng
2012, Ground Water (50) 329-333
No abstract available....
The science, information, and engineering needed to manage water availability and quality in 2050
Robert M. Hirsch
2012, Book chapter, Toward a sustainable water future: Visions for 2050
This chapter explores four water resources issues: 1) hydrologic variability, hazards, water supply and ecosystem preservation; 2) urban landscape design; 3) non-point source water quality, and 4) climate change, resiliency, and nonstationarity. It also considers what science, technology, and engineering practice may be needed in the coming decades to...
Explosive eruptions triggered by rockfalls at Kīlauea volcano, Hawaii
Tim R. Orr, Weston A. Thelen, Matthew R. Patrick, Donald A. Swanson, David C. Wilson
2012, Geology (41) 207-210
Ongoing eruptive activity at Kīlauea volcano’s (Hawai‘i) summit has been controlled in part by the evolution of its vent from a 35-m-diameter opening into a collapse crater 150 m across. Geologic observations, in particular from a network of webcams, have provided an unprecedented look at collapse crater development, lava lake...
Near-surface, marine seismic-reflection data defines potential hydrogeologic confinement bypass in a tertiary carbonate aquifer, southeastern Florida
Kevin J. Cunningham, Cameron Walker, Richard L. Westcott
2012, SEG Technical Program Expanded Abstracts (2012) 1-6
Approximately 210 km of near-surface, high-frequency, marine seismic-reflection data were acquired on the southeastern part of the Florida Platform between 2007 and 2011. Many high-resolution, seismic-reflection profiles, interpretable to a depth of about 730 m, were collected on the shallow-marine shelf of southeastern Florida in water as shallow as 1...
Small population size of Pribilof Rock Sandpipers confirmed through distance-sampling surveys in Alaska
Daniel R. Ruthrauff, T. Lee Tibbitts, Robert E. Gill Jr., Maksim N. Dementyev, Colleen M. Handel
2012, Condor (114) 544-551
The Rock Sandpiper (Calidris ptilocnemis) is endemic to the Bering Sea region and unique among shorebirds in the North Pacific for wintering at high latitudes. The nominate subspecies, the Pribilof Rock Sandpiper (C. p. ptilocnemis), breeds on four isolated islands in the Bering Sea and appears to spend the winter...
An exploratory investigation of the landscape-lake interface: Land cover controls over consumer N and C isotopic composition in Lake Michigan rivermouths
James H. Larson, William B. Richardson, Jonathan M. Vallazza, J. C. Nelson
2012, Journal of Great Lakes Research (38) 610-619
Rivermouth ecosystems are areas where tributary waters mix with lentic near-shore waters and provide habitat for many Laurentian Great Lakes fish and wildlife species. Rivermouths are the interface between terrestrial activities that influence rivers and the ecologically important nearshore. Stable isotopes of nitrogen (N) and carbon (C) in consumers were...
Heavy tails and earthquake probabilities
William L. Ellsworth
2012, Seismological Research Letters (83) 483-485
The 21st century has already seen its share of devastating earthquakes, some of which have been labeled as “unexpected,” at least in the eyes of some seismologists and more than a few journalists. A list of seismological surprises could include the 2004 Sumatra-Andaman Islands; 2008 Wenchuan, China; 2009 Haiti; 2011...
The native Florida Green Watersnak, Nerodia floridana (Goff 1936) , preying upon the nonindigenous African Jewelfish, Hemichromis letourneuxi Sauvage 1880, in Florida.
Kenneth L. Krysko, Stephen J. Walsh, Robert H. Robins
2012, IRCF Reptiles & Amphibians (19) 161-162
No abstract available...
Using hydrogeology to identify the source of groundwater to Montezuma Well, a natural spring in central Arizona: part 1
Raymond H. Johnson, Ed H. DeWitt, L. Rick Arnold
2012, Environmental Earth Sciences (67) 1821-1835
Montezuma Well is a natural spring located within a “sinkhole” in the desert environment of the Verde Valley in Central Arizona. It is managed by the National Park Service as part of Montezuma Castle National Monument. Because of increasing development of groundwater in the area, this research was undertaken to...
Measuring the orthogonality error of coil systems
B. Heilig, A. Csontos, K. Pajunpaa, Tim White, B. St. Louis, D. Calp
2012, Proceedings of the XVth IAGA Workshop on Geomagnetic Observatory Instruments 42-45
Recently, a simple method was proposed for the determination of pitch angle between two coil axes by means of a total field magnetometer. The method is applicable when the homogeneous volume in the centre of the coil system is large enough to accommodate the total field sensor. Orthogonality of calibration...
Synthesis of benthic flux components in the Patos Lagooncoastal zone, Rio Grande do Sul, Brazil
Jeffrey N. King
2012, Water Resources Research (48)
The primary objective of this work is to synthesize components of benthic flux in the Patos Lagoon coastal zone, Rio Grande do Sul, Brazil. Specifically, the component of benthic discharge flux forced by the terrestrial hydraulic gradient is 0.8 m3 d-1; components of benthic discharge and recharge flux associated with...
Sulfur, carbon, hydrogen, and oxygen isotope geochemistry of the Idaho cobalt belt
Craig A. Johnson, Arthur A. Bookstrom, John F. Slack
2012, Economic Geology (107) 1207-1221
Cobalt-copper ± gold deposits of the Idaho cobalt belt, including the deposits of the Blackbird district, have been analyzed for their sulfur, carbon, hydrogen, and oxygen isotope compositions to improve the understanding of ore formation. Previous genetic hypotheses have ranged widely, linking the ores to the sedimentary or diagenetic history...
