Effects of dynamically variable saturation and matrix-conduit coupling of flow in karst aquifers
Thomas Reimann, T. Geyer, W.B. Shoemaker, R. Liedl, M. Sauter
2011, Water Resources Research (47)
Well-developed karst aquifers consist of highly conductive conduits and a relatively low permeability fractured and/or porous rock matrix and therefore behave as a dual-hydraulic system. Groundwater flow within highly permeable strata is rapid and transient and depends on local flow conditions, i.e., pressurized or nonpressurized flow. The characterization of karst...
Adaptive finite volume methods with well-balanced Riemann solvers for modeling floods in rugged terrain: Application to the Malpasset dam-break flood (France, 1959)
D.L. George
2011, International Journal for Numerical Methods in Fluids (66) 1000-1018
The simulation of advancing flood waves over rugged topography, by solving the shallow-water equations with well-balanced high-resolution finite volume methods and block-structured dynamic adaptive mesh refinement (AMR), is described and validated in this paper. The efficiency of block-structured AMR makes large-scale problems tractable, and allows the use of accurate and...
Continuous salinity and temperature data from San Francisco estuary, 1982-2002: Trends and the salinity-freshwater inflow relationship
Gregory Shellenbarger, David H. Schoellhamer
2011, Journal of Coastal Research (27) 1191-1201
The U.S. Geological Survey and other federal and state agencies have been collecting continuous temperature and salinity data, two critical estuarine habitat variables, throughout San Francisco estuary for over two decades. Although this dynamic, highly variable system has been well studied, many questions remain relating to the effects of freshwater...
Seawater calcium isotope ratios across the Eocene-Oligocene transition
E.M. Griffith, A. Paytan, A. Eisenhauer, Thomas D. Bullen, E. Thomas
2011, Geology (39) 683-686
During the Eocene-Oligocene transition (EOT, ca. 34 Ma), Earth's climate cooled significantly from a greenhouse to an icehouse climate, while the calcite (CaCO3) compensation depth (CCD) in the Pacific Ocean increased rapidly. Fluctuations in the CCD could result from various processes that create an imbalance between calcium (Ca) sources to,...
Mapping rice areas of South Asia using MODIS multitemporal data
M.K. Gumma, A. Nelson, P.S. Thenkabail, A.N. Singh
2011, Journal of Applied Remote Sensing (5)
Our goal is to map the rice areas of six South Asian countries using moderate-resolution imaging spectroradiometer (MODIS) time-series data for the time period 2000 to 2001. South Asia accounts for almost 40% of the world's harvested rice area and is also home to 74% of the population that lives...
The indication of Martian gully formation processes by slope-area analysis
Susan J. Conway, Matthew R. Balme, John B. Murray, Martin C. Towner, Chris Okubo, Peter M. Grindrod
2011, Geological Society Special Publication (356) 171-201
The formation process of recent gullies on Mars is currently under debate. This study aims to discriminate between the proposed formation processes - pure water flow, debris flow and dry mass wasting - through the application of geomorphological indices commonly used in terrestrial geomorphology. High-resolution digital elevation models (DEMs) of...
Nitrogen uptake by the shoots of smooth cordgrass Spartina alterniflora
T. J. Mozdzer, M. Kirwan, K. J. McGlathery, J. C. Zieman
2011, Marine Ecology Progress Series (433) 43-52
The smooth cordgrass Spartina alterniflora is the foundation species in intertidal salt marshes of the North American Atlantic coast. Depending on its elevation within the marsh, S. alterniflora may be submerged for several hours per day. Previous ecosystem-level studies have demonstrated that S. alterniflora marshes are a net sink for nitrogen (N), and that removal of...
Effects of fringing reefs on tsunami inundation: American Samoa
G. Gelfenbaum, A. Apotsos, A.W. Stevens, B. Jaffe
2011, Earth-Science Reviews (107) 12-22
A numerical model of tsunami inundation, Delft3D, which has been validated for the 29 September 2009 tsunami in Tutuila, American Samoa, is used to better understand the impact of fringing coral reefs and embayments on tsunami wave heights, inundation distances, and velocities. The inundation model is used to explore the...
Geology, geochronology, and paleogeography of the southern Sonoma volcanic field and adjacent areas, northern San Francisco Bay region, California
David L. Wagner, George J. Saucedo, Kevin B. Clahan, Robert J. Fleck, Victoria E. Langenheim, Robert J. McLaughlin, Andrei M. Sarna-Wojcicki, James R. Allen, Alan L. Deino
2011, Geosphere (7) 658-683
Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that...
Wetland vegetation in Manzala lagoon, Nile Delta coast, Egypt: Rapid responses of pollen to altered nile hydrology and land use
C.E. Bernhardt, J.-D. Stanley, B. P. Horton
2011, Journal of Coastal Research (27) 731-737
The pollen record in a sediment core from Manzala lagoon on the Nile delta coastal margin of Egypt, deposited from ca. AD 1860 to 1990, indicates rapid coastal wetland vegetation responses to two primary periods of human activity. These are associated with artificially altered Nile hydrologic regimes in proximal areas and distal...
Mineralogic sources of metals in leachates from the weathering of sedex, massive sulfide, and vein deposit mining wastes
S. F. Diehl, P. L. Hageman, R.R. Seal II, N.M. Piatak, H. Lowers
2011, Conference Paper, SME Annual Meeting and Exhibit and CMA 113th National Western Mining Conference 2011
Weathered mine waste consists of oxidized primary minerals and chemically unstable secondary phases that can be sources of readily soluble metals and acid rock drainage. Elevated concentrations of metals such as Cd, Cu, Fe, Mn, Ni, Pb, and Zn are observed in deionized water-based leachate solutions derived from complex sedex...
Approach for environmental baseline water sampling
K. S. Smith
2011, Conference Paper, SME Annual Meeting and Exhibit and CMA 113th National Western Mining Conference 2011
Samples collected during the exploration phase of mining represent baseline conditions at the site. As such, they can be very important in forecasting potential environmental impacts should mining proceed, and can become measurements against which future changes are compared. Constituents in stream water draining mined and mineralized areas tend to...
Assessment of NE Greenland: Prototype for development of Circum-ArcticResource Appraisal methodology
Donald L. Gautier, L. Stemmerik, F.G. Christiansen, K. Sorensen, T. Bidstrup, J. A. Bojesen-Koefoed, Kenneth J. Bird, Ronald Charpentier, David W. Houseknecht, Timothy R. Klett, Christopher J. Schenk, Marilyn E. Tennyson
2011, Geological Society Memoir 663-672
Geological features of NE Greenland suggest large petroleum potential, as well as high uncertainty and risk. The area was the prototype for development of methodology used in the US Geological Survey (USGS) Circum-Arctic Resource Appraisal (CARA), and was the first area evaluated. In collaboration with the Geological Survey of Denmark...
Volcanic versus anthropogenic carbon dioxide
T. Gerlach
2011, Eos, Transactions, American Geophysical Union (92) 201-202
Which emits more carbon dioxide (CO2): Earth's volcanoes or human activities? Research findings indicate unequivocally that the answer to this frequently asked question is human activities. However, most people, including some Earth scientists working in fields outside volcanology, are surprised by this answer. The climate change debate has revived and...
Oil and gas resource potential north of the Arctic Circle
Donald L. Gautier, Kenneth J. Bird, Ronald Charpentier, Arthur Grantz, David W. Houseknecht, Timothy R. Klett, Thomas E. Moore, Janet K. Pitman, Christopher J. Schenk, J.H. Schuenemeyer, K. Sorensen, Marilyn E. Tennyson, Zenon C. Valin, Craig J. Wandrey
2011, Geological Society Memoir (35) 151-161
The US Geological Survey recently assessed the potential for undiscovered conventional petroleum in the Arctic. Using a new map compilation of sedimentary elements, the area north of the Arctic Circle was subdivided into 70 assessment units, 48 of which were quantitatively assessed. The Circum-Arctic Resource Appraisal (CARA) was a geologically...
Geology and petroleum potential of the West Greenland-East Canada Province
Christopher J. Schenk
2011, Geological Society Memoir (35) 627-645
The US Geological Survey (USGS) assessed the potential for undiscovered oil and gas resources of the West Greenland–East Canada Province as part of the USGS Circum-Arctic Resource Appraisal programme. The province lies in the offshore area between western Greenland and eastern Canada and includes Baffin Bay, Davis Strait, Lancaster Sound...
Coordinating standards and applications for optical water quality sensor networks
B. Bergamaschi, B. Pellerin
2011, Conference Paper, Eos
Joint USGS-CUAHSI Workshop: In Situ Optical Water Quality Sensor Networks; Shepherdstown, West Virginia, 8-10 June 2011; Advanced in situ optical water quality sensors and new techniques for data analysis hold enormous promise for advancing scientific understanding of aquatic systems through measurements of important biogeochemical parameters at the time scales over...
Seasonal movement, residency, and migratory patterns of Wilson's Snipe (Gallinago delicata)
Brittany B. Cline, Susan M. Haig
2011, The Auk (128) 543-555
Cross-seasonal studies of avian movement establish links between geographically distinct wintering, breeding, and migratory stopover locations, or assess site fidelity and movement between distinct phases of the annual cycle. Far fewer studies have investigated individual movement patterns within and among seasons over an annual cycle. Within western Oregon's Willamette Valley...
Effects of sediment-associated extractable metals, degree of sediment grain sorting, and dissolved organic carbon upon Cryptosporidium parvum removal and transport within riverbank filtration sediments, Sonoma County, California
D.W. Metge, R.W. Harvey, G. R. Aiken, R. Anders, G. Lincoln, James Jasperse, M. C. Hill
2011, Environmental Science & Technology (45) 5587-5595
Oocysts of the protozoan pathogen Cryptosporidium parvum are of particular concern for riverbank filtration (RBF) operations because of their persistence, ubiquity, and resistance to chlorine disinfection. At the Russian River RBF site (Sonoma County, CA), transport of C. parvumoocysts and oocyst-sized (3 μm) carboxylate-modified microspheres through poorly sorted (sorting indices, σ1, up to...
Using consumption rate to assess potential predators for biological control of white perch
N.J.C. Gosch, Kevin L. Pope
2011, Knowledge and Management of Aquatic Ecosystems
Control of undesirable fishes is important in aquatic systems, and using predation as a tool for biological control is an attractive option to fishery biologists. However, determining the appropriate predators for biological control is critical for success. The objective of this study was to evaluate the utility of consumption rate...
Pore networks in continental and marine mudstones: Characteristics and controls on sealing behavior
J.E. Heath, T.A. Dewers, B.J.O.L. McPherson, R. Petrusak, T.C. Chidsey, A.J. Rinehart, P.S. Mozley
2011, Geosphere (7) 429-454
Mudstone pore networks are strong modifiers of sedimentary basin fluid dynamics and have a critical role in the distribution of hydrocarbons and containment of injected fluids. Using core samples from continental and marine mudstones, we investigate properties of pore types and networks from a variety of geologic environments, together with...
Combined effects of tectonic and landslide-generated Tsunami Runup at Seward, Alaska during the Mw 9.2 1964 earthquake
E. Suleimani, D.J. Nicolsky, Peter J. Haeussler, R. Hansen
2011, Pure and Applied Geophysics (168) 1053-1074
We apply a recently developed and validated numerical model of tsunami propagation and runup to study the inundation of Resurrection Bay and the town of Seward by the 1964 Alaska tsunami. Seward was hit by both tectonic and landslide-generated tsunami waves during the MW"><span...
Environmental enrichment affects adrenocortical stress responses in the endangered black-footed ferret
S.A. Poessel, Dean E. Biggins, R.M. Santymire, T.M. Livieri, K.R. Crooks, L. Angeloni
2011, General and Comparative Endocrinology (172) 526-533
Potential stressors of wildlife living in captivity, such as artificial living conditions and frequent human contact, may lead to a higher occurrence of disease and reduced reproductive function. One successful method used by wildlife managers to improve general well-being is the provision of environmental enrichment, which is the practice of...
Few apparent short-term effects of elevated soil temperature and increased frequency of summer precipitation on the abundance and taxonomic diversity of desert soil micro- and meso-fauna
B.J. Darby, D.A. Neher, D.C. Housman, J. Belnap
2011, Soil Biology and Biochemistry (43) 1474-1481
Frequent hydration and drying of soils in arid systems can accelerate desert carbon and nitrogen mobilization due to respiration, microbial death, and release of intracellular solutes. Because desert microinvertebrates can mediate nutrient cycling, and the autotrophic components of crusts are known to be sensitive to rapid desiccation due to elevated...
Mantle to surface degassing of alkalic magmas at Erebus volcano, Antarctica
C. Oppenheimer, R. Moretti, P.R. Kyle, A. Eschenbacher, Jacob B. Lowenstern, R.L. Hervig, N. W. Dunbar
2011, Earth and Planetary Science Letters (306) 261-271
Continental intraplate volcanoes, such as Erebus volcano, Antarctica, are associated with extensional tectonics, mantle upwelling and high heat flow. Typically, erupted magmas are alkaline and rich in volatiles (especially CO2), inherited from low degrees of partial melting of mantle sources. We examine the degassing of the magmatic system at Erebus...
