Coastal deposits of heavy mineral sands; Global significance and US resources
Bradley S. Van Gosen, Donald I. Bleiwas, George M. Bedinger, Karl J. Ellefsen, Anjana K. Shah
2016, Mining Engineering (68) 36-43
Ancient and modern coastal deposits of heavy mineral sands (HMS) are the principal source of several heavy industrial minerals, with mining and processing operations on every continent except Antarctica. For example, HMS deposits are the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, obtained from the...
Primary production in the Delta: Then and now
James E. Cloern, April Robinson, Amy Richey, Letitia Grenier, Robin Grossinger, Katharyn E. Boyer, Jon Burau, Elizabeth A. Canuel, John F. DeGeorge, Judith Z. Drexler, Chris Enright, Emily R. Howe, Ronald Kneib, Anke Mueller-Solger, Robert J. Naiman, James L. Pinckney, Samuel M. Safran, David H. Schoellhamer, Charles A. Simenstad
2016, San Francisco Estuary and Watershed Science (3)
To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates...
A case study on evaluating impacts of potential climate change on groundwater resources: Groundwater recharge in the Upper Colorado River Basin
Fred D. Tillman, Subhrendu Gangopadhyay, Tom Pruitt
2016, Report
An investigation of the change in groundwater recharge in response to potential climate change was performed for the UCRB using the SWB groundwater recharge model and downscaled climate data from the CMIP5 multi-model dataset. Climate projections from 97 downscaled CMIP5 datasets were assumed to be equally likely and recharge simulation results were combined. Results...
Efficacy of GPS cluster analysis for predicting carnivory sites of a wide-ranging omnivore: the American black bear
Sarah R. Kindschuh, James W. Cain III, David Daniel, Mark A. Peyton
2016, Ecosphere (7) 1-17
The capacity to describe and quantify predation by large carnivores expanded considerably with the advent of GPS technology. Analyzing clusters of GPS locations formed by carnivores facilitates the detection of predation events by identifying characteristics which distinguish predation sites. We present a performance assessment of GPS cluster analysis as applied...
Ontogenetic development of otoliths in Alligator Gar
James M. Long, Richard A. Snow
2016, Transactions of the American Fisheries Society (145) 537-544
The Alligator Gar Atractosteus spatula is a species of conservation concern throughout its range, and better definition of otoliths during early development would aid understanding its life history and ecology. We conducted X-ray computed tomography scans, scanning electron microscopy, and light microscopy to examine the three pairs of otoliths and...
Synthesising empirical results to improve predictions of post-wildfire runoff and erosion response
Richard A. Shakesby, John A. Moody, Deborah A. Martin, Peter R. Robichaud
2016, International Journal of Wildland Fire (25) 257-261
Advances in research into wildfire impacts on runoff and erosion have demonstrated increasing complexity of controlling factors and responses, which, combined with changing fire frequency, present challenges for modellers. We convened a conference attended by experts and practitioners in post-wildfire impacts, meteorology and related research, including modelling, to focus on...
Dynamic distributions and population declines of Golden-winged Warblers
Kenneth V. Rosenberg, Tom Will, David A. Buehler, Sara Barker Swarthout, Wayne E. Thogmartin, Ruth E. Bennett, Richard Chandler
2016, Book chapter, Golden-winged Warbler ecology, conservation, and habitat management (Studies in Avian Biology, volume 49)
With an estimated breeding population in 2010 of 383,000 pairs, the Golden-winged Warbler (Vermivora chrysoptera) is among the most vulnerable and steeply declining of North American passerines. This species also has exhibited among the most dynamic breeding distributions, with populations expanding and then contracting over the past 150 years in...
Seismic imaging beneath an InSAR anomaly in eastern Washington State: Shallow faulting associated with an earthquake swarm in a low-hazard area
William J. Stephenson, Jackson K. Odum, Charles W. Wicks Jr., Thomas L. Pratt, Richard J. Blakely
2016, Bulletin of the Seismological Society of America (106) 1461-1469
In 2001, a rare swarm of small, shallow earthquakes beneath the city of Spokane, Washington, caused ground shaking as well as audible booms over a five‐month period. Subsequent Interferometric Synthetic Aperture Radar (InSAR) data analysis revealed an area of surface uplift in the vicinity of the earthquake swarm. To investigate...
Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments
David J. Ferguson, Helge M. Gonnermann, Philipp Ruprecht, Terry Plank, Erik H. Hauri, Bruce F. Houghton, Donald A. Swanson
2016, Bulletin of Volcanology (78)
The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions...
Geologic history of Martian regolith breccia Northwest Africa 7034: Evidence for hydrothermal activity and lithologic diversity in the Martian crust
Francis M. McCubbin, Jeremy W. Boyce, Timea Novak-Szabo, Alison Santos, Romain Tartese, Nele Muttik, Gabor Domokos, Jorge A. Vazquez, Lindsay P. Keller, Desmond E. Moser, Douglas J. Jerolmack, Charles K. Shearer, Andrew Steele, Stephen M. Elardo, Zia Rahman, Mahesh Anand, Thomas Delhaye, Carl B. Agee
2016, Journal of Geophysical Research E: Planets (121) 2120-2149
The timing and mode of deposition for Martian regolith breccia Northwest Africa (NWA) 7034 were determined by combining petrography, shape analysis, and thermochronology. NWA 7034 is composed of igneous, impact, and brecciated clasts within a thermally annealed submicron matrix of pulverized crustal rocks and devitrified impact/volcanic glass. The brecciated clasts...
Species traits and catchment-scale habitat factors influence the occurrence of freshwater mussel populations and assemblages
Tamara J. Pandolfo, Thomas J. Kwak, W. Gregory Cope, Ryan J. Heise, Robert B. Nichols, Krishna Pacifici
2016, Freshwater Biology (61) 1671-1684
Conservation of freshwater unionid mussels presents unique challenges due to their distinctive life cycle, cryptic occurrence and imperilled status. Relevant ecological information is urgently needed to guide their management and conservation.We adopted a modelling approach, which is a novel application to freshwater mussels to enhance inference on...
Determining the flux of methane into Hudson Canyon at the edge of methane clathrate hydrate stability
A. Weinsten, L Navarrete, Carolyn D. Ruppel, T.C. Weber, M. Leonte, M. Kellermann, E. Arrington, D.L. Valentine, M.L Scranton, John D. Kessler
2016, Geochemistry, Geophysics, Geosystems (17) 3882-3892
Methane seeps were investigated in Hudson Canyon, the largest shelf-break canyon on the northern US Atlantic Margin. The seeps investigated are located at or updip of the nominal limit of methane clathrate hydrate stability. The acoustic identification of bubble streams was used to guide water column sampling in a 32...
Forecasting climate change impacts on plant populations over large spatial extents
Andrew T. Tredennick, Mevin Hooten, Cameron L. Aldridge, Collin G. Homer, Andrew R. Kleinhesselink, Peter B. Adler
2016, Ecosphere (7)
Plant population models are powerful tools for predicting climate change impacts in one location, but are difficult to apply at landscape scales. We overcome this limitation by taking advantage of two recent advances: remotely sensed, species-specific estimates of plant cover and statistical models developed for spatiotemporal dynamics of animal populations....
Seismic evidence of glacial-age river incision into the Tahaa barrier reef, French Polynesia
Michael Toomey, Jonathan D. Woodruff, Andrew D. Ashton, J. Taylor Perron
2016, Marine Geology (380) 284-289
Rivers have long been recognized for their ability to shape reef-bound volcanic islands. On the time-scale of glacial–interglacial sea-level cycles, fluvial incision of exposed barrier reef lagoons may compete with constructional coral growth to shape the coastal geomorphology of ocean islands. However, overprinting of Pleistocene landscapes by Holocene erosion or...
Integrating seasonal information on nutrients and benthic algal biomass into stream water quality monitoring
Christopher P. Konrad, Mark D. Munn
2016, Journal of the American Water Resources Association (52) 1223-1237
Benthic chlorophyll a (BChl a) and environmental factors that influence algal biomass were measured monthly from February through October in 22 streams from three agricultural regions of the United States. At-site maximum BChl a ranged from 14 to 406 mg/m2 and generally varied with dissolved inorganic nitrogen (DIN): 8 out of...
Use of Atlantic Forest protected areas by free-ranging dogs: estimating abundance and persistence of use
Ana Maria Paschoal, Rodrigo Massara, Larissa L. Bailey, William L. Kendall, Paul F. Doherty Jr., Andre Hirsch, Adriano Chiarello, Adriano Paglia
2016, Ecosphere (7) 1-15
Worldwide, domestic dogs (Canis familiaris) are one of the most common carnivoran species in natural areas and their populations are still increasing. Dogs have been shown to impact wildlife populations negatively, and their occurrence can alter the abundance, behavior, and activity patterns of native species. However, little is known about...
The extra mile: Ungulate migration distance alters the use of seasonal range and exposure to anthropogenic risk
Hall Sawyer, Arthur D. Middleton, Matthew M. Hayes, Matthew J. Kauffman, Kevin L. Monteith
2016, Ecosphere (7) 1-11
Partial migration occurs across a variety of taxa and has important ecological and evolutionary consequences. Among ungulates, studies of partially migratory populations have allowed researchers to compare and contrast performance metrics of migrants versus residents and examine how environmental factors influence the relative abundance of each. Such studies tend to...
Comparative use of side and main channels by small-bodied fish in a large, unimpounded river
Ann Marie Reinhold, Robert G. Bramblett, Alexander V. Zale, David W. Roberts, Geoffrey C. Poole
2016, Freshwater Biology (61) 1611-1626
Ecological theory and field studies suggest that lateral floodplain connectivity and habitat heterogeneity provided by side channels impart favourable habitat conditions for lotic fishes, especially fluvial fishes dependent on large patches of shallow, slow velocity habitats for some portion of their life cycle. However, anthropogenic modification of...
Testing fault growth models with low-temperature thermochronology in the northwest Basin and Range, USA
Magdalena A. E. Curry, Jason B. Barnes, Joseph P. Colgan
2016, Tectonics (35) 2467-2492
Common fault growth models diverge in predicting how faults accumulate displacement and lengthen through time. A paucity of field-based data documenting the lateral component of fault growth hinders our ability to test these models and fully understand how natural fault systems evolve. Here we outline a framework for using apatite...
Climate change and dissolved organic carbon export to the Gulf of Maine
Thomas G. Huntington, William M. Balch, George R. Aiken, Justin Sheffield, Lifeng Luo, Collin S. Roesler, Philip Camill
2016, Journal of Geophysical Research: Biogeosciences (121) 2700-2716
Ongoing climate change is affecting the concentration, export (flux), and timing of dissolved organic carbon (DOC) exported to the Gulf of Maine (GoM) through changes in hydrologic regime. DOC export was calculated for water years 1950 through 2013 for 20 rivers and for water years 1930 through 2013 for 14...
Use of mineral/solution equilibrium calculations to assess the potential for carnotite precipitation from groundwater in the Texas Panhandle, USA
Anthony J. Ranalli, Douglas B. Yager
2016, Applied Geochemistry (73) 118-131
This study investigated the potential for the uranium mineral carnotite (K2(UO2)2(VO4)2·3H2O) to precipitate from evaporating groundwater in the Texas Panhandle region of the United States. The evolution of groundwater chemistry during evaporation was modeled with the USGS geochemical code PHREEQC using water-quality data from 100 groundwater wells downloaded from the...
Simulation modeling to explore the effects of length-based harvest regulations for Ictalurus fisheries
David R. Stewart, James M. Long, Daniel E. Shoup
2016, North American Journal of Fisheries Management (36) 1190-1204
Management of Blue Catfish Ictalurus furcatus and Channel Catfish I. punctatus for trophy production has recently become more common. Typically, trophy management is attempted with length-based regulations that allow for the moderate harvest of small fish but restrict the harvest of larger fish. However, the specific regulations used vary considerably...
Inferring invasive species abundance using removal data from management actions
Amy J. Davis, Mevin Hooten, Ryan S. Miller, Matthew L. Farnsworth, Jesse S. Lewis, Michael Moxcey, Kim M. Pepin
2016, Ecological Applications (26) 2339-2346
Evaluation of the progress of management programs for invasive species is crucial for demonstrating impacts to stakeholders and strategic planning of resource allocation. Estimates of abundance before and after management activities can serve as a useful metric of population management programs. However, many methods of estimating population size are too...
Inter-comparison of three-dimensional models of volcanic plumes
Yujiro Suzuki, Antonio Costa, Matteo Cerminara, Tomaso Esposti Ongaro, Michael Herzog, Alexa R. Van Eaton, Leif Denby
2016, Journal of Volcanology and Geothermal Research (326) 26-42
We performed an inter-comparison study of three-dimensional models of volcanic plumes. A set of common volcanological input parameters and meteorological conditions were provided for two kinds of eruptions, representing a weak and a strong eruption column. From the different models, we compared the maximum plume height, neutral buoyancy level (where...
Lateral and subsurface flows impact arctic coastal plain lake water budgets
Joshua C. Koch
2016, Hydrological Processes (30) 3918-3931
Arctic thaw lakes are an important source of water for aquatic ecosystems, wildlife, and humans. Many recent studies have observed changes in Arctic surface waters related to climate warming and permafrost thaw; however, explaining the trends and predicting future responses to warming is difficult without a stronger fundamental understanding of...