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2005

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Articles 361 - 390 of 417

Full-Text Articles in Earth Sciences

High-Resolution Ocean Color Remote Sensing Of Benthic Habitats: A Case Study At The Roatan Island, Honduras, Deepak R. Mishra, Sunil G. Narumalani, Donald Rundquist, Merlin P. Lawson Jan 2005

High-Resolution Ocean Color Remote Sensing Of Benthic Habitats: A Case Study At The Roatan Island, Honduras, Deepak R. Mishra, Sunil G. Narumalani, Donald Rundquist, Merlin P. Lawson

Department of Earth and Atmospheric Sciences: Faculty Publications

Natural resource managers clamor for detailed reef habitat maps for monitoring smaller scale disturbances in reef communities. Coastal ocean color remote sensing techniques permit benthic habitats to be explored with higher resolution than ever before. The objective of this research was to develop an accurate benthic habitat map for an area off the northwest coast of Roatan Island, Honduras, using high-resolution multispectral IKONOS data. Atmospheric (Rayleigh and aerosol path radiance) and water column corrections (water depth and water column attenuation) were applied to the imagery, making it a robust method for mapping benthic habitats. Water depth for each pixel was …


Groundwater Irrigation In The Development Of The Grand Prairie Rice Industry, 1896-1950, John B. Gates Jan 2005

Groundwater Irrigation In The Development Of The Grand Prairie Rice Industry, 1896-1950, John B. Gates

Department of Earth and Atmospheric Sciences: Faculty Publications

Elucidates some of the ways in which groundwater and groundwater irrigation have affected the Grand Prairie's rice industry over time and conversely how the development of the industry has altered the region's groundwater conditions. Concentrates on aspects of the industry's history that have often been overlooked in favor of rice cultivation's social dimensions and consider hydrological systems not just as resources awaiting exploitation or as simple constraints on production but as variables whose roles and effects can change over time.


New Stratigraphic Subdivision, Depositional Environment, And Age Estimate For The Upper Cretaceous Djadokhta Formation, Southern Ulan Nur Basin, Mongolia, Demberelyin Dashzeveg, Lowell Dingus, David B. Loope, Carl C. Swisher Iii, Togtokh Dulam, Mark R. Sweeney Jan 2005

New Stratigraphic Subdivision, Depositional Environment, And Age Estimate For The Upper Cretaceous Djadokhta Formation, Southern Ulan Nur Basin, Mongolia, Demberelyin Dashzeveg, Lowell Dingus, David B. Loope, Carl C. Swisher Iii, Togtokh Dulam, Mark R. Sweeney

Department of Earth and Atmospheric Sciences: Faculty Publications

Studies of key and newly discovered sections of the Upper Cretaceous Djadokhta Formation along the southern margin of the Ulan Nur Basin allow a new subdivision based on lithology. The formation and its members were mapped at both Bayn Dzak, an area that includes the Flaming Cliffs, and Tugrugyin Shireh, an area about 50 km to the northwest of Bayn Dzak. Stratigraphic sections at both localities were remeasured. The considerably enlarged formation comprises a lower Bayn Dzak Member, dominated by moderate reddish orange sands with subordinate mudstone units, and an upper Tugrugyin Member, composed of pale orange to light gray …


Do Meteorologists Suppress Thunderstorms? Radar-Derived Statics And The Behavior Of Moist Convection, Matthew D. Parker, Jason C. Knievel Jan 2005

Do Meteorologists Suppress Thunderstorms? Radar-Derived Statics And The Behavior Of Moist Convection, Matthew D. Parker, Jason C. Knievel

Department of Earth and Atmospheric Sciences: Faculty Publications

Most meteorologists are acquainted with the no- tion of a weather hole—that is, a place that receives less exciting weather than does its surroundings. Exciting weather takes many forms, but when people use the term weather hole, they tend to mean a place that thunderstorms often barely miss, or near which approaching storms often dissipate. For this paper, that is the meaning we adopt.

In our experience, many meteorologists and lay weather enthusiasts genuinely believe that they live in weather holes, and this belief, almost without fail, seems to stem from countless hours spent gazing at displays of radar reflectivity. …


Performance Of Quality Assurance Procedures For An Applied Climate Information System, K. G. Hubbard, S. Goddard, Bill Sorensen, N. Wells, Thomas Osugi Jan 2005

Performance Of Quality Assurance Procedures For An Applied Climate Information System, K. G. Hubbard, S. Goddard, Bill Sorensen, N. Wells, Thomas Osugi

Department of Earth and Atmospheric Sciences: Faculty Publications

Valid data are required to make climate assessments and to make climate-related decisions. The objective of this paper is threefold: to introduce an explicit treatment of Type I and Type II errors in evaluating the performance of quality assurance procedures, to illustrate a quality control approach that allows tailoring to regions and subregions, and to introduce a new spatial regression test. Threshold testing, step change, persistence, and spatial regression were included in a test of three decades of temperature and precipitation data at six weather stations representing different climate regimes. The magnitude of thresholds was addressed in terms of the …


A Multilocus Population Genetic Survey Of The Greater Sage-Grouse Across Their Range, S. J. Oyler-Mccance, S.E. Taylor, T. W. Quinn Jan 2005

A Multilocus Population Genetic Survey Of The Greater Sage-Grouse Across Their Range, S. J. Oyler-Mccance, S.E. Taylor, T. W. Quinn

United States Geological Survey: Staff Publications

The distribution and abundance of the greater sage-grouse (Centrocercus urophasianus) have declined dramatically, and as a result the species has become the focus of conservation efforts. We conducted a range-wide genetic survey of the species which included 46 populations and over 1000 individuals using both mitochondria1 sequence data and data from seven nuclear microsatellites. Nested clade and STRUCTURE analyses revealed that, in general, the greater sage-grouse populations follow an isolation-by-distance model of restricted gene flow. This suggests that movements of the greater sage-grouse are typically among neighboring populations and not across the species, range. This may have important …


Transport Of Chemical And Microbial Compounds From Known Wastewater Discharges: Potential For Use As Indicators Of Human Fecal Contamination, Susan Glassmeyer, Edward Furlong, Dana Kolpin, Jeffrey Cahill, Steven Zaugg, Stephen Werner, Michael Meyer, David Kryak Jan 2005

Transport Of Chemical And Microbial Compounds From Known Wastewater Discharges: Potential For Use As Indicators Of Human Fecal Contamination, Susan Glassmeyer, Edward Furlong, Dana Kolpin, Jeffrey Cahill, Steven Zaugg, Stephen Werner, Michael Meyer, David Kryak

United States Geological Survey: Staff Publications

The quality of drinking and recreational water is currently (2005) determined using indicator bacteria. However, the culture tests used to analyze for these bacteria require a long time to complete and do not discriminate between human and animal fecal material sources. One complementary approach is to use chemicals found in human wastewater, which would have the advantages of (1) potentially shorter analysis times than the bacterial culture tests and (2) being selected for human-source specificity. At 10 locations, water samples were collected upstream and at two successive points downstream from a waste-waster treatment plant (WWTP); a treated effluent sample was …


Climate Change And Amphibians, P.S. Corn Jan 2005

Climate Change And Amphibians, P.S. Corn

United States Geological Survey: Staff Publications

Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines in Central America to climate relies solely on correlations, and the mechanisms underlying the declines are not understood. Connections between embryo mortality and declines …


An Evaluation Of Weather And Disease As Causes Of Decline In Two Populations Of Boreal Toads, Rick D. Scherer, Erin Muths, Barry R. Noon, Paul Stephen Corn Jan 2005

An Evaluation Of Weather And Disease As Causes Of Decline In Two Populations Of Boreal Toads, Rick D. Scherer, Erin Muths, Barry R. Noon, Paul Stephen Corn

United States Geological Survey: Staff Publications

Two populations of boreal toads (Bufo boreas) experienced drastic declines in abundance in the late 1990s. Evidence supported the hypothesis of disease (the chytrid fungus, Batrachochytrium dendrobatidis) as the cause of these declines. but other hypotheses had not been evaluated. We used an 11-year capture-recapture data set to evaluate weather and disease as causes of these declines. We developed sets of mathematical models that reflected hypothesized relationships between several weather variables and annual survival rates of adult males in these populations. In addition, models that reflected the possibility that the declines were caused by an introduced fungus …


Amphibian Research And Monitoring Initiative (Armi): A Successful Start To A National Program In The United States, Erin Muths, Robin E. Jung, Larissa L. Bailey, Michael J. Adams, P. Stephen Corn, C. Kenneth Dodd Jr., Gary M. Fellers, Walter J. Sadinski, Cecil R. Schwalbe, Susan C. Walls, Robert N. Fisher, Alisa L. Gallant, William A. Battaglin, D. Earl Green Jan 2005

Amphibian Research And Monitoring Initiative (Armi): A Successful Start To A National Program In The United States, Erin Muths, Robin E. Jung, Larissa L. Bailey, Michael J. Adams, P. Stephen Corn, C. Kenneth Dodd Jr., Gary M. Fellers, Walter J. Sadinski, Cecil R. Schwalbe, Susan C. Walls, Robert N. Fisher, Alisa L. Gallant, William A. Battaglin, D. Earl Green

United States Geological Survey: Staff Publications

Most research to assess amphibian declines has focused on local-scale projects on one or a few species. The Amphibian Research and Monitoring Initiative (ARMI) is a national program in the United States mandated by congressional directive and implemented by the U.S. Department of the Interior (specifically the U.S. Geological Survey, USGS). Program goals are to monitor changes in populations of amphibians across U.S. Department of the Interior lands and to address research questions related to amphibian declines using a hierarchical framework of base-, mid- and apex-level monitoring sites. ARMI is currently monitoring 83 amphibian species (29% of species in the …


Holocene Paleoecology Along The Blekinge Coast, Southeast Sweden, And Implications For Climate And Sea-Level Changes, Shi-Yong Yu, Björn E. Berglund, Per Sandgren, Sherilyn C. Fritz Jan 2005

Holocene Paleoecology Along The Blekinge Coast, Southeast Sweden, And Implications For Climate And Sea-Level Changes, Shi-Yong Yu, Björn E. Berglund, Per Sandgren, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

To investigate the Holocene vegetation history and shoreline displacement along the southeastern Swedish coast, two radiocarbon dated pollen, macrofossil, and mineral magnetic sequences were studied in the western Blekinge coast: Hunnemara Lake and Smygen Bay. Both pollen records show mosaic vegetation with grasslands, heaths and woodlands prior to 11,300 cal. BP. Pinus-dominated mixed forest was initially established by 11,000 cal. BP. By 10,000 cal. BP, mixed forest with higher species diversity was fully established. Expansion of broad-leaved trees began at about 8,600 cal. BP, indicating the onset of the mid-Holocene thermal maximum in Scandinavia. Following the Ulmus decline ~5,800 …


Vertical Movement Of Water In A High Plains Aquifer Induced By A Pumping Well, Xunhong Chen, Yanfeng Yin, James W. Goeke, Robert F. Diffendal Jr. Jan 2005

Vertical Movement Of Water In A High Plains Aquifer Induced By A Pumping Well, Xunhong Chen, Yanfeng Yin, James W. Goeke, Robert F. Diffendal Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

Field observation and numerical simulations were carried out to evaluate the hydraulic relationship between the shallow and deep aquifer of a High Plains Aquifer system, in which shallow and deep aquifers are separated by an aquitard. Pumping from the lower aquifer resulted in a small drawdown in the upper aquifer and a larger drawdown in the aquitard; pumping from the shallow aquifer caused a small drawdown in the aquitard and the deep aquifer. Analysis of pumping test data gives the values of the hydraulic conductivity of the aquitard and the deep aquifer. Long-term observation of groundwater levels in the shallow …


Topographic, Bioclimatic, And Vegetation Characteristics Of Three Ecoregion Classification Systems In North America: Comparisons Along Continent-Wide Transects, Robert Thompson, Sarah Shafer, Katherine Anderson, Laura Strickland, Richard Pelltier, Patrick Bartlein, Michael Kerwin Jan 2005

Topographic, Bioclimatic, And Vegetation Characteristics Of Three Ecoregion Classification Systems In North America: Comparisons Along Continent-Wide Transects, Robert Thompson, Sarah Shafer, Katherine Anderson, Laura Strickland, Richard Pelltier, Patrick Bartlein, Michael Kerwin

United States Geological Survey: Staff Publications

Ecoregion classification systems are increasingly used for policy and management decisions, particularly among conservation and natural resource managers. A number of ecoregion classification systems are currently available, with each system defining ecoregions using different classification methods and different types of data. As a result, each classification system describes a unique set of ecoregions. To help potential users choose the most appropriate ecoregion system for their particular application, we used three latitudinal transects across North America to compare the boundaries and environmental characteristics of three ecoregion classification systems [Küchler, World Wildlife Fund (WWF), and Bailey]. A variety of variables were used …


Participant Observations On Environmental And Social Eff Ect S Of The Conservation Reserve Program: Results Of A National Survey, Arthur W. Alen Jan 2005

Participant Observations On Environmental And Social Eff Ect S Of The Conservation Reserve Program: Results Of A National Survey, Arthur W. Alen

United States Geological Survey: Staff Publications

A national survey of Conservation Reserve Program (CRP) contractees was completed to obtain information about environmental and social effects of the program on participants, farms, and communities. Over 75% of respondents believed CRP benefits to wildlife were important. Seventy-three percent of respondents observed increased numbers of wildlife associated with CRP lands. A majority of respondents (82%) believed the amount of assistance furnished by the U.S. Department of Agriculture related to planning and maintaining wildlife habitat associated with CRP lands was appropriate. The majority of respondents reported CRP benefits, including increased quality of surface and ground waters, improved air quality, control …


Paleoceanographic History Of The Guaymas Basin, Gulf Of California, During The Past 15,000 Years Based On Diatoms, Silicoflagellates, And Biogenic Sediments, John A. Barron, David Bukrya, Walter E. Dean Jan 2005

Paleoceanographic History Of The Guaymas Basin, Gulf Of California, During The Past 15,000 Years Based On Diatoms, Silicoflagellates, And Biogenic Sediments, John A. Barron, David Bukrya, Walter E. Dean

United States Geological Survey: Staff Publications

High-resolution records of calcium carbonate, biogenic opal, diatoms, and silicoflagellates from western Guaymas Basin gravity core GGC55 and piston core JPC56 and eastern Guaymas Basin DSDP Site 480 reveal a complex paleoceanographic history of the central Gulf of California during the past 15,000 years. Prior to ~6.2 ka, the eastern and western Guaymas Basin proxy records were remarkably similar. After conditions similar to those of today during the Bølling–Allerod, the Younger Dryas (YD) saw a major drop in diatom production, coincident with increased calcium carbonate and tropical microfossils suggestive of El Nino-like conditions. Biosiliceous productivity began increasing during the latter …


Acquisition And Evaluation Of Thermodynamic Data For Bieberite-Moorhouseite Equilibria At 0.1 Mpa, I-Ming Chou, Robert Seal Ii Jan 2005

Acquisition And Evaluation Of Thermodynamic Data For Bieberite-Moorhouseite Equilibria At 0.1 Mpa, I-Ming Chou, Robert Seal Ii

United States Geological Survey: Staff Publications

Published estimates for the equilibrium relative humidity (RH) at 25 °C for the reaction: bieberite (CoSO4•7H2O) = moorhouseite (CoSO4•6H2O) + H2O, range from 69.8 to 74.5%. To evaluate these data, the humidity-buffer technique was used to determine equilibrium constants for this reaction between 14 and 43 °C at 0.1 MPa. Reversals along fi ve humidity-buffer curves yield ln K = 18.03–6509.43/T, where K is the equilibrium constant, and T is temperature in K. The derived standard Gibbs free energy of reaction is 9.43 kJ/mol, which agrees well with several previously …


Determination Of Goslarite–Bianchite Equilibria By The Humidity-Buffer Technique At 0.1 Mpa, I-Ming Chou, Robert R. Seal Ii Jan 2005

Determination Of Goslarite–Bianchite Equilibria By The Humidity-Buffer Technique At 0.1 Mpa, I-Ming Chou, Robert R. Seal Ii

United States Geological Survey: Staff Publications

Goslarite–bianchite equilibria were determined along four humidity-buffer curves at 0.1 MPa and between 27 and 36 °C. Results, based on tight reversals along each humidity buffer, can be represented by ln K (±0.005)=19.643-7015.38/T, where K is the equilibrium constant and T is temperature in K. Our data are in excellent agreement with several previous vapor-pressure measurements and are consistent with the solubility data reported in the literature. Thermodynamic analysis of these data yields 9.634 (±0.056) kJ mol-1 for the standard Gibbs free energy of reaction, which is in good agreement with the value of 9.658 kJ mol-1 calculated …


Geochemistry Of Sulfate Minerals In High- And Low-Temperature Environments: A Tribute To Robert O. Rye, Robert R. Seal Ii, John L. Jambor, Charles N. Alpers Jan 2005

Geochemistry Of Sulfate Minerals In High- And Low-Temperature Environments: A Tribute To Robert O. Rye, Robert R. Seal Ii, John L. Jambor, Charles N. Alpers

United States Geological Survey: Staff Publications

This special issue is a tribute to Robert O. Rye, known as "Bob" to most, in light of his highly productive and ongoing career. Almost all of the papers in this issue are derived from topical sessions on sulfate minerals in hydrothermal and low-temperature environments. The sessions, held at the 2000 Geological Society of America meeting in Reno, NV, and sponsored jointly by the Mineralogical Society of America, the Society of Economic Geologists and the Geochemical Society, included 29 oral and 9 poster presentations. The sessions complemented a short course on the crystallography, geochemistry and environmental significance of sulfate minerals, …


U-Pb Zircon Ages And Pb Isotope Geochemistry Of Gold Deposits In The Carolina Slate Belt Of South Carolina, R. A. Ayuso, J. L. Wooden, N. K. Foley, Robert R. Seal Ii, A. K. Sinha Jan 2005

U-Pb Zircon Ages And Pb Isotope Geochemistry Of Gold Deposits In The Carolina Slate Belt Of South Carolina, R. A. Ayuso, J. L. Wooden, N. K. Foley, Robert R. Seal Ii, A. K. Sinha

United States Geological Survey: Staff Publications

Volcanic rocks of the Persimmon Fork Formation host the largest known gold mines of the Carolina slate belt. U-Pb (SHRIMP) zircon ages have been obtained from rocks closely associated with pyrite-enargite-gold deposits at Brewer (quartz-topaz rhyolite breccia from the argillic alteration zone in the Brewer pit and felsic ash-flow tuff from the quartz sericite alteration zone), from the disseminated and semimassive pyrite-gold deposits at Haile (crystal lithic rhyolitic ash-flow tuffs from the Champion pit), and from the Ridgeway deposit (felsic ash-flow tuff from the stratigraphic host of the North pit gold deposit). Generally, the zircons are fine grained, fractured, and …


Comparison Of A Novel Passive Sampler To Standard Water-Column Sampling For Organic Contaminants Associated With Wastewater Effluents Entering A New Jersey Stream, D. A. Alvarez, P. E. Stackelberg, J. D. Petty, J. N. Huckins, E. T. Furlong, S. D. Zaugg, M. T. Meyer Jan 2005

Comparison Of A Novel Passive Sampler To Standard Water-Column Sampling For Organic Contaminants Associated With Wastewater Effluents Entering A New Jersey Stream, D. A. Alvarez, P. E. Stackelberg, J. D. Petty, J. N. Huckins, E. T. Furlong, S. D. Zaugg, M. T. Meyer

United States Geological Survey: Staff Publications

Four water samples collected using standard depth and width water-column sampling methodology were compared to an innovative passive, in situ, sampler (the polar organic chemical integrative sampler or POCIS) for the detection of 96 organic wastewater-related contaminants (OWCs) in a stream that receives agricultural, municipal, and industrial wastewaters. Thirty-two OWCs were identified in POCIS extracts whereas 9–24 were identified in individual water-column samples demonstrating the utility of POCIS for identifying contaminants whose occurrence are transient or whose concentrations are below routine analytical detection limits. Overall, 10 OWCs were identified exclusively in the POCIS extracts and only six solely identified in …


Selenium Impactson Razorback Sucker, Colorado River, Colorado I. Adults, Steven J. Hamilton, Kathy M. Holley, Kevin J. Buhl, Fern A. Bullard, L. Ken Weston, Susan F. Mcdonald Jan 2005

Selenium Impactson Razorback Sucker, Colorado River, Colorado I. Adults, Steven J. Hamilton, Kathy M. Holley, Kevin J. Buhl, Fern A. Bullard, L. Ken Weston, Susan F. Mcdonald

United States Geological Survey: Staff Publications

Adult razorback sucker (Xyrauchen texanus) were exposed to various selenium concentrations in ponds and isolated river channels of the Colorado River near Grand Junction, CO, to determine effectson their growth and residue accumulation over an 11-month period. Adults at Horsethief ponds were fed a commercial diet, whereas fish at Adobe Creek channel and North Pond foraged on natural food items. Selenium concentrations at Horsethief were 2.2 μg/L in water, 0.1–1.4 μg/g in sediment, and 2.3–3.1 μg/g in food organisms (1.1 μg/g in commercial fish food), at Adobe Creek were 3.8 μg/L in water, 0.5–2.1 μg/g in sediment, and …


Conceptual Model Of Sediment Processes In The Upper Yuba River Watershed, Sierra Nevada, Ca, Jennifer A. Curtis, Lorraine E. Flint, Charles N. Alpers, Sarah M. Yarnell Jan 2005

Conceptual Model Of Sediment Processes In The Upper Yuba River Watershed, Sierra Nevada, Ca, Jennifer A. Curtis, Lorraine E. Flint, Charles N. Alpers, Sarah M. Yarnell

United States Geological Survey: Staff Publications

This study examines the development of a conceptual model of sediment processes in the upper Yuba River watershed; and we hypothesize how components of the conceptual model may be spatially distributed using a geographical information system (GIS). The conceptual model illustrates key processes controlling sediment dynamics in the upper Yuba River watershed and was tested and revised using field measurements, aerial photography, and low elevation videography. Field reconnaissance included mass wasting and channel storage inventories, assessment of annual channel change in upland tributaries, and evaluation of the relative importance of sediment sources and transport processes. Hillslope erosion rates throughout the …


Characterization Of Waste Rock Associated With Acid Drainage At The Penn Mine, California, By Ground-Based Visible To Short-Wave Infrared Reflectance Spectroscopy Assisted By Digital Mapping, Irene C. Montero S., George H. Brimhall, Charles N. Alpers, Gregg A. Swayze Jan 2005

Characterization Of Waste Rock Associated With Acid Drainage At The Penn Mine, California, By Ground-Based Visible To Short-Wave Infrared Reflectance Spectroscopy Assisted By Digital Mapping, Irene C. Montero S., George H. Brimhall, Charles N. Alpers, Gregg A. Swayze

United States Geological Survey: Staff Publications

Prior to remediation at the abandoned Cu–Zn Penn Mine in the Foothills massive sulfide belt of the Sierra Nevada, CA, acid mine drainage (AMD) was created, in part, by the subaerial oxidation of sulfides exposed on several waste piles. To support remediation efforts, a mineralogical study of the waste piles was undertaken by acquiring reflectance spectra (measured in the visible to short-wave infrared range of light (0.35–2.5 Am) using a portable, digitally integrated pen tablet PC mapping system with differential global positioning system and laser rangefinder support. Analysis of the spectral data made use of a continuum removal and band-shape …


High Dispersal In A Frog Species Suggest That It Is Vulnerable To Habitat Fragmentation, W. Chris Funk, Allison E. Greene, Paul Stephen Corn, Fred W. Allendorf Jan 2005

High Dispersal In A Frog Species Suggest That It Is Vulnerable To Habitat Fragmentation, W. Chris Funk, Allison E. Greene, Paul Stephen Corn, Fred W. Allendorf

United States Geological Survey: Staff Publications

Global losses of amphibian populations are a major conservation concern and have generated substantial debate over their causes. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disregarded as a cause of amphibian declines and conservation efforts can be focused elsewhere. We examined dispersal rates in Columbia spotted frogs (Rana luteiventris) using capture– recapture analysis …


Population Structure Of Columbia Spotted Frogs (Rana Luteiventris) Is Strongly Affected By The Landscape, W. Chris Funk, Michael S. Blouin, Paul Stephen Corn, Bryce A. Maxell, David S. Pilliod, Stephen Amish, Fred W. Allendorf Jan 2005

Population Structure Of Columbia Spotted Frogs (Rana Luteiventris) Is Strongly Affected By The Landscape, W. Chris Funk, Michael S. Blouin, Paul Stephen Corn, Bryce A. Maxell, David S. Pilliod, Stephen Amish, Fred W. Allendorf

United States Geological Survey: Staff Publications

Landscape features such as mountains, rivers, and ecological gradients may strongly affect patterns of dispersal and gene flow among populations and thereby shape population dynamics and evolutionary trajectories. The landscape may have a particularly strong effect on patterns of dispersal and gene flow in amphibians because amphibians are thought to have poor dispersal abilities. We examined genetic variation at six microsatellite loci in Columbia spotted frogs (Rana luteiventris) from 28 breeding ponds in western Montana and Idaho, USA, in order to investigate the effects of landscape structure on patterns of gene flow. We were particularly interested in addressing …


Late-Holocene Flooding And Drought In The Northern Great Plains, Usa, Reconstructed From Tree Rings, Lake Sediments And Ancient Shorelines, M. D. Shapley, W. C. Johnson, D. R. Engstrom, W. R. Osterkamp Jan 2005

Late-Holocene Flooding And Drought In The Northern Great Plains, Usa, Reconstructed From Tree Rings, Lake Sediments And Ancient Shorelines, M. D. Shapley, W. C. Johnson, D. R. Engstrom, W. R. Osterkamp

United States Geological Survey: Staff Publications

During the AD 1990s the Waubay Lakes complex in eastern South Dakota experienced historically unprecedented high water levels. Property damage from this flooding led to an examination of the occurrence of past pluvial episodes and their relation to climate. A lOOO-year hydroclimate reconstruction was developed from local bur oak (Quercus macrocarpa) tree-ring records and lake-sediment cores. Analysis of lake shoreline and drainage features provides late-Quaternary geomorphic context for this high-resolution record. Tree-ring width and shell geochemistry of the ostracode Candona rawsoni show marked coherence, indicating synchronous responses to moisture balance in vegetation and lake salinity; geomorphic evidence …


Variations In Mineralogy, Temperature, And Oxygen Fugacity In A Suite Of Strongly Peralkaline Lavas And Tuffs, Pantelleria, Italy., John C. White, Minghua Ren, Don Parker Jan 2005

Variations In Mineralogy, Temperature, And Oxygen Fugacity In A Suite Of Strongly Peralkaline Lavas And Tuffs, Pantelleria, Italy., John C. White, Minghua Ren, Don Parker

EKU Faculty and Staff Scholarship

Eight samples of pantelleritic lava and tuff and a lithic inclusion of trachyte from Pantelleria, Italy, have been thoroughly analyzed with an electron microprobe. These samples reveal five different mineral assemblages if classified by the presence of fayalite, aenigmatite, ilmenite, and magnetite: (1) augite + fayalite + ilmenite + magnetite, (2) augite + fayalite + ilmenite, (3) hedenbergite or sodian hedenbergite + fayalite + ilmenite + aenigmatite + quartz, (4) sodian hedenbergite or aegirine-augite + ilmenite + aenigmatite + quartz ± ferrorichterite, and (5) aegirine-augite + aenigmatite + quartz. Alkali feldspar (Or35–37) is present as the dominant phyric phase in …


Introduction To Salinity - Workshop Development Guide For Facilitator, T M. Lacey Jan 2005

Introduction To Salinity - Workshop Development Guide For Facilitator, T M. Lacey

Agriculture reports

Participants will be able to recognise landscape components on their farm, which are at risk of salinity (current, imminent or future) and will be aware of a range of available options available to them to managing this risk.


Step Workshops - Guide For Facilitators, Department Of Agriculture And Food, Western Australia Jan 2005

Step Workshops - Guide For Facilitators, Department Of Agriculture And Food, Western Australia

Agriculture reports

The STEP workshops can be run as independent modules or as part of the ?A Million Hectares for the Future? workshop series of which the overarching learning outcome is: Participants will be able to identify and make informed decisions to profitably manage salinity on their farms. Outlines the preferred pathway for the modules in the Million Hectares for the Future series.


Microstructural Characterization Of Ice Cores, Ian Baker, Daniel Iliescu, Rachel Obbard, Hui Chang, Benjamin Bostick, Charles Daghlian Jan 2005

Microstructural Characterization Of Ice Cores, Ian Baker, Daniel Iliescu, Rachel Obbard, Hui Chang, Benjamin Bostick, Charles Daghlian

Dartmouth Scholarship

No abstract provided.