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Full-Text Articles in Geology

Co2 Sequestration Validation Test In A Deep Oil Field In The Williston Basin, University Of North Dakota. Energy And Environmental Research Center Apr 2008

Co2 Sequestration Validation Test In A Deep Oil Field In The Williston Basin, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Williston Basin Field Validation Test conducted by the Plains CO2 Reduction (PCOR) Partnership. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


The Weyburn Oil Field – A Model For Value-Added Direct Co2 Sequestration, University Of North Dakota. Energy And Environmental Research Center Apr 2008

The Weyburn Oil Field – A Model For Value-Added Direct Co2 Sequestration, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Weyburn Oil Field. Discusses CO2 enhanced oil recovery (EOR) at Weyburn and research on combining EOR and CO2 sequestration at the site. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


What Is Co2 Sequestration?, University Of North Dakota. Energy And Environmental Research Center Apr 2008

What Is Co2 Sequestration?, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the CO2 sequestration and the Plains CO2 Reduction (PCOR) Partnership. Defines CO2 sequestration and lists Phase I partners. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Pcor Partnership Phase Iii – Commercial-Scale Demonstrations Of Geologic Co2 Storage In The Northern Great Plains, University Of North Dakota. Energy And Environmental Research Center Apr 2008

Pcor Partnership Phase Iii – Commercial-Scale Demonstrations Of Geologic Co2 Storage In The Northern Great Plains, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet on Phase III of the Plains CO2 Reduction (PCOR) Partnership, conducted under the U.S. Department of Energy. Includes information on commercial-scale demonstrations of CO2 geologic sequestration. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Zama Acid Gas Eor, Co2 Sequestration, And Monitoring Project, University Of North Dakota. Energy And Environmental Research Center Apr 2008

Zama Acid Gas Eor, Co2 Sequestration, And Monitoring Project, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Zama Field acid gas demonstration site, a Plains CO2 Reduction (PCOR) Partnership CO2 sequestration validation project. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


An Ordovician Global Reference Section Recently Selected In Oklahoma, Daniel Goldman, Stephen A. Leslie, Stig M. Bergström, Jaak Nõlvak, Seth A. Young, Stanley C. Finney Apr 2008

An Ordovician Global Reference Section Recently Selected In Oklahoma, Daniel Goldman, Stephen A. Leslie, Stig M. Bergström, Jaak Nõlvak, Seth A. Young, Stanley C. Finney

Department of Earth, Environment and Sustainability Faculty Publications

Ordovician fossil faunas are characterized by a marked biogeographic differentiation that results in a minimal similarity between most North American faunas and those of major Ordovician areas elsewhere in the world. This provincial distribution of most fossils has led to establishment of different schemes of fossil-based regional stages in, for instance, North America, Baltoscandia, China, and the British Isles.

Because these chrono-stratigraphic units have been largely based on shelly fossils with distributions restricted to a particular region, it has been impossible in most cases to establish a precise international correlation of these regional stages. Furthermore, some general terms, such as …


Metamorphic Style And Development Of The Blueschist- To Eclogite-Facies Rocks, Cyclades, Greece, John C. Schumacher, John B. Brady, John T. Cheney Apr 2008

Metamorphic Style And Development Of The Blueschist- To Eclogite-Facies Rocks, Cyclades, Greece, John C. Schumacher, John B. Brady, John T. Cheney

Geosciences: Faculty Publications

The island of Syros, Greece is part of the Attic-Cycladic blueschist belt, formed during Mesozoic Eurasia-Africa subduction. The rocks of Syros can be broadly divided into three tectono-stratigraphic units: (I) metamorphosed sedimentary and volcanic rocks (marble-schist sequence), (II) remnants of oceanic crust with fault-bounded packages of blueschist/eclogite-facies mafic rocks and serpentinite (mafic-ultramafic rocks) and (III) the Vari gneiss, which is a tectonic klippe. Low-temperature, high-pressure assemblages are found on several islands in the Cyclades. The best preserved of these rocks are on Syros and Sifnos islands. Mineral compositions and peak metamorphic assemblages are similar on both islands. Both islands are …


California Drought, An Update April 2008, Baryohay Davidoff, Fawzi Karajeh, Dean Reynolds, Eric Senter, John Woodling Apr 2008

California Drought, An Update April 2008, Baryohay Davidoff, Fawzi Karajeh, Dean Reynolds, Eric Senter, John Woodling

United States Geological Survey: Staff Publications

TABLE OF CONTENTS

CHAPTER 1. RECENT HYDROLOGIC CONDITIONS AND IMPACTS

Introduction....................................................... 1

Water Year 2007 .................................................. 1

Drought in the Colorado River Basin ..................................................... 5

Drought and Dry Conditions in the Early 2000s .................................... 7

The 2001 Klamath Basin Drought Emergency ............................... 11

CHAPTER 2. PROGRAMMATIC AND INSTITUTIONAL UPDATES

The San Francisco Bay-Sacramento/San Joaquin River Delta.................................................................. 15

The Colorado River .................................................................... 16

State Financial Assistance to Local Agencies.................................... 17

Urban Water Management Planning ................................................... 20

Water Transfers .............................................................................. 20

Small Water Systems and Drought Preparedness ................................. 21


Morphological Analysis Of The Charlevoix-Antrim And Northport Drumlin Fields, Michigan Using Digital Elevation Models, Alan M. Lefever Apr 2008

Morphological Analysis Of The Charlevoix-Antrim And Northport Drumlin Fields, Michigan Using Digital Elevation Models, Alan M. Lefever

Masters Theses

The Charlevoix-Antrim and Northport drumlin fields, located in northwest Lower Michigan, lie on opposite sides of Grand Traverse Bay. Morphological measurements were derived from topographic maps and Digital Elevation Models (DEMs), combined with grain size analyses performed on collected drumlin sediments. Comparison of the morphological results demonstrates that statistical analysis of equal or better accuracy can be performed on drumlins using high resolution DEMs. The grain size analysis determined that the drumlins contain more gravel near the coast and become sandier to the south and east.

Spindle drumlins are the dominant drumlin form in both the Charlevoix-Antrim and Northport fields. …


Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden Apr 2008

Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden

Masters Theses

The Chesapeake Bay impact structure is a ca. 35.4 Ma old crater located on the coastal plain of Virginia along the eastern seaboard of North America. The impact generated a crater between 85 and 90 km in diameter, and over 2000 meters deep. Deposition returned to normal shortly after impact, resulting in a unique record of both the impact related and subsequent passive margin sedimentation. We use backstripping to show that the impact strongly affected sedimentation for 7 m.y. through a combination of impact derived crustal scale tectonics, dominated by the introduction and subsequent removal of a negative thermal anomaly, …


Rise And Demise Of The New Lakes Of Sahara, Mohamed G. Abdel Salam, Ahmed M. Youssef, Sayed Arafat, Mohamed Alfarhan Apr 2008

Rise And Demise Of The New Lakes Of Sahara, Mohamed G. Abdel Salam, Ahmed M. Youssef, Sayed Arafat, Mohamed Alfarhan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Multispectral remote sensing data and digital elevation models were used to examine the spatial and temporal evolution of the New Lakes of Sahara in southern Egypt. These lakes appeared in September 1998, when water spilled northwestward toward the Tushka depression due to an unusual water rise in Lake Nasser induced by high precipitation in the Ethiopian Highlands. Five lakes were formed in local depressions underlain by an impermeable Paleocene shale and chalk formation. The lakes developed through three stages. (1) A rise stage occurred from September 1998 to August 2001; the area covered by the lakes reached ~1586 km2 …


Characteristics Of Mantle Fabrics Beneath The South-Central United States: Constraints From Shear-Wave Splitting Measurements, Stephen S. Gao, Kelly H. Liu, Robert J. Stern, G. R. Keller, John Patrick Hogan, J. Pulliam, E. Y. Anthony Apr 2008

Characteristics Of Mantle Fabrics Beneath The South-Central United States: Constraints From Shear-Wave Splitting Measurements, Stephen S. Gao, Kelly H. Liu, Robert J. Stern, G. R. Keller, John Patrick Hogan, J. Pulliam, E. Y. Anthony

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

New shear-wave splitting measurements at permanent broadband seismic stations in the south-central United States reveal the orientation and degree of polarization of mantle fabrics, and provide constraints on models for the formation of these fabrics. For stations on the stable North American craton, correspondence between observed polarization direction of the fast wave and the trend of Proterozoic and Paleozoic structures associated with rifts and orogenic belts implies a lithospheric origin for the observed anisotropy. The largest splitting times (up to 1.6 s) are observed at stations located in the ocean-continent transition zone, in which the fast directions are parallel to …


Natrolitite, An Unusual Rock -- Occurrence And Petrographic And Geochemical Characteristics (Eastern Turkey), Emin Ciftci, John Patrick Hogan, Hasan Kolayli, Emin Cadirli Apr 2008

Natrolitite, An Unusual Rock -- Occurrence And Petrographic And Geochemical Characteristics (Eastern Turkey), Emin Ciftci, John Patrick Hogan, Hasan Kolayli, Emin Cadirli

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Very unusual rocks consisting of natrolite (>95 vol.%) ± pargasite (<5 vol.%) and rare albite (<1 vol. %) have been discovered in the Kop mountain range, eastern Turkey. We propose to call these rocks 'natrolitite' and 'pargasite natrolitite'. They were produced by Na Si metasomatism of dikes and stocks of diorite through replacement of the intermediate primary igneous plagioclase to produce natrolite. The metasomatic alteration produced concentric elliptical zones characterized by distinct mineral assemblages centered on intrusions of diorite. The Central Zone 1 consists of variably albitized diorite with preserved magmatic textures (albite ± andesine ± pargasite ± quartz). Transition Zone 2 comprises natrolite-bearing diorite (natrolite ± albite ± andesine ± pargasite ± calcite ± quartz). Marginal Zone 3 is a rock made up almost entirely of natrolite (natrolite ± pargasite ± albite ± calcite ± chlorite). Outer Zone 4 occurs along the boundary between the natrolitite and the surrounding serpentinite and consists of listvenite, a rock which comprises magnesite, quartz, calcite, mica, talc, and hematite, indicating a role for CO2 in the metasomatic reactions, consistent with the presence of calcite in the alteration zones. Zone 5 consists essentially of brecciated serpentinite with numerous hydrothermal quartz veins and calcite veins. Whole-rock compositions document an increase in Na2O, Al2O3, and H2O from the core (central zone) to the margin while CaO, MgO, and SiO2 decrease. Plagioclase abundance and composition also varies outwards from the central core rocks where it occurs as a primary magmatic phase (~95 vol.% An41-38) …


Tree - Ring Analysis Of Cores Extracted From The Osu Cabin, Holmes County, Ohio Mar 2008

Tree - Ring Analysis Of Cores Extracted From The Osu Cabin, Holmes County, Ohio

Historic Structures

Dating historical structures in Holmes County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Wiles, Greg


The Influence Of Metal Exposure History And Ultraviolet-B Radiation On Benthic Communities In Colorado Rocky Mountain Streams, Robert E. Zuellig, Donna R. Kashian, Marjorie L. Brooks, Peter M. Kiffney, William H. Clements Mar 2008

The Influence Of Metal Exposure History And Ultraviolet-B Radiation On Benthic Communities In Colorado Rocky Mountain Streams, Robert E. Zuellig, Donna R. Kashian, Marjorie L. Brooks, Peter M. Kiffney, William H. Clements

Environmental Science and Geology Faculty Research Publications

Interest in understanding the influence of ultraviolet-B (UVB; 280–320 nm) radiation in aquatic ecosystems has increased since the early 1990s. Pollution from historic mining operations coupled with physicochemical characteristics of Rocky Mountain streams that increase exposure of benthic communities to UVB provided an opportunity to examine how UVB interacted with heavy metal contamination to structure stream communities. We integrated a series of UVB addition experiments done in stream microcosms with a large-scale UVB shading experiment to test the hypothesis that effects of UVB were greater on benthic communities from metal-polluted streams than from reference streams. Microcosm experiments involved short-term exposure …


A Conceptual Model Of Groundwater Flow In Spring Valley, Nv, And Snake Valley, Nv-Ut, Jeremy Micheal Gillespie Feb 2008

A Conceptual Model Of Groundwater Flow In Spring Valley, Nv, And Snake Valley, Nv-Ut, Jeremy Micheal Gillespie

Theses and Dissertations

A geochemical study of major springs and wells in Spring Valley, Nevada, and Snake Valley, Utah-Nevada was initiated in response to the Clark, Lincoln and White Pine Counties Groundwater Development Project proposed by the South Nevada Water Authority (SNWA). Water budget estimates suggest that interbasin flow accounts for a significant portion (~25%) of the water budgets in Spring and Snake Valleys. Although interbasin flow is possible in some areas, alternative plausible explanations place significant uncertainty on water budget allocations. To examine the plausibility of local and interbasin flow paths the groundwater flow in Spring and Snake Valleys was evaluated using …


Manual Pumping Test Method For Characterizing The Productivity Of Drilled Wells Equipped With Rope Pumps, Essa L. Gross Jan 2008

Manual Pumping Test Method For Characterizing The Productivity Of Drilled Wells Equipped With Rope Pumps, Essa L. Gross

Dissertations, Master's Theses and Master's Reports - Open

Since the introduction of the rope-pump in Nicaragua in the 1990s, the dependence on wells in rural areas has grown steadily. However, little or no attention is paid to rope-pump well performance after installation. Due to financial restraints, groundwater resource monitoring using conventional testing methods is too costly and out of reach of rural municipalities. Nonetheless, there is widespread agreement that without a way to quantify the changes in well performance over time, prioritizing regulatory actions is impossible. A manual pumping test method is presented, which at a fraction of the cost of a conventional pumping test, measures the specific …


Pamphlet To Accompany Geologic Map Gmc-34: Geologic Map Of The O’Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert F. Diffendal Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins Jan 2008

Pamphlet To Accompany Geologic Map Gmc-34: Geologic Map Of The O’Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert F. Diffendal Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins

Robert F. Diffendal, Jr., Publications

This map is necessarily generalized. It is based primarily on data from 7.5’ surficial geologic quadrangle maps of the map area prepared by the authors principally from 1991 to 2000, from Voorhies (unpublished data, 1974), as well as data from test-hole drilling done across the quadrangle by the Conservation and Survey Division, University of Nebraska, and its cooperators over many years since the 1930s. For more detailed information, consult the geologic data files of the Conservation and Survey Division, School of Natural Resources, University of Nebraska-Lincoln. The quadrangle is mostly covered by vegetation and Holocene sediments. Limited good exposures of …


Visualization Of Groundwater Flow Within Touching-Vu And Matrix Porosity In An Eogenetic Karst Aquifer, Lee J. Florea, Kevin J. Cunningham, Stephen Altobelli Jan 2008

Visualization Of Groundwater Flow Within Touching-Vu And Matrix Porosity In An Eogenetic Karst Aquifer, Lee J. Florea, Kevin J. Cunningham, Stephen Altobelli

Earth, Environmental, and Atmospheric Sciences Faculty Publications

In this study, we use an innovative, non-invasive technology, nuclear magnetic resonance imaging (NMRI), to visualize the direction and magnitude of groundwater flow in field samples of late Pleistocene limestone of the Biscayne aquifer. Specific goals of the first set of NMRI experiments are to map the advective velocity of water flowing at two rates of specific discharge (0.00025 and 0.00013 m/s) through a 10-cm-diameter cylindrical, epoxy-resin model. The model interior accurately reproduces a well-connected maze of ichnologically influenced, centimeter-scale, touching-vug macroporosity common within preferred flow zones in parts of the Biscayne aquifer. A second set of NMRI experiments investigates …


Biogenic Porosity And Its Lattice Boltzmann Method Permeability In The Karst Biscayne Aquifer, Kevin Cunningham, Mike Sukop, Haibo Huang, Pedro Alvarez, Allen Curran, Michael Waker, Lee J. Florea, Robert Renken, Joann F. Dixon Jan 2008

Biogenic Porosity And Its Lattice Boltzmann Method Permeability In The Karst Biscayne Aquifer, Kevin Cunningham, Mike Sukop, Haibo Huang, Pedro Alvarez, Allen Curran, Michael Waker, Lee J. Florea, Robert Renken, Joann F. Dixon

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.


Focus Group On Karst Hydrology - Conceptual Models, Aquifer Characterization, And Numerical Modeling, Martin Sauter, Lee J. Florea, Others Jan 2008

Focus Group On Karst Hydrology - Conceptual Models, Aquifer Characterization, And Numerical Modeling, Martin Sauter, Lee J. Florea, Others

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.


How Human And Natural Driving Forces Affect Pheasants And Pheasant Hunting In South Dakota, Chris Laingen Jan 2008

How Human And Natural Driving Forces Affect Pheasants And Pheasant Hunting In South Dakota, Chris Laingen

Faculty Research and Creative Activity

No abstract provided.


Hypogene Calcitization: Evaporite Diagenesis In The Western Delaware Basin, Kevin W. Stafford, Dana Ulmer-Scholle, Laura Rosales-Lagarde Jan 2008

Hypogene Calcitization: Evaporite Diagenesis In The Western Delaware Basin, Kevin W. Stafford, Dana Ulmer-Scholle, Laura Rosales-Lagarde

Faculty Publications

Evaporite calcitization within the Castile Formation of the Delaware Basin is more widespread and diverse than originally recognized. Coupled field and GIS studies have identified more than 1000 individual occurrences of calcitization within the Castile Formation outcrop area, which includes both calcitized masses (limestone buttes) and laterally extensive calcitized horizons (limestone sheets). Both limestone buttes and sheets commonly contain a central brecciated zone that we attribute to hypogene dissolution. Lithologic fabric of calcitized zones ranges from little alteration of original varved laminae to fabrics showing extensive laminae distortion as well as extensive vuggy and open cavernous porosity. Calcitization is most …


Hypogene Speleogenesis Within The Central Basin Platform: Karst Porosity In The Yates Field, Pecos County, Texas, U.S.A., Kevin W. Stafford, Fred H. Behnken, Jesse G. White Jan 2008

Hypogene Speleogenesis Within The Central Basin Platform: Karst Porosity In The Yates Field, Pecos County, Texas, U.S.A., Kevin W. Stafford, Fred H. Behnken, Jesse G. White

Faculty Publications

The Yates Unit Oil Field is located on the southeastern tip of the Central Basin Platform in eastern Pecos County, Texas. It produces from Middle Permian strata, primarily the upper San Andres Formation. Locally, the productive upper San Andres Formation is comprised of successively vertically stacked progradational shelf carbonates. Stratigraphically overlying the Yates Field reservoir, the Toborg Field produces from the uppermost Triassic and Cretaceous units. Both fields are bounded on the north and east sides by the Pecos River, which has remained entrenched in its current location since the early Tertiary. As mapped, the top of the San Andres …


Castile Evaporite Karst Potential Map Of The Gypsum Plain, Eddy County, New Mexico And Culberson County, Texas: A Gis Methodological Comparison, Kevin W. Stafford, Laura Rosales-Lagarde, Penelope J. Boston Jan 2008

Castile Evaporite Karst Potential Map Of The Gypsum Plain, Eddy County, New Mexico And Culberson County, Texas: A Gis Methodological Comparison, Kevin W. Stafford, Laura Rosales-Lagarde, Penelope J. Boston

Faculty Publications

Castile Formation gypsum crops out over ,1,800 km2 in the western Delaware Basin where it forms the majority of the Gypsum Plain. Karst development is well recognized in the Gypsum Plain (i.e., filled and open sinkholes with associated caves); however, the spatial occurrence has been poorly known. In order to evaluate the extent and distribution of karst development within the Castile portion of the Gypsum Plain, combined field and Geographic Information System (GIS) studies were conducted, which enable a first approximation of regional speleogenesis and delineate karst-related natural resources for management. Field studies included physical mapping of 50, 1-km2 sites, …


Introgression And Dispersal Among Spotted Owl (Strix Occidentalis) Subspecies, W. Chris Funk, Eric D. Forsman, Thomas D. Mullins, Susan M. Haig Jan 2008

Introgression And Dispersal Among Spotted Owl (Strix Occidentalis) Subspecies, W. Chris Funk, Eric D. Forsman, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

Population genetics plays an increasingly important role in the conservation and management of declining species, particularly for defining taxonomic units. Subspecies are recognized by several conservation organizations and countries and receive legal protection under the US Endangered Species Act (ESA). Two subspecies of spotted owls, northern (Strix occidentalis caurina) and Mexican (S. o. lucida) spotted owls, are ESA-listed as threatened, but the California (S. o. occidentalis) spotted owl is not listed. Thus, determining the boundaries of these subspecies is critical for effective enforcement of the ESA. We tested the validity of previously recognized spotted …


Development And Evaluation Of Geochemical Methods For The Sourcing Of Archaeological Maize, L.V. Benson, H. E. Taylor, K.A. Peterson, B.D. Shattuck, C.A. Ramotnik, J.R. Stein Jan 2008

Development And Evaluation Of Geochemical Methods For The Sourcing Of Archaeological Maize, L.V. Benson, H. E. Taylor, K.A. Peterson, B.D. Shattuck, C.A. Ramotnik, J.R. Stein

United States Geological Survey: Staff Publications

Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths ranging from 25 to 95 cm contain Sr that is more accessible to the deep roots of maize; thus, synthetic soil solutions provide better data for the sourcing of archaeological maize. However, the Sr-isotope composition of mice may be more valuable in sourcing archaeological remains of animals such as rabbit, …


Tools And Technology Article: Estimation And Correction Of Visibility Bias In Aerial Surveys Of Wintering Ducks, Aaron T. Pearse, Patrick D. Gerard, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke Jan 2008

Tools And Technology Article: Estimation And Correction Of Visibility Bias In Aerial Surveys Of Wintering Ducks, Aaron T. Pearse, Patrick D. Gerard, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke

United States Geological Survey: Staff Publications

Incomplete detection of all individuals leading to negative bias in abundance estimates is a pervasive source of error in aerial surveys of wildlife, and correcting that bias is a critical step in improving surveys. We conducted experiments using duck decoys as surrogates for live ducks to estimate bias associated with surveys of wintering ducks in Mississippi, USA. We found detection of decoy groups was related to wedand cover type (open vs. forested), group size (1-100 decoys), and interaction of these variables. Observers who detected decoy groups reported counts that averaged 78% of the decoys actually present, and this counting bias …


Tools And Technology Article: Evaluation Of An Aerial Survey To Estimate Abundance Of Wintering Ducks In Mississippi, Aaron T. Pearse, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke Jan 2008

Tools And Technology Article: Evaluation Of An Aerial Survey To Estimate Abundance Of Wintering Ducks In Mississippi, Aaron T. Pearse, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke

United States Geological Survey: Staff Publications

Researchers have successfully designed aerial surveys that provided precise estimates of wintering populations of ducks over large physiographic regions, yet few conservation agencies have adopted these probability-based sampling designs for their surveys. We designed and evaluated an aerial survey to estimate abundance of wintering mallards (Anas platyrhynchos), dabbling ducks (tribe Anatini) other than mallards, diving ducks (tribes Aythini, Mergini, and Oxyurini), and total ducks in western Mississippi, USA. We used design-based sampling of fixed width transects to estimate population indices (/), and we used model-based methods to correct population indices for visibility bias and estimate population abundance (N) for 14 …


Relations Between And Among Contaminant Concentrations And Biomarkers In Black Bass (Micropterus Spp.) And Common Carp (Cyprinus Carpio) From Large U.S. Rivers, 1995–2004, Jo Ellen Hinck, Christopher J. Schmitt, Mark R. Ellersieck, Donald E. Tillitt Jan 2008

Relations Between And Among Contaminant Concentrations And Biomarkers In Black Bass (Micropterus Spp.) And Common Carp (Cyprinus Carpio) From Large U.S. Rivers, 1995–2004, Jo Ellen Hinck, Christopher J. Schmitt, Mark R. Ellersieck, Donald E. Tillitt

United States Geological Survey: Staff Publications

Environmental contaminant and biomarker monitoring data from major U.S. river basins were summarized for black bass (Micropterus spp.) and common carp (Cyprinus carpio) sampled over a nine year period. Cumulative frequency distributions revealed taxon differences for many organochlorine residue concentrations, elemental contaminant concentrations, and biomarkers, but few gender differences were evident for chemical concentrations. Concentrations of dacthal, pentachloroanisole, p,p'-DDE, endosulfan sulfate, barium, cadmium, copper, manganese, lead, selenium, vanadium, and zinc were greater in carp than bass, but concentrations of mercury and magnesium were greater in bass. Gender differences were evident in bass for mercury and in carp …