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Full-Text Articles in Geology

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.


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 …


Impact Of Drought On Prehistoric Western Native Americans, Larry Benson Jan 2008

Impact Of Drought On Prehistoric Western Native Americans, Larry Benson

United States Geological Survey: Staff Publications

Some droughts that occurred during the so-called Medieval Climate Anomaly (approximately AD 800-1300) appear to have been catalysts for major changes in settlement patterns of two western Native American groups - the Lovelock culture in Nevada’s Great Basin and the Anasazi people of the Four Corners area. Both groups’ subsistence bases were impacted by diminished water supplies associated with prolonged drought, leading to the dispersal of these Native Americans from their former territories.

Tree-ring-based Palmer Drought Severity Index (PDSI) reconstructions by Cook et al. (2004) indicate that over 50% of the western U.S. experienced drought conditions during the middle-12th and …


Grenetic Evidence Of Intercontinental Movement Of Avian Influenza In A Migratory Bird: The Northern Pintail (Anas Acuta), Anson V. Koehler, John M. Pearce, Paul L. Flint, J. Christian Franson, Hon S. Ip Jan 2008

Grenetic Evidence Of Intercontinental Movement Of Avian Influenza In A Migratory Bird: The Northern Pintail (Anas Acuta), Anson V. Koehler, John M. Pearce, Paul L. Flint, J. Christian Franson, Hon S. Ip

United States Geological Survey: Staff Publications

The role of migratory birds in the movement of the highly pathogenic (HP) avian influenza H5N1 remains a subject of debate. Testing hypotheses regarding intercontinental movement of low pathogenic avian influenza (LPAI) viruses will help evaluate the potential that wild birds could carry Asian-origin strains of HP avian influenza to North America during migration. Previous North American assessments of LPAI genetic variation have found few Asian reassortment events. Here, we present results from whole-genome analyses of LPAI isolates collected in Alaska from the northern pintail (Anas acuta), a species that migrates between North America and Asia. Phylogenetic analyses …


Holocene Sediment Magnetic Properties Along A Transect From Isafjardardjup To Djupall, Northwest Iceland, Sarah M. Principato, J.T. Andrews, J. Hardardottir, J.S. Stoner Jan 2008

Holocene Sediment Magnetic Properties Along A Transect From Isafjardardjup To Djupall, Northwest Iceland, Sarah M. Principato, J.T. Andrews, J. Hardardottir, J.S. Stoner

Environmental Studies Faculty Publications

Holocene changes in terrestrial provenance and processes of sediment transport and deposition are tracked along a fjord-to-shelf transect adjacent to Vestfirdir, Iceland, using the magnetic properties ofmarine sediments.Magnetic susceptibility (MS) profiles of 10 cores (gravity and piston) were obtained onboard using a Bartington MS loop. Remanent magnetizations were measured at 1-cm intervals from u-channel samples taken from six cores on a cryogenic magnetometer. Between six and nine alternating field demagnetization steps were used to isolate the characteristic magnetization directions. The chronologies of the cores used in this study were determined from AMS14 C dates on mollusks and foraminifera and contrained …


Foundation Problems And Pyrite Oxidation In The Chattanooga Shale, Estill County, Kentucky, Warren H. Anderson Jan 2008

Foundation Problems And Pyrite Oxidation In The Chattanooga Shale, Estill County, Kentucky, Warren H. Anderson

Report of Investigations--KGS

Pyrite oxidation in the Chattanooga Shale has caused serious foundation problems in numerous buildings and structures in Estill County, Ky. Pyrite oxidizes and various secondary sulfates form when excavated shale or shale fill are used in foundations. These secondary sulfates are water- and humidity-sensitive and can form when only minor amounts of water are present in foundation materials. These sulfates form by crystal growth and expand by volume change, which causes subsequent soil expansion and heaving of any foundation materials when the materials are confined. Several structures have undergone expensive remediation to repair damaged sidewalks, floors, walls, and foundations. Zones …


Apparent Tolerance Of Turkey Vultures (Cathartes Aura) To The Non-Steroidal Anti-Inflammatory Drug Diclofenac, Barnett A. Rattner, Maria A. Whitehead, Grace Gasper, Carol U. Meteyer, William A. Link, Mark A. Taggart, Andrew A. Meharg, Oliver H. Pattee, Deborah J. Pain Jan 2008

Apparent Tolerance Of Turkey Vultures (Cathartes Aura) To The Non-Steroidal Anti-Inflammatory Drug Diclofenac, Barnett A. Rattner, Maria A. Whitehead, Grace Gasper, Carol U. Meteyer, William A. Link, Mark A. Taggart, Andrew A. Meharg, Oliver H. Pattee, Deborah J. Pain

United States Geological Survey: Staff Publications

The nonsteroidal anti-inflammatory drug diclofenac is extremely toxic to Old World Gyps vultures (median lethal dose ~0.1–0.2 mg/kg), evoking visceral gout, renal necrosis, and mortality within a few days of exposure. Unintentional secondary poisoning of vultures that fed upon carcasses of diclofenac-treated livestock decimated populations in the Indian subcontinent. Because of the widespread use of diclofenac and other cyclooxygenase-2 inhibiting drugs, a toxicological study was undertaken in turkey vultures (Cathartes aura) as an initial step in examining sensitivity of New World scavenging birds. Two trials were conducted entailing oral gavage of diclofenac at doses ranging from 0.08 to …


Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig Jan 2008

Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

The dynamic geological and climatic history of northwestern North America has made it a focal region for phylogeography. We conducted a range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) across its range in northwestern North America to understand its evolutionary history and the distribution of clades to inform conservation of R. pretiosa and Great Basin R. luteiventris, candidates for listing under the US Endangered Species Act. Mitochondrial DNA sequence data from a segment of the cytochrome b gene were obtained from 308 R. luteiventris and R. pretiosa from 96 sites. Phylogenetic analysis …


Management And Conservation Note: Conserving Waste Rice For Wintering Waterfowl In The Mississippi Alluvial Valley, Jennifer P. Kross, Richard M. Kaminski, Aaron T. Pearse Jan 2008

Management And Conservation Note: Conserving Waste Rice For Wintering Waterfowl In The Mississippi Alluvial Valley, Jennifer P. Kross, Richard M. Kaminski, Aaron T. Pearse

United States Geological Survey: Staff Publications

The Mississippi Alluvial Valley (MAV), USA, is an internationally important migration and wintering region for North American waterfowl (Reinecke et al. 1989). The Lower Mississippi Valley Joint Venture (LMVJV) assumes food availability is the primary factor influencing carrying capacity of wintering waterfowl in this region (Reinecke and Loesch 1996). Because much of the MAV was converted from a seasonally flooded bottomland-hardwood ecosystem to a landscape dominated by agriculture, the LMVJV has incorporated estimates of the abundance of agricultural seeds such as rice into habitat conservation plans (Reinecke et al. 1988, Fredrickson et al. 2005). Biologists designed these plans to provide …


Biogeochemical Evolution Of Cryoconite Holes On Canada Glacier, Taylor Valley, Antarctica, Elizabeth A. Bagshaw, Martyn Tranter, Andrew G. Fountain, Kathleen A. Welch, Hassan J. Basagic, W. Berry Lyons Dec 2007

Biogeochemical Evolution Of Cryoconite Holes On Canada Glacier, Taylor Valley, Antarctica, Elizabeth A. Bagshaw, Martyn Tranter, Andrew G. Fountain, Kathleen A. Welch, Hassan J. Basagic, W. Berry Lyons

Geography Faculty Publications and Presentations

The cryoconite holes of the McMurdo Dry Valleys are simple, closed biogeochemical systems involving water, ice, mineral and organic debris, which serve as ecosystems for consortia of microorganisms. This study is the first to document the seasonal and annual chemical evolution of solutes in cryoconite holes. Samples of glacier ice, frozen cryoconite holes and those containing water were collected during the austral summer of 2005–2006. The isolation age was calculated from the excess Cl‾ in the holes, and varied from 0 to 5 years (a), consistent with the last hot summer when the cryoconite holes were open to the atmosphere. …


The Pcor Partnership – Building On Successful Regional, National, And International Partnerships, University Of North Dakota. Energy And Environmental Research Center Dec 2007

The Pcor Partnership – Building On Successful Regional, National, And International Partnerships, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Plains CO2 Reduction (PCOR) Partnership. The PCOR Partnership supports regional research to advance safe and effective CO2 storage. [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 Global Stratotype Section And Point (Gssp) For The Base Of The Katian Stage Of The Upper Ordovician Series At Black Knob Ridge, Southeastern Oklahoma, Usa, Daniel Goldman, Stephen A. Leslie, Jaak Nõlvak, Seth Young, Stig M. Bergström, Warren D. Huff Dec 2007

The Global Stratotype Section And Point (Gssp) For The Base Of The Katian Stage Of The Upper Ordovician Series At Black Knob Ridge, Southeastern Oklahoma, Usa, Daniel Goldman, Stephen A. Leslie, Jaak Nõlvak, Seth Young, Stig M. Bergström, Warren D. Huff

Department of Earth, Environment and Sustainability Faculty Publications

The International Subcomission on Ordovician Stratigraphy (ISOS) of the International Commission on Stratigraphy (ICS) recently defined the base of the global Upper Ordovician Series to be at the first appearance datum (FAD) of the graptolite species Nemagraptus gracilis in the Fågelsång GSSP in southern Sweden. This designation recognized the tremendous utility for global correlation of the first appearance of a cosmopolitan taxon that occurs within a consistent succession of other first appearance datums (e.g., Finney and Bergström, 1986; Bergström et al., 2000). Current efforts by the ISOS have focused on subdividing the Upper Ordovician into three stages and choosing appropriate …


Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise Nov 2007

Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise

United States Geological Survey: Staff Publications

Submersible observations during four missions over the North Carolina and Virginia continental slopes (184–900 m) documented the occurrence of large aggregations of mesopelagic Wshes and macronektonic invertebrates near or on the bottom. Aggregated mesopelagics formed a layer up to tens of meters deep positioned from a few centimeters to 20 m, usually <10 >m, above the substrate. Aggregations were numerically dominated by microvores, notably the myctophid Wsh Ceratoscopelus maderensis and the penaeid shrimp Sergestes arcticus. Consistently present but in relatively lower numbers, were mesopelagic predators, including the paralepidids Notolepis rissoi and Lestidium atlanticum, the eel Nemichthys scolopaceus, the …


Demersal Fishes Associated With Lophelia Pertusa Coral And Hard-Substrate Biotopes On The Continental Slope, Northern Gulf Of Mexico, Kenneth J. Sulak, R. Allen Brooks, Kirsten E. Luke, April D. Norem, Michael Randall, Andrew J. Quaid, George E. Yeargin, Jana M. Miller, William M. Harden, John H. Caruso, Steve W. Ross Nov 2007

Demersal Fishes Associated With Lophelia Pertusa Coral And Hard-Substrate Biotopes On The Continental Slope, Northern Gulf Of Mexico, Kenneth J. Sulak, R. Allen Brooks, Kirsten E. Luke, April D. Norem, Michael Randall, Andrew J. Quaid, George E. Yeargin, Jana M. Miller, William M. Harden, John H. Caruso, Steve W. Ross

United States Geological Survey: Staff Publications

The demersal fish fauna of Lophelia pertusa (Linnaeus, 1758) coral reefs and associated hard-bottom biotopes was investigated at two depth horizons in the northern Gulf of Mexico using a manned submersible and remote sampling. The Viosca Knoll fauna consisted of at least 53 demersal fish species, 37 of which were documented by submersible video. On the 325 m horizon, dominant taxa determined from frame-by-frame video analysis included Stromateidae, Serranidae, Trachichthyidae, Congridae, Scorpaenidae, and Gadiformes. On the 500 m horizon, large mobile visual macrocarnivores of families Stromateidae and Serranidae dropped out, while a zeiform microcarnivore assumed importance on reef “Thicket” biotope, …


An Update On Groundwater Conditions At The Site Of The York College Cuny Campus In Southeastern Queens County, New York City, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Edward A. Molteni Oct 2007

An Update On Groundwater Conditions At The Site Of The York College Cuny Campus In Southeastern Queens County, New York City, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Edward A. Molteni

Publications and Research

The wells operated by the Jamaica Water Supply Company in Queens represent the only large scale utilization of groundwater for public water supply in New York City in recent years. These wells were shut down, for the most part, beginning in 1996. Since that time, water table elevations in the area, which had been drawn down by the withdrawal activity of the Jamaica Water Supply Company, have risen significantly causing some high groundwater problems, including flooding of basements. The New York City Department of Environmental Protection (NYCDEP) has held public hearings on a contemplated resumption of ground water withdrawal in …


Pcor Partnership Atlas, Wesley D. Peck, Barry W. Botnen, Lisa S. Botnen, Daniel J. Daly, John A. Harju, Melanie D. Jensen, Erin M. O'Leary, Steven A. Smith, James A. Sorensen, Edward N. Steadman, Stephanie L. Wolfe, Darin R. Damiani, John T. Litynski, David W. Fischer Oct 2007

Pcor Partnership Atlas, Wesley D. Peck, Barry W. Botnen, Lisa S. Botnen, Daniel J. Daly, John A. Harju, Melanie D. Jensen, Erin M. O'Leary, Steven A. Smith, James A. Sorensen, Edward N. Steadman, Stephanie L. Wolfe, Darin R. Damiani, John T. Litynski, David W. Fischer

EERC Maps and Infographics

The Plains CO2 Reduction (PCOR) Partnership Atlas, 2nd edition, introduces global climate change and provides a regional profile of CO2 sources and potential sinks across the PCOR Partnership region. Carbon sequestration offers a promising set of technologies through which CO2 can be stored for long periods of time.


Agricultural Contaminant Source And Transport In A Karst Groundwater Basin, Patricia Kambesis May 2007

Agricultural Contaminant Source And Transport In A Karst Groundwater Basin, Patricia Kambesis

Masters Theses & Specialist Projects

Agricultural land use in areas that are located in karst groundwater basins negatively impact groundwater quality because karst terrains provide multiple, direct hydrologic connections from the surface into karst aquifers. The connections and rapid velocities associated with surface and subsurface flow in karst aquifers allow for contaminants to move quickly into and through a groundwater basin. When groundwater returns to the surface via a spring or springs, any contaminants within the water become part of surface streams and rivers. These in turn, impact water quality in areas located downstream of the spring or springs. The purpose of this study was …


Unlv Magazine, Grace Russell, Gian Galassi, Shane Bevell, Karyn S. Hollingsworth, Jennifer Lawson, Lori Bachand, Cate Weeks, Erin O'Donnell, Peter Starkweather Apr 2007

Unlv Magazine, Grace Russell, Gian Galassi, Shane Bevell, Karyn S. Hollingsworth, Jennifer Lawson, Lori Bachand, Cate Weeks, Erin O'Donnell, Peter Starkweather

UNLV Magazine

No abstract provided.


Frequency Of Sublethal Injury In A Deepwater Ophiuroid, Ophiacantha Bidentata, An Important Component Of Western Atlantic Lophelia Reef Communities, R. Allen Brooks, Martha S. Nizinski, Steve W. Ross, Kenneth J. Sulak Mar 2007

Frequency Of Sublethal Injury In A Deepwater Ophiuroid, Ophiacantha Bidentata, An Important Component Of Western Atlantic Lophelia Reef Communities, R. Allen Brooks, Martha S. Nizinski, Steve W. Ross, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The occurrence and relative abundance of tissue (arm) regeneration in the ophiuroid, Ophiacantha bidentata (Retzius), was examined in individuals collected primarily among colonies of the deep-water coral Lophelia pertusa off the southeastern United States. Seven deep-water coral sites (384–756 m), located between Cape Lookout, NC, and Cape Canaveral, FL, were sampled in June 2004 using a manned submersible. The presence of regenerative tissue was evaluated by visual inspection of each individual ophiuroid, and the proportion of regenerating arms per individual was examined relative to size of individual, geographic location, and depth of collection. Ophiacantha bidentata, the dominant brittle star collected, …


Residence Times And Temporal Variations Of 210Po In Aerosols And Precipitation From Southeastern Michigan, United States, Daphne Mcneary, Mark Baskaran Feb 2007

Residence Times And Temporal Variations Of 210Po In Aerosols And Precipitation From Southeastern Michigan, United States, Daphne Mcneary, Mark Baskaran

Environmental Science and Geology Faculty Research Publications

Daughter products of 222Rn (such as 210Pb, half-life = 22.1 years, and 210Po, half-life = 138 days) have been widely used as tracers to determine the removal rates of aerosols as well to obtain analog information on the behavior of other chemical species in the lower atmosphere. To establish the first data set on the depositional fluxes of 210Po in bulk precipitation and concentrations in air samples from the midwestern United States, we measured the depositional fluxes of 210Pb and 210Po in the bulk (wet plus dry) and dry fallout by deploying a rain …


I Sinkholes Nella Letteratura Scientifica Internazionale: Una Breve Rassegna, Con Particulare Riferimento Agli Stati Uniti D'America, Lee J. Florea, Mario Parise Jan 2007

I Sinkholes Nella Letteratura Scientifica Internazionale: Una Breve Rassegna, Con Particulare Riferimento Agli Stati Uniti D'America, Lee J. Florea, Mario Parise

Earth, Environmental, and Atmospheric Sciences Faculty Publications

Fenomeni di sinkholes sono diffusi in moltissimi paesi del mondo, in ambiti geologici e morfologici alquanto differenziati, e coinvolgono svariate litologie, sia nelle successioni di copertura che in quelle direttamente affioranti alla superficie. Il presente contributo intende fornire una breve rassegna, certamente non esaustiva, sullo stato dell’arte delle ricerche relative ai sinkholes in ambito internazionale. Esso consiste in una descrizione della più aggiornata e diffusa classificazione dei sinkholes e, a seguire, in descrizioni delle più tipiche casistiche di sinkholes nei vari paesi. Tra questi, viene dato particolare risalto agli Stati Uniti d’America (e, più in particolare, alla Florida), dove le …


International, Cooperative Research In The Apuseni Mountains Of Western Romania, Lee J. Florea, Bogdan P. Onac Jan 2007

International, Cooperative Research In The Apuseni Mountains Of Western Romania, Lee J. Florea, Bogdan P. Onac

Earth, Environmental, and Atmospheric Sciences Faculty Publications

In May of 2006, nine American scientists and cavers from the Karst Research Group at the University of South Florida traveled to western Romania to attend and present at an international conference on records of climate change in caves in the historic Roman town of Baile Hurculane. The conference, co-sponsored by the “Emil Racoviţă” Speleological Institute of Romania and the Karst Waters Institute, drew more than 100 experts in the field of climate change and karst, and was a wonderful time spent alongside the thermal springs and Austro-Hungarian bathhouses nestled within the massive limestone canyon of the Cerna River.

Following …


Loess Deposits, Origins And Properties, Daniel R. Muhs Jan 2007

Loess Deposits, Origins And Properties, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is an eolian (windblown) sediment that is an important archive of Quaternary climate changes. It may provide one of the most complete terrestrial records of interglacial–glacial cycles. Loess is unusual as a record of Quaternary climate change because it is one of the few sediments that is deposited directly from the atmosphere. Thus, it is a geologic deposit that contains a record of atmospheric circulation and can be used to reconstruct synoptic-scale paleoclimatology. Loess is also unusual in that it can be dated directly using ‘trapped electron’ or luminescence methods that require only the sediment itself. Commonly, loess deposits …


Adaptive Data-Driven Models For Estimating Carbon Fluxes In The Northern Great Plains, Bruce K. Wylie, Eugene A. Fosnight, Tagir G. Gilmanov, Albert B. Frank, Jack A. Morgan, Marshall R. Haferkamp, Tilden P. Meyers Jan 2007

Adaptive Data-Driven Models For Estimating Carbon Fluxes In The Northern Great Plains, Bruce K. Wylie, Eugene A. Fosnight, Tagir G. Gilmanov, Albert B. Frank, Jack A. Morgan, Marshall R. Haferkamp, Tilden P. Meyers

United States Geological Survey: Staff Publications

Rangeland carbon fluxes are highly variable in both space and time. Given the expansive areas of rangelands, how rangelands respond to climatic variation, management, and soil potential is important to understanding carbon dynamics. Rangeland carbon fluxes associated with Net Ecosystem Exchange (NEE) were measured from multiple year data sets at five flux tower locations in the Northern Great Plains. These flux tower measurements were combined with 1-km2 spatial data sets of Photosynthetically Active Radiation (PAR), Normalized Difference Vegetation Index (NDVI), temperature, precipitation, seasonal NDVI metrics, and soil characteristics. Flux tower measurements were used to train and select variables for …


Possible Impacts Of Early-11th-, Middle-12th-, And Late-13th-Century Droughts On Western Native Americans And The Mississippian Cahokians, Larry V. Benson, Michael S. Berry, Edward A. Jolie, Jerry D. Spangler, David W. Stahle, Eugene M. Hattori Jan 2007

Possible Impacts Of Early-11th-, Middle-12th-, And Late-13th-Century Droughts On Western Native Americans And The Mississippian Cahokians, Larry V. Benson, Michael S. Berry, Edward A. Jolie, Jerry D. Spangler, David W. Stahle, Eugene M. Hattori

United States Geological Survey: Staff Publications

One or more of three intense and persistent droughts impacted some Native American cultures in the early-11th, middle-12th and late- 13th centuries, including the Anasazi, Fremont, Lovelock, and Mississippian (Cahokian) prehistorical cultures. Tree-ring-based reconstructions of precipitation and temperature indicate that warm drought periods occurred between AD 990 and 1060, AD 1135 and 1170, and AD 1276 and 1297. These droughts occurred during minima in the Pacific Decadal Oscillation and may have been associated with positive values of the Atlantic Multidecadal Oscillation. Each of the Native American cultures was supported, to a greater or lesser degree, by precipitation-dependent resources. Both the …


Hydrologic Connectivity And The Contribution Of Stream Headwaters To Ecological Integrity At Regional Scales1, Mary C. Freeman, Catherine M. Pringle, C. Rhett Jackson Jan 2007

Hydrologic Connectivity And The Contribution Of Stream Headwaters To Ecological Integrity At Regional Scales1, Mary C. Freeman, Catherine M. Pringle, C. Rhett Jackson

United States Geological Survey: Staff Publications

Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water-mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two-thirds of total stream length in a typical river drainage and directly connect the upland and riparian landscape to the rest of the stream ecosystem. Altering headwater streams, e.g., by channelization, diversion through pipes, impoundment and burial, modifies fluxes between uplands and downstream river segments and eliminates distinctive habitats. The large-scale ecological effects of altering headwaters are amplified by land uses that alter …