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2004

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Articles 61 - 90 of 155

Full-Text Articles in Geology

Hydrogeochemical Controls On Uranium In Aquifers Of The Jacobsville Sandstone, Heidi M. Sherman Jan 2004

Hydrogeochemical Controls On Uranium In Aquifers Of The Jacobsville Sandstone, Heidi M. Sherman

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

The occurrence of elevated uranium (U) in sandstone aquifers was investigated in the Upper Peninsula of Michigan, focusing on aquifers of the Jacobsville Sandstone. The hydrogeochemical controls on groundwater U concentrations were characterized using a combination of water sampling and spectral gamma-ray logging of sandstone cliffs and residential water wells. 235U/238U isotope ratios were consistent with naturally occurring U. Approximately 25% of the 270 wells tested had U concentrations above the U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) of 30 μg/L, with elevated U generally occurring in localized clusters. Water wells were logged to determine whether …

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Guano, Donald A. Mcfarlane Jan 2004

Guano, Donald A. Mcfarlane

WM Keck Science Faculty Papers

This is an encyclopedia article.

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Light & Dark: The Hidden Wonders Of Buck Creek, Lee J. Florea Jan 2004

Light & Dark: The Hidden Wonders Of Buck Creek, Lee J. Florea

Earth, Environmental, and Atmospheric Sciences Faculty Publications

As early morning mists rise from the banks of its supple waters, beams of light penetrate the Buck Creek valley illuminating its beauty. While light illuminates most of the land, there are secret places, nestled within the forest where darkness reigns supreme. Places beyond the touch of the sun, beyond the influence of seasons. Here time is measured not in cycles of light but by the flow of water and fall of rock. These are the caves, conduits for water past and present. Nestled in the hills of south-central Kentucky the caves along Buck Creek provide the lifeblood for a …

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Hydrochemical Variations During Flood Pulses In The South-West China Peak Cluster Karst: Impacts Of Caco3–H2o–Co2 Interactions, Chris Groves, Zaihua Liu, Daoxian Yuan, Joe Meiman, Guanghui Jiang, Shiyi He, Qiang Li Jan 2004

Hydrochemical Variations During Flood Pulses In The South-West China Peak Cluster Karst: Impacts Of Caco3–H2o–Co2 Interactions, Chris Groves, Zaihua Liu, Daoxian Yuan, Joe Meiman, Guanghui Jiang, Shiyi He, Qiang Li

Earth, Environmental, and Atmospheric Sciences Faculty Publications

High-resolution measurements of rainfall, water level, pH, conductivity, temperature and carbonate chemistry parameters of groundwater at two adjacent locations within the peak cluster karst of the Guilin Karst Experimental Site in Guangxi Province, China, were made with different types of multiparameter sonde. The data were stored using data loggers recording with 2 min or 15 min resolution. Waters from a large, perennial spring represent the exit for the aquifer's conduit flow, and a nearby well measures water in the conduit-adjacent, fractured media. During flood pulses, the pH of the conduit flow water rises as the conductivity falls. In contrast, and …

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The Exterior Orientation Of Aerial Imagery Using Existing Orthoimagery And Terrain Models:A Performance Test, Finnian O'Cionnaith Jan 2004

The Exterior Orientation Of Aerial Imagery Using Existing Orthoimagery And Terrain Models:A Performance Test, Finnian O'Cionnaith

Masters

In every part of the world the rate of map revision is alarmingly low when compared to the rate of change of many human influenced surface features. There is therefore a requirement to regularly gather up-to-date information about surface features and to incorporate changes in maps both quickly and effectively before it becomes history. When an aerial photograph is taken, it contains errors one category of which is caused by the aircraft taking the photograph being tilted. This aerial photograph by itself is of little commercial value. Accurate maps cannot be created from it, its use in GIS (Geographical Information …

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An Inventory And Condition Survey Of The Pilbara Region, Western Australia, A M E Van Vreeswyk, K A. Leighton, A L. Payne, P Hennig Jan 2004

An Inventory And Condition Survey Of The Pilbara Region, Western Australia, A M E Van Vreeswyk, K A. Leighton, A L. Payne, P Hennig

Technical Bulletins

The inventory and condition survey of the Pilbara region, undertaken by the Department of Agriculture, Western Australia between 1995 and 1999, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The area surveyed covers about 181 723 km². Seven …

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Experimental Determination Of Stiffness Of Joints In Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski Jan 2004

Experimental Determination Of Stiffness Of Joints In Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski

Publications (YM)

Fourteen uniaxial joint compression tests were run to determine the normal and shear stiffnesses of type 1 fracture joints (healed joints filled with vapor-phase mineral deposits) obtained from the Yucca Mountain site. The uniaxial joint compression results show that these joints behave linearly up to over 85% of their loading history. They are stiff with strengths very close to the strength of the intact rock. Five direct shear tests were run on open, separated, joints. Results obtained from the direct shear testing show that the normal stiffness increases with increasing normal stress. Shearing through asperities gives high joint shear stiffness …

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An Association Of Benthic Foraminifera And Gypsum In Holocene Sediments Of Estuarine Chesapeake Bay, Usa, John Cann, Thomas Cronin Jan 2004

An Association Of Benthic Foraminifera And Gypsum In Holocene Sediments Of Estuarine Chesapeake Bay, Usa, John Cann, Thomas Cronin

United States Geological Survey: Staff Publications

Two cores of Holocene sediments recovered from the Cape Charles Channel of Chesapeake Bay yielded radiocarbon ages of about 6.8 to 5.8 ka for the lower intervals. Fossil foraminifera preserved in these lower sediments are dominated by species of Elphidium, which make up about 90% of the assemblage throughout, and probably signify deposition in hypersaline waters. Buccella frigida and Ammonia beccarii are the only other species commonly present. Hypersalinity of bottom waters seems to have been maintained by water-density stratification in a basin-like section of the channel. In core PTXT -4-P-I transition to modem Chesapeake conditions, in which numbers …

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Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr. Jan 2004

Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr.

United States Geological Survey: Staff Publications

Structure and composition of vegetation and abundance of breeding birds in grasslands seeded to Old World bluestem (Bothriochloa ischmaeum) were compared to native mixed prairie in the southern Great Plains of North America. Abundance of birds was determined using fixed-radius point counts. Detrended correspondence analysis was used to compare plant community composition and canonical correspondence analysis was used to examine the relationships between plant species composition and vegetation structure with the bird community. Plant species composition differed distinctly between seeded grassland and native mixed prairie, but the differences were not reflected in habitat structure, bird community composition, or …

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Mudfish On The Menu? Rise Of The Much-Maligned Bowfin, Ken Sulak Jan 2004

Mudfish On The Menu? Rise Of The Much-Maligned Bowfin, Ken Sulak

United States Geological Survey: Staff Publications

Cajuns call it “choupique” (say “shoe-pick”), from its Choctaw name. Elsewhere, it’s the dogfish, blackfish, grindle, cottonfish, or cypress trout. Its official common name is “Bowfin” (Amia calva)1. But to most anglers, this is the “mudfish,” a strange, unusual, and much-maligned fish, most everywhere considered a useless trash fish. One look and the words relict, prehistoric, primitive, and living fossil come to mind. Indeed, the bowfin is the last of its line, the sole-surviving species of a very ancient group of fishes. Its predecessors flourished in the Jurassic and Cretaceous periods during the Mesozoic (= Middle-Animal) Era, a …

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West Antarctic Ice Stream Discharge Variability: Mechanism, Controls, And Pattern Of Grounding Line Retreat, Christina L. Hulbe, Mark A. Fahnestock Jan 2004

West Antarctic Ice Stream Discharge Variability: Mechanism, Controls, And Pattern Of Grounding Line Retreat, Christina L. Hulbe, Mark A. Fahnestock

Geology Faculty Publications and Presentations

West Antarctic ice streams show pronounced flow variability in their downstream reaches, with changes stranding formerly fast-flowing ice and redirecting discharge. A simple model, in which the temperature gradient in basal ice provides control of fast sliding in the downstream reach, can explain this behavior. Downstream thinning steepens the temperature gradient near the bed, increasing upward heat flow and the tendency toward basal freezing. The basal temperature gradient is steepest and the tendency toward basal freezing the strongest in ice that has experienced the most rapid downstream thinning, that is, the fastest-flowing ice. The most ?successful? rapid outflows are regions …

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Generalized Geologic Map For Land-Use Planning: Mclean County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Mclean County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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The Cape Ann Plutonic Suite: A Field Trip For Petrology Classes, John B. Brady, John T. Cheney Jan 2004

The Cape Ann Plutonic Suite: A Field Trip For Petrology Classes, John B. Brady, John T. Cheney

Geosciences: Faculty Publications

Cape Ann, because of its proximity to Boston and many universities, has long been a focus of geologic study. Nineteenth century papers that consider mineralogy or petrology of Cape Ann rocks include Prescott (1839), Nichols (1856), Kimball (1860), Gregory (1862), Mudge (1862), Balch (1864), Cooke (1866, 1867), Knowlton (1867), Hyatt (1869, 1871a,b), Hunt (1871), Wadsworth (1878, 1882a,b, 1885), McDaniel (1884), Sears (1888, 1889, 1890a, 1891a,b, 1893a,b, 1894a,b, 1895, 1898), Shaler (1889), Pearce (1893), Penfield and Forbes (1896), and Washington (1898a,b,c, 1899a,b,c,d). More recent studies of note include Wright (1900), Clapp (1921), Warren and McKinstry (1924), Bowen and Schairer (1935), Palache …

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Advances In The Geology Of The Tobacco Root Mountains, Montana, And Their Implications For The History Of The Northern Wyoming Province, Tekla A. Harms, John B. Brady, H. Robert Burger, John T. Cheney Jan 2004

Advances In The Geology Of The Tobacco Root Mountains, Montana, And Their Implications For The History Of The Northern Wyoming Province, Tekla A. Harms, John B. Brady, H. Robert Burger, John T. Cheney

Geosciences: Faculty Publications

Integrated studies by Keck Geology Consortium participants have generated many new insights into the Precambrian geology of the Tobacco Root Mountains. We have clarified the tectonic setting and origin of two suites of metamorphic rocks: (1) a quartzofeldspathic gneiss complex with associated metasupracrustal rocks (the combined Indian Creek and Pony–Middle Mountain Metamorphic Suites) that originated in a continental arc setting between 3.35 and 3.2 Ga with subsequent sedimentation and (2) mafic metavolcanic rocks with intercalated metasedimentary rocks (the Spuhler Peak Metamorphic Suite) from a suprasubduction zone ophiolite or backarc basin possibly of Proterozoic age. A poorly preserved metamorphic event at …

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40Ar/ 39Ar Ages Of Metamorphic Rocks From The Tobacco Root Mountains Region, Montana, John B. Brady, Dana N. Kovaric, John T. Cheney, Lisa J. Jacob, J. Toby King Jan 2004

40Ar/ 39Ar Ages Of Metamorphic Rocks From The Tobacco Root Mountains Region, Montana, John B. Brady, Dana N. Kovaric, John T. Cheney, Lisa J. Jacob, J. Toby King

Geosciences: Faculty Publications

Measurements of 60 single-grain, UV laser microprobe 40Ar/39Ar total gas ages for hornblende from metamorphic rocks of the Tobacco Root Mountains in southwest Montana yield a mean age of 1.71 ± 0.02 Ga. Measurements of 40Ar/39Ar step-heating plateau ages of three bulk hornblende samples from the Tobacco Root Mountains metamorphic rocks average 1.70 ± 0.02 Ga. We believe that these and the K/Ar or 40Ar/39Ar ages reported by previous workers are cooling ages from a 1.78 to 1.72 Ga, upper-amphibolite to granulite facies, regional metamorphism (Big Sky orogeny) that affected the northwestern portion of the Wyoming province, including the Tobacco …

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Precambrian Meta-Ultramafic Rocks From The Tobacco Root Mountains, Montana, Kathleen E. Johnson, John B. Brady, William A. Macfarlane, Rebecca B. Thomas, Chris J. Poulsen, M. Jennifer Sincock Jan 2004

Precambrian Meta-Ultramafic Rocks From The Tobacco Root Mountains, Montana, Kathleen E. Johnson, John B. Brady, William A. Macfarlane, Rebecca B. Thomas, Chris J. Poulsen, M. Jennifer Sincock

Geosciences: Faculty Publications

Meta-ultramafic rocks occur as small (2 to 100 m long), podiform bodies in all three major Precambrian rock suites of the Tobacco Root Mountains of southwest Montana. Most samples consist of a randomly oriented, coarse-grained assemblage of orthopyroxene, olivine, and magnesiohornblende ± spinel, partially replaced by a fine-grained assemblage that may include anthophyllite, talc, cummingtonite, magnesiohornblende, chlorite, serpentine, and/ or magnetite. Blackwall reaction zones of anthophyllite, actinolite, chlorite, and/or biotite surround several of the meta-ultramafic bodies. The absence of clinopyroxene with orthopyroxene limits the metamorphic pressure-temperature history of these rocks to temperatures below ~800 °C. The presence of anthophyllite with …

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Holocene Tufa-Coated Serpulid Mounds From The Dominican Republic: Depositional And Diagenetic History, With Comparison To Modern Serpulid Aggregates From Baffin Bay, Texas, Bosiljka Glumac, Lisa Berrios, Lisa Greer, H. Allen Curran Jan 2004

Holocene Tufa-Coated Serpulid Mounds From The Dominican Republic: Depositional And Diagenetic History, With Comparison To Modern Serpulid Aggregates From Baffin Bay, Texas, Bosiljka Glumac, Lisa Berrios, Lisa Greer, H. Allen Curran

Geosciences: Faculty Publications

Ronald D. Lewis and Bruce C. Panuska (eds.) Proceedings of the 11th Symposium on the Geology of the Bahamas and Other Carbonate Regions: San Salvador, Gerace Research Center

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Geology Of Long Island, Bahamas: A Field Trip Guide, H. Allen Curran, John E. Mylroie, Douglas W. Gamble, Mark A. Wilson, R. Laurence Davis, Neil E. Sealey, Vincent J. Voegeli Jan 2004

Geology Of Long Island, Bahamas: A Field Trip Guide, H. Allen Curran, John E. Mylroie, Douglas W. Gamble, Mark A. Wilson, R. Laurence Davis, Neil E. Sealey, Vincent J. Voegeli

Geosciences: Faculty Publications

See other Smith authored Field Trip Guides of Gerace Research Centre.

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Spectacular Recovery In The Ord River Catchment, A L. Payne, I W. Watson, P E. Novelly Jan 2004

Spectacular Recovery In The Ord River Catchment, A L. Payne, I W. Watson, P E. Novelly

Agriculture reports

Regeneration work on severely damaged country in what is now known as the Ord River Regeneration Reserve (ORRR) commenced in 1960. The ORRR is in the East Kimberley area of Western Australia with an associated small area in the Northern Territory. The work included strip contour cultivation and seeding (which proceeded at various levels of intensity during the 1960s, 1970s and 1980s), fencing and destocking of cattle by mustering over many years, and the eradication of donkeys.

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Groundwater-Level Changes In Nebraska - Spring 2002 To Spring 2003/Groundwater-Level Changes In Nebraska - Predevelopment To Spring 2003, Conservation Survey Division Jan 2004

Groundwater-Level Changes In Nebraska - Spring 2002 To Spring 2003/Groundwater-Level Changes In Nebraska - Predevelopment To Spring 2003, Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Simulated Changes In Shallow Groundwater And Vegetation Distributions Under Different Reservoir Operations Scenarios, Mark Cable Rains, Jeffery F. Mount, Eric W. Larsen Jan 2004

Simulated Changes In Shallow Groundwater And Vegetation Distributions Under Different Reservoir Operations Scenarios, Mark Cable Rains, Jeffery F. Mount, Eric W. Larsen

Geology Faculty Publications

The objectives of this study were to develop and use a linked groundwater and vegetation model to simulate groundwater and vegetation distributions in a riverine and reservoir-fringe system under different reservoir operations scenarios. This study was conducted where Little Stony Creek flows into East Park Reservoir on the east front of the Coast Range, northern California. A numerical groundwater model was used to model mean depth to groundwater during the growing season for water years 1980–1999 for each of five community types identified on the study site. Multiple vegetation models were developed, each of which described the probability that a …

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Catastrophic Ice Shelf Breakup As The Source Of Heinrich Event Icebergs, Christina L. Hulbe, D. R. Macayeal, George H. Denton, Johan Kleman, Thomas Lowell Jan 2004

Catastrophic Ice Shelf Breakup As The Source Of Heinrich Event Icebergs, Christina L. Hulbe, D. R. Macayeal, George H. Denton, Johan Kleman, Thomas Lowell

Geology Faculty Publications and Presentations

Heinrich layers of the glacial North Atlantic record abrupt widespread iceberg rafting of detrital carbonate and other lithic material at the extreme-cold culminations of Bond climate cycles. Both internal (glaciologic) and external (climate) forcings have been proposed. Here we suggest an explanation for the iceberg release that encompasses external climate forcing on the basis of a new glaciological process recently witnessed along the Antarctic Peninsula: rapid disintegrations of fringing ice shelves induced by climate-controlled meltwater infilling of surface crevasses. We postulate that peripheral ice shelves, formed along the eastern Canadian seaboard during extreme cold conditions, would be vulnerable to sudden …

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Generalized Geologic Map For Land-Use Planning: Madison County, Kentucky, Bart Davidson, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Madison County, Kentucky, Bart Davidson, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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Generalized Geologic Map For Land-Use Planning: Marshall County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Marshall County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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Generalized Geologic Map For Land-Use Planning: Livingston County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Livingston County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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Generalized Geologic Map For Land-Use Planning: Henderson County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Henderson County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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Generalized Geologic Map For Land-Use Planning: Daviess County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Daviess County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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A Holocene Record Of Changing Arctic Ocean Ice Drift Analogous To The Effects Of The Arctic Oscillation, Dennis A. Darby, Jens F. Bischof Jan 2004

A Holocene Record Of Changing Arctic Ocean Ice Drift Analogous To The Effects Of The Arctic Oscillation, Dennis A. Darby, Jens F. Bischof

OES Faculty Publications

The Arctic Oscillation (AO) controls the configuration of the Transpolar Drift (TPD). If thicker ice from the Beaufort Gyre were exported, the volume of fresh water/sea ice in the Nordic seas would significantly increase, decreasing the formation of North Atlantic deep water. This would cool large parts of the Northern Hemisphere and affect global climate. Therefore, in order to understand how the global climate system functions, it is imperative to know how the TPD changed over the last millennium or more. The provenance of grains in a sediment core located near the confluence of the TPD and the Beaufort Gyre …

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Rugose Corals Of The Livingston Limestone Member, Bond Formation, Coles And Edgar County, Illinois, John Tobias Burke Jan 2004

Rugose Corals Of The Livingston Limestone Member, Bond Formation, Coles And Edgar County, Illinois, John Tobias Burke

Masters Theses

No abstract provided.

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A Boundary Element Method For Thermo-Poroelasticity With Applications In Rock Mechanics, Qiang Zhang Jan 2004

A Boundary Element Method For Thermo-Poroelasticity With Applications In Rock Mechanics, Qiang Zhang

Theses and Dissertations

Coupled thermal and poromechanical processes play an important role in many geomechanics problems, such as borehole stability analysis and studies of initiation and propagation of hydraulic fractures. Thermal effects, as well as hydraulic effects, can greatly change the stresses and pore pressure fields around an underground opening. This is due to the fact that thermal loading induces a volumetric deformation because of thermal expansion/contraction of both the pore fluid and the rock solid. Volumetric expansion can result in significant pressurization of the pore fluid. In order to take into account the influence of temperature gradients on pore pressure and stresses, …

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