Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

2000

Discipline
Institution
Keyword
Publication
Publication Type

Articles 121 - 150 of 296

Full-Text Articles in Earth Sciences

Western Australia Soil Acidity Research And Development Update 2000 : Time To Lime, Department Of Agriculture And Food, Western Australia Jan 2000

Western Australia Soil Acidity Research And Development Update 2000 : Time To Lime, Department Of Agriculture And Food, Western Australia

Bulletins 4000 -

We have come a long way over the past three or four years in terms of both, the level of understanding and recognition of Soil Acidity as a major land degradation issue for the wheatbelt of Western Australia, and, in our actions to treat the problem.

During 1999 there were three very significant changes relating to acid soils in Western Australia.

  • Lime use in WA increased by over 200,000 tonnes from 1998 to 1999 to a record 653,000 tonnes, which was double the amount applied in 1997.
  • The Agricultural Lime Industry adopted a voluntary Lime Industry Code of Practice in …


Feature Extraction In Geobiophysical Modeling Of Mining Activity Impacting Dewey Lake, Kentucky, Sean K. Litteral Jan 2000

Feature Extraction In Geobiophysical Modeling Of Mining Activity Impacting Dewey Lake, Kentucky, Sean K. Litteral

Theses, Dissertations and Capstones

Surface coal mining activity has effects on watershed and lake morphology within the Appalachian Mountains that continue to be problematic. A watershed’s natural dynamic balance has been subject to the influence of various natural and anthropogenic parameters such as mining sediment transport, wind, wave effects and currents. Many techniques have been developed to improve image processing in geobiophysical modeling, which can assist scientists, government officials, and industry personal with decisions affecting environmental concerns. One of the more advanced techniques involves 3D visualization and geobiophysical modeling. This process was used in combining remotely sensed digital aerial imagery with Digital Elevation Models …


The Microstratigraphy Of The Meadville Member Of Lodi, Northeastern Ohio: A Lithofacies Analysis, Andrew S. Madof Jan 2000

The Microstratigraphy Of The Meadville Member Of Lodi, Northeastern Ohio: A Lithofacies Analysis, Andrew S. Madof

Honors Papers

During the Lower (Osagian) Mississippian Period, Ohio was about 7 degrees south of the equator in a tropical epicontinental sea at the northwestern edge of the Appalachian foreland Basin. Present day Lodi, northeastern Ohio, lay within the midst of a westward deepening syncline whose sediment was derived from the Acadian uplifts to the east. This sediment, composed primarily of illite and quartz, was deposited about 100 m below sea level in a middle to outer deltaic environment. From the base (Meadville Member) to the top (Armstrong Member) of the strata exposed at Lodi, a general increase in grain size occurs. …


Reflections Of A Naturalist: Papers Honoring Professor Eugene D. Fleharty, Jerry R. Choate Jan 2000

Reflections Of A Naturalist: Papers Honoring Professor Eugene D. Fleharty, Jerry R. Choate

Fort Hays Studies Series

Science and academia tend to be dominated by persons who are utterly brilliant, or who are proficient at self-promotion, or who are willing to sacrifice their personal lives and work twice as hard as their peers, or who exhibit some combination of these attributes. Occasionally, however, someone comes along who is just "ordinary" compared with academic overachievers but whose accomplishments far exceed reasonable expectations. Eugene D. Fleharty is such a person. Although he is extraordinarily bright, few would describe him as utterly brilliant. He has never been inclined to "toot his own horn" or otherwise promote himself. And, although he …


Type Locality For The Great Blue Limestone In The Bingham Nappe, Oquirrh Mountains, Utah, United States Geological Survey Jan 2000

Type Locality For The Great Blue Limestone In The Bingham Nappe, Oquirrh Mountains, Utah, United States Geological Survey

All U.S. Government Documents (Utah Regional Depository)

The Great Blue Limestone was named originally by Spurr (1895) from exposures near the Mercur mining district in the Oquirrh Mountains, Utah. The formation was described in greater detail by Gilluly (1932) in the Ophir mining district. Neither formally established a type locality for this formation in the Oquirrh Mountains. However, the formation has since been correlated broadly with similar sedimentary rocks elsewhere in the adjoining Rocky Mountains and Great Basin regions. For the record, and to assist future correlations, a type measured section of the Great Blue Limestone in the Oquirrh Mountains is located, described, and a detailed measured …


Environmental Assessment Wild Horse Gathering For The Fifteenmile Wild Horse Herd Management Area, United States Bureau Of Land Management Jan 2000

Environmental Assessment Wild Horse Gathering For The Fifteenmile Wild Horse Herd Management Area, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

The purpose for management of wild, free roaming horses is to comply with law and policy pertaining to wild, free roaming horses on public lands. The policy of the BLM addresses a range of topics including establishment and maintenance of Appropriate Management Levels (AMLs) in Herd Managment Areas (HMAs) in a humane, safe, efficient, and environmentally sound manner.


New Specimens Of Late Quaternary Extinct Mammals From Caves In Sanchez Ramirez Province, Dominican Republic, Donald A. Mcfarlane, Abel Vale, Keith Christenson, Joyce Lundberg, Gabriel Atilles, Stein Erik Lauritzen Jan 2000

New Specimens Of Late Quaternary Extinct Mammals From Caves In Sanchez Ramirez Province, Dominican Republic, Donald A. Mcfarlane, Abel Vale, Keith Christenson, Joyce Lundberg, Gabriel Atilles, Stein Erik Lauritzen

WM Keck Science Faculty Papers

During the late Quaternary, the island of Hispaniola supported one of the most diverse mammalian faunas in the West Indies. Much of this diversity was lost to extinction in the past 100,000 years, but the timing of these events is poorly known. Here we report the paleontological findings of a multidisciplinary investigation of caves in the central Dominican Republic. These findings include new 'last occurrence' dates for the rodents Isolobodon portoricensis and Brotomys cf. voratus that take these genera to the dawn of the historic era; a first record of a last-interglacial sloth, and the first report of the upper …


Katanning Area Land Resources Survey, Heather M. Percy, G M. Wilson, Ted A. Griffin Jan 2000

Katanning Area Land Resources Survey, Heather M. Percy, G M. Wilson, Ted A. Griffin

Land resources series

This report presents results from soil and landform mapping at a scale of 1:150,000 in the Katanning area of Western Australia. It is accompanied by two soil-landscape maps covering 1.45 million hectares in the Kojonup and Darkan area (map 1) and the Katanning and Dumbleyung area (map 2). Most of the Katanning survey occurs within the Blackwood River catchment but also covers the upper catchments of the Pallinup, Frankland-Gordon and Tone-Warren Rivers. The Katanning survey falls within the Narrogin and Katanning advisory districts for Agriculture Western Australia. Twenty one soil-landscape systems have been identified and are represented on the accompanying …


Investigation Of The Role Of The Urella Fault And The Impact Of Salinity Development In The Nebru Catchment, Upper Arrowsmith, C E. Mcconnell Jan 2000

Investigation Of The Role Of The Urella Fault And The Impact Of Salinity Development In The Nebru Catchment, Upper Arrowsmith, C E. Mcconnell

Resource management technical reports

No abstract provided.


Principal Meridians Of The Federal System Of Rectangular Surveys, Bureau Of Land Management Jan 2000

Principal Meridians Of The Federal System Of Rectangular Surveys, Bureau Of Land Management

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Grassland Bird Use Of Conservation Reserve Program Fields In The Great Plains, Douglas H. Johnson Jan 2000

Grassland Bird Use Of Conservation Reserve Program Fields In The Great Plains, Douglas H. Johnson

United States Geological Survey: Publications

The area enrolled in the Conservation Reserve Program in the Great Plains is enormous: nearly 18 million acres, or more than 7 million hectares, in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. This change in land use has had a huge influence on grassland bird populations. Many, but certainly not all, grassland species flourish in CRP habitats. Responses to the program vary not only by species, but by region, year, vegetation composition in a field, and whether or not a field was hayed or grazed. Further, the large scale of CRP has allowed researchers to …


Metals Transport In The Sacramento River, California, 1996–1997 Volume 1: Methods And Data, Charles N. Alpers, Howard E. Taylor, Joseph L. Domagalski Jan 2000

Metals Transport In The Sacramento River, California, 1996–1997 Volume 1: Methods And Data, Charles N. Alpers, Howard E. Taylor, Joseph L. Domagalski

United States Geological Survey: Publications

Metals transport in the Sacramento River, northern California, was evaluated on the basis of samples of water, suspended colloids, streambed sediment, and caddisfly larvae that were collected on one to six occasions at 19 sites in the Sacramento River Basin from July 1996 to June 1997. Four of the sampling periods (July, September, and November 1996; and May–June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions; respectively. Tangential-flow ultrafiltration with 10,000 nominal molecular weight limit, or daltons (0.005 micrometer equivalent), pore-size membranes was used to …


Water Quality In The Sacramento River Basin, California,1994–98, Joseph L. Domagalski, Donna L. Knifong, Peter D. Dileanis, Larry R. Brown, Jason T. May, Valerie Connor, Charles N. Alpers Jan 2000

Water Quality In The Sacramento River Basin, California,1994–98, Joseph L. Domagalski, Donna L. Knifong, Peter D. Dileanis, Larry R. Brown, Jason T. May, Valerie Connor, Charles N. Alpers

United States Geological Survey: Publications

This report summarizes major findings about water quality in the Sacramento River Basin that emerged from an assessment conducted between 1994 and 1998 by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program. Water quality is discussed in terms of local and regional issues and compared to conditions found in all 36 NAWQA study areas, called Study Units, assessed to date. Findings are also explained in the context of selected national benchmarks, such as those for drinking-water quality and the protection of aquatic organisms. The NAWQA Program was not intended to assess the quality of the Nation's drinking water, …


Chronology And Geochemistry Of Late Holocene Eolian Deposits In The Brandon Sand Hills, Manitoba, Canada, Stephen A. Wolfe, Daniel R. Muhs, Peter P. David, John P. Mcgeehin Jan 2000

Chronology And Geochemistry Of Late Holocene Eolian Deposits In The Brandon Sand Hills, Manitoba, Canada, Stephen A. Wolfe, Daniel R. Muhs, Peter P. David, John P. Mcgeehin

United States Geological Survey: Staff Publications

Accelerator mass spectrometry and conventional radiocarbon age determinations of organic matter from paleosols indicate that the Brandon Sand Hills area of southern Manitoba has been subjected to recurrent intervals of eolian activity in the past 5000 years. Although precise regional correlations are precluded by dating uncertainties, periods of most notable paleosol development occurred around 2300 to 2000, 1400 to 1000, and 600 to 500 cal yr BP with eolian activity occurring before and after each of these periods. Episodes of eolian activity may correspond to periods of regional drought, whereas paleosols mark periods of increased moisture availability and stabilization by …


Relation Of Pathways And Transit Times Of Recharge Water To Nitrate Concentrations Using Stable Isotopes, Matthew K. Landon, Geoffrey N. Delin, Stephen C. Komor, Charles P. Regan Jan 2000

Relation Of Pathways And Transit Times Of Recharge Water To Nitrate Concentrations Using Stable Isotopes, Matthew K. Landon, Geoffrey N. Delin, Stephen C. Komor, Charles P. Regan

United States Geological Survey: Staff Publications

Oxygen and hydrogen stable isotope values of precipitation, irrigation water, soil water, and ground water were used with soil-moisture contents and water levels to estimate transit times and pathways of recharge water in the unsaturated zone of a sand and gravel aquifer.


Paleoclimate Reconstruction Along The Pole-Equator-Pole Transect Of The Americas (Pep 1), Vera Markgraf, T.R Baumgartner, J. P. Bradbury, H. F. Diaz, R. B. Dunbar, B. H. Luckman, G. O. Seltzer, T. W. Swetnam, R. Villalba Jan 2000

Paleoclimate Reconstruction Along The Pole-Equator-Pole Transect Of The Americas (Pep 1), Vera Markgraf, T.R Baumgartner, J. P. Bradbury, H. F. Diaz, R. B. Dunbar, B. H. Luckman, G. O. Seltzer, T. W. Swetnam, R. Villalba

United States Geological Survey: Staff Publications

Examples are presented of inter-hemispheric comparison of instrumental climate and paleoclimate proxy records from the Americas for different temporal scales. Despite a certain symmetry of seasonal precipitation patterns along the PEP 1 transect, decadal variability of winter precipitation shows different characteristics in terms of amplitude and frequency in both the last 100 and last 1000 years. Such differences in variability are also seen in a comparison of time series of different El Nino/Southern Oscillation proxy records from North and South America, however, these differences do not appear to affect the spatial correlation with Pacific sea surface temperature patterns. Local and …


Land Cover Trends Dataset, 1973–2000, Christopher E. Soulard, William Acevedo, Roger F. Auch, Terry L. Sohl, Mark A. Drummond, Benjamin M. Sleeter, Daniel G. Sorenson, Steve Kambly, Tamara S. Wilson, Janis L. Taylor, Kristi L. Sayler, Michael P. Stier, Christopher A. Barnes, Steve C. Methven, Thomas R. Loveland, Rachel Headley, Mark S. Brooks Jan 2000

Land Cover Trends Dataset, 1973–2000, Christopher E. Soulard, William Acevedo, Roger F. Auch, Terry L. Sohl, Mark A. Drummond, Benjamin M. Sleeter, Daniel G. Sorenson, Steve Kambly, Tamara S. Wilson, Janis L. Taylor, Kristi L. Sayler, Michael P. Stier, Christopher A. Barnes, Steve C. Methven, Thomas R. Loveland, Rachel Headley, Mark S. Brooks

United States Geological Survey: Publications

The U.S. Geological Survey Land Cover Trends Project is releasing a 1973–2000 time-series land-use/land-cover dataset for the conterminous United States. The dataset contains 5 dates of land-use/land-cover data for 2,688 sample blocks randomly selected within 84 ecological regions. The nominal dates of the land-use/land-cover maps are 1973, 1980, 1986, 1992, and 2000. The land-use/land-cover maps were classified manually from Landsat Multispectral Scanner, Thematic Mapper, and Enhanced Thematic Mapper Plus imagery using a modified Anderson Level I classification scheme. The resulting land-use/land-cover data has a 60-meter resolution and the projection is set to Albers Equal-Area Conic, North American Datum of 1983. …


Modeling Regional Salinization Of The Ogallala Aquifer, Southern High Plains, Tx, Usa, S. Mehta, A. E. Fryar, R. M. Brady, Roger H. Morin Jan 2000

Modeling Regional Salinization Of The Ogallala Aquifer, Southern High Plains, Tx, Usa, S. Mehta, A. E. Fryar, R. M. Brady, Roger H. Morin

United States Geological Survey: Staff Publications

Two extensive plumes (combined area >1000 km2) have been delineated within the Ogallala aquifer in the Southern High Plains, TX, USA. Salinity varies within the plumes spatially and increases with depth; Cl ranges from 50 to >500 mg l21. Variable-density flow modeling using SUTRA has identified three broad regions of upward cross-formational flow from the underlying evaporite units. The upward discharge within the modeled plume area is in the range of 10-4–10-5 m3 day-1, and the TDS concentrations are typically >3000 mg l-1. Regions of increased salinity, identified within the …


Occurrence Of Pesticides In Rain And Air In Urban And Agricultural Areas Of Mississippi, April-September 1995, R. H. Coupe, M. A. Manning, W. T. Foreman, D. A. Goolsby, M. S. Majewski Jan 2000

Occurrence Of Pesticides In Rain And Air In Urban And Agricultural Areas Of Mississippi, April-September 1995, R. H. Coupe, M. A. Manning, W. T. Foreman, D. A. Goolsby, M. S. Majewski

United States Geological Survey: Staff Publications

In April 1995, the US Geological Survey began a study to determine the occurrence and temporal distribution of 49 pesticides and pesticide metabolites in air and rain samples from an urban and an agricultural sampling site in Mississippi. The study was a joint effort between the National Water-Quality Assessment and the Toxic Substances Programs and was part of a larger study examining the occurrence and temporal distribution of pesticides in air and rain in the Mississippi River basin. Concurrent high-volume air and wet-only deposition samples were collected weekly. The air samplers consisted of a glass-fiber filter to collect particles and …


Pore Fluid Pressure, Apparent Friction, And Coulomb Failure, N. M. Beeler, R. W. Simpson, S. H. Hickman, D. A. Lockner Jan 2000

Pore Fluid Pressure, Apparent Friction, And Coulomb Failure, N. M. Beeler, R. W. Simpson, S. H. Hickman, D. A. Lockner

United States Geological Survey: Staff Publications

Many recent studies of stress-triggered seismicity rely on a fault failure
model with a single free parameter, the apparent coefficient of friction, presumed to be a material constant with possible values 0 ≤ μ ' ≤ 1. These studies may present a misleading view of fault strength and the role of pore fluid pressure in earthquake failure. The parameter μ ' is intended to incorporate the effects of both friction and pore pressure, but is a material constant only if changes in pore fluid pressure induced by changes in stress are proportional to the normal stress change across the potential …


Metal Exposure In A Benthic Macroinvertebrate, Hydropsyche Californica, Related To Mine Drainage In The Sacramento River, Daniel J. Cain, James L. Carter, Steven V. Fend, Samuel N. Luoma, Charles N. Alpers, Howard E. Taylor Jan 2000

Metal Exposure In A Benthic Macroinvertebrate, Hydropsyche Californica, Related To Mine Drainage In The Sacramento River, Daniel J. Cain, James L. Carter, Steven V. Fend, Samuel N. Luoma, Charles N. Alpers, Howard E. Taylor

United States Geological Survey: Staff Publications

A biomonitoring technique was employed to complement studies of metal transport in the upper Sacramento River affected by acid mine drainage. Metals (Al, Cd, Cu, Fe, Hg, Pb, and Zn) were determined in a resident invertebrate, Hydropsyche californica (Insecta: Trichoptera), and streambed sediments (<62 >μm) to assess metal contamination within a 111-km section of the river downstream of the mining area. Metals in H. californica also were interpreted to be broadly indicative of metal exposure in fish. Total Hg was determined in the whole body of the insect, whereas Al, Cd, Cu, Fe, Pb, and Zn were additionally separated into …


Fractured-Aquifer Hydrogeology From Geophysical Logs: Brunswick Group And Lockatong Formation, Pennsylvania, Roger H. Morin, Lisa A. Senior, Edward R. Decker Jan 2000

Fractured-Aquifer Hydrogeology From Geophysical Logs: Brunswick Group And Lockatong Formation, Pennsylvania, Roger H. Morin, Lisa A. Senior, Edward R. Decker

United States Geological Survey: Staff Publications

The Brunswick Group and the underlying Lockatong Formation are composed of lithified Mesozoic sediments that constitute part of the Newark Basin in southeastern Pennsylvania. These fractured rocks form an important regional aquifer that consists of gradational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures. An extensive suite of geophysical logs was obtained in seven wells located at the borough of Lansdale, Pennsylvania, in order to better characterize the areal hydrogeologic system and provide guidelines for the refinement of numerical ground water models. Six of the seven wells are approximately 120 m deep and the seventh …


Hayes County Test Hole Logs, Duane A. Eversoll Jan 2000

Hayes County Test Hole Logs, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Facies Analysis And Sequence Stratigraphy Of Crp-2/2a, Victoria Land Basin, Antarctica, Christopher R. Fielding, T R. Naish, K J. Woolfe, M A. Lavelle Jan 2000

Facies Analysis And Sequence Stratigraphy Of Crp-2/2a, Victoria Land Basin, Antarctica, Christopher R. Fielding, T R. Naish, K J. Woolfe, M A. Lavelle

Department of Earth and Atmospheric Sciences: Faculty Publications

The Oligocene to Quaternary succession encountered in CRP-2/2A is divided into twelve recurrent lithofacies (some of which have been subdivided further), reflecting a range of marine, glacimarine and possibly subglacial environments of sediment accumulation. A cyclical vertical arrangement of lithofacies was noted throughout the core, and is used as the basis for a sequence stratigraphic analysis. Twenty-four sequences are recognised, each of which begins with a Sequence Boundary (Glacial Surface of Erosion), and each is interpreted to record a cycle of glacial advance and retreat with associated changes in relative sea-level. During at least some of these cycles, ice is …


Chronostratigraphy Of Crp-2/2a, Victoria Land Basin, Antarctica, G S. Wilson, S. M. Bohaty, Christopher R. Fielding, F. Florindo, M. J. Hannah, David M. Harwood, W. C. Mcintosh, T. R. Naish, A. P. Roberts, L. Sagnotti, R. P. Scherer, C. P. Strong, K. L. Verosub, G. Villa, David K. Watkins, P. N. Webb, K. J. Woolfe Jan 2000

Chronostratigraphy Of Crp-2/2a, Victoria Land Basin, Antarctica, G S. Wilson, S. M. Bohaty, Christopher R. Fielding, F. Florindo, M. J. Hannah, David M. Harwood, W. C. Mcintosh, T. R. Naish, A. P. Roberts, L. Sagnotti, R. P. Scherer, C. P. Strong, K. L. Verosub, G. Villa, David K. Watkins, P. N. Webb, K. J. Woolfe

Department of Earth and Atmospheric Sciences: Faculty Publications

The 624.15 m glaciomarine sedimentary succession recovered in the CRP-2/2A drillcore comprises lower Oligocene (< c. 31 Ma) to lower Miocene (18.5 Ma) strata that are overlain by a thin succession of Pliocene and Pleistocene strata. The age model for the CRP-2/2A drillhole, as presented in this paper, is based on combined microfossil biostratigraphy, 40Ar/39Ar ages on volcanic material, 87Sr/86Sr analyses on mollusc shells, and correlation of a magnetic polarity zonation to the magnetic polarity time scale (MPTS). Between 25.92 and 109.05 metres below sea floor (mbsf), several alternative correlations to the MPTS are possible, all of which suggest that sediment accumulation rates averaged ~180 m/m.y. between unconformities, although actual sedimentation rates may have been higher. Between 109.05 and 306.65 mbsf, the age model is straightforward and average sedimentation rates were much higher …


Expression Of A Dominant-Negative Mutant Of P21ras Inhibits Induction Of Nitric Oxide Synthase And Activation Of Nuclear Factor-Kb In Primary Astrocytes, Kalipada Pahan, Xiaojuan Lu, Michael J. Mckinney, Charles Wood, Faruk G. Sheikh, John R. Raymond Jan 2000

Expression Of A Dominant-Negative Mutant Of P21ras Inhibits Induction Of Nitric Oxide Synthase And Activation Of Nuclear Factor-Kb In Primary Astrocytes, Kalipada Pahan, Xiaojuan Lu, Michael J. Mckinney, Charles Wood, Faruk G. Sheikh, John R. Raymond

School of Biological Sciences: Faculty Publications

The present study underlines the importance of p21ras in regulating the inducible nitric oxide synthase (iNOS) in primary astrocytes. Bacterial lipopolysaccharides induced the GTP loading of p21ras, and the expression of a dominant-negative mutant of p21ras (Dp21ras) inhibited lipopolysaccharide-induced GTP loading in rat primary astrocytes. To delineate the role of p21ras in the induction of iNOS, we examined the effect of Dp21ras on the expression of iNOS and the production of nitric oxide. It is interesting that expression of Dp21ras markedly inhibited the production of nitric oxide and the expression of iNOS in lipopolysaccharide- and pro-inflammatory cytokine (tumor necrosis factor-a, …


Multibeam Sonar Backscatter Lineaments And Anthropogenic Organic Components In Lacustrine Silty Clay, Evidence Of Shipping In Western Lake Ontario, C F Michael Lewis, L A. Mayer, Prasanta K. Mukhopadhyay, Michael A. Kruge, John P. Coakley, M D. Smith Jan 2000

Multibeam Sonar Backscatter Lineaments And Anthropogenic Organic Components In Lacustrine Silty Clay, Evidence Of Shipping In Western Lake Ontario, C F Michael Lewis, L A. Mayer, Prasanta K. Mukhopadhyay, Michael A. Kruge, John P. Coakley, M D. Smith

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

A multibeam sonar survey (95 kHz) covering more than 500 km2 of western Lake Ontario revealed anomalous lineaments of relatively high backscatter. The lineaments did not align with or parallel the most prominent structural zones beneath the lake as expected. Instead, the principal lineaments lay on lines between ports on opposite sides of the lake, especially between Toronto and Welland Canal, and Toronto and Niagara River mouth. As the lineaments underlie current and historical shipping routes used during the steamship era, they are interpreted as an acoustic response to shipping debris cumulated in the near-surface bottom sediment. An exploratory …


In Situ Stress Tensor Measured In An Alaskan Glacier, W. Tad Pfeffer, Neil Humphrey, B. Amadei, Joel T. Harper, J. Wegmann Jan 2000

In Situ Stress Tensor Measured In An Alaskan Glacier, W. Tad Pfeffer, Neil Humphrey, B. Amadei, Joel T. Harper, J. Wegmann

Geosciences Faculty Publications

An experimental program at Worthington Glacier, Alaska, U.S.A., has yielded the first in situ measurements of the full stress tensor in glacier ice. Measurements were made with an array of stiff (low-compliance) normal-force sensors frozen into a borehole at 120 m depth. Freezing in temperate ice was accomplished by a down-hole heat exchanger which extracted heat at the rate of 15 W. Under slowly varying stress conditions, relaxation of stress anomalies by viscous creep following drilling of the hole and installation of the sensors allows for equilibration of measured stresses with far-field stresses. Equilibration of local and far-field stresses was …


Effects Of Longwall Mining On Hydrology, Leslie County, Kentucky Part 2: During-Mining Conditions, Shelley Minns Hutcheson, James A. Kipp, James S. Dinger, Lyle V.A. Sendlein, Daniel I. Carey, Gregory L. Secrist Jan 2000

Effects Of Longwall Mining On Hydrology, Leslie County, Kentucky Part 2: During-Mining Conditions, Shelley Minns Hutcheson, James A. Kipp, James S. Dinger, Lyle V.A. Sendlein, Daniel I. Carey, Gregory L. Secrist

Report of Investigations--KGS

The effects of longwall coal mining on hydrology in the Eastern Kentucky Coal Field are being investigated. The study area is in the Edd Fork watershed in southern Leslie County, over Shamrock Coal Company's Beech Fork Mine. Longwall panels approximately 700 ft wide are separated by three-entry gateways that are approximately 200 ft wide. The mine is operated in the Fire Clay (Hazard No. 4) coal; overburden thickness ranges from 300 to 800 ft. Mining began in panel 1 in September 1991 and concluded with panel 8 in September 1994. Long-term monitoring consisting of a network of piezometers and time-domain …


Evaporation Reduction Potential In An Undisturbed Soil Irrigated With Surface Drip And Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman Jan 2000

Evaporation Reduction Potential In An Undisturbed Soil Irrigated With Surface Drip And Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The efficiency of drip irrigation is highly dependent on evaporation losses occurring from the constantly saturated soil beneath emitters. Advent of subsurface drip irrigation is in part an approach to curb this inefficiency. An irrigation method, Sand Tube Irrigation (STI), is proposed to increase the efficiency of “Normal” surface applied drip Irrigation (NI method) on permanent tree crops without the need for burying the irrigation tubing. The sand tube consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was constructed in the laboratory and instrumented to directly measure temporal evaporation …