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2001

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Articles 91 - 120 of 285

Full-Text Articles in Earth Sciences

Spatial Variability In The Flow Of A Valley Glacier: Deformation Of A Large Array Of Boreholes, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer, Snehalata V. Huzurbazar, David B. Bahr, Brian C. Welch May 2001

Spatial Variability In The Flow Of A Valley Glacier: Deformation Of A Large Array Of Boreholes, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer, Snehalata V. Huzurbazar, David B. Bahr, Brian C. Welch

Geosciences Faculty Publications

Measurements of the deformation of a dense array of boreholes in Worthington Glacier, Alaska, show that the glacier moves with generally bed-parallel motion. Strain in the 200 m deep valley glacier is constant near the surface but follows a nonlinear vertical profile below a depth of about 120 m. By a depth of 180 m, the octahedral strain rate reaches 0.35 yr-1. The three-dimensional velocity field shows spatial complexity with significant deviations from plane strain, despite relatively simple valley geometry in the vicinity of the 6 x 106 m3 study volume. No evidence was found for …


Groundwater Study Of The Pingelly Townsite, Edward K. Crossley May 2001

Groundwater Study Of The Pingelly Townsite, Edward K. Crossley

Resource management technical reports

A groundwater study was carried out in the townsite of Pingelly, Western Australia. It aimed to accelerate the implementation of effective salinity management options. The study consisted of a drilling investigation, expansion of a piezometer network, groundwater flow modelling and a flood risk analysis.


Effects Of Woody Cover In The Landscaping On Riparian Avifauna And A Preliminary Nesting Assessment, Micah W. Perkins May 2001

Effects Of Woody Cover In The Landscaping On Riparian Avifauna And A Preliminary Nesting Assessment, Micah W. Perkins

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Movements And Habitat Use By Hatchery-Reared Pallid Sturgeon In The Lower Platte River, Nebraska, Vaughn A. Snook May 2001

Movements And Habitat Use By Hatchery-Reared Pallid Sturgeon In The Lower Platte River, Nebraska, Vaughn A. Snook

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Groundwater Study Of The Piawaning Townsite, Russell John Speed, Ali S. Mahtab May 2001

Groundwater Study Of The Piawaning Townsite, Russell John Speed, Ali S. Mahtab

Resource management technical reports

A groundwater study was carried out in and around the townsite of Piawaning. It aimed to accelerate the implementation of effective salinity management options. The study consisted of a drilling investigation, expansion of a piezometer network, a pumping test and a flood risk analysis.


Characteristics Of Nest Sites Of Northern Bobwhites In Western Oklahoma, Darrell E. Townsend Ii, Ronald E. Masters, Robert L. Lochmiller, David M. Leslie Jr., Stephen J. Demaso, Alan D. Peoples May 2001

Characteristics Of Nest Sites Of Northern Bobwhites In Western Oklahoma, Darrell E. Townsend Ii, Ronald E. Masters, Robert L. Lochmiller, David M. Leslie Jr., Stephen J. Demaso, Alan D. Peoples

United States Geological Survey: Staff Publications

Previous authors have described nesting habitat of the northern bobwhite (Colinus virginianus) throughout its range, but few have compared structural or compositional differences of vegetation between nest sites and random non-use sites, and successful and non-successful nests. From 1996-1998, we compared cover and structure of 85 plant species from 80 nest sites of northern bobwhite in western Oklahoma. Nest sites were consistently associated with greater structural complexity than what was available at random. Bobwhites selected nest sites with a greater coverage of grass (ca. 50%) and woody (ca. 20-30%) vegetation with a relatively low percentage of bare ground, …


Structural Analysis And A Kink Band Model For The Formation Of The Gemini Fault Zone, An Exhumed Left-Lateral Strike Slip Fault Zone In The Central Sierra Nevada, California, Matthew A. Pachell May 2001

Structural Analysis And A Kink Band Model For The Formation Of The Gemini Fault Zone, An Exhumed Left-Lateral Strike Slip Fault Zone In The Central Sierra Nevada, California, Matthew A. Pachell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The structure and regional tectonic setting of an exhumed, 9.3-km long, left-lateral strike-slip fault zone eludicates processes of growth, linkage, and termination for strike-slip fault zones in granitic rocks. The Gemini fault zone is composed of three steeply dipping, southwest-striking, noncoplanar segments that nucleated and grew along preexisting joints. The fault zone has a maximum slip of 131 m and is an example of a segmented, hard-linked fault zone in which geometrical complexities of the faults and compositional variations of protolith and host rock resulted in nonuniform slip orientations, complex interactions at fault segments, and an asymmetric slip-distance profile. Regional …


Structural And Geochemical Analyses Of Disseminated-Gold Deposits, Bald Mountain-Alligator Ridge District, Nevada: Insights Into Fault-Zone Architecture And Its Effect On Mineralization, K. Jill Hammond May 2001

Structural And Geochemical Analyses Of Disseminated-Gold Deposits, Bald Mountain-Alligator Ridge District, Nevada: Insights Into Fault-Zone Architecture And Its Effect On Mineralization, K. Jill Hammond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Structural and geochemical analyses of the Top and Casino deposits, Bald Mountain-Alligator Ridge district, Nevada, were conducted to determine how structures affected gold deposition in Carlin-type deposit s. We also examined how permeability changed over time in a fault that cuts siltstone-dominated sedimentary rocks. The association of gold and related arsenic with faults at the margins of a Jurassic pluton and sedimentary rocks suggests that ore fluids migrated along faults and fracture s. Permeability of the faults changed over time within the Casino deposit, where the ore-controlling fault was a distributed conduit in the early stages of mineralization but a …


Controls On Channel Organization And Morphology In A Glaciated Basin In The Uinta Mountains, Utah, Betty E. Paepke May 2001

Controls On Channel Organization And Morphology In A Glaciated Basin In The Uinta Mountains, Utah, Betty E. Paepke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The organization and morphology of Middle Fork Sheep Creek and South Fork Sheep Creek, two mountain streams in the upper Sheep Creek basin, are controlled by the spatial distribution of glacial moraines. Both channels are organized into a reoccurring sequence of steep-gradient reaches changing downstream to low-gradient reaches. Steep-gradient reaches are located where the channels flow through moraine s. Low-gradient reaches are located in meadows downstream of the steep-gradient reaches and immediately upstream of the next moraine. Knickpoints in the longitudinal profiles of both streams coincide with the location of moraines.

Large boulder s, beyond the size transportable by the …


Effects Of High Ammonium/Nitrate Ratios On Nitrification And Growth Of Wheat In Hydroponics, Dawn J. Muhlestein May 2001

Effects Of High Ammonium/Nitrate Ratios On Nitrification And Growth Of Wheat In Hydroponics, Dawn J. Muhlestein

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is the only plant nutrient taken up as both a cation (NH4+) and anion (NO3-). Nitrate is considered the "safe" form of N and NH/ is generally thought to be toxic, especially at high levels. High NH4+/NO3- ratios are thought to be toxic because they result in a rhizosphere pH low enough to damage root membranes, induced cation deficiencies, and build-up of NH3 caused by delayed NH/ assimilation. These factors can be minimized in hydroponic culture. The objective of these studies was to quantify the effects of high …


The Efficacy Of Plant Residue Degradation Products On Phosphorus, Iron, Iodine, And Fluorine Bioavailability To Plants, Cheryl L. Mackowiak May 2001

The Efficacy Of Plant Residue Degradation Products On Phosphorus, Iron, Iodine, And Fluorine Bioavailability To Plants, Cheryl L. Mackowiak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant and animal wastes degrade in soils to form relatively stable humified compounds, which form ion complexes that affect the bioavailability of elements in the soil solution. Hydroponic studies with wheat and rice were conducted to characterize the effect of humic acid (HA) on phosphorus (P), iron (Fe), fluorine (F), and iodine (I) bioavailability. Ferrihydrite [Fe(OH)3] precipitation was greater on root surfaces without HA or synthetic chelates. Oxides such as ferrihydrite strongly adsorb P and provide exchange sites for metals. HA reduced this precipitate and increased P and Fe uptake.

Humic acid had no effect on F toxicity …


Observations Of Volcanic Clouds In Their First Few Days Of Atmospheric Residence: The 1992 Eruptions Of Crater Peak, Mount Spurr Volcano, Alaska, William I. Rose, Gregg J. Bluth, David J. Schneider, Gerald G. J. Ernst, Colleen M. Riley, Lydia J. Henderson, Robert G. Mcgimsey Apr 2001

Observations Of Volcanic Clouds In Their First Few Days Of Atmospheric Residence: The 1992 Eruptions Of Crater Peak, Mount Spurr Volcano, Alaska, William I. Rose, Gregg J. Bluth, David J. Schneider, Gerald G. J. Ernst, Colleen M. Riley, Lydia J. Henderson, Robert G. Mcgimsey

Department of Geological and Mining Engineering and Sciences Publications

Satellite SO2 and ash measurements of Mount Spurr’s three 1992 volcanic clouds are compared with ground‐based observations to develop an understanding of the physical and chemical evolution of volcanic clouds. Each of the three eruptions with ratings of volcanic explosivity index three reached the lower stratosphere (14 km asl), but the clouds were mainly dispersed at the tropopause by moderate to strong (20–40 m/s) tropospheric winds. Three stages of cloud evolution were identified. First, heavy fallout of large (>500 μm) pyroclasts occurred close to the volcano (vent) during and immediately after the eruptions, and the cloud resembled an advected …


Addressing Uncertainty In Tmdls: Short Course At Arkansas Water Resources Center 2001 Annual Conference, Marty Matlock, Matthew Murawski Apr 2001

Addressing Uncertainty In Tmdls: Short Course At Arkansas Water Resources Center 2001 Annual Conference, Marty Matlock, Matthew Murawski

Arkansas Water Resources Center Technical Reports

Management of a critical natural resource like water requires information on the status of that resource. The US Environmental Protection Agency (EPA) reported in the 1998 National Water Quality Inventory that more than 291,000 miles of assessed rivers and streams and 5 million acres of lakes do not meet State water quality standards. This inventory represents a compilation of State assessments of 840,000 miles of rivers and 17.4 million acres of lakes; a 22 percent increase in river miles and 4 percent increase in lake acres over their 1996 reports. Siltation, bacteria, nutrients and metals were the leading pollutants of …


Esperance Downs Research Station : Rehabilitation Report, Harvey Jones Apr 2001

Esperance Downs Research Station : Rehabilitation Report, Harvey Jones

Resource management technical reports

Esperance Downs Research Station (EDRS) was established in 1949 as an experimental farm. Knowledge from trials on the station has been instrumental in development of agriculture throughout the Esperance region. However, land degradation and in particular secondary salinity became widespread by the 1980s. With potential for similar problems to develop in the region, the EDRS rehabilitation program began in 1990/91. This report details the objectives of this project along with implementation procedures and an assessment of its achievements.

The stated aim of the rehabilitation was 'To research and demonstrate economic methods of obtaining production from land affected by salinity, waterlogging …


Calibration And Use Of A Combination Atmometer To Estimate Evapotranspiration And Monitor Soil Moisture Storage On Farmland Catchments In Western Australia, K J. Bligh Apr 2001

Calibration And Use Of A Combination Atmometer To Estimate Evapotranspiration And Monitor Soil Moisture Storage On Farmland Catchments In Western Australia, K J. Bligh

Resource management technical reports

The readily-operated combination method of estimating evapotranspiration was applied using simple atmometers, calibrated against absolute evapotranspiration. While 76.6 per cent of the variance of estimates was accounted for by the regression in the first season under wheat, no significant results were achieved in a further four seasons. Combined data for two seasons under legume pastures enabled 30.1 per cent of the variance of estimates to be accounted for.


Groundwater Study Of The Carnamah Townsite, Russell John Speed Apr 2001

Groundwater Study Of The Carnamah Townsite, Russell John Speed

Resource management technical reports

Report on a hydrological investigation of Carnamah townsite in Western Australia to establish present groundwater levels and to provide a groundwater monitoring network so that any future risk of salinity could be assessed.


Evidence Of Earliest Known Wildfires, Walter L. Cressler Iii Apr 2001

Evidence Of Earliest Known Wildfires, Walter L. Cressler Iii

Earth & Space Sciences Faculty Publications

No abstract provided.


Gps-Determination Of Along-Strike Variation In Cascadia Margin Kinematics: Implications For Relative Plate Motion, Subduction Zone Coupling, And Permanent Deformation, M. Meghan Miller, Daniel J. Johnson, Charles M. Rubin, Herb Dragert, Kelin Wang, Anthony Qamar, Chris Goldfinger Apr 2001

Gps-Determination Of Along-Strike Variation In Cascadia Margin Kinematics: Implications For Relative Plate Motion, Subduction Zone Coupling, And Permanent Deformation, M. Meghan Miller, Daniel J. Johnson, Charles M. Rubin, Herb Dragert, Kelin Wang, Anthony Qamar, Chris Goldfinger

All Faculty Scholarship for the College of the Sciences

High‐precision GPS geodesy in the Pacific Northwest provides the first synoptic view of the along‐strike variation in Cascadia margin kinematics. These results constrain interfering deformation fields in a region where typical earthquake recurrence intervals are one or more orders of magnitude longer than the decades‐long history of seismic monitoring and where geologic studies are sparse. Interseismic strain accumulation contributes greatly to GPS station velocities along the coast. After correction for a simple elastic dislocation model, important residual motions remain, especially south of the international border. The magnitude of northward forearc motion increases southward from western Washington (3–7 mm/yr) to northern …


Environmental Change And The Central Great Plains, David Gosselin Apr 2001

Environmental Change And The Central Great Plains, David Gosselin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Environmental Change And The Central Great Plain, Water Resources, David Gosselin Apr 2001

Environmental Change And The Central Great Plain, Water Resources, David Gosselin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Agricultural Management Practices And The Groundwater System Of Northern Holt County, Nebraska, With A Focus On The Holt County Groundwater Education Project, Susan Olafsen Lackey, Charles Shapiro, William Kranz Apr 2001

Agricultural Management Practices And The Groundwater System Of Northern Holt County, Nebraska, With A Focus On The Holt County Groundwater Education Project, Susan Olafsen Lackey, Charles Shapiro, William Kranz

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Determination Of The Pollutant Loads In The Kings River Near Berryville, Thomas S. Soerens, Marc A. Nelson Mar 2001

Determination Of The Pollutant Loads In The Kings River Near Berryville, Thomas S. Soerens, Marc A. Nelson

Arkansas Water Resources Center Technical Reports

An automatic sampler and a U.S. Geological Swvey (USGS) gauging station were established in 1998 and water quality sampling was begun in 1999 on the Kings River near Benyville, Arkansas. Continuous stage and discharge measurements and frequent water quality sampling have been used to determine pollutant concentrations and loads in t11e river. In addition, ten samples were taken by Arkansas Water Resources Center (A WRC) concurrently with USGS samples in order to assess whether A WRC and USGS samples can be compared. This report presents the results from the sampling and analysis for January 1, I999 to December 31, 1999. …


Nebraska's Test-Hole Drilling Program And Records, Duane R. Mohlman, Charles A. Flowerday Mar 2001

Nebraska's Test-Hole Drilling Program And Records, Duane R. Mohlman, Charles A. Flowerday

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


An Environmental Geochemical Study Of Connecticut Marsh Sediments, Nicole A. Heller, Michael A. Kruge, Johan C. Varekamp, Tabitha Zierzow Mar 2001

An Environmental Geochemical Study Of Connecticut Marsh Sediments, Nicole A. Heller, Michael A. Kruge, Johan C. Varekamp, Tabitha Zierzow

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Core material from Spartina-dominated Housatonic and Connecticut River estuarine sites (ranging from low to high marsh) were investigated in order to test the hypothesis that organic and inorganic pollutants preferentially accumulate in the low marsh environment. Radiometric data indicate that the low marsh setting experienced sedimentation rates an order of magnitude greater than that of the mid to high marsh. The low marsh sediments from the Housatonic tend to have significantly higher concentrations of trace metals (e.g., Cu and Zn, likely contributed by brass mills formerly active upstream). Petrographic examination of the samples under reflected white and blue light …


Geology Of Pioneers Park, Lancaster County, Nebraska, Roger K. Pabian Mar 2001

Geology Of Pioneers Park, Lancaster County, Nebraska, Roger K. Pabian

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Management Of Soil Organic Matter And Gypsum For Sustainable Production In The Carnarvon Horticultural District Of Western Australia, R.S.B. Greene, A.J. Lin, D. C. Parr Mar 2001

Management Of Soil Organic Matter And Gypsum For Sustainable Production In The Carnarvon Horticultural District Of Western Australia, R.S.B. Greene, A.J. Lin, D. C. Parr

Agriculture reports

Soil quality is critically important for the long-term production of high quality and high yielding fruit and vegetable crops in the Carnarvon horticultural district of Western Australia. A stable soil structure is essential for good soil quality.


Alfalfa As A Cash Hay Crop, John Nowak Feb 2001

Alfalfa As A Cash Hay Crop, John Nowak

Kentucky Alfalfa and Stored Forage Conference

Over the years we have all learned of the great potential alfalfa has as a forage crop in Kentucky. We have seen it used as hay, haylage and even pasture. Many aspects of our agri-business community have alfalfa as an important part of their business.


Alfalfa For Beef Cattle, W. Roy Burris Feb 2001

Alfalfa For Beef Cattle, W. Roy Burris

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is sometimes said to be "too good" for beef cattle. Although it's nutritional value may sometimes exceed beef cows' needs, to dismiss it's potential for beef cattle would be a mistake. Alfalfa can be useful as a harvested feed or as a grazing crop.


Alfalfa For Dairy Cattle, Donna M. Amaral-Phillips Feb 2001

Alfalfa For Dairy Cattle, Donna M. Amaral-Phillips

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is known as the queen of the forage crops and for good reasons. Alfalfa is an excellent forage for dairy cattle because it provides nutrients needed by dairy cows in a package which is highly digestible and cost effective. Alfalfa can be grazed directly by cattle or harvested as hay, haylage, or batage. Dairy farmers will purchase locally-grown hay if it is high quality (RFV greater than 150). When marketing cash hay one needs to understand that the quality of alfalfa greatly impacts milk production and economics of a dairy operation. This impact is felt even when as little …


Alfalfa Hay For Horses, Laurie Lawrence Feb 2001

Alfalfa Hay For Horses, Laurie Lawrence

Kentucky Alfalfa and Stored Forage Conference

Horse owners frequently mention cleanliness, color and cutting when it comes to choosing hay. Cleanliness should be the most important factor in selecting horse hay. Hay that contains dust or mold can inflame the respiratory tract. It is also possible for hay mold to affect other systems in the horse such as the digestive system and liver. Some horses suffer from a chronic respiratory condition that seriously impairs their ability to breathe normally. This condition, commonly known as heaves, worsens when horses are fed moldy or dusty hay. Horses with heaves are exercise intolerant and thus have little value except …