Earth Sciences Commons^™

Local And Landscape Factors Affecting Nest Site Selection And Nest Success Of Burrowing Owls In Western Nebraska, Rebecca T. Ekstein

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

No abstract provided.

Ecology Of Elk In Northwestern Nebraska: Demographics, Effects Of Human Disturbance, And Characteristics Of Calving Habitat, Bruce A. Stillings

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

No abstract provided.

Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Changes in ideas and in technology can come about as slow incremental modifications, as well as by major paradigm shifts. In the case of the development of the ideas of geologic history and time, I will try to present these changes broadly and then look at how some of these have affected interpretation of Nebraska geology. Changes of view on three fronts were important in the development of geologic history and time concepts.

First is the question of the nature of time. Is time cyclic or is it linear? The Greco-Oriental cultures had a world view based on cosmic cycles, …

Regional Hydrology Of The Dixie Valley Geothermal Field, Nevada: Preliminary Interpretations Of Chemical And Isotopic Data, Gregory Nimz, Cathy Janik, Fraser Goff, Charles Dunlap, Mark Huebner, Dale Counce, Stuart Johnson

Charles Dunlap

Chemical and isotopic analyses of Dixie Valley regional waters indicate several distinct groups ranging in recharge age from Pleistocene (<20 ka) to recent (<50a). Valley groundwater is older than water from perennial springs and artesian wells in adjacent ranges, with Clan Alpine range (east) much younger (most <50a) than Stillwater range (west; most > 1OOOa).Geothermal field fluids (-12-14 ka) appear derived from water similar in composition to non-thermal groundwater observed today in valley artesian wells (also -14 ka). Geothermal fluid interaction with mafic rocks (Humboldt Lopolith) appears to be common, and significant reaction with granodiorite may also occur. Despite widespread occurrence of carbonate rocks, largescale chemical interaction appears minor. Age asymmetry of the ranges, more extensive interaction with deep- seated waters in the west, and distribution of springs and artesian wells suggest the existence …

Maximum Temperature Trends In The Himalaya And Its Vicinity: An Analysis Based On Temperature Records From Nepal For The Period 1971-94, Arun B. Shrestha, Camerson P. Wake, Paul Andrew Mayewski, Jack E. Dibb

Earth Science Faculty Scholarship

Analyses of maximum temperature data from 49 stations in Nepal for the period 1971-94 reveal warming trends after 1977 ranging from 0.06° to 0.12°C yr¹ in most of the Middle Mountain and Himalayan regions, while the Siwalik and Terai (southern plains) regions show warming trends less than 0.03°C yr¹. The subset of records (14 stations) extending back to the early 1960s suggests that the recent warming trends were preceded by similar widespread cooling trends. Distributions of seasonal and annual temperature trends show high rates of warming in the high-elevation regions of the country (Middle Mountains and Himalaya), …

Antarctic's Role Pursued In Global Climate Change, Paul Andrew Mayewski, I. Goodwin

Earth Science Faculty Scholarship

The impact of Antarctica on global climate change and the impact of global climate change on Antarctica are the focal points of a current series of expeditions there, and an international, interdisciplinary array of researchers met this past spring to go over the expeditions' progress. Advances were reported in describing the impact of the seasonal cycle, semiannual oscillation, and the El Niño-Southern Oscillation (ENSO) cycle on Antarctic accumulation in recent decades.

Difficulties still remain, however, in explaining fully the history and forcing of the Antarctic climate and the links between tropical forcing and high-latitude response. The difficulties arise largely because …

Soil Moisture Within The Windbreak/Crop Interface And A Comparison Of Three Types Of Sensors For Measuring Soil Water Content, Qingjiang Hou

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

No abstract provided.

Central Platte River Forests: Breeding Birds And Woody Vegetation, Barbara K. Good

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

No abstract provided.

The Effects Of Phosphorus Enrichment On The Dominant Phytoplankton Communities Of Chaney Lake, Kathy Tehrani

Masters Theses & Specialist Projects

Chaney Lake is a temporary karst wetland located in southern Warren County, Kentucky. Because of an impermeable chert layer between the surface and the porous limestone, Chaney Lake fills with water over the winter and spring and then gradually drains over the summer. Three experiments were conducted over the course of the 1998 flooding season to assess the effects of phosphorus addition on the phytoplankton community in Chaney Lake. Ten plastic-sided mesocosms were constructed and placed in the marsh area of the wetland at three different periods: early spring, early summer, and late summer. Phosphorus in the form of K2HPO4 …

Modeling Macrophytes Of The Columbia Slough, Oregon, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. It is a eutrophic water body susceptible to algae blooms and crashes and periods of high pH which violate water quality standards. High nutrient loads from groundwater principally controls algae productivity. Past structural changes to the Columbia Slough have included filling of wetlands and lakes and the construction of levees, dikes, culverts and irrigation channels. These changes have altered the natural flow dynamics creating an environment more conducive to eutrophication. …

A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury

Dissertations

Groundwater vulnerability to contamination from surface sources was evaluated for Nottawa Creek Watershed, Calhoun County Michigan using AQUIPRO and DRASTIC vulnerability methods. A geographic information system (GIS) was used to analyze and map the data. Forty groundwater samples were collected following a statistical sampling protocol from private wells. Samples were analyzed for nitrate-N and atrazine. Atrazine was not detected (detection limit 0.1 ppb) in any of the samples. Five samples contained detectable nitrate-N (detection limit 0.05 mg/L). Due to insufficient chemical data, the relative AQUIPRO and DRASTIC vulnerability scores could not be compared with the frequency of occurrences o f …

Close-Range And Satellite Remote Sensing Of Algal Biomass In The Iowa Great Lakes, Eric A. Wilson

Department of Geography: Dissertations, Theses, and Student Research

The utility of both close-range and satellite remote sensing for assessing inland water quality was examined in the Iowa Great Lakes. The water quality of this system is of considerable interest because of its status as an environmental, recreational, and therefore, economic resource. The broad range of optical conditions present in the lakes and the wealth of literature on the system make it an ideal environment for water quality remote sensing research. The goal of this research was to survey the water quality of the Iowa Great Lakes via remote sensing, evaluate different predictive algorithms, and map the distribution of …

Cheyenne County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 17, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test-holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies. Also included are logs of test-holes drilled by cooperators with the South Platte Natural Resources District.

The maps in this report …

Spatial Variability Of Climate And Past Atmospheric Circulation Patterns From Central West Antarctic Glaciochemistry, David B. Reusch, Paul Andrew Mayewski, Sallie I. Whitlow, Iqbal I. Pittalawa, Mark S. Twickler

Earth Science Faculty Scholarship

Atmospheric circulation patterns and the spatial variability of atmospheric chemistry and moisture transport in central West Antarctica are investigated using new 40 year long (1954–1994 A.D.) glaciochemical and accumulation rate records developed from four firn cores from this region. The core sites lie on a 200 km traverse from 82° 22′ S, 119° 17′ W to 81° 22′ S, 107° 17′ W. The glaciochemical records represent the major ionic species present in Antarctic snow: Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃⁻, and SO₄²⁻. High spatial …

Deuel County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 25, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies.

The map in this report shows the location of all test holes drilled in the county since 1942.

Present techniques …

Test-Hole Drilling Program In Nebraska, Duane R. Mohlman

Conservation and Survey Division

No abstract provided.

The Weddell Sea Region: An Important Precipitation Channel To The Interior Of The Antarctic Ice Sheet As Revealed By Glaciochemical Investigation Of Surface Snow Along The Longest Trans-Antarctic Route, Qin Dahe, Paul Andrew Mayewski, Ren Jiawen, Xiao Cunde, Sun Junying

Earth Science Faculty Scholarship

Glaciochemical analysis of surface snow samples, collected along a profile crossing the Antarctic ice sheet from the Larsen Ice Shelf, Antarctic Peninsula, via the Antarctic Plateau through South Pole, Vostok and Komsomolskaya to Mirny station (at the east margin of East Antarctica), shows that the Weddell Sea region is an important channel for air masses to the high plateau of the Antarctic ice sheet (>2000 m a.s.l.). This opinion is supported by the following. (1) The fluxes of sea-salt ions such as Na⁺, Mg²⁺ and Cl⁻ display a decreasing trend from the west to the …

Seasonal Variations Of Glaciochemical, Isotopic And Stratigraphic Properties In Siple Dome (Antarctica) Surface Snow, K. J. Kreutz, Paul Andrew Mayewski, M. S. Twickler, S. I. Whitlow, J. W.C. White, C. A. Shuman, C. F. Raymond, H. Conway, J. R. Mcconnell

Earth Science Faculty Scholarship

Six snow-pit records recovered from Siple Dome, West Antarctica, during 1994 are used to study seasonal variations in chemical (major ion and H2O2), isotopic (deuterium) and physical stratigraphic properties during the 1988-94 period. Comparison of dD measurements and satellite-derived brightness temperature for the Siple Dome area suggests that most seasonal dD maxima occur within ±4 weeks of each 1 January. Several other chemical species (H2O2, non-sea-salt (nss) SO42-, methanesulfonic acid and NO3-) show coeval peaks with dD, together providing an accurate method for identifying summer accumulation. Sea-salt-derived species generally peak during winter/spring, but episodic input is noted throughout some years. …

Climatological Significance Of Δ18O In Precipitation And Ice Cores: A Case Study At The Head Of The Ürütnqi River, Tien Shan, China, Hou Shugui, Qin Dahe, Paul Andrew Mayewski, Yang Qinzhao, Ren Jiawen, Li Zhongqin, Xiao Cunde

Earth Science Faculty Scholarship

Stable-oxygen-isotope ratios (δ¹⁸O) collected from the headwaters of the Ürümqi river, Tien Shan, China, were used to test the relationship between δ¹⁸O temporal relationship is found between δ¹⁸O monthly averages which remove synoptic-scale influences such as changes in condensation level, condensation temperature and moisture sources (Yao and others, 1996). Linear fits as high as 0.95‰°C^-1 for precipitation events and 1.23‰°C^-1 for monthly averages are found. Although the δ¹⁸O (∼2 km from the precipitation sampling site) decreased dramatically compared to the precipitation samples , the ice-core records of annually averaged δ …

The Effect Of Water Level Management On The Soils And Vegetation Of Two Coastal Louisiana Marshes, Brian J. Wilsey, K. M. Flynn, I. A. Mendelssohn

Brian J. Wilsey

Wetland degradation and loss is the result of a combination of natural causes and anthropogenic activities and is a serious problem in coastal Louisiana, where approximately 80% of the total US coastal wetland loss since the 1930’s has occurred. One method currently used to address this wetland loss problem is structural marsh management,which is the use of levees and water control structures to control hydroperiod. The effects of structural marsh management on two managed marshes in Southern Louisiana (Unit 4 of the Rockefeller Wildlife Refuge and the Fina LaTerre Mitigation Bank) were evaluated by comparing the soils and the dominant …

Monitoring The 1996 Drought Using The Standardized Precipitation Index, Michael J. Hayes, Mark D. Svoboda, Donald A. Wilhite, Olga V. Vanyarkho

Drought Mitigation Center: Faculty Publications

Droughts are difficult to detect and monitor. Drought indices, most commonly the Palmer Drought Severity Index (PDSI), have been used with limited success as operational drought monitoring tools and triggers for policy responses. Recently, a new index, the Standardized Precipitation Index (SPI), was developed to improve drought detection and monitoring capabilities. The SPI has several characteristics that are an improvement over previous indices, including its simplicity and temporal flexibility, that allow its application for water resources on all timescales. In this article, the 1996 drought in the southern plains and southwestern United States is examined using the SPI. A series …

Dawson County Test Hole Logs, Frank A. Smith

Conservation and Survey Division

No abstract provided.

Howard County Test Hole Logs, Vincent H. Dreeszen

Conservation and Survey Division

No abstract provided.

Kearney County Test Hole Logs, Scott E. Summerside

Conservation and Survey Division

No abstract provided.

Wayne County Test Hole Logs, Sue Olafsen Lackey, Frank A. Smith, Raymond R. Burchett

Conservation and Survey Division

No abstract provided.

Stanton County Test Hole Logs, Sue Olafsen Lackey, Frank A. Smith, Raymond R. Burchett

Conservation and Survey Division

No abstract provided.

Nitrate Attenuation In A Narrow Non-Forested Riparian Buffer Zone In An Agricultural Watershed In Southern Ontario, Mark David Harris

Theses and Dissertations (Comprehensive)

Riparian buffer zones are defined as strips of natural vegetation separating streams or lakes from surrounding upland landscapes. These zones may effectively reduce the nitrate-N load in shallow ground water draining intensively fertilized agricultural regions. Contemporary research has tended to focus on wide, forested riparian zones situated on poorly drained lowland sites. In addition, research has typically focused on the growing season, when the ecosystem is biologically active, with relatively day hydrological conditions. This field study monitored spatial and temporal patterns of nitrate-N in a comparatively narrow, non-forested buffer zone situated in an upland agricultural watershed in southern Ontario. Results …

Nitrate Reduction At The Groundwater - Salt Marsh Interface, Craig -1967 Tobias

Dissertations, Theses, and Masters Projects

The influence of groundwater discharge on the hydrology and biogeochemical cycling of nitrogen in a fringing intertidal wetland was studied by characterizing groundwater discharge, determining N-cycling rates in cores, and examining nitrate reduction in situ using 15N enrichment and natural gradient tracer techniques. Groundwater discharge was estimated by three independent methods: Darcy's Law, a water/salt mass balance, and a subsurface tracer test. Seasonal patterns of discharge predicted by Darcy's Law and the mass balance were similar. Discharge maxima and minima occurred in April and September, respectively. The water/salt mass balance provided the more reasonable estimate of groundwater flux at high …

Salinity And Hydrology Of The Fence Road Catchment : A Focus Catchment Of The Blackwood Basin, Ben Whitfield

Resource management technical reports

It is the clearing of native vegetation and replacement with lower water-use annual crops and pastures that is responsible for the developing salinity problem. Traditional farming practices have led to increased recharge to the groundwater systems resulting in increased storage and/or greater areas or rates of discharge. Groundwater monitoring has revealed variable rates of rise throughout the Fence Road catchment, from static to 0.6 metres per year, in a period of average to below average rainfall.

Morphometry And Limnology Of Ferguson Lake, Saline County, Arkansas, John D. Rickett, E. P. (Perk) Floyd

Journal of the Arkansas Academy of Science

To more fully understand Ferguson Lake as an ecosystem and eventually relate its water quality and production potential to fisheries management, several limnological variables were sampled monthly from April 1997 through March 1999. Vertical profiles of temperature and dissolved oxygen were recorded, and water samples from 0.5 m. depth were tested for turbidity, pH, total alkalinity, total hardness, ortho-phosphate, nitrate-nitrogen, sulfate, iron and specific conductance. Evaporation rate experiments, spillway discharge and rainfall records were used to estimate lake hydrology. Depth transects on the lake and USGS topographic maps were used to measure and calculate morphometric and watershed features. The lake …