Physical Sciences and Mathematics Commons^™

A Watershed-Based Classification System For Lakes In Agriculturally-Dominated Ecosystems: A Case Study Of Nebraska Reservoirs, Henry N. N. Bulley

Department of Geography: Dissertations, Theses, and Student Research

In recent decades substantial progress has been made in improving the quality of surface waters in the United States (Hawkins et al., 2000; EPA, 2000; EPA, 2001); nevertheless, much work remains to be done in assessing the state of impairment of lake waters. Impairment implies that the existing water quality of a lake, as measured by selected criteria (e.g., nitrogen, phosphorus, chlorophyll-a, Secchi depth), exceeds a threshold value or standard that presumably reflects optimal attainable lake water quality conditions (or "reference" conditions) (Hughes, 1995; EPA, 2000; EPA, 2001). Such impaired waters are not suitable for designated uses such as drinking, …

Patterns Of Early Lake Evolution In Boreal Landscapes: A Comparison Of Stratigraphic Inferences With A Modern Chronosequence In Glacier Bay, Alaska, Sherilyn C. Fritz, Daniel R. Engstrom, Stephen Juggins

Department of Earth and Atmospheric Sciences: Faculty Publications

The chronosequence approach, which infers temporal patterns of environmental change from a spatial array of modern sites, has been a major tool for studying successional processes. A model of early lake ontogeny in boreal landscapes, developed from a chronosequence of lakes in Alaska, suggests that long-term soil development and related hydrological change produce a loss of alkalinity and base cations, a decrease in pH, an increase in DOC and a transient increase followed by a decrease in lakewater nitrogen concentrations over time. We compare this model of lake ontogeny with patterns of change reconstructed from diatom assemblages in 10 sediment …

Low Marine Sulphate And Protracted Oxygenation Of The Proterozoic Biosphere, Linda C. Kah, Timothy W. Lyons, Tracy D. Frank

Department of Earth and Atmospheric Sciences: Faculty Publications

Progressive oxygenation of the Earth’s early biosphere is thought to have resulted in increased sulphide oxidation during continental weathering, leading to a corresponding increase in marine sulphate concentration. Accurate reconstruction of marine sulphate reservoir size is therefore important for interpreting the oxygenation history of early Earth environments. Few data, however, specifically constrain how sulphate concentrations may have changed during the Proterozoic era (2.5–0.54 Gyr ago). Prior to 2.2 Gyr ago, when oxygen began to accumulate in the Earth’s atmosphere, sulphate concentrations are inferred to have been <200 >μM, on the basis of limited isotopic variability preserved in sedimentary sulphides4 and experimental …

High Dispersal In A Frog Species Suggests That It Is Vulnerable To Habitat Fragmentation, W. Chris Funk, Allison E. Greene, Paul Stephen Corn, Fred W. Allendorf

United States Geological Survey: Staff Publications

Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disregarded as a cause of amphibian declines and conservation efforts can be focused elsewhere. We examined dispersal rates in Columbia spotted frogs (Rana luteiventris) using capture–recapture analysis of over …

Correction To ‘‘A Concept Of Maximum Stream Depletion Rate For Leaky Aquifers In Alluvial Valleys" By Vitaly A. Zlotnik, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

In the paper ‘‘A concept of maximum stream depletion rate for leaky aquifers in alluvial valleys’’ by Vitaly A. Zlotnik (Water Resources Research, 40(6), W06507, doi:10.1029/2003WR002932, 2004), equations (24), (25), (A11), and (A12) were published with typographical errors. The correct equations are published below.

Three-Dimensional Modeling Of Lacustrine Diatom Habitat Areas: Improving Paleolimnological Interpretation Of Planktic : Benthic Ratios, Jeffery R. Stone, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

Three-dimensional modeling of lake morphometry enables the calculation of lake volume, planar surface area, and basin surface area, which are critical components of a conceptual model of how planktic and benthic habitat areas change with changing lake level. We have applied three-dimensional modeling to Foy Lake, Montana, and compared model results of changing ratios of planktic and benthic habitat areas at all possible lake levels to sediment cores recovered from the lake. The model allows us to produce semiquantitative depth reconstructions and greatly improves lake-level reconstruction of this morphometrically complex basin. The conceptual model also was modified to examine the …

Impact Of Heterogeneity, Bed Forms, And Stream Curvature On Subchannel Hyporheic Exchange, M. Bayani Cardenas, J. L. Wilson, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

Advection through hyporheic zones (HZ) consisting of heterogeneous channel bend streambed deposits and their equivalent homogenous medium was investigated using finite difference groundwater flow and transport simulations and forward particle tracking. The top prescribed head boundary was varied in order to mimic various stream channel head distributions resulting from the presence of bed forms and channel curvature. Flux calculations show that heterogeneity causes significant additional HZ flux compared to an equivalent homogenous medium. However, the major cause of HZ flux is a spatially periodic (sinusoidal) head distribution along the boundary, representing the effect of bed forms. The additional influence of …

Efficacy Of Offshore Breakwater Structures In A Eutrophic Midwestern Reservoir, Larry D. Pape

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

No abstract provided.

Mesopredator Movement, Abundance, And Habitat Selection In The Rainwater Basins Of Nebraska, Christina J. Kocer

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

No abstract provided.

Systematics And Phylogeny Of Late Paleocene And Early Eocene Palaeoryctinae (Mammalia, Insectivora) From The Clarks Fork And Bighorn Basins, Wyoming, Jonathan I. Bloch, Ross Secord, Philip D. Gingerich

Department of Earth and Atmospheric Sciences: Faculty Publications

New specimens of Palaeoryctes punctatus from the middle Clarkforkian of the Clarks Fork Basin include a left dentary preserving the crowns of I₁-C₁, P₃, and M_1-2, with alveoli for P₂, P₄, and M₃. The lower dental formula, previously unknown for this species, is 3.1.3.3. A maxillary fragment preserves the crowns of a broken P⁴, complete M¹, and a broken M². Specimens previously referred to Palaeoryctes cf. P. punctatus and cf. Palaeoryctes sp. from the late Tiffanian are morphologically distinct and …

Lewis And Clark State Park Signs, Robert F. Diffendal Jr., Les Howard

School of Natural Resources: Faculty Publications

Bob Diffendal wrote text and Les Howard created maps for new Lewis and Clark signs at Ponca State Park on the Missouri River.

The Corps of Discovery led by Meriwether Lewis and William Clark reached what is now southeastern Nebraska on July 10, 1804. It arrived at the point on the Missouri River adjacent to what is now Ponca State Park on August 22, 1804; and entered fully into South Dakota on September 8, 1804. Over this span of nearly two months members of the expedition saw and described many geologic features. The locations of some of the more prominent …

Enhanced Marine Productivity Off Western North America During Warm Climate Intervals Of The Past 52 K.Y., J.D. Ortiz, S.B. O’Connell, J. Delviscio, W. Dean, J.D. Carriquiry, T. Marchitto, Y. Zheng, A. Van Geen

United States Geological Survey: Staff Publications

Studies of the Santa Barbara Basin off the coast of California have linked changes in its bottom-water oxygen content to millennial-scale climate changes as recorded by the oxygen isotope composition of Greenland ice. Through the use of detailed records from a sediment core collected off the Magdalena Margin of Baja California, Mexico, we demonstrate that this teleconnection predominantly arose from changes in marine productivity, rather than changes in ventilation of the North Pacific, as was originally proposed. One possible interpretation is that the modern balance of El Nino–La Nina conditions that favors a shallow nutricline and high productivity today and …

A Concept Of Maximum Stream Depletion Rate For Leaky Aquifers In Alluvial Valleys, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

Existing analytical models for evaluating stream depletion by wells in alluvial aquifers are based on the assumption that stream depletion supplies 100% of groundwater withdrawals. Analysis of specific hydrostratigraphic conditions in leaky aquifers indicates that stream depletion may range from 0 to 100%. A new concept of maximum stream depletion rate (MSDR) is introduced and defined as a maximum fraction of the pumping rate contributed by the stream depletion. Several new analytical solutions indicate that the MSDR is determined by aquifer hydrostratigraphic conditions, geometry of recharge and discharge zones, and locations of pumping wells.

Twentieth Century Water Quality Trends In Minnesota Lakes Compared With Presettlement Variability, Joy M. Ramstack, Sherilyn C. Fritz, Daniel R. Engstrom

Department of Earth and Atmospheric Sciences: Faculty Publications

Abstract: A diatom-based transfer function was used to reconstruct water chemistry before European settlement in 55 Minnesota lakes. The lakes span three natural ecoregions, which differ in their history of land use, as well as in surficial geology, climate, and vegetation. Postsettlement trends were compared with water chemistry change reconstructed from two presettlement core sections (circa 1750 and 1800) as a measure of natural variability. Presettlement water quality changes were generally small and nondirectional in all three ecoregions. In contrast, half of the urban lakes showed a statistically significant increase in chloride, whereas 30% of urban and 30% of agricultural …

What Does It Take To Get Tenure?, Annabelle Foos, Mary Anne Holmes, Suzanne O'Connell

Department of Earth and Atmospheric Sciences: Faculty Publications

Data from the National Science Foundation and the American Geological Institute indicate that women geoscientists remain underrepresented at all levels in academia. In addition, the proportion of women geoscience faculty declines with increasing rank, from around 20 percent as assistant professors to 5 percent as full professors.

In 2001, we began a project to collect information that can help mentor women faculty early in their geoscience careers and improve their chances of obtaining tenure. We also wanted to provide institutions with information on retention, tenure and promotion procedures and criteria as they are practiced across the country.

Tropical Westerlies Over Pangaean Sand Seas, David B. Loope, Maureen B. Steiner, Clinton M. Rowe, Nicholas Lancaster

Department of Earth and Atmospheric Sciences: Faculty Publications

Cross-equatorial, westerly winds are key features of tropical circulation in monsoonal regions. Although prominent in numerical climate models of Pangaea (the supercontinent straddling earth’s equator, Late Paleozoic to Early Mesozoic), such flow has not been confirmed previously by migration directions of ancient dunes. Windblown sandstones that span 100 million years of earth history are widely exposed in south-western USA. If recent paleomagnetic data from the Colorado Plateau are used to correct Mesozoic paleogeographic maps, the Plateau is placed about 10° further south than previously assumed, and the prevailing north-westerly surface winds recorded by dune-deposited sandstones are explicable as cross-equatorial westerlies …

Keith County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 51, Robert F. Diffendal Jr., James W. Goeke

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the U.S. 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 maps in this report show the locations of all test holes drilled in the county since 1934.

Present techniques of …

Prairie Wetlands Are Important For Carbon Storage, Jay Hestbeck

Publications of the US Geological Survey

USGS’s Northern Prairie Wildlife Research Center and USDA’s Agricultural Research Service collaborated to study the potential of prairie pothole region wetlands to sequester carbon emitted into the atmosphere from the burning of fossil fuels. Results suggest that wetlands traditionally functioned as sinks for atmospheric carbon, but cultivation, the current principal land use, has shifted their function to be sources of atmospheric carbon. Data suggest that equal or greater amounts of atmospheric carbon can be stored in wetlands through restoration programs when compared with cropland, even though the acreage of wetlands is much smaller. These restored wetlands will also provide improved …

Characterization Of Ground-Water Quality, Upper Republican Natural Resources District, Nebraska, 1998–2001, Jill D. Frankforter, Daniele T. Chafin

Publications of the US Geological Survey

Nearly all rural inhabitants and livestock in the Upper Republican Natural Resources District (URNRD) in southwestern Nebraska use ground water that can be affected by elevated nitrate concentrations. The development of ground-water irrigation in this area has increased the vulnerability of ground water to the introduction of fertilizers and other agricultural chemicals. In 1998, the U.S. Geological Survey, in cooperation with the Upper Republican Natural Resources District, began a study to characterize the quality of ground water in the Upper Republican Natural Resources District area with respect to physical properties and concentrations of major ions, coliform bacteria, nitrate, and pesticides, …

Stream Bank Stability In Eastern Nebraska, Philip J. Soenksen, Mary J. Turner, Benjamin J. Dietsch, Andrew Simon

Publications of the US Geological Survey

Dredged and straightened channels in eastern Nebraska have experienced degradation leading to channel widening by bank failure. Degradation has progressed headward and affected the drainage systems upstream from the modified reaches. This report describes a study that was undertaken to analyze bank stability at selected sites in eastern Nebraska and develop a simplified method for estimating the stability of banks at future study sites. Bank cross sections along straight reaches of channel and geotechnical data were collected at approximately 150 sites in 26 counties of eastern Nebraska. The sites were categorized into three groups based on mapped soil permeability. With …

Geomorphic And Environmental Change Around A Large, Aging Reservoir: Lake C. W. Mcconaughy, Western Nebraska, Usa, R. Matthew Joeckel, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lake C. W. McConaughy, a 63-year-old manmade reservoir in the North Platte Valley of western Nebraska, is the largest standing body of water in the state. From the time that Kingsley Dam was completed in 1941 until the present day (2004), many geomorphic and environmental changes have occurred along the shores and within the North Platte Valley. Erosion on the southeastern shoreline of the lake had been perceived as a problem for landowners and managers for at least three decades, but the full scale of erosion was revealed only after a cumulative 18-m drawdown in lake level: bedrock platforms, extending …

Geology And Paleontology Of The Upper John Day Beds, John Day River Valley, Oregon: Lithostratigraphic And Biochronologic Revision In The Haystack Valley And Kimberly Areas (Kimberly And Mt. Misery Quadrangles), Robert M. Hunt Jr., Ellen Stepleton

Department of Earth and Atmospheric Sciences: Faculty Publications

The John Day Formation of north-central Oregon preserves a succession of speciose, superposed Oligocene through early Miocene mammalian faunas that establish the sequence of mid-Cenozoic mammalian evolution within the Pacific Northwest. Upper John Day rock units initially described by Merriam (1900, 1901) in the Kimberly and Haystack Valley areas were later divided into lower (Kimberly) and upper (Haystack Valley) members by Fisher and Rensberger (1972). We focused our study on the lithostratigraphic succession within the Haystack Valley Member. Rocks previously included in the Haystack Valley Member can be subdivided into four unconformity-bounded, genetic lithostratigraphic units that range in age from …

Do Meteorologists Suppress Thunderstorms? Radar-Derived Statistics And The Behavior Of Moist Convection, Matthew D. Parker, Jason C. Knievel

Department of Earth and Atmospheric Sciences: Faculty Publications

Most meteorologists are acquainted with the notion of a weather hole—that is, a place that receives less exciting weather than does its surroundings. Exciting weather takes many forms, but when people use the term weather hole, they tend to mean a place that thunderstorms often barely miss, or near which approaching storms often dissipate. For this paper, that is the meaning we adopt.

In our experience, many meteorologists and lay weather enthusiasts genuinely believe that they live in weather holes, and this belief, almost without fail, seems to stem from countless hours spent gazing at displays of radar reflectivity. We …

Paleocene Cyclic Sedimentation In The Western North Atlantic, Odp Site 1051, Blake Nose, Mary Anne Holmes, David K. Watkins, Richard D. Norris

Department of Earth and Atmospheric Sciences: Faculty Publications

Upper Paleocene (zone CP8b) cyclic sediment from Ocean Drilling Program (ODP) Site 1051 on Blake Nose, western North Atlantic, alternates from white carbonate-rich to green carbonate-poor in response to precessional forcing. Compositional differences between the two bed types are minor: mineral and nannofossil composition of the beds vary subtly, but grain size of the terrigenous component and biogenic silica content remain constant. Iron content determined by sediment magnetic susceptibility and iron intensity determined by a core-scanning XRF correlates negatively with carbonate content and are higher in green beds. Kaolinite content of green beds is slightly higher as well. Green beds …

Federal Listing Of Prairie Grouse: Lessons From The Attwater’S Prairie Chicken, Michael Morrow, Terry A. Rossignol, Nova J. Silvy

United States Geological Survey: Staff Publications

Considerable controversy has often surrounded proposals to confer official status (i.e., list) species under the authority of the Endangered Species Act (ESA) of 1973 as amended or its precursors. Recent proposals to list the lesser prairie-chicken (Tympanuchus pallidicinctus), the western sage grouse (Centrocercus urophasianus phaios), and the Gunnison sage grouse (C. minimus) were met with strong opposition by those concerned with prospects of an increased regulatory environment associated with such an action. The Attwater's prairie-chicken (T. cupido attwateri) was one of the first species listed under The Endangered Species Conservation Act of …

Hydrologic Variation During The Last 170,000 Years In The Southern Hemisphere Tropics Of South America, Sherilyn C. Fritz, Paul A. Baker, Tim K. Lowenstein, Geoffrey O. Seltzer, Catherine A. Rigsby, Gary S. Dwyer, Pedro M. Tapia, Kimberly K. Arnold, Teh-Lung Ku, Shangde Luo

Department of Earth and Atmospheric Sciences: Faculty Publications

Despite the hypothesized importance of the tropics in the global climate system, few tropical paleoclimatic records extend to periods earlier than the last glacial maximum (LGM), about 20,000 years before present. We present a well-dated 170,000-year time series of hydrologic variation from the southern hemisphere tropics of South America that extends from modern times through most of the penultimate glacial period. Alternating mud and salt units in a core from Salar de Uyuni, Bolivia reflect alternations between wet and dry periods. The most striking feature of the sequence is that the duration of paleolakes increased in the late Quaternary. This …

National Water Quality Inventory: Report To Congress 2004 Reporting Cycle

United States Environmental Protection Agency: Staff Publications

Table of Contents

Section Page

List of Figures.............................................................................................................................iv List of Tables...............................................................................................................................iv List of Acronyms..........................................................................................................................v Executive Summary..........................................................................................................................1

I. Background...................................................................................................................5

About the Water Quality Assessment and TMDL Information Database (ATTAINS)..........................................................................................................................5

Assessing Water Quality................................................................................................................................7

II. Findings.......................................................................................................................13 Rivers and Streams...........................................................................................................................13 Lakes, Ponds, and Reservoirs.......................................................................................................................16

Bays and Estuaries.........................................................................................................................20 Other Waters..............................................................................................................................23 Coastal Resources.......................................................................................................................23

Great Lakes.....................................................................................................................24 Wetlands..........................................................................................................................24

III. Probability Surveys of Water Quality.......................................................................26

National Coastal Assessment....................................................................................26

The Wadeable Streams Assessment.......................................................................27

Survey of the Nation’s Lakes.......................................................................................29

National Rivers and Streams Assessment.............................................................30

National Wetland Condition Assessment...............................................................30

State-Scale Statistical Surveys..................................................................................31

South Carolina..............................................................................................................32 Indiana............................................................................................................................33 Florida.............................................................................................................................34 IV. Future Reporting......................................................................................................36

V. References………………………………………………………………………….37

Mammals Of Carlsbad Caverns National Park, New Mexico, Kenneth N. Geluso, Keith Geluso

Bulletin of the University of Nebraska State Museum

Carlsbad Cavern was established as a national park on 14 May 1930, after being designated as a national monument for nearly seven years. The park is located in southeastern New Mexico, and today it encompasses 189.3 km² (73.1 mi²). Eighty-eight percent of the park lies in the rugged Guadalupe Mountains, while 12% is located on relatively flat land along the base of the mountains. The park contains a variety of habitats ranging from desert scrub at the lowest elevations to coniferous woodlands on the highest summits. Five months after Carlsbad Cavern was declared a national monument, Vernon …

An Agricultural Drought Risk-Assessment Model For Corn And Soybeans, Hong Wu, Kenneth G. Hubbard, Donald A. Wilhite

Drought Mitigation Center: Faculty Publications

Copyright © 2004 Royal Meteorological Society. Published by Wiley InterScience. Used by permis-sion.

Holocene Loess Deposition And Soil Formation As Competing Processes, Matanuska Valley, Southern Alaska, Daniel R. Muhs, John P. Mcgeehin, Jossh Beann, Eric Fisher

United States Geological Survey: Staff Publications

Although loess–paleosol sequences are among the most important records of Quaternary climate change and past dust deposition cycles, few modern examples of such sedimentation systems have been studied. Stratigraphic studies and 22 new accelerator mass spectrometry radiocarbon ages from the Matanuska Valley in southern Alaska show that loess deposition there began sometime after ~6500 ¹⁴C yr B.P. and has continued to the present. The silts are produced through grinding by the Matanuska and Knik glaciers, deposited as outwash, entrained by strong winds, and redeposited as loess. Over a downwind distance of ~40 km, loess thickness, sand content, and sand-pluscoarse- …