Digital Commons Network^™

Methyl Bromide In Preindustrial Air: Measurements From An Antarctic Ice Core, Eric S. Saltzman, Murat Aydin, Warren J. De Bruyn, Daniel B. King, Shari A. Yvon-Lewis

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

This paper presents the first ice core measurements of methyl bromide (CH3Br). Samples from a shallow Antarctic ice core (Siple Dome, West Antarctica), ranging in mean gas dates from 1671 to 1942, had a mean CH3Br mixing ratio of 5.8 ppt. These results extend the existing historical record derived from air and Antarctic firn air to about 350 years before present. Model simulations illustrate that the ice core results are consistent with estimates of the impact of anthropogenic activity ( fumigation, combustion, and biomass burning) on the atmospheric CH3Br burden, given the large current uncertainties in the modern atmospheric CH3Br …

Improving Nutrient Management At Lake Joondalup, Western Australia, Through Identification Of Key Sources And Current Trajectories, Michelle Cumbers

Theses : Honours

Eutrophication has become a considerable issue for managers of water bodies across Australia. Rapid urbanisation in the south-west of Western Australia is causing the eutrophication of many wetlands within the region. Lake Joondalup is a eutrophic, urban lake, located approximately 20km north of Perth city. It comprises part of the Yellagonga Regional Park, having a high conservation value. The aim of this study was to provide managers of Lake Joondalup with information on the relative importance of different nutrient sources into the lake, thus enabling the development of appropriate management strategies. Additionally, a historical examination of available water quality data …

In-Situ Apparent Conductivity Measurements And Microbial Population Distribution At A Hydrocarbon-Contaminated Site, Estella A. Atekwana, D. Dale Werkema, Joseph W. Duris, Silvia Rossbach, Eliot A. Atekwana, William A. Sauck, Daniel P. Cassidy, Jay Means, Franklyn D. Legall

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We investigated the bulk electrical conductivity and microbial population distribution in sediments at a site contaminated with light nonaqueous-phase liquid (LNAPL). The bulk conductivity was measured using in-situ vertical resistivity probes; the most probable number method was used to characterize the spatial distribution of aerobic heterotrophic and oil-degrading microbial populations. The purpose of this study was to assess if high conductivity observed at aged LNAPL-impacted sites may be related to microbial degradation of LNAPL. The results show higher bulk conductivity coincident with LNAPL-impacted zones, in contrast to geoelectrical models that predict lower conductivity in such zones. The highest bulk conductivity …

Modeling The Hydrogeochemistry Of Denitrification In The Elk Valley Aquifer, Paul A. Skubinna

Theses and Dissertations

Nitrate (NO₃¯) in groundwater has become an important tissue in the last few decades. It is known to cause methemoglobinemia, commonly known as “blue baby syndrome,” and is suspected of being a carcinogen. The most common sources for dissolved NO₃¯ in shallow groundwater include excessive application of nitrogenous fertilizers, misuse of septic systems, improper disposal of domestic wastewater or sludge, and livestock waste.

Denitrification is the most effective sink for NO₃¯. The Elk Valley aquifer (EVA) of eastern North Dakota is known to support denitrification. The objective of this study was to gain a better understanding of the geochemical processes …

Great Plains Ecosystems: Past, Present, And Future, Fred B. Samson, Fritz L. Knopf, Wayne Ostlie

United States Geological Survey: Staff Publications

Little questions exists that the main bodies of North American prairie (i.e., the tall-grass, mixed, and shortgrass) are among the most endangered resources on the continent. The purpose of this paper is to provide a past and present biological base- line by which to understand North American prairies and to provide a platform for future conservation. Events both immediate to the end of the Pleistocene and historic suggest that the present grassland conditions are different from those within which most of the grassland organisms evolved. Our analysis suggests that few grassland landscapes remain adequate in area and distribution to sustain …

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 …

History Of Greater Sage-Grouse In The Dakotas: Distribution And Population Trends, Joe T. Smith, Lester D. Flake, Kenneth F. Higgins, Gerald D. Kobriger

United States Geological Survey: Staff Publications

The greater sage-grouse (Centrocercus urophasianus) has declined throughout its range and its status is of major concern to federal, state, and provincial wildlife agencies. We collected information on current and historical greater sage-grouse distribution and lek activity in western North and South Dakota. A steady decline in lek attendance by males occurred over the entire recorded period in North Dakota (1951-2002) and South Dakota (1972-2002). There was no apparent change in numbers of known active leks due to discovery of new leks, but there was an abandonment of regions once occupied by active leks.

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 …

High Resolution Paleoceanography Of The Guaymas Basin, Gulf Of California, During The Past 15 000 Years, John A. Barron, David Bukry, James L. Bischoff

United States Geological Survey: Staff Publications

Deep Sea Drilling Project Site 480 (27°54.10’N, 111°39.34’W; 655 m water depth) contains a high resolution record of paleoceanographic change of the past 15 000 years for the Guaymas Basin, a region of very high diatom productivity within the central Gulf of California. Analyses of diatoms and silicoflagellates were completed on samples spaced every 40-50 yr, whereas ICP-AES geochemical analyses were completed on alternate samples (sample spacing 80-100 yr). The Bolling-Allerod interval (14.6-12.9 ka) (note, ka refers to 1000 calendar years BP throughout this report) is characterized by an increase in biogenic silica and a decline in calcium carbonate relative …

The History Of Recent Limnological Changes And Human Impact On Upper Klamath Lake, Oregon, J. Platt Bradbury, Steven M. Colman, Richard L. Reynolds

United States Geological Survey: Staff Publications

Hypereutrophic Upper Klamath Lake has been studied for almost 50 years to evaluate the nature, cause, and effects of its very productive waters. Mitigation of undesirable effects of massive cyanobacterial blooms requires understanding their modern causes as well as their history. Knowledge of the pre-settlement natural limnology of this system can provide guidelines for lake restoration and management of land and water use strategies to maximize the benefits of this aquatic resource. This investigation uses a paleolimnological approach to document the nature and chronology of limnological and biological changes in Upper Klamath Lake for the past 200 years, covering the …

Geochemical Cycles In Sediments Deposited On The Slopes Of The Guaymas And Carmen Basins Of The Gulf Of California Over The Last 180 Years, Walter E. Dean, Carol Prideb, Robert Thunell

United States Geological Survey: Staff Publications

Sediments deposited on the slopes of the Guaymas and Carmen Basins in the central Gulf of California were recovered in two box cores. Q-mode factor analyses identified detrital-clastic, carbonate, and redox associations in the elemental composition of these sediments. The detrital-clastic fraction appears to contain two source components, a more mafic component presumably derived from the Sierra Madre Occidental along the west coast of Mexico, and a more felsic component most likely derived from sedimentary rocks (mostly sandstones) of the Colorado Plateau and delivered by the Colorado River. The sediments also contain significant siliceous biogenic components and minor calcareous biogenic …

Genetic Identification Of Spotted Owls, Barred Owls, And Their Hybrids: Legal Implications Of Hybrid Identity, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman, Pepper W. Trail, Liv Wennerberg

United States Geological Survey: Staff Publications

Recent population expansion of Barred Owls (Strix varia) into western North America has led to concern that they may compete with and further harm the Northern Spotted Owl (S. occidentalis caurina), which is already listed as threatened under the U.S. Endangered Species Act (ESA). Because they hybridize, there is a legal need under the ESA for forensic identification of both species and their hybrids. We used mitochondrial control-region DNA and amplified fragment-length polymorphism (AFLP) analyses to assess maternal and biparental gene flow in this hybridization process. Mitochondrial DNA sequences (524 base pairs) indicated large divergence between …

Sedimentological And Geochemical Characterization Of East Pond, Belgrade Lakes Watershed, Central Maine, Robin H. Nesbeda

Honors Theses

The present study focuses on East Pond, the head of the lake-chain system. East Pond is roughly oval in shape with several coves along the margins; it has an average 3 depth of 4.5 m, a maximum depth of 7.3 m, and a total volume of 26.35 x 10 6 m . The lake is surrounded by North temperate hardwood forest and a marshy outlet to the other lakes exists in the northwest comer. East Pond has suffered severe yearly algal blooms during the late summer and into the fall since 1993. This project aims to develop a baseline for …

Paranthropus Paleobiology, Paul J. Constantino, Bernard A. Wood

Biological Sciences Faculty Research

No abstract provided.

A Comparison Of Land Use And Nonpoint Source Pollution In The Cedar River Tributaries In Iowa, Chad Levi Fields

Dissertations and Theses @ UNI

A comparative water analysis on major Cedar River tributaries was conducted to determine nutrient and sediment concentration, nutrient loads, and watershed land use during the spring and summer of 2002. The Cedar River watershed is located on a primarily agricultural land, and has a drainage area of20,242 km2. The watershed extends from southern Minnesota to southeastern Iowa, where it joins the Iowa River which subsequently flows into the Mississippi River. Past studies have concluded that the Cedar River contributes much of the nutrients entering the Mississippi River and the Gulf of Mexico. These nutrients then contribute to the zone of …

Effects Of Vegetation Removal On Native Soil Quality In Eastern Arkansas, Lorena Moreno, Kristofor R. Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Aboveground vegetation removal practices, such as cutting and baling and burning, can both positively and negatively affect a prairie ecosystem. Burning can stimulate growth and species diversity, but removing vegetation and the nutrients it contains without equal replenishment of those nutrients could cause a steady decline in available soil nutrients. The objective of this study was to evaluate the effects of vegetation removal techniques in a native tallgrass prairie in east-central Arkansas. Soil samples were collected from the top 10 cm in each soil mapping unit that existed in each of three prairie areas that differed by the amount of …

Estimation Of Primary Production And Carbon Flux In Antarctic Coastal Waters: A Modeling Study, Hae-Cheol Kim

OES Theses and Dissertations

This study presents results from models that are designed to simulate the underwater light field, to simulate phytoplankton primary production, and to estimate the fate of phytoplankton carbon in continental shelf waters of the west Antarctic Peninsula (WAP) and Ross Sea. Simulation of the underwater light field required derivation of new coefficient sets for power function-type cloud cover correction algorithms, which were found to be influenced by multiple reflections between the bottom of clouds and the surface. The coefficient sets indicate that the spectral effect of clouds on the properties of the surface irradiance was spectrally-neutral for wavelengths greater than …

An Investigation Of Dissolved Organic Matter In A Shallow Coastal Bay Subject To Aureococcus Anophagefferens Blooms, Jean-Paul Simjouw

OES Theses and Dissertations

Aureococcus anophagefferens, the pelagophyte responsible for brown tide blooms, was identified in Chincoteague Bay in 1997 and has “bloomed” there since at least 1998. Aureococcus anophagefferens is capable of using dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) substrates to support growth, and this utilization is hypothesized to give the organism a competitive advantage relative to other phytoplankton when inorganic nutrient concentrations are low or depleted. Because previous studies suggest dissolved organic matter (DOM) is important in initiating and sustaining brown tide blooms, a field study of the variations in DOC concentration and DOM composition was performed at …

Metal Concentrations In Sediment And Fish Of Lake Victoria Near And Away From Catchments With Gold Mining Acctivities, Jf Machiwa

Tanzania Journal of Science

Concentrations of metals in sediment and fish as well as organic matter contents of sediment from Lake Victoria were investigated. The objective of the study was to compare levels of metals in sediment and fish from areas of the lake that are within and outside catchments with gold mining activities.The results showed that the concentration of As was less than 6 mg g-1 dw and Cd was below 1.9 mg g-1 dw in sediment samples. Lead, zinc and copper concentrations were highest (58.1±17.6 mg g-1 dw, 101.9±20.6 mg g-1 dw and 32.6±2.8 mg g-1 dw respectively) in sediment samples that …

Lewis And Clark And The Geology Of Nebraska And Parts Of Adjacent States, Robert F. Diffendal Jr., Anne P. Diffendal

School of Natural Resources: Faculty Publications

Meriwether Lewis and William Clark undertook their journey with the Corps of Discovery in 1804–1806 in order to explore the area that the United States had purchased from France in 1803. Then known as Louisiana, this region included almost everything west of the Mississippi to the continental divide (illustrated below). In order to find the best route across the continent, President Thomas Jefferson charged Lewis to follow the Missouri River to its headwaters and then locate rivers flowing down the west side of the Rocky Mountains to the Columbia River and into the Pacific Ocean. Jefferson's written instructions further specified …

Where Are The Women Geoscientist Professors?, Mary Anne Holmes, Suzanne O'Connell

Department of Earth and Atmospheric Sciences: Faculty Publications

Nearly 50 geo- and social scientists recently gathered for a workshop on women in the geosciences. The two-fold purpose was to compile data on the status of women in the geosciences, and to arrive at a consensus on strategies to increase the proportion of women and their diversity in the field. The Workshop on Women in the Geosciences was held September 25-27, 2003, in Washington, D.C.

New Studies Initiated By The U.S. Geological Survey: Effects Of Nutrient Enrichment On Stream Ecosystems, Mark D. Munn, Pixie A. Hamilton

United States Geological Survey: Publications

In 2001, the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program began an intensive study of nutrient enrichment—elevated concentrations of nitrogen and phosphorus— in streams in five agricultural basins across the Nation (see map, p. 2). This study is providing nationally consistent and comparable data and analyses of nutrient conditions, including how these conditions vary as a result of natural and human-related factors, and how nutrient conditions affect algae and other biological communities. This information will benefit stakeholders, including the U.S. Environmental Protection Agency (USEPA) and its partners, who are developing nutrient criteria to protect the aquatic health of streams …

Effect Of Heavy Metals On Bacteria, Elena Vratonjic

Theses and Dissertations

Heavy metals have become devastating environmental contaminants due to their widespread use in the manufacture of electronics, plastics, batteries and dyes. The discharge of heavy metals into the environment has caused concern about their effects on the ecosystem. Many metals are essential for growth in small amounts. However, at higher concentrations heavy metals are toxic because they bind to organic compounds. This accounts for their effects on some important parts of the cell structure, like their ability to denature protein molecules. The initial objective of this study was to find out the growth rate of E.coli and M.roseus in the …

Laboratory Testing Of Select Geotextiles As Biointrusion Barriers And Sediment Filters, David R. Beck

Masters Theses

It has been proposed that placing a geotextile over sediments with adsorbed contaminants can prevent bioaccumulation of the contaminants in larger animals by isolating the benthic organisms living within these sediments from fish. In conjunction with a field study carried out at Gull Creek, a laboratory study testing two geotextiles as biointrusion barriers and sediment filters was conducted.

Constant-head permeameters were run for seven days using cores from the field study area with a geotextile placed over the cores. For biointrusion barrier tests, medium sand was placed over the geotextile and spiked with nutrients. Following each trial, benthic organisms in …

Using Spreadsheets In Geoscience Education: Survey And Annotated Bibliography Of Articles In The Journal Of Geoscience Education Through 2003, Beth Fratesi, H. L. Vacher

School of Geosciences Faculty and Staff Publications

Thirty-eight papers published in the Journal of Geoscience Education ( JGE) from 1989 through 2003 explicitly use or recommend the use of spreadsheets as part of classroom or field exercises, projects, or entire courses. Many of the papers include the spreadsheets, and some include the equations. The papers demonstrate how spreadsheets allow students to explore a subject through problem-oriented, interactive, and quantitative exercises. We provide an annotated bibliography and classify the 38 JGE papers by spreadsheet use, mathematics skill area, and geologic subdiscipline. Our discussion of five selected articles — abundance of elements in the Earth’s crust; directional properties of …

Body Mass Of Late Quaternary Mammals (Data Set), Felisa A. Smith, S. Kathleen Lyons, S.K. Morgan Ernest, Kate E. Jones, Kansas State University, Tamar Dayan, Pablo A. Marquet, James H. Brown, John P. Haskell

School of Biological Sciences: Faculty Publications

The purpose of this data set was to compile body mass information for all mammals on Earth so that we could investigate the patterns of body mass seen across geographic and taxonomic space and evolutionary time. We were interested in the heritability of body size across taxonomic groups (How conserved is body mass within a genus, family, and order?), in the overall pattern of body mass across continents (Do the moments and other descriptive statistics remain the same across geographic space?), and over evolutionary time (How quickly did body mass patterns iterate on the patterns seen today? Were the Pleistocene …

Ancient Maize From Chacoan Great Houses: Where Was It Grown?, Larry Benson, Linda Cordell, Kirk Vincent, Howard E. Taylor, John Stein, G. Lang Farmer, U.S. Geological Survey

United States Geological Survey: Staff Publications

In this article, we compare chemical (⁸⁷Sr/⁸⁶Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in …

Geogram 2003, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

Moore River : Catchment Appraisal 2003, A Alderman, M Clarke, Natural Heritage Trust (Australia), Moore River Catchment Support Team (Wa)

Resource management technical reports

Using the Rapid Catchment Appraisal process, this report summarises current information for the Moore River catchment, Western Australia. The headwaters of the Moore River commence in Perenjori, Carnamah and Dalwallinu shires and drain southwards through Moora.

Earth News, V27, Fall 2003, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Earth Science Staff Activities
--- Earth Science Majors
--- 2002 Earth Science Graduates
--- Student Internships
--- Student Research Presentations
--- STORM Project Team
--- Earth Science Seminar Series
--- Sigma Gamma Epsilon - Gamma Sigma Chapter
--- Gifts to the Department of Earth Science
--- 2003-2004 Scholarship and Award Recipients
--- Spring Break 2003 Field Course: Geology and Natural History of Big Bend National Park
--- Earth Science Alumni News