Digital Commons Network^™

Limitation Of Algal Growth By Iron Deficiency In The Australian Subantarctic Region, Peter N. Sedwick, Giacomo R. Ditullio, David A. Hutchins, Philip W. Boyd, F. Brian Griffiths, A. Clive Crossley, Thomas W. Trull, Bernard Queguiner

OES Faculty Publications

In March 1998 we measured iron in the upper water column and conducted iron- and nutrient-enrichment bottle-incubation experiments in the open-ocean Subantarctic region southwest of Tasmania, Australia. In the Subtropical Convergence Zone (∼42°S, 142°E), silicic acid concentrations were low (< 1.5μM) in the upper water column, whereas pronounced vertical gradients in dissolved iron concentration (0.12-0.84 nM) were observed., presumably reflecting the interleaving of Subtropical and Subantarctic waters, and mineral aerosol input. Results of a bottle-incubation experiment performed at this location indicate that phytoplankton growth rates were limited by iron deficiency within the iron-poor layer of the euphotic zone. In the Subantarctic water mass (∼46.8°S, 142°E), low concentrations of dissolved iron (0.05-0.11nM) and silicic acid (< 1μM) were measured throughout the upper water column, and our experimental results indicate that algal growth was limited by iron deficiency. These observations suggest that availability of dissolved iron is a primary factor limiting phytoplankton growth over much of the Subantarctic Southern Ocean in the late summer and autumn.

A Geomorphology Of Megaliths: Neolithic Landscapes In The Alto Alentejo, Portugal, Gregory A. Pope, Vera C. Miranda

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Alentejo region of Portugal is known for a high concentration of Neolithic-aged megalithic monuments: tombs (dolmens or antas) and ceremonial features such as standing stones (menhirs) and stone circles (cromleques). Concentrations of these monuments tend to be found on or near weathered granite terrains. Unloading slabs and remnant corestones appear to be the stones of preference for megalith makers in the Alentejo district of Portugal. Some of the stones may have been imported from distant sources, but most appear to be of local origin. In general, most stones do not appear to have been altered much from their original …

The Carbon Cycle And Biogeochemical Dynamics In Lake Sediments, Walter E. Dean

United States Geological Survey: Staff Publications

The concentrations of organic carbon (OC) and CaCO₃ in lake sediments are often inversely related. This relation occurs in surface sediments from different locations in the same lake, surface sediments from different lakes, and with depth in Holocene sediments. Where data on accumulation rates are available, the relation holds for organic carbon and CaCO₃ accumulation rates as well. An increase of several percent OC is accompanied by a decrease of several tens of percent CaCO₃ indicating that the inverse relation is not due to simple dilution of one component by another. It appears from core data that …

Negative Ph, Efflorescent Mineralogy, And Consequences For Environmental Restoration At The Iron Mountain Superfund Site, California, D. Kirk Nordstrom, Charles N. Alpers

United States Geological Survey: Staff Publications

The Richmond Mine of the Iron Mountain copper deposit contains some of the most acid mine waters ever reported. Values of pH have been measured as low as -3.6, combined metal concentrations as high as 200 g/liter, and sulfate concentrations as high as 760 g/liter. Copious quantities of soluble metal sulfate salts such as melanterite, chalcanthite, coquimbite, rhomboclase, voltaite, copiapite, and halotrichite have been identified, and some of these are forming from negative-pH mine waters. Geochemical calculations show that, under a mine-plugging remediation scenario, these salts would dissolve and the resultant 600,000-m³ mine pool would have a pH of …

In-Situ Measurement Of Denitrification In The Elk Valley Aquifer, Allen Schlag

Theses and Dissertations

Groundwater serves more than half of North Dakota's population as a drinking water source. Nitrate (NO₃¯) is a common groundwater contaminant associated with fertilizers, septic systems and livestock waste in shallow unconfined aquifers. As a suspected carcinogen and cause of potentially lethal methemoglobinemia in infants, the natural attenuation of NO₃¯ by denitrification can be an important process in keeping groundwater as a reliable source of clean drinking water for North Dakota. Organic carbon is often considered the most important electron donor for the chemical reduction of NO₃¯ into harmless nitrogen gas. However, several studies have shown that inorganic electron donors …

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 …

The Use Of Bauxite Residue As A Soil Amendment In The Peel -Harvey Coastal Plain Catchment - Environmental Monitoring Report August 1999, Mark Rivers

Natural resources published reports

The Peel-Harvey Coastal Plain Catchment is located immediately south of Perth in Western Australia and covers approximately 190,000 ha. It extends from Forrestdale in the north to Harvey in the south, and west from the Darling Scarp to Mandurah on the coast. The boundary of the catchment, as illustrated in Figure 1, represents the area which has been approved by the DEP for the broadscale application of Alkaloam as a soil amendment. (This figure also indicates features and regions of importance in this project).

The region experiences a Mediterranean climate with hot, dry summers and mild, wet winters with most …

Avon And Upper Hotham Region Natural Resource Atlas, Sarah Weaving, Jason Batory

All other publications

The Avon and Upper Hotham Region Atlas is one of a series of Natural Resource Atlases covering the agricultural region of Western Australia. The purpose of the Atlas is to provide data for local people who manage or have an interest in natural resources. This includes the members of Land Conservation District Committees (LCDC), catchment groups, local government, non-government organisations, conservation groups, schools and libraries.

The aim of this publication is to bring together land and natural resource information from a number of sources and present it in a clear and accessible way. The data covers a number of topics …

Surface Features Of The Salt Basin Of Lancaster County, Nebraska, R. M. Joeckel, B. A. Clement

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Atrazine Degradation In A Small Stream In Iowa, Dana W. Kolpin, Stephen J. Kalkhoff

United States Geological Survey: Staff Publications

A study was conducted during 1990 through an 11.2-km reach of Roberts Creek in northeastern Iowa to determine the fate of atrazine in a surface water environment. Water samples were collected at ~1-month intervals from April through November during stable low to medium flow conditions and analyzed for atrazine and two of its initial biotic degradation products, desethylatrazine and deisopropylatrazine. Samples were collected on the basis of a Lagrangian model of streamflow in order to sample the same parcel of water as it moved downstream. Atrazine concentrations substantially decreased (roughly 25-60% ) between water entering and exiting the study reach …

A Memorial For William V. Sliter, Robert G. Douglas, Jere H. Lipps, James C. Ingle Jr., John Barron

United States Geological Survey: Staff Publications

William V. (Bill) Sliter, an internationally known micropaleontologist and research geologist for the U.S. Geological Survey, passed away suddenly, October, 1997, while talking to a colleague in his office. In his honor, B. Huber, T. Bralower, and M. Leckie organized a keynote symposium ‘‘Paleoecological and Geochemical Signatures of Cretaceous Anoxic Events’’ at the 1998 annual meeting of the Geological Society of America in Toronto, Canada. This theme issue of the Journal of Foraminiferal Research contains the published papers from the symposium and is dedicated to his memory.

Comparison Of An Enzyme-Linked Immunosorbent Assay (Elisa) To Gas Chromatography (Gc) - Measurement Of Polychlorinated Biphenyls (Pcbs) In Selected Us Fish Extracts, James L. Zajicek, Donald E. Tillitt, Ted R. Schwartz, Christopher J. Schmitt, Robert O. Harrison

United States Geological Survey: Staff Publications

The analysis of PCBs in fish tissues by immunoassay methods was evaluated using fish collected from a US monitoring program, the National Contaminant Biomonitoring Program of the US Department of Interior, Fish and Wildlife Service. Selected composite whole fish samples, which represented widely varying concentrations and sources of PCBs, were extracted and subjected to congener PCB analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs) calibrated against technical Aroclor 1248. PCB congener patterns in these fishes were different from the patterns found in commercial Aroclors or their combinations as demonstrated by principal component analysis of normalized …

Analytical Modeling Of Cake Filtration, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The specific resistance model of cake filtration is based on the assumption that the average cake resistance is constant over time. This implies also that the spatially average values of porosity and pressure differential are also constant over time since specific resistance is a function of both parameters.

An analytical cake filtration model based on Tiller (1975) was derived using constitutive properties of kaolin suspensions in distilled water. Constitutive properties were determined by experiments performed using high-energy X-rays and porewater pressure probes to determine the spatial and temporal distributions of porosity and porewater pressure. Using these constitutive properties, predictions were …

Impact Of Agricultural Land Use On Some Hungarian Karst Regions, Ilona Bárány-Kevei

International Journal of Speleology

The karst regions are found in the medium altitude mountains of Hungary. Their land use types are natural and sustainable forestry, grazing and vineyards. In international comparison, Hungary belongs to those countries of Europe where arable land is abundant, therefore, in the future its extension has to be reduced. That means agricultural activity has to be restricted on the sensitive karst surfaces. This paper presents ways of sustainable forestry and other land use types for three karst regions of Hungary.

Sustainable Development Of Agriculture In Karst Areas, South China, Linhua Song

International Journal of Speleology

The exposed carbonate rocks aged from Sinian to Mid-Triassic Periods cover an area of 500,000 km² in south-west China. In karst areas with spectacular landscapes characterized by magnificent tower karst and conical karst, rare surface drainage systems and prevalent subsurface drainage systems, the environment is ecologically very fragile. The rapid increase of population, over deforested and cultivated lands, worsted the ecological system, causing a higher frequency of draught, flood and various disasters, backward economic development, low living standard of the people. In order to improve the sustainability of the agriculture the experience shows that the following operations should be …

Agriculture, Landscape And Human Impact In Some Karst Areas Of Italy, Ezio Burri, Benedetta Castiglioni, Ugo Sauro

International Journal of Speleology

Italy is made up for about 1/5 of its surface by soluble rocks, which represent the arena of karst environments. The karst morpho-units, some hundreds, are mainly distributed inside the alpine structure of the Mediterranean mountains. A very large number of rock formations are present, different in facies, lithology, age, etc. Among these, carbonate rocks prevail, followed by gypsum and salt. Most of the carbonate rocks are limestones sedimented in a platform environment and they show a wide range of porosity, frequency of fractures and bedding planes. The climatic processes, the expression of some different sub-types of Mediterranean climate (from …

Karst And Agriculture In Australia, David Gillieson, Mia Thurgate

International Journal of Speleology

Much of the development and degradation of karst lands in Australia has occurred in the last two centuries since European settlement. Recent prolonged El Niño events add further climatic uncertainty and place real constraints on sustainable agriculture. The lower southeast of South Australia is perhaps the one area in Australia where karst, and particularly karst hydrology, impinge on the daily lives of the community in that pollution and overexploitation of the aquifer are readily apparent to the local population. Effluent from intensive dairy farms, piggeries and cheese factories enters the karst and has caused concern over pollution of water supplies. …

Field Methods To Enhance Degradation Of Nitrate In Surficial Soils, Urko Atxotegi Alegria

Dissertations and Theses @ UNI

An environmental field study was conducted from April to October 1998 in the Black Hawk County, Iowa. The main goal of the study was to find an appropriate field method to enhance degradation of nitrates in the surficial soil. Seven different methods were developed in the study to compare between four variables. The variables that were investigated were the source of nitrates, the moisture content of the soil, the uptake by plants and the total carbon content of the soil. The investigation has also been conducted to find out the specific influence of each parameter on landuse. A weather station …

Physical Control Of Biological Processes In The Central Equatorial Pacific: A Data Assimilative Modeling Study, Marjorie Anne Macwhorter Friedrichs

OES Theses and Dissertations

A five-component data assimilative ecosystem model is developed in order to investigate the effects of physical processes encompassing a wide range of space and time scales, on the lower trophic levels of the highly dynamic central equatorial Pacific (140°W). Many of the biological processes included in the ecosystem model respond to environmental fluctuations with time scales between one and ten days, which are not typically resolved by basin to global scale circulation models. Therefore, the ecosystem model is forced using daily observations from the TAO mooring array. Model simulations successfully reproduce data collected both during and after the 1991–92 El …

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 …

New Caribbean Locality For The Extinct Great White Shark Carcharodon, Clare Flemming, Donald A. Mcfarlane

WM Keck Science Faculty Papers

Carcharodon is represented by a single upper tooth (Fig. 1) which we extracted from the eroding Pliocene limestone wall, some six meters above the floor at the northern end of Darby Sink. Much of the tooth is missing, but the remaining portion includes features diagnostic of this genus. The tooth conforms in size and morphology to Carcharodon megalodon (Agassiz, 1843), an extinct great white shark.

A Second Pre-Wisconsinan Locality For The Extinct Jamaican Rodent, Clidomys (Rodentia: Heptaxodontidae), Donald A. Mcfarlane, Joyce Lundberg, Clare Flemming, Ross D. E. Macphee, Stein-Erik Lauritzen

WM Keck Science Faculty Papers

Clidomys is the most distinctive but least well known member of the late Quaternary terrestrial mammal fauna of Jamaica. Here we report the second dated locality for this genus. The Illinoisan age we report further strengthens arguments we have made elsewhere, that Clidomys represents an early - probably pre-Wisconsinan - extinction that contrasts with the growing record of Holocene extinctions in the Antilles.

Highline Breaks Watershed [Microform] : Otero County, Colorado, Pueblo County, Colorado : Watershed Plan And Environmental Assessment, United States Natural Resources Conservation Service, Colorado State Soil Conservation Board

Environmental Assessments (NV)

No abstract provided.

Factors Affecting The Movements Of Rainbow Trout (Oncorhynchus Mykiss) In Lake Ogallala, Nebraska, Tadd M. Barrow

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

No abstract provided.

Uncertainty In Recharge From Subsidence Craters At Frenchman Flat, Nevada Test Site: Impacts Of Initial And Boundary Conditions And Media Properties, David Matthew Ely

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada Test Site has over 400 subsidence craters formed by the collapse of overlying rock following underground nuclear tests. Under natural conditions, infiltration and recharge would not be considered likely due to infrequent precipitation events and extreme evapotranspiration. Crater U5a in Frenchman Flat was chosen for study because it intercepts significantly more drainage than surrounding craters. Vadose zone modeling was conducted to test the sensitivity of water movement to boundary and initial conditions. The effects of ponding depth was negligible but depth of wetting front movement was highly dependent on the lateral extent of the ponds. The model was …

Field Scale Variability Of Nitrogen And Δ15n In Soil And Plants, D. E. Clay, J. Chang, S. A. Clay, M. Ellsbury, C. G. Carlson, D. D. Malo, D. Woodson, T. Desttur

Agronomy, Horticulture and Plant Science Faculty Publications

Understanding the factors that influence soil and plant nitrogen (N) spatial variability may improve our ability to develop management systems that maximize productivity and minimize environmental hazards. The objective of this study was to determine the field (65 ha) scale spatial variability of N and δ¹⁵N in soil and corn (Zea mays). Soil, grain, and stover samples were collected from grids that ranged in size from 30 by 30 m to 60 by 60 m. Plant samples, collected following physiological maturity in 1995, were analyzed for total N and δ¹⁵N. Soil samples, collected prior …

A Late Cambrian Positive Carbon-Isotope Excursion In The Southern Appalachians: Relation To Biostratigraphy, Sequence Stratigraphy, Environments Of Deposition, And Diagenesis, Bosiljka Glumac, Kenneth R. Walker

Geosciences: Faculty Publications

A positive carbon-isotope excursion is recorded within the Upper Cambrian sedimentary succession in the southern Appalachians that consists of the Nolichucky Shale, the Maynardville Formation, and the Copper Ridge Dolomite. The lower part of the succession contains Aphelaspis zone fauna (Early Steptoean). The extensively dolomitized and poorly fossiliferous nature of the upper part of the succession precludes any detailed biostratigraphic determinations. Correlation with similar positive carbon-isotope excursions in coeval successions elsewhere suggests that this excursion represents a perturbation in the global cycling of carbon. Comparison of excursions at different localities in North America provides a means for the application of …

Ua66/8/3 Geogram, Wku Geography & Geology

WKU Administration Documents

Newsletter created by and about the WKU Geography & Geology highlighting activities of faculty, students and alumni.

Earth News, Fall 1998, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Faculty Achievements and Activities
--- 1998 Earth Science Graduates
--- Student Research Presentations
--- Sigma Gamma Epsilon - Gamma Sigma Chapter
--- Earth Science Majors
--- Observatory: Room with a Stellar View
--- Gifts to the Department of Earth Science
--- 1998 Scholarship and Award Recipients
--- Earth Science Seminar Series
--- UNI Students Get Up Close and Personal with Nature
--- Earth Science Alumni Notes

Chemical Signals From Submarine Fluid Advection Onto The Continental Shelf, W. S. Moore, Timothy J. Shaw

Faculty Publications

No abstract provided.