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Articles 3271 - 3300 of 3978
Full-Text Articles in Entire DC Network
Diatom Biostratigraphy Of The Cenozoic Glaciomarine Pagodroma Group, Northern Prince Charles Mountains, East Antarctica, Jason M. Whitehead, David M. Harwood, Barrie Mckelvey, Andrew Mcminn
Diatom Biostratigraphy Of The Cenozoic Glaciomarine Pagodroma Group, Northern Prince Charles Mountains, East Antarctica, Jason M. Whitehead, David M. Harwood, Barrie Mckelvey, Andrew Mcminn
Department of Earth and Atmospheric Sciences: Faculty Publications
In the northern Prince Charles Mountains glaciomarine sediments of the Pagodroma Group outcrop on Fisher Massif (Mt Johnston and Fisher Bench Formations) and at the Amery Oasis (Battye Glacier and Bardin Bluffs Formations), at locations 300 and 250 km south of the Amery Ice Shelf edge, respectively. Most of the Pagodroma Group consists of ice-proximal glaciomarine diamict, and a much subordinate (<2%) amount of more ice-distal mudstone. Microfossil biostratigraphy based upon in situ and glacially reworked diatoms constrains the ages of the four formations, and identifies at least six intervals of marine fjordal deposition. Sparse diatoms in Mt Johnston Formation diamicts indicate an Early Oligocene age. However, it is …2%)>
Federal Listing Of Prairie Grouse: Lessons From The Attwater’S Prairie Chicken, Michael Morrow, Terry A. Rossignol, Nova J. Silvy
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 …
Subspecific Relationships And Genetic Structure In The Spotted Owl, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman
Subspecific Relationships And Genetic Structure In The Spotted Owl, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman
United States Geological Survey: Staff Publications
Hierarchical genetic structure was examined in the three geographically-defined subspecies of spotted owl (Strix occidentalis) to define relationships among subspecies and quantify variation within and among regional and local populations. Sequences (522 bp) from domains I and II of the mitochondrial control region were analyzed for 213 individuals from 30 local breeding areas. Results confirmed significant differences between northern spotted owls and the other traditional geographically defined subspecies but did not provide support for subspecific level differences between California and Mexican spotted owls. Divergence times among subspecies estimated with a 936 bp portion of the cytochrome b gene …
A Holocene Pollen Record Of Persistent Droughts From Pyramid Lake, Nevada, Usa, Scott A. Mensing, Larry Benson, Michaele Kashgarian, Steve Lund
A Holocene Pollen Record Of Persistent Droughts From Pyramid Lake, Nevada, Usa, Scott A. Mensing, Larry Benson, Michaele Kashgarian, Steve Lund
United States Geological Survey: Staff Publications
Pollen and algae microfossils preserved in sediments from Pyramid Lake, Nevada, provide evidence for periods of persistent drought during the Holocene age. We analyzed one hundred nineteen 1-cm-thick samples for pollen and algae from a set of cores that span the past 7630 years. The early middle Holocene, 7600 to 6300 cal yr B.P., was found to be the driest period, although it included one short but intense wet phase. We suggest that Lake Tahoe was below its rim for most of this period, greatly reducing the volume and depth of Pyramid Lake. Middle Holocene aridity eased between 5000 and …
Quaternary Sea-Level History Of The United States, Daniel R. Muhs, John F. Wehmiller, Kathleen R. Simmons, Linda L. York
Quaternary Sea-Level History Of The United States, Daniel R. Muhs, John F. Wehmiller, Kathleen R. Simmons, Linda L. York
United States Geological Survey: Staff Publications
In the past 30 years, there have been tremendous advances in our understanding of Quaternary sea-level history, due directly to developments in Quaternary dating methods, particularly uranium-series disequilibrium and amino acid racemization. Another reason for this progress is that coastline history can now be tied to the oxygen-isotope record of foraminifera in deep-sea cores. Furthermore, both records have been linked to climate change on the scale of glacial-interglacial cycles that are thought to be forced by changes in Earth-Sun geometry, or “orbital forcing” (Milankovitch, 1941).
Temporal Variability In Nutrient Transport In A First-Order Agricultural Basin In Southern Ontario, Merrin L. Macrae
Temporal Variability In Nutrient Transport In A First-Order Agricultural Basin In Southern Ontario, Merrin L. Macrae
Theses and Dissertations (Comprehensive)
This thesis examines phosphorus and nitrate transport in a first-order agricultural catchment in Southern Ontario. Specific areas of concern relate to (1) long- and short-term temporal variability in nutrient export patterns, (2) the role of drainage tiles in annual nutrient export, (3) the effects of antecedent hydrologic conditions (AHC) on nutrient export patterns and (4) temporal variability in the nutrient retention in riparian buffer strips and streams. Temporal variability in hydrochemical export from the study basin over a two-year period is described and quantified and the importance of high magnitude events is highlighted. This is the first comprehensive study to …
Trace Elements In Speleothems. A Short Review Of The State Of The Art, Sophie Verheyden
Trace Elements In Speleothems. A Short Review Of The State Of The Art, Sophie Verheyden
International Journal of Speleology
A state of the art of the research on trace elements of speleothems is given. First studies focussed on problems such as the colour of speleothems and the aragonite problem. Insitu studies and studies oriented towards a better understanding of vadose hydrology brought new insights in the controls on trace elemental composition of speleothems. Recent studies deal with microscale analyses and annual and intra-annual chemistry changes. Further in-situ studies should be performed to further differentiate influences, such as climate, soil/weathering and local hydrology in order to better constrain possible transfer functions between the surface and a speleothem.
Geometric And Kinematic Evolution Of The Bessemer Transverse Zone, Alabama Alleghanian Thrust Belt, Margaret Colette Brewer
Geometric And Kinematic Evolution Of The Bessemer Transverse Zone, Alabama Alleghanian Thrust Belt, Margaret Colette Brewer
University of Kentucky Doctoral Dissertations
Transverse zones are important syn-kinematic components of thrust belt development. Various scales of data were utilized to develop three-dimensional geometric and kinematic models for the Bessemer transverse zone (BTZ) of the Alabama Alleghanian thrust belt.
Regional analysis of the BTZ began with the examination of geologic maps (1:250,000, 1:48,000, and 1:24,000 scales), seismic reflection profiles, well data, and previous stratigraphic research. All Paleozoic-age stratigraphic contacts, major thrust faults and associated folds, and various unnamed minor structures were compiled to create two strike-perpendicular, and five-strike parallel, cross sections transecting the extent of the BTZ at a scale of 1:100,000. The balanced …
Glacial Deposits, Vol. 32, 2003-2004, Department Of Geography-Geology
Glacial Deposits, Vol. 32, 2003-2004, Department Of Geography-Geology
Glacial Deposits
Newsletter of the Department of Geography-Geology
Modeling And Measuring The Dispersion Of Odors From Hog Confinements, François Béra
Modeling And Measuring The Dispersion Of Odors From Hog Confinements, François Béra
Dissertations and Theses @ UNI
A comparison was made between predicted and measured odor concentration downwind of two hog finishing confinements. Two Gaussian dispersion models, STINK.BAK and AERMOD, were used. The experimental cases examined odor emanating from a mechanically-ventilated facility and a curtain-sided facility during summer 2003. A field olfactometer was used to measure odor concentration. The odor concentrations served as input to STINK.BAK, which then estimated the odor emission rate from the confinement. AERMOD used this emission rate and other meteorological data to predict the peak concentration of odor around the confinement over the sampling hour. The calculated odor emission rates are slightly higher …
Where Are The Women Geoscientist Professors?, Mary Anne Holmes, Suzanne O'Connell
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.
Delineation Of Mass Movement Prone Areas By Landsat 7 And Digitial Image Processing, Shiloh Marie Howland
Delineation Of Mass Movement Prone Areas By Landsat 7 And Digitial Image Processing, Shiloh Marie Howland
Theses and Dissertations
The problem of whether Landsat 7 data could be used to delineate areas prone to mass movement, particularly debris flows and landslides, was examined using three techniques: change detection in NDVI (Normalized Difference Vegetation Index), change detection in band 5, and the tasseled cap transformation. These techniques were applied to areas that had recently experienced mass movement: Layton, Davis County and Alpine, Spanish Fork Canyon and Santaquin, Utah County. No distinctive spectral characteristics were found with any of these techniques with two possible explanations: 1. That despite improved spatial resolution in Landat 7 over its predecessors and improved digital image …
Using Spreadsheets In Geoscience Education: Survey And Annotated Bibliography Of Articles In The Journal Of Geoscience Education Through 2003, Beth Fratesi, H. L. Vacher
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
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 …
Using Cesium 137 To Understand Recent In Cave Sedimentation In The Tongass National Forest, Southeast Alaska, William Curry
Using Cesium 137 To Understand Recent In Cave Sedimentation In The Tongass National Forest, Southeast Alaska, William Curry
Masters Theses & Specialist Projects
Removal of vegetation and subsequent erosion in karst regions such as central Kentucky or southeastern Alaska often leads to increased sedimentation in karst features such as caves and dolines. This sedimentation can impact the ground water by altering flow paths and the bio-geochemistry of the karst aquifer itself. Various methodologies have been used to obtain quantitative erosion and sedimentation rates for surface areas in karst and non-karst settings, but few quantitative studies have taken place in caves. The purpose of this study is to examine the effects of timber harvesting and development upon the caves and karst of southeastern Alaska …
Mantle Layering Across Central South America, Kelly H. Liu, Stephen S. Gao, Paul G. Silver, Yongkai K. Zhang
Mantle Layering Across Central South America, Kelly H. Liu, Stephen S. Gao, Paul G. Silver, Yongkai K. Zhang
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Imaging of seismic velocity discontinuities along a 3000 km profile across central South America at 20°S suggests that the depth variations of the 410-km (d410) and 660-km (d660) discontinuities are closely associated with the high-velocity Nazca slab and juxtaposed low-velocity oceanic mantle beneath the slab. The mantle transition zone thickness ranges from 220 km in the oceanic mantle to 270 km in a 600-km-wide area occupied by the deflected Nazca slab. The slab deflection has also been suggested by previous studies of seismic tomography and seismicity. This 50 km difference in the thickness corresponds to a lateral temperature variation of …
Geogram 2003, David J. Keeling Editor, Wku Department Of Geography And Geology
Geogram 2003, David J. Keeling Editor, Wku Department Of Geography And Geology
Earth, Environmental, and Atmospheric Sciences Publications
No abstract provided.
Sedimentary Aggregates In The Peoria Loess Of Nebraska, Usa, Joseph A. Mason, Peter M. Jacobs, Richard S. B. Greene
Sedimentary Aggregates In The Peoria Loess Of Nebraska, Usa, Joseph A. Mason, Peter M. Jacobs, Richard S. B. Greene
Department of Earth and Atmospheric Sciences: Faculty Publications
Loess grain size data used to infer transport direction or wind strength are generally derived from vigorously disaggregated samples. However, these data may not adequately represent the effective particle size distribution during loess transport, if the transported dust contained aggregates of fine-grained material. Thin sections of minimally altered C and BC horizons in the late Pleistocene Peoria Loess of Nebraska, USA, indicate the presence of aggregates with diameters of 30–1000 Am. The larger aggregates (>250 μm) are unlikely to have been transported, and are interpreted as the result of soil faunal activity and other pedogenic processes after deposition. Aggregates …
Validation Of A Radiometric Normalization Procedure For Satellite-Derived Imagery Within A Change Detection Framework, Karin E. Callahan
Validation Of A Radiometric Normalization Procedure For Satellite-Derived Imagery Within A Change Detection Framework, Karin E. Callahan
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Detecting changes in land cover through time using remotely sensed imagery is a powerful application that has seen increased use as imagery has become more widely available and inexpensive. Before a time series of remotely sensed imagery can be used for change detection, images must first be standardized for effects outside of real surface change. This thesis established a validation protocol to evaluate the effectiveness of an automated technique for normalizing temporally separate but spatially coincident imagery. Using the concept of pseudo-invariant features between master-slave image pairs, spatially coincident dark and bright points are identified from images and a regression …
Using Geographic Information Systems And Remote Sensing To Analyze Fire Likelihood Areas At The Regional Scale In The Western United States, Russell W. Reading
Using Geographic Information Systems And Remote Sensing To Analyze Fire Likelihood Areas At The Regional Scale In The Western United States, Russell W. Reading
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Geographic Information Systems (GIS) are increasingly used to examine fire activity. This study uses GIS to determine fire likelihood probabilities at an intermediate scale ( I-kilometer) on a daily basis given readily available data. Layers used for the analysis included slope, aspect, elevation, fuel type, proximity to existing fires, maximum temperature, minimum temperature, relative humidity, average vapor pressure deficit, precipitation, 1-hour fuel moisture, and 10-hour fuel moisture.
There were three objectives of this study: 1. Establish a correlation between burn perimeters and readily available topographic and environmental data, and map the spatial distribution of these as fire likelihood areas; 2. …
Sequence Stratigraphy And Depositional Facies Of Lower Ordovician Cyclic Carbonate Rocks, Southern Missouri, U.S.A., Robert Brandon Overstreet, Francisca Oboh-Ikuenobe, Jay M. Gregg
Sequence Stratigraphy And Depositional Facies Of Lower Ordovician Cyclic Carbonate Rocks, Southern Missouri, U.S.A., Robert Brandon Overstreet, Francisca Oboh-Ikuenobe, Jay M. Gregg
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Lower Ordovician cyclic carbonate strata of southern Missouri were deposited in a warm, shallow, epeiric sea on a fully aggraded carbonate platform. Sedimentological characteristics distinguish the Jefferson City and Cotter dolomites from the underlying Gasconade and Roubidoux formations. Mixed carbonate-siliciclastic sedimentation characterizes the Roubidoux Formation, with sandstones accounting for up to 60% of sedimentation. The Gasconade, Jefferson City, and Cotter dolomites exhibit an increased occurrence of chalcedonic chert nodules in very similar shape and texture to the gypsum and anhydrite nodules common on modern sabkha supratidal flats. Casts of halite and ghosts of gypsum laths also exist in the Jefferson …
Geographic Information System Methodologies To Evaluate Relationships Between Land Use And Groundwater Quality In South Central Kentucky, Rhonda Pfaff
Masters Theses & Specialist Projects
The development of Geographic Information System (GIS) technology has provided techniques for a holistic approach to the study of karst groundwater contamination. While karst groundwaters supply water to a large percentage of the earth's population, its complex environments often have lacked the scientific examination and conservation measures typical of non-karst regions. In this study, GIS methodologies were explored to examine the relationships between land-use and water quality in karst watersheds. Eight watersheds throughout southern and western Kentucky were examined. The study areas included the Mammoth Cave Karst Aquifer, which is the watershed that drains the Mammoth Cave System, and seven …
Effects Of Holocene Climate Change On Mercury Deposition In Elk Lake, Minnesota: The Importance Of Eolian Transport In The Mercury Cycle, W.F. Cannon, Walter E. Dean, John H. Bullock Jr.
Effects Of Holocene Climate Change On Mercury Deposition In Elk Lake, Minnesota: The Importance Of Eolian Transport In The Mercury Cycle, W.F. Cannon, Walter E. Dean, John H. Bullock Jr.
United States Geological Survey: Staff Publications
Sediments in Elk Lake, Minnesota, consist of 10,400 varve layers that provide a precise chronology for Holocene fluctuations in climate and biota recorded in the strata. Progressively greater concentrations and accumulation rates of mercury since ca. A.D. 1875 reflect deposition of anthropogenic mercury additions to the atmosphere. Within the Holocene record are numerous short intervals in which mercury concentrations and accumulation rates exceed the modern values. The highest mercury concentrations formed ca. 8 ka, coincident with a rapid change from cool, moist conditions to warm, dry conditions. A related change in flora from pine forest to prairie caused destruction of …
Preliminary Investigations Of Seasonal Changes In The Geochemical Evolution Of The Logdson River, Mammoth Cave, Kentucky, Chris Groves, Darlene M. Anthony, Joe Meiman
Preliminary Investigations Of Seasonal Changes In The Geochemical Evolution Of The Logdson River, Mammoth Cave, Kentucky, Chris Groves, Darlene M. Anthony, Joe Meiman
Earth, Environmental, and Atmospheric Sciences Faculty Publications
Many geochemical studies have been made of karst waters worldwide. Most data that provide the framework for our current understanding of the evolution of karst waters have come from sampling at discrete times and locations, such as springs or wells. Relatively few studies have been made of the geochemical evolution of groundwater as it moves through an open flow system. This paper addresses the seasonal changes in the geochemistry of the Logsdon River conduit as it passes through nearly 10km of the carbonate aquifer of south-central Kentucky . The most important control on the ability of groundwaters to dissolve limestone …
Could Mammoth Cave Be Reduced To A Single Equation?, Chris Groves, Joe Meiman
Could Mammoth Cave Be Reduced To A Single Equation?, Chris Groves, Joe Meiman
Earth, Environmental, and Atmospheric Sciences Faculty Publications
Since the evolution of any cave system is largely deterministic, in theory the processes responsible for this development could be described mathematically. In a practical sense, we will never have such a model to realistically describe the evolution of the Mammoth Cave System in detail. However, the search itself can provide a framework within which to understand what processes areimportant. This can guide the design of rate process studies that would eventually be coupled to provide a comprehensive understanding of the cave's evolution. Data gaps, as well, are identified during this process. The geometry of a cave system depends on …
Mid-Holocene Climates Of The Americas: A Dynamical Response To Changed Seasonality, S. P. Harrison, J. E. Kutzbach, Z. Liu, P. J. Bartlein, B. Otto-Bliesner, Daniel R. Muhs, I. C. Prentice, R. S. Thompson
Mid-Holocene Climates Of The Americas: A Dynamical Response To Changed Seasonality, S. P. Harrison, J. E. Kutzbach, Z. Liu, P. J. Bartlein, B. Otto-Bliesner, Daniel R. Muhs, I. C. Prentice, R. S. Thompson
United States Geological Survey: Staff Publications
Abstract Simulations of the climatic response to mid- Holocene (6 ka BP) orbital forcing with two coupled ocean–atmosphere models (FOAM and CSM) show enhancement of monsoonal precipitation in parts of the American Southwest, Central America and northernmost South America during Northern Hemisphere summer. The enhanced onshore flow that brings precipitation into Central America is caused by a northward displacement of the inter-tropical convergence zone, driven by cooling of the equatorial and warming of the northern subtropical and mid-latitude ocean. Ocean feedbacks also enhance precipitation over the American Southwest, although the increase in monsoon precipitation there is largely driven by increases …
Unprecedented Last-Glacial Mass Accumulation Rates Determined By Luminescence Dating Of Loess From Western Nebraska, Helen M. Roberts, Daniel R. Muhs, Ann G. Wintle, Geoff A. T. Duller, E. Arthur Bettis Iii
Unprecedented Last-Glacial Mass Accumulation Rates Determined By Luminescence Dating Of Loess From Western Nebraska, Helen M. Roberts, Daniel R. Muhs, Ann G. Wintle, Geoff A. T. Duller, E. Arthur Bettis Iii
United States Geological Survey: Staff Publications
A high-resolution chronology for Peoria (last glacial period) Loess from three sites in Nebraska, midcontinental North America, is determined by applying optically stimulated luminescence (OSL) dating to 35–50 µm quartz. At Bignell Hill, Nebraska, an OSL age of 25,000 yr near the contact of Peoria Loess with the underlying Gilman Canyon Formation shows that dust accumulation occurred early during the last glacial maximum (LGM), whereas at Devil’s Den and Eustis, Nebraska, basal OSL ages are significantly younger (18,000 and 21,000 yr, respectively). At all three localities, dust accumulation ended at some time after 14,000 yr ago. Mass accumulation rates …
Paleolimnology Of Lake Tanganyika, East Africa, Over The Past 100 K Yr, Christopher A. Scholz, John W. King, Geoffrey S. Ellis, Peter K. Swart, J. Curt Stager, Steven M. Colman
Paleolimnology Of Lake Tanganyika, East Africa, Over The Past 100 K Yr, Christopher A. Scholz, John W. King, Geoffrey S. Ellis, Peter K. Swart, J. Curt Stager, Steven M. Colman
United States Geological Survey: Staff Publications
New sediment core data from a unique slow-sedimentation rate site in Lake Tanganyika contain a much longer and continuous record of limnological response to climate change than have been previously observed in equatorial regions of central Africa. The new core site was first located through an extensive seismic reflection survey over the Kavala Island Ridge (KIR), a sedimented basement high that separates the Kigoma and Kalemie Basins in Lake Tanganyika.
Proxy analyses of paleoclimate response carried out on core T97-52V include paleomagnetic and index properties, TOC and isotopic analyses of organic carbon, and diatom and biogenic silica analyses. A robust …
A Geological And Geophysical Investigation Of Ice Mountain Algific Talus, Hampshire County, West Virginia, Kevin M. Andrews
A Geological And Geophysical Investigation Of Ice Mountain Algific Talus, Hampshire County, West Virginia, Kevin M. Andrews
Graduate Theses, Dissertations, and Problem Reports (ETD)
Ice Mountain is an algific talus slope located in Hampshire County, West Virginia, protected for its status as a biological refugium. Both the origin of the slope and the mechanism by which cold air is produced from the base of the slope have remained mysteries to local residents and tourists for many years. This research effort takes a scientific approach to exploring the mysteries of Ice Mountain. Bedrock and surficial geologic mapping provides an understanding of the physical environment of the slope area, while geophysical survey data provide clues to the subsurface of the slope. The algific talus consists of …
Phosphorus Contamination And Storage In Bottom Sediments Of The James River Arm Of Table Rock Lake, Southwest Missouri, Marc R. Owen
Phosphorus Contamination And Storage In Bottom Sediments Of The James River Arm Of Table Rock Lake, Southwest Missouri, Marc R. Owen
Graduate Theses/Dissertations
Eutrophic conditions in the upper James River Arm (JRA) of Table Rock Lake have been linked to phosphorus (P) inputs by wastewater treatment facilities and increasing urban development in the upper James River Basin (3,770 km2). Since the majority of P in aquatic environments is bound to sediments, bottom sediment can function as both a source and sink of P in lake systems. This study evaluates the spatial distribution, physical and chemical characteristics, and storage of sediment-P in the active layer ( < 5cm) of bottom sediments in the JRA. The JRA makes up about 20% of Table Rock Lake’s surface area, contributes about 30% of the inflow, and has the poorest water quality of the entire lake. For this study, grab samples were collected in the main arm and tributary coves at the deepest part of the lake and at several shallow sites along the main arm. Concentrations increase in a down-lake direction in the main arm ranging from 5 to >2000 ppm P. However, water-column P concentrations show a decrease down-lake, indicating that sedimentation is removing P from …