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Articles 481 - 510 of 696
Full-Text Articles in Entire DC Network
Fisheries Research Contract Report No. 2 - Towards An Assessment Of Natural And Human Use Impacts On The Marine Environment Of The Abrolhos Islands (Phase 1 : Data Consolidation And Scoping - Final Report For Frdc Project 2000/1 66), C. F. Chubb, K. Nardi
Fisheries Research Contract Reports
This project has drawn together existing research data relating to natural and human impacts on the Abrolhos Islands marine habitats. It has surveyed current uses of these habitats and placed anthropogenic impacts within the context of natural perturbations. Through public forum presentation and debate, this work has allowed real issues, not perceptions, to surface and be addressed properly. This was achieved by defining a strategic programme of research through a scientific workshop process involving all community stakeholders. A two volume Fisheries Research Report (WA) summarizes current knowledge and details the workshop proceedings and strategic research plan.
Automatic Processing Of High-Rate, High-Density Multibeam Echosounder Data, Brian R. Calder, Larry A. Mayer
Automatic Processing Of High-Rate, High-Density Multibeam Echosounder Data, Brian R. Calder, Larry A. Mayer
Center for Coastal and Ocean Mapping
Multibeam echosounders (MBES) are currently the best way to determine the bathymetry of large regions of the seabed with high accuracy. They are becoming the standard instrument for hydrographic surveying and are also used in geological studies, mineral exploration and scientific investigation of the earth's crustal deformations and life cycle. The significantly increased data density provided by an MBES has significant advantages in accurately delineating the morphology of the seabed, but comes with the attendant disadvantage of having to handle and process a much greater volume of data. Current data processing approaches typically involve (computer aided) human inspection of all …
Geologic Studies Of Mercury By The U.S. Geological Survey
Geologic Studies Of Mercury By The U.S. Geological Survey
United States Geological Survey: Publications
A liquid at room temperature, mercury is a unique metal with unusual properties. Elemental mercury has long been used in thermometers because it responds to changes in temperature. In fact, mercury’s many diverse properties have made it useful for many products. Mercury is a good metallic conductor with a low electrical resistivity; it has been used in electrical products including electrical wiring and switches, fluorescent lamps, mercury batteries, and thermostats (Eisler, 1987). Mercury also is used in navigational instruments to measure changes in temperature and pressure. In the medical field, mercury is used as a component in dental fillings and …
Status Of Coral Reefs Of Little Cayman, Grand Cayman And Cayman Brac, British West Indies, In 1999 And 2000 (Part 1: Stony Corals And Algae), Carrie Manfrino, Bernhard Riegl, Jerome L. Hall, Robert Graifman
Status Of Coral Reefs Of Little Cayman, Grand Cayman And Cayman Brac, British West Indies, In 1999 And 2000 (Part 1: Stony Corals And Algae), Carrie Manfrino, Bernhard Riegl, Jerome L. Hall, Robert Graifman
Marine & Environmental Sciences Faculty Articles
A benthic assessment of the isolated Cayman Islands was completed at 42 sites. Major changes in the reef community structure were documented by comparison with earlier studies. Acropora palmata and A. cervicornis, once abundant as shallow framework builders, were uncommon. Diseased stony corals were seen in >90% of the study sites, with the highest averages in Little Cayman, especially at Bloody Bay which is one of the most highly regulated marine parks in the Cayman Islands. The Montastraea annularis species complex accounted for two-thirds of the diseased corals which, along with other massive species, were affected largely by white-plague …
Evolution Of A Miocene-Pliocene Low-Angle Normal-Fault System In The Southern Bannock Range, Southeast Idaho, Stephanie M. Carney
Evolution Of A Miocene-Pliocene Low-Angle Normal-Fault System In The Southern Bannock Range, Southeast Idaho, Stephanie M. Carney
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Geologic mapping, basin analysis, and tephrochronologic analysis in the Clifton quadrangle of southeast Idaho indicates that the modern Basin-and-Range topography is only a few million years old and that the bulk of Cenozoic extension was accommodated by slip on an older low-angle normal-fault system, the Bannock detachment system. The detachment system was active between ~12 and < 4 Ma and accommodated ~50 % extension.
Cross-cutting relationships show that the master detachment fault, the Clifton fault, is the youngest low-angle normal fault of the system, was active at a low angle, and has not been rotated to a low-dip angle through time. Map patterns and relationships indicate that the …
Temporal Variation Of Seismic B-Values Beneath Northeastern Japan Island Arc, Aimin Cao, Stephen S. Gao
Temporal Variation Of Seismic B-Values Beneath Northeastern Japan Island Arc, Aimin Cao, Stephen S. Gao
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Analysis of a high quality seismic catalog reveals that the average of seismic b-values in the crust beneath most part of northeastern Japan island arc decreased from 0.86 between 1984 and 1990, to 0.73 between 1991 and 1995. The two areas with the largest decrease are found to be in the same areas where the coupling between the North American and the Pacific plates is the highest, as suggested by a recent geodetic study. In the same time period, the annual seismic moment release increased by 10 times. In addition, there seems to be a corresponding increase in volcanic activities …
Geometry And Physical Properties Of The Chelungpu Fault, Taiwan, And Their Effect On Fault Rupture, Richard V. Heermance
Geometry And Physical Properties Of The Chelungpu Fault, Taiwan, And Their Effect On Fault Rupture, Richard V. Heermance
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Rupture of the Chelungpu fault during the September 21, 1999, 7.6 Mwearthquake in Taiwan caused a 90-Jr,m-long surface rupture with variable displacement along strike. Analysis of core from two holes drilled through the fault zone, combined with geologic mapping and detailed investigation from three outcrops, define the fault geometry and physical properties of the Chelungpu fault in its northern and southern regions. In the northern region, the fault dips 45-60° east parallel to bedding and consists of a narrow (1-20 cm) core of dark-gray, sheared clay gouge at the base of a 30-50 m zone of increased fracture …
Structural And Kinematic Evolution Of Eocene-Oligocene Grasshopper Extensional Basin, Southwest Montana, Julie C. Kickham
Structural And Kinematic Evolution Of Eocene-Oligocene Grasshopper Extensional Basin, Southwest Montana, Julie C. Kickham
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Grasshopper basin of southwest Montana is a complex east-dipping graben containing five unconformity-bounded sequences of Tertiary sedimentary rocks. The Eocene-Oligocene basin lies within the northern Rocky Mountain Basin and Range province. Geologic mapping in five and a half 7.5 minute quadrangles indicates that at least three distinct phases of extension characterize the Cenozoic tectonic evolution of Grasshopper basin from approximately 46 Ma to < Ma.
The significant phases of extension in Grasshopper basin were phases 1 and 3. During the first phase of extension (46-27 Ma) the nonplanar Muddy-Grasshopper fault was initiated and 90% of the basin fill was deposited. At …
An Economic Analysis Of The Arsenic Standard On Nevada, Jill S. Dale
An Economic Analysis Of The Arsenic Standard On Nevada, Jill S. Dale
UNLV Theses, Dissertations, Professional Papers, and Capstones
In 2001, the arsenic standard for drinking water was lowered from 50 parts per billion to 10 parts per billion. The clean-up costs for Nevada are estimated at approximately 400 million dollars. The purpose of this project is to examine the economic impacts the State of Nevada will absorb as a result of the new regulation. Research of historical data will be the basis for the project. National data from the U.S. Environmental Protection Agency and data collected from the State of Nevada will be accompanied by comparable research data found through other sources
Fisheries Research Report No. 134, Volume 2 - Towards An Assessment Of The Natural And Human Use Impacts On The Marine Environment Of The Abrolhos Islands, C F. Chubb, F J. Webster, C J. Dibden
Fisheries Research Report No. 134, Volume 2 - Towards An Assessment Of The Natural And Human Use Impacts On The Marine Environment Of The Abrolhos Islands, C F. Chubb, F J. Webster, C J. Dibden
Fisheries Research Reports
These proceedings form the second of two public documents resulting from the project “Towards an assessment of the natural and human use impacts on the marine environment” funded by the Fisheries Research and Development Corporation (project no. 2000/166). Volume 1, a summary of existing information and assessment of current levels of human use, was presented at a Public Forum in Geraldton on July 11, 2001.
A two-day workshop was held immediately after the forum and was attended by invited representatives from professional fishing and recreational groups together with research and management experts. The issues identified in Volume 1, and those …
Techniques And Algorithms For Immersive And Interactive Visualization Of Large Datasets, Ashish Sharma
Techniques And Algorithms For Immersive And Interactive Visualization Of Large Datasets, Ashish Sharma
LSU Master's Theses
Advances in computing power have made it possible for scientists to perform atomistic simulations of material systems that range in size, from a few hundred thousand atoms to one billion atoms. An immersive and interactive walkthrough of such datasets is an ideal method for exploring and understanding the complex material processes in these simulations. However rendering such large datasets at interactive frame rates is a major challenge. A scalable visualization platform is developed that is scalable and allows interactive exploration in an immersive, virtual environment. The system uses an octree based data management system that forms the core of the …
A New Occurrence Of Archaeoscyphia Pulchra (Bassler) From The Ordovician Of Western Canada, J. Keith Rigby, Godfrey S. Nowlan, Peter A. Rowlands
A New Occurrence Of Archaeoscyphia Pulchra (Bassler) From The Ordovician Of Western Canada, J. Keith Rigby, Godfrey S. Nowlan, Peter A. Rowlands
Faculty Publications
A few specimens of the ornate anthaspidellid demosponge, Archaeoscyphia pulchra (Bassler), have been collected from the Lower Ordovician Outram Formation or Skoki Formation, from a saddle at the head of South Rice Brook in northeastern British Columbia. This is the first report of the flanged-appearing annulate, steeply obconical sponge in western Canada, although it has been reported from the Mingan Islands of Quebec and was initially described from Nevada, in the western United States. The taxon has also been reported as other species of Archaeoscyphia from Ordovician rocks of Missouri and from the San Juan region of Argentina.
Lithospheric Structure Of The Basin And Range Province-Southwestern Colorado Plateau. Southeastern California, Southern Nevada, And Western Arizona, Nigel Oakley Hicks
Lithospheric Structure Of The Basin And Range Province-Southwestern Colorado Plateau. Southeastern California, Southern Nevada, And Western Arizona, Nigel Oakley Hicks
Open Access Theses & Dissertations
The Basin and Range Province of the western United States is an unusually wide continental rift zone and its structure and evolution have been the topic of much debate. Active source seismic surveys within the Basin and Range Province have delineated a relatively uniform crustal thickness (-30 km) despite varying magnitudes of crustal extension (<10-300 km). Large scale Cenozoic crustal extension has exhumed midcrustal rocks (from 10-20 km depth) along low angle detachment faults to create metamorphic core complexes (exposed lower plate rocks). In contrast to the extreme amounts of extension and internal deformation of the Basin and Range, the Colorado Plateau has remained a relatively rigid block, with a crustal thickness of 40-50 km, apparently resistant to the deformation processes that have shaped the Basin and Range observed today. In general, geophysical surveys reveal a significant contrast in crustal structure between the Basin and Range and it's transition into the Colorado Plateau.
The debate about the origin of the Basin and Range has underscored the need for additional geophysical constraints. Thus in this study, a regional analysis of lithospheric structure in the region of southeastern California, southern Nevada, and western Arizona that includes the Basin and Rangesouthwestern …
10-300>Genesis And Evolution Of Proterozoic Crustal Boundaries In The Southern Rocky Mountains., Colin Arthur Shaw
Genesis And Evolution Of Proterozoic Crustal Boundaries In The Southern Rocky Mountains., Colin Arthur Shaw
Earth and Planetary Sciences ETDs
The lithosphere of the southwestern United States is a mosaic of Proterozoic arc terranes assembled to the southern margin of the Archean Wyoming craton between 1.8 and 1.6 Ga. This mosaic was profoundly transformed by ca. 1.4 Ga intracontinental plutonism, metamorphism, and tectonism. These processes of assembly and tectonic reactivation during the early stages of continental evolution laid the foundation for the development of the continental architecture of the southwestern United States.
This dissertation comprises three independent studies focused on different aspects of the Proterozoic evolution of tectonic boundaries exposed in the Southern Rocky Mountains. The first study is a …
Gps-Determination Of Along-Strike Variation In Cascadia Margin Kinematics: Implications For Relative Plate Motion, Subduction Zone Coupling, And Permanent Deformation, M. Meghan Miller, Daniel J. Johnson, Charles M. Rubin, Herb Dragert, Kelin Wang, Anthony Qamar, Chris Goldfinger
Gps-Determination Of Along-Strike Variation In Cascadia Margin Kinematics: Implications For Relative Plate Motion, Subduction Zone Coupling, And Permanent Deformation, M. Meghan Miller, Daniel J. Johnson, Charles M. Rubin, Herb Dragert, Kelin Wang, Anthony Qamar, Chris Goldfinger
All Faculty Scholarship for the College of the Sciences
High‐precision GPS geodesy in the Pacific Northwest provides the first synoptic view of the along‐strike variation in Cascadia margin kinematics. These results constrain interfering deformation fields in a region where typical earthquake recurrence intervals are one or more orders of magnitude longer than the decades‐long history of seismic monitoring and where geologic studies are sparse. Interseismic strain accumulation contributes greatly to GPS station velocities along the coast. After correction for a simple elastic dislocation model, important residual motions remain, especially south of the international border. The magnitude of northward forearc motion increases southward from western Washington (3–7 mm/yr) to northern …
Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Timothy H. Dixon, Roy K. Dokka
Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Timothy H. Dixon, Roy K. Dokka
All Faculty Scholarship for the College of the Sciences
Global Positioning System (GPS) results from networks spanning the Eastern California shear zone and adjacent Sierra Nevada block, occupied annually between 1993 and 1998, constrain plate margin kinematics. We use an elastic block model to relate GPS station velocities to long‐term fault slip rate estimates. The model accounts for elastic strain accumulation on the San Andreas fault, as well as faults of the Eastern California shear zone. South of the Garlock fault, 14 mm/yr of dextral shear is distributed across the Eastern California shear zone. Some of this slip penetrates eastward into the Basin and Range, and a collective budget …
A Proposal For A Method To Establish Natural-Hazard-Based Land-Use Planning: The Adapazarı Case Study, Alper Çabuk
A Proposal For A Method To Establish Natural-Hazard-Based Land-Use Planning: The Adapazarı Case Study, Alper Çabuk
Turkish Journal of Earth Sciences
As a result of recent disasters in northwest Turkey (Marmara earthquake August 17, 1999/Düzce earthquake November 12, 1999), many buildings collapsed and many people experienced physical and mental problems. We can suppose that the problems caused by these earthquakes will be solved in the future, but geological studies show that the problems will not disappear in that many scientists are predicting a new disaster that will affect the same region. A design of natural-hazard land-use planning for minimising the consequences of recent and possible earthquakes is presented herein. The Adapazarı case is used to demonstrate the fundamentals of this study. …
Normal Faults And Extensional Folds Of Southwest Montana And Eastern Idaho, Susanne U. Janecke, J. J. Blankenau, C. J. Vandenburg, B. S. Van Gosen
Normal Faults And Extensional Folds Of Southwest Montana And Eastern Idaho, Susanne U. Janecke, J. J. Blankenau, C. J. Vandenburg, B. S. Van Gosen
Geosciences Faculty Publications
No abstract provided.
Magmatic Processes Operating During The Middle To Late Pliocene And Pleistocene Along The Transition Zone Near 43º North, Christy L. Lee
Magmatic Processes Operating During The Middle To Late Pliocene And Pleistocene Along The Transition Zone Near 43º North, Christy L. Lee
Dissertations and Theses
A geochemical and structural transition zone exists between the Cascades and Basin and Range provinces in Oregon. Geologic mapping in this area has allowed the definition of six volcanic rock sequences: 1) interfingered alkali-rich basaltic trachyandesite to trachydacite lava flows and low-alkali basaltic andesite lava flows, 2) HAOT lava flows, 3) basaltic andesite lava flows, 4) andesite lava flows and vent deposits with minor basaltic andesite lava flows, 5) HAB lava flows, and 6) interfingered basaltic andesite, andesite, and trachyandesite lava flows.
Geochemical models of sequence 1 alkali-rich rocks suggest the fractionation of the parent assemblage plag (An55)+magn+ol±aug …
Geosciences Newsletter - 2000, Department Of Geosciences
Geosciences Newsletter - 2000, Department Of Geosciences
Geological and Environmental Sciences News
Vol.1, No. 25
- Greetings All
- Faculty News
- Groundwater Education in Michigan News
- Graduate Student News
- Alumni News
- Advisory Council News
The John Muir Newsletter, Fall 2000, The John Muir Center For Regional Studies
The John Muir Newsletter, Fall 2000, The John Muir Center For Regional Studies
Muir Center Newsletters (1981-2015)
I J ' Ov Volume 10, Number 4 NEWSLETTER I Fall 2000 A Sense of the Natural by Richard F. Fleck w rom the time of my first published essay about a Maine sea coast tidal pool in June, 1954 (when I was not quite seventeen), until now, some forty-six fpars later, my major source of inspiration has been the Batural world, be it the Irish Mountains of Mourne rolling flown to the sea or the rocky coast of Maine, or the windy Himmits of Longs Peak, Colorado or Mount Fuji, Japan, ■have always delighted in the smell of turf …
Late Quaternary Glacier Fluctuations And Vegetation Change In The Northwestern Ahklun Mountains, Southwestern Alaska, Yarrow L. Axford
Late Quaternary Glacier Fluctuations And Vegetation Change In The Northwestern Ahklun Mountains, Southwestern Alaska, Yarrow L. Axford
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This research examines moraine and lacustrine records of glacier fluctuations, in combination with palynological records of vegetation change, from the previously unstudied northwestern Ahklun Mountains in southwestern Alaska.
Moraine mapping reveals that ice-cap outlet glaciers in the study area extended ca. 60 km from the center of the Ahklun Mountians ice dome during the early Wisconsin (sensu lato), and ca. 40 km during the late Wisconsin. Correlations with well-studied moraines in the southern Ahklun Mountains indicate an asymmetry of glaciation over the range, with ice-cap outlet glaciers more extensive to the south. This asymmetry was more striking during …
Type Locality For The Great Blue Limestone In The Bingham Nappe, Oquirrh Mountains, Utah, United States Geological Survey
Type Locality For The Great Blue Limestone In The Bingham Nappe, Oquirrh Mountains, Utah, United States Geological Survey
All U.S. Government Documents (Utah Regional Depository)
The Great Blue Limestone was named originally by Spurr (1895) from exposures near the Mercur mining district in the Oquirrh Mountains, Utah. The formation was described in greater detail by Gilluly (1932) in the Ophir mining district. Neither formally established a type locality for this formation in the Oquirrh Mountains. However, the formation has since been correlated broadly with similar sedimentary rocks elsewhere in the adjoining Rocky Mountains and Great Basin regions. For the record, and to assist future correlations, a type measured section of the Great Blue Limestone in the Oquirrh Mountains is located, described, and a detailed measured …
Seismic Reflection Study Of Upheaval Dome, Canyonlands National Park, Utah, Z. Kanbur, J. N. Louie, S. Chavez-Perez, G. Plank, D. Morey
Seismic Reflection Study Of Upheaval Dome, Canyonlands National Park, Utah, Z. Kanbur, J. N. Louie, S. Chavez-Perez, G. Plank, D. Morey
Canyonlands Research Bibliography
The origin of Upheaval Dome, in Canyonlands National Park of southeastern Utah, has been a topic of controversy among geologists and planetary scientists. The structure has long been thought to have been created by salt diapirism from the underlying Paradox Formation. Recent studies have suggested that impact could have formed the dome. To test the various hypotheses, we acquired, processed, and interpreted seismic reflection data within and adjacent to the structure. Both conventionally stacked and prestack-migrated images show <100 m relief in the Paradox Formation, contrary to salt diapirism hypotheses. Further, we have identified features within the images typical of impact structures, such as listric normal faults having displacements toward the center of the dome. Deformation occurs in two depth ranges, with the faulting that created the central uplift appearing only above the Hermosa Formation, in the upper 800 m of the structure. The images also suggest limited fracturing of the Hermosa and salt flow in the Paradox Formation, perhaps due to gravitational relaxation of the crater form. Our image of a nearly flat top of the Paradox salt strongly favors an impact origin for Upheaval Dome.
The History Of Archeological Research At Medicine Creek Reservoir, Robert Blasing
The History Of Archeological Research At Medicine Creek Reservoir, Robert Blasing
United States National Park Service: Publications
Medicine Creek is a tributary which flows southeast into the Republican River, which in turn contributes to the Kansas River. The drainage basin is in southwest Nebraska and is about 75 km or 50 miles in length. It drains an area of slightly under 700 square miles.
Medicine Creek Reservoir (Reservoir) was completed in 1949. It was built primarily to control destructive flooding on both the Medicine and Republican drainages. It is also part of the Frenchman-Cambridge Irrigation Project, administered by the Bureau of Reclamation (Reclamation).
The area around the Reservoir is covered by a deep mantel of wind blown …
Carbonate Deposition And Sequence Stratigraphy Of The Terminal Cambrian Grand Cycle In The Southern Appalachians, U.S.A, Bosiljka Glumac, Kenneth R. Walker
Carbonate Deposition And Sequence Stratigraphy Of The Terminal Cambrian Grand Cycle In The Southern Appalachians, U.S.A, Bosiljka Glumac, Kenneth R. Walker
Geosciences: Faculty Publications
The cessation of shale and carbonate deposition of the Conasauga Group grand cycles (Middle to Upper Cambrian) and the establishment of the widespread peritidal carbonate deposition of the Knox Group (Upper Cambrian to Lower Ordovician) represent a prominent change in sedimentation along the early Paleozoic passive continental margin in the southern Appalachians. To evaluate the causes for this change, this study focuses on the Maynardville Formation, which is the uppermost carbonate unit of the Conasauga Group. The Maynardville consists of: (1) a lower subtidal faciès succession, which is underlain by the Nolichucky Shale and resembles the rest of the Conasauga …
Distribution, Speciation, And Transport Of Mercury In Stream-Sediment, Stream-Water, And Fish Collected Near Abandoned Mercury Mines In Southwestern Alaska, Usa, John E. Gray, Peter M. Theodorakos, Elizabeth A. Bailey, Ralph R. Turner
Distribution, Speciation, And Transport Of Mercury In Stream-Sediment, Stream-Water, And Fish Collected Near Abandoned Mercury Mines In Southwestern Alaska, Usa, John E. Gray, Peter M. Theodorakos, Elizabeth A. Bailey, Ralph R. Turner
United States Geological Survey: Staff Publications
Concentrations of total Hg, Hg(II), and methylmercury were measured in stream-sediment, stream-water, and fish collected downstream from abandoned mercury mines in southwestern Alaska to evaluate environmental effects to surrounding ecosystems. These mines are found in a broad belt covering several tens of thousands of square kilometers, primarily in the Kuskokwim River basin. Mercury ore is dominantly cinnabar (HgS), but elemental mercury (Hg °) is present in ore at one mine and near retorts and in streams at several mine sites. Approximately 1400 t of mercury have been produced from the region, which is approximately 99% of all mercury produced from …
Geochemical And Mineralogical Evidence From Eolian Sediments For Northwesterly Mid-Holocene Paleowinds, Central Kansas, Usa, Alan F. Arbogast, Daniel R. Muhs
Geochemical And Mineralogical Evidence From Eolian Sediments For Northwesterly Mid-Holocene Paleowinds, Central Kansas, Usa, Alan F. Arbogast, Daniel R. Muhs
United States Geological Survey: Staff Publications
A prominent (4500 km2) dune field in the Great Plains is the Great Bend Sand Prairie of south-central Kansas. Dunes here overlie late Quaternary alluvium and were reactivated extensively in the late Holocene. Geomorphic and soil evidence suggests that the most likely eolian sand source is the Arkansas River valley to the northwest. Nevertheless, orientations of stabilized dunes indicate that the most recent dune-forming winds came from the south or southwest, in agreement with modern wind data.
Mineralogy and trace element concentrations in eolian sands of the Great Bend Sand Prairie are similar to those of the Arkansas …
A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury
A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury
Dissertations
Groundwater vulnerability to contamination from surface sources was evaluated for Nottawa Creek Watershed, Calhoun County Michigan using AQUIPRO and DRASTIC vulnerability methods. A geographic information system (GIS) was used to analyze and map the data. Forty groundwater samples were collected following a statistical sampling protocol from private wells. Samples were analyzed for nitrate-N and atrazine. Atrazine was not detected (detection limit 0.1 ppb) in any of the samples. Five samples contained detectable nitrate-N (detection limit 0.05 mg/L). Due to insufficient chemical data, the relative AQUIPRO and DRASTIC vulnerability scores could not be compared with the frequency of occurrences o f …
Benthic Community Analysis Of Hog Island Bay, Virginia, David James Lewis
Benthic Community Analysis Of Hog Island Bay, Virginia, David James Lewis
Biological Sciences Theses & Dissertations
The benthic infaunal macroinvertebrate communities of Hog Island Bay of the Virginia Eastern Shore were quantitatively sampled at 30 locations on August 31 and September 1, 1995. The primary objectives of this study were: (1) to characterize the subtidal macroinfaunal benthic communities of Hog Island Bay, (2) to examine relationships between abiotic factors and the macroinfaunal communities and (3) to characterize the environmental condition of the system using the Benthic Index of Biotic Integrity (B-IBI) (Weisburg et al. 1997) and the EMAP Benthic Index for the Virginian Province (Strobel et al. 1995).
The ecological condition of Hog Island Bay appears …