Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 8071 - 8100 of 9404

Full-Text Articles in Entire DC Network

Investigation Of Optimum Sample Number And Timing For Determining Pollution Loads, T. S. Soerens, Marc A. Nelson Oct 2000

Investigation Of Optimum Sample Number And Timing For Determining Pollution Loads, T. S. Soerens, Marc A. Nelson

Arkansas Water Resources Center Technical Reports

In order to determine the impacts of non point source (NPS) pollution and to develop Total Maximum Daily Loads (Tr\tfDLs), accurate measurements of pollution loads in streams are critical. The objectives of this study were to accurately detemline pollutant loads at two sites by intensive storm sampling, to develop sub-sampling and other data analysis techniques, to detemline the effect of sample interval on load calculation accuracy, and to find the minimum sample interval required to determine storm loads at a required accuracy. The two stream sites used were a 1st order and a 3rd order stream in the Illinois River …


Ground Water In Northwest Arkansas: Minimizing Nutrient Contamination From Non-Point Sources In Karst Terrane, R. K. Davis, J. V. Brahana, J. S. Johnston Sep 2000

Ground Water In Northwest Arkansas: Minimizing Nutrient Contamination From Non-Point Sources In Karst Terrane, R. K. Davis, J. V. Brahana, J. S. Johnston

Arkansas Water Resources Center Technical Reports

The purpose of the project is to evaluate the effectiveness of Best Management Practices (BPMs) in preventing non-point source contamination of the ground-water resources in the karst terrane of northwestern Arkansas. Limestone and dolomite aquifers in the region are highly vulnerable to contamination. Ground-water studies performed in the region during the last two decades indicate degradation of these carbonate aquifers by nutrients and bacteria. The expeditious growth of the poultry industry during this period, in combination with the inordinate population growth of the region constitute a threat to the ground-water resources from both point sources and non-point sources of contamination. …


Bulletin 4418 - Nebru Focus Catchment Report, Agriculture Western Australia Jul 2000

Bulletin 4418 - Nebru Focus Catchment Report, Agriculture Western Australia

Bulletins 4000 -

Nehru Focus Catchment is located in the upper reaches of the Arrowsmith Catchment. It is roughly bounded by Sunset Road in the north, the north-south Kadathinni Hills to the east, the Three Springs - Eneabba Road to the south and Reed Road in the west. It changes in elevation from 372 metres Australian Height Datum (AHD) at roughly the intersection of Nehru Rd the Kadathinni Hills to the east and 220 metres AHD near the outlet of the catchment into the Arrowsmith River.

The total area of the catchment is just over 7,400 hectares.

One of the prime areas of …


Degradation In The Brockman River And Ellen Brook Catchments, Western Australia, Brian Lloyd Jul 2000

Degradation In The Brockman River And Ellen Brook Catchments, Western Australia, Brian Lloyd

Natural resources published reports

An eight day survey of degradation in the Ellen Brook and Brockman River catchments revealed several areas of concern. Key concerns are:

Erosion and sedimentation

Various forms of erosion were observed during the survey that would cumulatively have an effect on the quality of both the Ellen Brook and the Brockman Rivers, and ultimately the Swan River. Erosion resulted from many situations including landholder management, subdivision design and infrastructure maintenance. Raising awareness as to consequences of erosion and sedimentation, along with remedial techniques and best management practices is recommended for the various levels of stakeholders.

Eutrophication

Eutrophication has been established …


Identity, Conflict And Cooperation In International River Basins, Jack V. Kalpakian Jul 2000

Identity, Conflict And Cooperation In International River Basins, Jack V. Kalpakian

Graduate Program in International Studies Theses & Dissertations

This dissertation tests the hypothesis that water disputes cause serious conflict within and between states. It uses a structured case study approach to see whether there is a link between the independent and dependent variables. It also considers the effect of other variables on serious conflict. Specifically it addresses the effects of national identity and the othering process on conflict. The three case studies are built around rivers in the drier parts of the world. This biases the dissertation towards affirming the established mainstream hypothesis which states that water disputes cause serious conflict. In all three cases, historical animosities and …


Impacts Of Water Transfers On The Agricultural Sector, Don Ament Jun 2000

Impacts Of Water Transfers On The Agricultural Sector, Don Ament

Water and Growth in the West (Summer Conference, June 7-9)

2 pages.

Contains one reference.


Water, Growth And The Endangered Species Act, Holly Doremus Jun 2000

Water, Growth And The Endangered Species Act, Holly Doremus

Water and Growth in the West (Summer Conference, June 7-9)

24 pages.


The Effects Of Development On Indian Water Rights: Obstacles And Disincentives To Development Of Indian Water Rights, Jerilyn Decoteau Jun 2000

The Effects Of Development On Indian Water Rights: Obstacles And Disincentives To Development Of Indian Water Rights, Jerilyn Decoteau

Water and Growth in the West (Summer Conference, June 7-9)

17 pages.

Contains references.


Growth Pressures And Tmdls, David G. Davis, Jamal M. Kadri, Teresa J. Norfleet Jun 2000

Growth Pressures And Tmdls, David G. Davis, Jamal M. Kadri, Teresa J. Norfleet

Water and Growth in the West (Summer Conference, June 7-9)

18 pages.


Comparative Ecosystem Analysis Of Hydrologic Restoration Of Tates Hell Swamp, Chris Robert, Thomas Crisman, Loren Anderson, Carolyn Kendell Jun 2000

Comparative Ecosystem Analysis Of Hydrologic Restoration Of Tates Hell Swamp, Chris Robert, Thomas Crisman, Loren Anderson, Carolyn Kendell

School of Geosciences Faculty and Staff Publications

No abstract provided.


The Age Of The Woolly Rhino From Dream Cave, Derbyshire, Uk, Donald A. Mcfarlane, Joyce Lundberg, Derek C. Ford Apr 2000

The Age Of The Woolly Rhino From Dream Cave, Derbyshire, Uk, Donald A. Mcfarlane, Joyce Lundberg, Derek C. Ford

WM Keck Science Faculty Papers

The Dream Cave woolly rhinoceros, Coelodonta antiquitatis, is a "classic" specimen of a "cold-stage" fossil fauna from central England. The find was illustrated and described by Dean William Buckland in his seminal tome Reliquiae Diluvianae (1823) during the first half of the 19th century, and made a significant contribution to the development of Buckland's views on the origin of extinct and extirpated fossil vertebrates. The report presents the first, albeit indirect, radiometric dates on the specimen, and argues that the animal fell into the cave just before 37,000 years BP, during the middle of Marine Isotope Stage 3 Interstadial (41 …


Changes In Alfalfa Breeding — Where Is Alfalfa Headed?, Becky Greenwald Feb 2000

Changes In Alfalfa Breeding — Where Is Alfalfa Headed?, Becky Greenwald

Kentucky Alfalfa and Stored Forage Conference

Alfalfa didn't earn the title "Queen of the Forages" just because of its good looks on rolling hills or sweet smell at harvest. Alfalfa was first described nearly 2,500 years ago, in 490 B.C in the desert regions of what is now Iran. From the Middle East, alfalfa was taken into Europe and South America by invading armies, explorers, and missionaries.


Little Known Facts About Alfalfa, Don Ball Feb 2000

Little Known Facts About Alfalfa, Don Ball

Kentucky Alfalfa and Stored Forage Conference

During the previous nineteen Kentucky Alfalfa Conferences, many topics pertaining to alfalfa have undoubtedly been addressed. In fact, some topics such as establishment techniques, varieties, and factors affecting yield are important enough that they have probably been discussed in one form or another during most of these conferences.

However, a twentieth-year state commodity conference is a milestone that deserves some special consideration, and which should justify inclusion of one or more unique topics on the program. This line of thinking led to idea that for this presentation it might be interesting to discuss some facts about alfalfa that are not …


Opportunities For Alfalfa As A Grazing Crop In Kentucky, Ken Johnson Feb 2000

Opportunities For Alfalfa As A Grazing Crop In Kentucky, Ken Johnson

Kentucky Alfalfa and Stored Forage Conference

Why do we continue to hear people talk about Alfalfa as a grazing crop? In my opinion there are two words that come to mind when I think of grazing Alfalfa, quality and yield. Alfalfa is without a doubt the highest quality forage we can graze. Alfalfa is also one of the highest yielding forages we can graze and maybe the highest yielding widely known and widely grown forage available to Kentucky farmers.


Hay Testing And New Marketing Program, Allen Johnson Feb 2000

Hay Testing And New Marketing Program, Allen Johnson

Kentucky Alfalfa and Stored Forage Conference

The Kentucky Department of Agriculture (Hay & Grain Branch) Hay testing program is now entering its 13th year of testing hay for Kentucky producers. The Department continues to use NIR forage analysis equipment. The program has made many improvements and much information has been gained. We continue to strive for quality control and producing accurate results. Recently, many new updates have occurred. New hardware and software have been added, along with the recent purchase of a second hay testing van. By placing a toll free call (1-800- 248-4628) to the Department of Agriculture in Frankfort, we will find a …


Fertilizing Alfalfa For Profit, Monroe Rasnake, Steven G. Isaacs Feb 2000

Fertilizing Alfalfa For Profit, Monroe Rasnake, Steven G. Isaacs

Kentucky Alfalfa and Stored Forage Conference

Alfalfa has the potential for producing high yields of high quality forage with good management. A key component of good management is supplying plant nutrients in adequate quantities and proper balance. In Kentucky, this requires fertilizing soils with agricultural limestone, commercial fertilizers and/or animal manures. Good soil fertility is necessary for alfalfa stand establishment, high yields and long stand life.


Crop Updates 2000 - Oilseeds, Paul Carmody, Ping Si, Rodney Mailer, Nick Galwey, David Turner, Kevin Morthorpe, Stephen Addenbrooke, Peter Nelson, Mike Jackson, Scott Paton, Ross Brennan, Noeleen Edwards, Mike Bolland, Bill Bowden, C. P. Gunasekera, L. D. Martin, G. H. Walton, K. H. M. Siddique, Sharon R. Niknam, David W. Turner, Abul Hashem, Harmonhinder Dhammu, David Bowran, The Canola Association Of Western Australia, Syed H. Zaheer, Ravjit Khangura, Martin J. Barbetti, Peter Carlton, Debbie Thackray, Jenny Hawkes, Roger Jones, Brenda Coutts, Françoise Berlandier, Ross Kingwell, Michael O'Connell, Simone Bennerhasset Feb 2000

Crop Updates 2000 - Oilseeds, Paul Carmody, Ping Si, Rodney Mailer, Nick Galwey, David Turner, Kevin Morthorpe, Stephen Addenbrooke, Peter Nelson, Mike Jackson, Scott Paton, Ross Brennan, Noeleen Edwards, Mike Bolland, Bill Bowden, C. P. Gunasekera, L. D. Martin, G. H. Walton, K. H. M. Siddique, Sharon R. Niknam, David W. Turner, Abul Hashem, Harmonhinder Dhammu, David Bowran, The Canola Association Of Western Australia, Syed H. Zaheer, Ravjit Khangura, Martin J. Barbetti, Peter Carlton, Debbie Thackray, Jenny Hawkes, Roger Jones, Brenda Coutts, Françoise Berlandier, Ross Kingwell, Michael O'Connell, Simone Bennerhasset

Crop Updates

This session covers seventeen papers from different authors:

Introduction, Paul Carmody, Centre for Cropping Systems

CANOLA AGRONOMY

2. Genotype, location and year influence the quality of canola grown across southern Australia, PingSi1, Rodney Mailer2, Nick Galwey1 and David Turner1, 1Plant Sciences, Faculty of Agriculture, The University of Western Australia, 2Agricultural Research Institute, New South Wales Agriculture

3. Development of Pioneer® Canola varieties for Australian market,Kevin Morthorpe, StephenAddenbrooke, Pioneer Hi-Bred Australia Pty Ltd

4. Canola, Erucic Acid, Markets and Agronomic Implications, Peter Nelson, The Grain Pool …


Crop Updates 2000 - Pulses, Kerry Regan, Peter White, Kamdambot Siddique, W. O'Neill, J. Russell, R. J. French, N. Brandon, C. Gaskin, N. Runciman, M. Seymore, J. Berger, N. C. Turner, R. Carpenter, C. Ludwig, R. Kenny, Q. Ma, M. H. Behboudian, J. A. Palta, H. Clarke, J. Stott, J. Howieson, K. L. Regan, R. Shackles, C. Francis, N. Acikgoz, N. Atikyilmaz, R. S. Malholtra, M. Baker, J. Clements, C. Hanbury, C. White, B. P. Mullan, R. Lancaster, I. Guthridge, I. Pritchard, P. Fisher, M. Braimbridge, J. Bignell, R. Beermier, W. Bowden, M. D. A. Bolland, G. P. Riethmuller, R. F. Brennan, S. Lawrence, Zen Rengel, S. P. Loss, P. Vedeniapine, C. Kirkwood, D. Wright, L. Latham, R. Jones, M. J. De Sousa Majer, D. Hardie, Oonagh Byrne, Penny Smith, Françoise Berlandier, N. Keals, R. Emery Feb 2000

Crop Updates 2000 - Pulses, Kerry Regan, Peter White, Kamdambot Siddique, W. O'Neill, J. Russell, R. J. French, N. Brandon, C. Gaskin, N. Runciman, M. Seymore, J. Berger, N. C. Turner, R. Carpenter, C. Ludwig, R. Kenny, Q. Ma, M. H. Behboudian, J. A. Palta, H. Clarke, J. Stott, J. Howieson, K. L. Regan, R. Shackles, C. Francis, N. Acikgoz, N. Atikyilmaz, R. S. Malholtra, M. Baker, J. Clements, C. Hanbury, C. White, B. P. Mullan, R. Lancaster, I. Guthridge, I. Pritchard, P. Fisher, M. Braimbridge, J. Bignell, R. Beermier, W. Bowden, M. D. A. Bolland, G. P. Riethmuller, R. F. Brennan, S. Lawrence, Zen Rengel, S. P. Loss, P. Vedeniapine, C. Kirkwood, D. Wright, L. Latham, R. Jones, M. J. De Sousa Majer, D. Hardie, Oonagh Byrne, Penny Smith, Françoise Berlandier, N. Keals, R. Emery

Crop Updates

This session covers fifty nine papers from different authors:

1.1999 PULSE INDUSTRY HIGHLIGHTS

2. CONTRIBUTORS

3. BACKGROUND

4. SUMMARY OF PREVIOUS RESULTS

5. 1999 REGIONAL ROUNDUP

6. Northern Agricultural Region, W. O’Neill, AGWEST

7. Central Agricultural Region J. Russell and R.J. French AGWEST

8. Great Southern and Lakes N. Brandon, C. Gaskin and N. Runciman, AGWEST

9. Esperance Mallee M. Seymour, AGWEST

PULSE PRODUCTION AGRONOMY AND GENETIC IMPROVEMENT

10. Faba Bean

11. Desi chickpea Traits associated with drought resistance in chickpea, J. Berger, N.C. Turner, CLIMA and CSIRO Plant Industry, R.J. French, AGWEST, R. Carpenter, C. Ludwig and R. …


Stocking Rate Guidelines For Rural Small Holdings, Swan Coastal Plain And Darling Scarp And Surrounds, Western Australia, Dennis Van Gool, Ken Angell, Lindsay Stephens Feb 2000

Stocking Rate Guidelines For Rural Small Holdings, Swan Coastal Plain And Darling Scarp And Surrounds, Western Australia, Dennis Van Gool, Ken Angell, Lindsay Stephens

Agriculture reports

Small rural holdings are often owned by people who want to pursue a semi-rural lifestyle but who are inexperienced in land management issues. This can result in landholders stocking their properties with animals at rates higher than the land resources can sustain, leading to degradation problems such as soil erosion, water pollution and damage to vegetation. This document provides information and guidelines to help planners, developers, local authorities and land owners determine the base stocking rates for rural small holdings on the Swan Coastal Plain and Darling Scarp and immediate surrounds. The advice utilises Agriculture Western Australia’s rural stocking rate …


Environmental Assessment Wild Horse Gathering For The Fifteenmile Wild Horse Herd Management Area, United States Bureau Of Land Management Jan 2000

Environmental Assessment Wild Horse Gathering For The Fifteenmile Wild Horse Herd Management Area, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

The purpose for management of wild, free roaming horses is to comply with law and policy pertaining to wild, free roaming horses on public lands. The policy of the BLM addresses a range of topics including establishment and maintenance of Appropriate Management Levels (AMLs) in Herd Managment Areas (HMAs) in a humane, safe, efficient, and environmentally sound manner.


Grassland Bird Use Of Conservation Reserve Program Fields In The Great Plains, Douglas H. Johnson Jan 2000

Grassland Bird Use Of Conservation Reserve Program Fields In The Great Plains, Douglas H. Johnson

United States Geological Survey: Publications

The area enrolled in the Conservation Reserve Program in the Great Plains is enormous: nearly 18 million acres, or more than 7 million hectares, in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. This change in land use has had a huge influence on grassland bird populations. Many, but certainly not all, grassland species flourish in CRP habitats. Responses to the program vary not only by species, but by region, year, vegetation composition in a field, and whether or not a field was hayed or grazed. Further, the large scale of CRP has allowed researchers to …


Chronology And Geochemistry Of Late Holocene Eolian Deposits In The Brandon Sand Hills, Manitoba, Canada, Stephen A. Wolfe, Daniel R. Muhs, Peter P. David, John P. Mcgeehin Jan 2000

Chronology And Geochemistry Of Late Holocene Eolian Deposits In The Brandon Sand Hills, Manitoba, Canada, Stephen A. Wolfe, Daniel R. Muhs, Peter P. David, John P. Mcgeehin

United States Geological Survey: Staff Publications

Accelerator mass spectrometry and conventional radiocarbon age determinations of organic matter from paleosols indicate that the Brandon Sand Hills area of southern Manitoba has been subjected to recurrent intervals of eolian activity in the past 5000 years. Although precise regional correlations are precluded by dating uncertainties, periods of most notable paleosol development occurred around 2300 to 2000, 1400 to 1000, and 600 to 500 cal yr BP with eolian activity occurring before and after each of these periods. Episodes of eolian activity may correspond to periods of regional drought, whereas paleosols mark periods of increased moisture availability and stabilization by …


Land Cover Trends Dataset, 1973–2000, Christopher E. Soulard, William Acevedo, Roger F. Auch, Terry L. Sohl, Mark A. Drummond, Benjamin M. Sleeter, Daniel G. Sorenson, Steve Kambly, Tamara S. Wilson, Janis L. Taylor, Kristi L. Sayler, Michael P. Stier, Christopher A. Barnes, Steve C. Methven, Thomas R. Loveland, Rachel Headley, Mark S. Brooks Jan 2000

Land Cover Trends Dataset, 1973–2000, Christopher E. Soulard, William Acevedo, Roger F. Auch, Terry L. Sohl, Mark A. Drummond, Benjamin M. Sleeter, Daniel G. Sorenson, Steve Kambly, Tamara S. Wilson, Janis L. Taylor, Kristi L. Sayler, Michael P. Stier, Christopher A. Barnes, Steve C. Methven, Thomas R. Loveland, Rachel Headley, Mark S. Brooks

United States Geological Survey: Publications

The U.S. Geological Survey Land Cover Trends Project is releasing a 1973–2000 time-series land-use/land-cover dataset for the conterminous United States. The dataset contains 5 dates of land-use/land-cover data for 2,688 sample blocks randomly selected within 84 ecological regions. The nominal dates of the land-use/land-cover maps are 1973, 1980, 1986, 1992, and 2000. The land-use/land-cover maps were classified manually from Landsat Multispectral Scanner, Thematic Mapper, and Enhanced Thematic Mapper Plus imagery using a modified Anderson Level I classification scheme. The resulting land-use/land-cover data has a 60-meter resolution and the projection is set to Albers Equal-Area Conic, North American Datum of 1983. …


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 Jan 2000

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 …


Metal Exposure In A Benthic Macroinvertebrate, Hydropsyche Californica, Related To Mine Drainage In The Sacramento River, Daniel J. Cain, James L. Carter, Steven V. Fend, Samuel N. Luoma, Charles N. Alpers, Howard E. Taylor Jan 2000

Metal Exposure In A Benthic Macroinvertebrate, Hydropsyche Californica, Related To Mine Drainage In The Sacramento River, Daniel J. Cain, James L. Carter, Steven V. Fend, Samuel N. Luoma, Charles N. Alpers, Howard E. Taylor

United States Geological Survey: Staff Publications

A biomonitoring technique was employed to complement studies of metal transport in the upper Sacramento River affected by acid mine drainage. Metals (Al, Cd, Cu, Fe, Hg, Pb, and Zn) were determined in a resident invertebrate, Hydropsyche californica (Insecta: Trichoptera), and streambed sediments (<62 >μm) to assess metal contamination within a 111-km section of the river downstream of the mining area. Metals in H. californica also were interpreted to be broadly indicative of metal exposure in fish. Total Hg was determined in the whole body of the insect, whereas Al, Cd, Cu, Fe, Pb, and Zn were additionally separated into …


Multibeam Sonar Backscatter Lineaments And Anthropogenic Organic Components In Lacustrine Silty Clay, Evidence Of Shipping In Western Lake Ontario, C F Michael Lewis, L A. Mayer, Prasanta K. Mukhopadhyay, Michael A. Kruge, John P. Coakley, M D. Smith Jan 2000

Multibeam Sonar Backscatter Lineaments And Anthropogenic Organic Components In Lacustrine Silty Clay, Evidence Of Shipping In Western Lake Ontario, C F Michael Lewis, L A. Mayer, Prasanta K. Mukhopadhyay, Michael A. Kruge, John P. Coakley, M D. Smith

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

A multibeam sonar survey (95 kHz) covering more than 500 km2 of western Lake Ontario revealed anomalous lineaments of relatively high backscatter. The lineaments did not align with or parallel the most prominent structural zones beneath the lake as expected. Instead, the principal lineaments lay on lines between ports on opposite sides of the lake, especially between Toronto and Welland Canal, and Toronto and Niagara River mouth. As the lineaments underlie current and historical shipping routes used during the steamship era, they are interpreted as an acoustic response to shipping debris cumulated in the near-surface bottom sediment. An exploratory …


Ecogeochemistry Of The Subsurface Food Web At Ph 0–2.5 In Iron Mountain, California, U.S.A., Eleanora I. Robbins, Teresa M. Rodgers, Charles N. Alpers, D. Kirk Nordstrom Jan 2000

Ecogeochemistry Of The Subsurface Food Web At Ph 0–2.5 In Iron Mountain, California, U.S.A., Eleanora I. Robbins, Teresa M. Rodgers, Charles N. Alpers, D. Kirk Nordstrom

United States Geological Survey: Staff Publications

Pyrite oxidation in the underground mining environment of Iron Mountain, California, has created the most acidic pH values ever reported in aquatic systems. Sulfate values as high as 120 000 mg 1-1 and iron as high as 27600mg 1-1 have been measured in the mine water, which also carries abundant other dissolved metals including Al, Zn, Cu, Cd, Mn, Sb and Pb. Extreme acidity and high metal concentrations apparently do not preclude the presence of an underground acidophilic food web, which has developed with bacterial biomass at the base and heliozoans as top predators. Slimes, oil-like films, flexible …


Nutrients In Groundwaters Of The Conterminous United States, 1992-1995, Bernard Nolan, Jeffrey Stoner Jan 2000

Nutrients In Groundwaters Of The Conterminous United States, 1992-1995, Bernard Nolan, Jeffrey Stoner

United States Geological Survey: Staff Publications

Results of a national water quality assessment indicate that nitrate is detected in 71% of groundwater samples, more than 13 times as often as ammonia, nitrite, organic nitrogen, and orthophosphate, based on a common detection threshold of 0.2 mg/L. Shallow groundwater (typically 5 m deep or less) beneath agricultural land has the highest median nitrate concentration (3.4 mg/L), followed by shallow groundwater beneath urban land (1.6 mg/L) and deeper groundwater in major aquifers (0.48 mg/L). Nitrate exceeds the maximum contaminant level, 10 mg/L as nitrogen, in more than 15% of groundwater samples from 4 of 33 major aquifers commonly used …


Disarticulation And Dissolution Of Crab Remains Across A Depth Gradient In The Bahamas: A Taphonomic Study, Rebecca A. Lincoln Jan 2000

Disarticulation And Dissolution Of Crab Remains Across A Depth Gradient In The Bahamas: A Taphonomic Study, Rebecca A. Lincoln

Honors Papers

The fields of Paleontology and Paleoecology would not be complete without taphonomy, the study of the processes affecting organisms between death and fossilization. Taphonomy is important because it allows us to make more complete conjectures about prehistoric organisms and environments, and makes us aware of possible holes and biases in the fossil record due to highly destructive processes or the loss of delicate, non-resistant organisms. Studies on the processes affecting modern organisms have contributed greatly to the understanding of ancient processes; however, most of these studies are nearshore and short-term. What is lacking is information on the effects of these …


Bad-Boy Bryozoan Biomarkers: Cheilostome Distribution Patterns Along A Bahamian Depth Gradient, Christopher J. Nytch Jan 2000

Bad-Boy Bryozoan Biomarkers: Cheilostome Distribution Patterns Along A Bahamian Depth Gradient, Christopher J. Nytch

Honors Papers

In 1993 and 1994, the Shelf and Slope Experimental Taphonomy Initiative (SSETI) deployed thirty-five samples of sea urchins along the continental shelf/slope of the Bahamas in an effort to explore the paleoecology and taphonomic potentials of shallow water carbonate environments. Samples were retrieved at 1-, 2-, and 6-year intervals for examination and comparison of epibiont accumulation. Tests and spines of the sea urchin Eucidaris were examined for encrusting cheilostome Bryozoa. Specimens were identified to the genus level. Assessment of abundance and distribution patterns with water depth shows that cheilostomes are prevalent in photic waters, and lacking at depth. Burial of …