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 49261 - 49290 of 59458

Full-Text Articles in Entire DC Network

Reconstructing Sea-Level Change From The Internal Architecture Of Stromatolite Reefs: An Example From The Mesoproterozoic Sulky Formation, Dismal Lakes Group, Arctic Canada, L C. Kah, Julie K. Bartley, Tracy D. Frank, Timothy W. Lyons Jan 2006

Reconstructing Sea-Level Change From The Internal Architecture Of Stromatolite Reefs: An Example From The Mesoproterozoic Sulky Formation, Dismal Lakes Group, Arctic Canada, L C. Kah, Julie K. Bartley, Tracy D. Frank, Timothy W. Lyons

Department of Earth and Atmospheric Sciences: Faculty Publications

The Mesoproterozoic Dismal Lakes Group, arctic Canada, contains a relatively thin, yet regionally extensive stromatolitic reef complex that developed subtidally during a major transgression, shoaled to sea level, and was overlain by intertidal to supratidal carbonate and evaporite strata. The September Lake reef complex exhibits a complex internal architecture that records the interaction between stromatolite growth and changes in accommodation space derived from both higher order (4th- or 5th-order, parasequence-scale) changes in sea level and the variable bathymetry of the sea floor. Reef growth, which was initiated during three sea-level cycles, records progressive marine transgression over depositional lows that were …


A Cool Eastern Pacific Ocean At The Close Of The Last Interglacial Complex, Daniel R. Muhs, Kathleen R. Simmons, George L. Kennedy, Kenneth R. Ludwig, Lindsey T. Groves Jan 2006

A Cool Eastern Pacific Ocean At The Close Of The Last Interglacial Complex, Daniel R. Muhs, Kathleen R. Simmons, George L. Kennedy, Kenneth R. Ludwig, Lindsey T. Groves

United States Geological Survey: Staff Publications

New high-precision thermal ionization mass-spectrometric (TIMS) U-series ages of solitary corals (Balanophyllia elegans) from several marine terrace localities along the California and southern Oregon coasts date to the ~80,000 yr BP high stand of sea, correlative with marine isotope substage 5a, late in the last interglacial complex. Ages of multiple corals from localities north of Point Año Nuevo (central California) and San Nicolas Island (southern California) suggest that this high sea stand could have lasted at least 8000 yr, from ~84,000 to ~76,000 yr BP. These ages overlap with those from marine deposits on tectonically stable Bermuda and …


Paleoclimatic Evidence For Future Ice-Sheet Instability And Rapid Sea-Level Rise, Jonathan T. Overpeck, Bette L. Otto-Bliesner, Gifford H. Miller, Daniel R. Muhs, Richard B. Alley, Jeffrey T. Kiehl Jan 2006

Paleoclimatic Evidence For Future Ice-Sheet Instability And Rapid Sea-Level Rise, Jonathan T. Overpeck, Bette L. Otto-Bliesner, Gifford H. Miller, Daniel R. Muhs, Richard B. Alley, Jeffrey T. Kiehl

United States Geological Survey: Staff Publications

Sea-level rise from melting of polar ice sheets is one of the largest potential threats of future climate change. Polar warming by the year 2100 may reach levels similar to those of 130,000 to 127,000 years ago that were associated with sea levels several meters above modern levels; both the Greenland Ice Sheet and portions of the Antarctic Ice Sheet may be vulnerable. The record of past ice-sheet melting indicates that the rate of future melting and related sea-level rise could be faster than widely thought.


Status Of Feral Pigs In Kansas And Nebraska, Philip S. Gipson, Charles D. Lee, Sam Wilson, James R. Thiele, Deke Hobbick Jan 2006

Status Of Feral Pigs In Kansas And Nebraska, Philip S. Gipson, Charles D. Lee, Sam Wilson, James R. Thiele, Deke Hobbick

United States Geological Survey: Staff Publications

Wild pigs have expanded their range markedly during the last 30 years. In Kansas feral pigs from domestic stock were first reported in 1994 on Fort Riley Army Base. During 2005, 2006, and 2007 the occurrence of reproducing wild pigs was confirmed on 18 sites throughout Kansas and 4 sites in Nebraska. One Nebraska population is in a county neighboring Kansas. Estimated numbers of pigs ranged from 8-10 individuals at each of 2 sites in Kansas to more than 30 on each of 3 other sites. The wild pig population in Kansas appears to be changing from 1 predominantly of …


Multi-Species Patterns Of Avian Cholera Mortality In Nebraska’S Rainwater Basin, Julie A. Blanchong, Michael D. Samuel, Gene Mack Jan 2006

Multi-Species Patterns Of Avian Cholera Mortality In Nebraska’S Rainwater Basin, Julie A. Blanchong, Michael D. Samuel, Gene Mack

United States Geological Survey: Staff Publications

Nebraska’s Rainwater Basin (RWB) is a key spring migration area for millions of waterfowl and other avian species. Avian cholera has been endemic in the RWB since the 1970s and in some years tens of thousands of waterfowl have died from the disease. We evaluated patterns of avian cholera mortality in waterfowl species using the RWB during the last quarter of the 20th century. Mortality patterns changed between the years before (1976–1988) and coincident with (1989–1999) the dramatic increases in lesser snow goose abundance and mortality. Lesser snow geese (Chen caerulescens caerulescens) have commonly been associated with mortality …


A Continuous 250,000 Yr Record Of Oxygen And Carbon Isotopes In Ostracode And Bulk-Sediment Carbonate From Bear Lake, Utah-Idaho, Walter E. Dean, Jordon Bright, Darrell S. Kaufman, Richard M. Forester Jan 2006

A Continuous 250,000 Yr Record Of Oxygen And Carbon Isotopes In Ostracode And Bulk-Sediment Carbonate From Bear Lake, Utah-Idaho, Walter E. Dean, Jordon Bright, Darrell S. Kaufman, Richard M. Forester

United States Geological Survey: Staff Publications

Oxygen and carbon isotopes from a continuous, 120-m-long, carbonate-rich core from Bear Lake, Utah-Idaho, document dramatic fluctuations in the hydrologic budget of the lake over the last 250,000 yr. Isotopic analyses of bulk sediment samples capture millennialscale variability. Ostracode calcite was analyzed from 78 levels, mainly from the upper half of the core where valves are better preserved, to compare the isotopic value of purely endogenic carbonate with the bulk sediment, which comprises both endogenic and detrital components. The long core exhibits three relatively brief intervals with abundant endogenic aragonite (50±10%) and enriched δ18O and δ13C. …


Alpersite (Mg,Cu)So4•7h2O, A New Mineral Of The Melanterite Group, And Cuprian Pentahydrite: Their Occurrence Within Mine Waste, Ronald C. Peterson, Jane M. Hammarstrom, Robert R. Seal Ii Jan 2006

Alpersite (Mg,Cu)So4•7h2O, A New Mineral Of The Melanterite Group, And Cuprian Pentahydrite: Their Occurrence Within Mine Waste, Ronald C. Peterson, Jane M. Hammarstrom, Robert R. Seal Ii

United States Geological Survey: Staff Publications

Alpersite, Mg0.58 Cu0.37 Zn0.02 Mn0.02 Fe0.01SO4 •7H2 O, a new mineral species with direct relevance to reactions in mine waste, occurs in a mineralogically zoned assemblage in sheltered areas at the abandoned Big Mike mine in central Nevada at a relative humidity of 65% and T = 4 °C. Blue alpersite, which is isostructural with melanterite (FeSO4 •7H2 O), is overlain by a light blue to white layer dominated by pickeringite, alunogen, and epsomite. X-ray diffraction data (MoKα radiation) from a single crystal of alpersite were refined in P21 …


Abundance And Distribution Of Selected Elements In Soils, Stream Sediments, And Selected Forage Plants From Desert Tortoise Habitats In The Mojave And Colorado Deserts, Usa, M. A. Chaffee, K. H. Berry Jan 2006

Abundance And Distribution Of Selected Elements In Soils, Stream Sediments, And Selected Forage Plants From Desert Tortoise Habitats In The Mojave And Colorado Deserts, Usa, M. A. Chaffee, K. H. Berry

United States Geological Survey: Staff Publications

A baseline and background chemical survey was conducted in southeastern California, USA, to identify potential sources of toxicants in natural and anthropogenically-altered habitats of the threatened desert tortoise (Gopherus agassizii). Soil, stream sediment, and plant samples were collected from six tortoise habitat study areas in the Mojave and Colorado deserts and analysed for up to 66 different elements. The chemical analyses provided new information on the abundances and distributions of selected elements in this region. Soil, stream-sediment, and plant analyses showed distinct variations in bulk chemistries from locality to locality. Variations were, in general, consistent with the many …


Mineralogical Characterization Of Protolith And Fault Rocks From The Safod Main Hole, John G. Solum, Stephen H. Hickman, David A. Lockner, Diane E. Moore, Ben A. Van Der Pluijm, James P. Evans Jan 2006

Mineralogical Characterization Of Protolith And Fault Rocks From The Safod Main Hole, John G. Solum, Stephen H. Hickman, David A. Lockner, Diane E. Moore, Ben A. Van Der Pluijm, James P. Evans

United States Geological Survey: Staff Publications

Washed cuttings provide a continuous record of the rocks encountered during drilling of the main hole of the San Andreas Fault Observatory at Depth (SAFOD). Both protolith and fault rocks exhibit a wide variety of mineral assemblages that reflect variations in some combination of lithology, P-T conditions, deformation mechanisms, and fluid composition and abundance. Regions of distinct neomineralization bounded by faults may record alteration associated with fluid reservoirs confined by faults. In addition, both smectites occurring as mixed-layer phases and serpentine minerals are found in association with active strands of the San Andreas Fault that were intersected during drilling, although …


A Method For Mapping Corn Using The Us Geological Survey 1992 National Land Cover Dataset, S. K. Maxwell, J. R. Nuckols, M. H. Ward Jan 2006

A Method For Mapping Corn Using The Us Geological Survey 1992 National Land Cover Dataset, S. K. Maxwell, J. R. Nuckols, M. H. Ward

United States Geological Survey: Staff Publications

Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin’s lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type. Corn requires the highest application of nitrogen fertilizer of crops grown in the Midwest US.We developed a method to refine the US Geological Survey National Land Cover Dataset (NLCD) (including map and original Landsat images) to distinguish corn from other crops. Overall average agreement between the resulting corn and other …


Seasonal And Spatial Patterns Of Metals At A Restored Copper Mine Site. I. Stream Copper And Zinc, Dustin G. Bambic, Charles N. Alpers, Peter G. Green, Eileen Fanelli, Wendy K. Silk Jan 2006

Seasonal And Spatial Patterns Of Metals At A Restored Copper Mine Site. I. Stream Copper And Zinc, Dustin G. Bambic, Charles N. Alpers, Peter G. Green, Eileen Fanelli, Wendy K. Silk

United States Geological Survey: Staff Publications

Seasonal and spatial variations in metal concentrations and pH were found in a stream at a restored copper mine site located near a massive sulfide deposit in the Foothill copper-zinc belt of the Sierra Nevada, California. At the mouth of the stream, copper concentrations increased and pH decreased with increased streamflow after the onset of winter rain and, unexpectedly, reached extreme values 1 or 2 months after peaks in the seasonal hydrographs. In contrast, aqueous zinc and sulfate concentrations were highest during low-flow periods. Spatial variation was assessed in 400 m of reach encompassing an acidic, metal-laden seep. At this …


Use Of Mammal Manure By Nesting Burrowing Owls: A Test Of Four Functional Hypotheses, Matthew D. Smith, Courtney J. Conway Jan 2006

Use Of Mammal Manure By Nesting Burrowing Owls: A Test Of Four Functional Hypotheses, Matthew D. Smith, Courtney J. Conway

United States Geological Survey: Staff Publications

Animals have evolved an impressive array of behavioural traits to avoid depredation. Olfactory camouflage of conspicuous odours is a strategy to avoid depredation that has been implicated only in a few species of birds. Burrowing owls, Athene cunicularia, routinely collect dried manure from mammals and scatter it in their nest chamber, in the tunnel leading to their nest and at the entrance to their nesting burrow. This unusual behaviour was thought to reduce nest depredation by concealing the scent of adults and juveniles, but a recent study suggests that manure functions to attract arthropod prey. However, burrowing owls routinely …


Renewing The Conservation Commitment, Frank W. Davis, Dale D. Goble, J. Michael Scott Jan 2006

Renewing The Conservation Commitment, Frank W. Davis, Dale D. Goble, J. Michael Scott

United States Geological Survey: Staff Publications

As we write this in early 2005 there are several ESA-related pieces of legislation pending before Congress. Most of the proposed legislation is championed by Republican leaders from western states, who promise to strengthen the use of science or ensure fairer treatment of private landowners. Ir has become a perennial drama on the American political stage: "conservatives" rally to rein in a law that they believe has reached too far and "conservationists" mobilize ro defend the law that they believe offers the best ho pe for protecting biodiversity from relentless economic exploitation. There is much posturing, finger pointing, and, ultimately, …


Introduction To "The Endangered Species Act At Thirty, Volume 2", Frank W. Davis, J. Michael Scott, Dale D. Goble Jan 2006

Introduction To "The Endangered Species Act At Thirty, Volume 2", Frank W. Davis, J. Michael Scott, Dale D. Goble

United States Geological Survey: Staff Publications

More than thirty years after its passage, the Endangered Species Act (ESA) of 1973 continues to be a corners tone of U.S. biodiversity policy and among our most powerful environmentallaws. The ESA set the nation's biodiversity conservation policy on a path that emphasized species-based conservation and triggered action only when a species faced imminent extinction. However, promoting recovery has proven more challenging than the original designers of the law anticipated. The number of listed species has mushroomed from 78 in 1973 to 1,267 in 2005, while in that time only 13 species have recovered sufficiently to be removed from the …


Introduction To "The Endangered Species Act At Thirty, Volume 1", J. Michael Scott, Dale D. Goble, Frank W. Davis Jan 2006

Introduction To "The Endangered Species Act At Thirty, Volume 1", J. Michael Scott, Dale D. Goble, Frank W. Davis

United States Geological Survey: Staff Publications

This book examines one legislative effoft to resolve the dilemma, the Endangered Speeies Aet of 1973 (ESA 1973). The ESA was an idealistic and perhaps naive attempt to preserve humanity by preserving other species in the ecological support system that makes life possible. In the words of the House report accompanying the bill:

A certain humility, and a sense of urgency seem indicated .... One might analogize the case to one in which one copy of all the books ever printed were gathered together in one huge building. The position in which we find ourselves today is that of custodians …


By The Numbers, J. Michael Scott, Dale D. Goble, Leona K. Svancara, Anna Pidgorna Jan 2006

By The Numbers, J. Michael Scott, Dale D. Goble, Leona K. Svancara, Anna Pidgorna

United States Geological Survey: Staff Publications

The current endangered species list has its administrative beginnings in 1964 when the Department of the Interior's Committee on Rare and Endangered Wildlife Species published a preliminary list of 62 species at risk of extinction (Goble, forthcoming). Following the enactment of the Endangered Species Preservation Act of 1966 (ESPA), the secretary of the interior in 1967 published the first official list of 78 "native fish and wildlife threatened with extinction" (ESPA sec. l(c); U.S. Department of the Interior 1967; Wilcove and McMillan, this volume). By the time the Endangered Species Act (ESA) was adopted in 1973, there were 392 species …


Breeding Biology And Success Of A Reintroduced Population Of The Critically Endangered Puaiohi (Myadestes Palmeri), Erik J. Tweed, Jeffrey T. Foster, Bethany L. Woodworth, William B. Monahan, Jherime L. Kellerman, Alan Lieberman Jan 2006

Breeding Biology And Success Of A Reintroduced Population Of The Critically Endangered Puaiohi (Myadestes Palmeri), Erik J. Tweed, Jeffrey T. Foster, Bethany L. Woodworth, William B. Monahan, Jherime L. Kellerman, Alan Lieberman

United States Geological Survey: Staff Publications

The ultimate success of reintroduction programs for endangered species depends on the ability of reintroduced animals to breed in the wild. We studied the nesting success and breeding biology of a reintroduced population of Puaiohi (Myadestes palmeri) on the island of Kaua‛i, Hawaii. Thirty-four captive-bred Puaiohi were released into the Alaka‛i Swamp in 1999–2001 and monitored using radiotelemetry. Ten females and two males paired with wild and other released birds, including one polygynous trio. From March to September, 31 nests were built. Mean clutch size was 2.0 eggs, daily nest survival was 0.97 ± 0.01 (mean ± SE) …


Reply To The Discussion By F. Lagroix And S.K. Banerjee Of “Geochemical Evidence For The Origin Of Late Quaternary Loess In Central Alaska”, Daniel R. Muhs, James R. Budahn Jan 2006

Reply To The Discussion By F. Lagroix And S.K. Banerjee Of “Geochemical Evidence For The Origin Of Late Quaternary Loess In Central Alaska”, Daniel R. Muhs, James R. Budahn

United States Geological Survey: Staff Publications

We thank F. Lagroix and S.K. Banerjee (2006) for their Muhs and Budahn 1895 interest in our recent paper and welcome this opportunity to clarify our thoughts on the issues they raise. ...

The loess deposits of central Alaska contain a long and detailed record of sedimentation and soil formation. However, we are convinced that this history is a complex one and, therefore, we again thank Lagroix and Banerjee (2006) for the opportunity to articulate some additional thoughts on the geologic record here. We applaud the use of new methods, such as those of Lagroix and Banerjee (2002, 2004), in …


Patterns Of Total Suspended Solids Concentration And The Influence Of Antecedent Conditions On Hydrograph Response To Precipitation Events On Beaver Creek, Ontario, Matthew Peter Roy Mittler Jan 2006

Patterns Of Total Suspended Solids Concentration And The Influence Of Antecedent Conditions On Hydrograph Response To Precipitation Events On Beaver Creek, Ontario, Matthew Peter Roy Mittler

Theses and Dissertations (Comprehensive)

This study explored relationships between suspended solids concentration and discharge, the influence of antecedent conditions on event hydrograhs and the state of dynamic equilibrium in a second-order stream (Beaver Creek), draining an agricultural basin in southern Ontario, near the City of Waterloo. Beaver creek was monitored for nineteen weeks from July to November of 2005. Thirteen precipitation events of various magnitude and duration were examined within the study period. Discharge and total suspended soils were sampled throughout the events. Cross sectional profiles of six transects were measured prior to and after each event. Base flow, antecedent conditions and event response …


Ce-Qual-W2: A Two-Dimensional, Laterally Averaged, Hydrodynamic And Water Quality Model, Version 3.5, Thomas M. Cole, Scott A. Wells Jan 2006

Ce-Qual-W2: A Two-Dimensional, Laterally Averaged, Hydrodynamic And Water Quality Model, Version 3.5, Thomas M. Cole, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

This manual documents the two-dimensional, laterally averaged, hydrodynamic and water quality model CE-QUAL-W2. This manual was prepared in the Environmental Laboratory (EL), us Army Engineer Waterways Experiment Station (WES), Vicksburg, MS. Bonita Niel and Dr. William Roper, CERD-C provided funding for Version 3.1 of the manual under the Numerical Model Maintenance Program. The principal investigator for Version 3.2 of CE-QUAL-W2 and the User Manual was Mr. Thomas M. Cole of the Water Quality and Contaminant Modeling Branch (WQCMB), Environmental Processes and Effects Division (EPED), EL. This report supersedes the Version 3.2 manual. Revisions made in this V3.5 manual were made …


Canopy-Tree Influences Along A Soil Parent Material Gradient In Pinus-Ponderosa-Quercus Gambelii Forests, Northern Arizona, Scott R. Abella, Judith D. Springer Jan 2006

Canopy-Tree Influences Along A Soil Parent Material Gradient In Pinus-Ponderosa-Quercus Gambelii Forests, Northern Arizona, Scott R. Abella, Judith D. Springer

Public Policy and Leadership Faculty Research

ABELLA, S. R. (Public Lands Institute and School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-2040) AND J. D. SPRINGER (Ecological Restoration Institute, Northern Arizona University, Flagstaff, AZ 86011-5017). Canopy-tree influences along a soil parent material gradient in Pinus ponderosa- Quercus gambelii forests, northern Arizona. J. Torrey Bot. Soc. 135: 26–36. 2008.—The distribution of canopy trees can impose within-site patterns of soil properties and understory plant composition. At ten sites spanning a soil parent material gradient in northern Arizona Pinus ponderosa-Quercus gambelii forests, we compared soils and plant composition among five canopy types: openings, Pinus ponderosa …


Bomb-Pulse Chlorine-36 At The Proposed Yucca Mountain Repository Horizon: An Investigation Of Previous Conflicting Results And Collection Of New Data, James Cizdziel, Amy J. Smiecinski Jan 2006

Bomb-Pulse Chlorine-36 At The Proposed Yucca Mountain Repository Horizon: An Investigation Of Previous Conflicting Results And Collection Of New Data, James Cizdziel, Amy J. Smiecinski

Publications (YM)

Previous studies by scientists at Los Alamos National Laboratory (LANL) found elevated ratios of chlorine-36 to total chloride (36C1/C1) in samples of rock collected from the Exploratory Studies Facility (ESF) and the Enhanced Characterization of the Repository Block (ECRB) at Yucca Mountain as the tunnels were excavated. The data were interpreted as an indication that fluids containing "bomb-pulse" 36C1 reached the repository horizon in the -50 years since the peak period of above-ground nuclear testing. Moreover, the data support the concept that so-called fast pathways for infiltration not only exist but are active, possibly through a combination of porous media, …


Brittle Compressive Failure Of Ice: Proportional Straining Vs Proportional Loading, E. M. Schulson, D. Iliescu Jan 2006

Brittle Compressive Failure Of Ice: Proportional Straining Vs Proportional Loading, E. M. Schulson, D. Iliescu

Dartmouth Scholarship

Proportional straining experiments have been performed on columnar-grained S2 fresh- water ice biaxially compressed across the columns at –108C at a strain rate of (4.5 􏰀 1.5) 􏰁 10–3 s–1. The results are compared with those obtained earlier (Iliescu and Schulson, 2004) from the same kind of material deformed to terminal failure under the same conditions, but through proportional loading. The exercise shows that the biaxial strength is practically independent of the path taken, at least under low confinement where Coulombic shear faulting limits terminal failure. First-year sea ice is expected to exhibit the same behavior.


Exploration Of Ground Penetrating Radar And Time Domain Reflectometry Methods For The Determination Of Pavement Dielectric Constant, Baron W. Colbert Jan 2006

Exploration Of Ground Penetrating Radar And Time Domain Reflectometry Methods For The Determination Of Pavement Dielectric Constant, Baron W. Colbert

Dissertations, Master's Theses and Master's Reports - Open

Traditionally, densities of newly built roadways are checked by direct sampling (cores) or by nuclear density gauge measurements. For roadway engineers, density of asphalt pavement surfaces is essential to determine pavement quality. Unfortunately, field measurements of density by direct sampling or by nuclear measurement are slow processes. Therefore, I have explored the use of rapidly-deployed ground penetrating radar (GPR) as an alternative means of determining pavement quality. The dielectric constant of pavement surface may be a substructure parameter that correlates with pavement density, and can be used as a proxy when density of asphalt is not known from nuclear or …


Carbon Dioxide Sequestration In Cement Kiln Dust Through Miner Carbonation, Deborah N. Huntzinger Jan 2006

Carbon Dioxide Sequestration In Cement Kiln Dust Through Miner Carbonation, Deborah N. Huntzinger

Dissertations, Master's Theses and Master's Reports - Open

The feasibility of carbon sequestration in cement kiln dust (CKD) was investigated in a series of batch and column experiments conducted under ambient temperature and pressure conditions. The significance of this work is the demonstration that alkaline wastes, such as CKD, are highly reactive with carbon dioxide (CO2). In the presence of water, CKD can sequester greater than 80% of its theoretical capacity for carbon without any amendments or modifications to the waste. Other mineral carbonation technologies for carbon sequestration rely on the use of mined mineral feedstocks as the source of oxides. The mining, pre-processing and reaction …


Analyzing The Effects Of Vertical Acceleration And Deceleration In Multi-Phase, Debris-Flow Sediment-Column Experiments / By Christine Marie Williams., Christine Marie Williams Jan 2006

Analyzing The Effects Of Vertical Acceleration And Deceleration In Multi-Phase, Debris-Flow Sediment-Column Experiments / By Christine Marie Williams., Christine Marie Williams

Dissertations, Master's Theses and Master's Reports - Open

Water-saturated debris flows are among some of the most destructive mass movements. Their complex nature presents a challenge for quantitative description and modeling. In order to improve understanding of the dynamics of these flows, it is important to seek a simplified dynamic system underlying their behavior. Models currently in use to describe the motion of debris flows employ depth-averaged equations of motion, typically assuming negligible effects from vertical acceleration. However, in many cases debris flows experience significant vertical acceleration as they move across irregular surfaces, and it has been proposed that friction associated with vertical forces and liquefaction merit inclusion …


Dry Creek Long Term Watershed Study: Buffer Zone Performance As Viable Amphibian Habitat, Brooke L. Talley, Thomas Crisman Jan 2006

Dry Creek Long Term Watershed Study: Buffer Zone Performance As Viable Amphibian Habitat, Brooke L. Talley, Thomas Crisman

School of Geosciences Faculty and Staff Publications

As bioindicators, amphibians typically require both terrestrial and aquatic habitats to complete their life cycles. Pre- timber-harvest monitoring (December 2002 through September 2003) of salamander and frog (Hylidae) populations was conducted in four watersheds of Decatur County, GA. Post- timber-harvest monitoring (December 2003 through September 2004) continued in the same watersheds (two reference and two treatment watersheds). Coverboards were used to monitor adult salamanders, larval salamanders were surveyed with dipnet sweeps, and frogs were monitored with vertical PVC pipes. Six salamander species (Desmognathus apalachicolae, Eurycea cirrigera, E. guttolineata, Notophthalmus viridescens, Plethodon grobmani, and Pseudotriton ruber) and five frog species (Hyla …


Dry Creek Long Term Watershed Study: Assessment Of Immediate Response Of Aquatic Macroinvertebrates To Watershed Level Harvesting And Thinning Of Streamside Management Zones, M. W. Griswold, R. T. Winn, Thomas Crisman, W. R. White Jan 2006

Dry Creek Long Term Watershed Study: Assessment Of Immediate Response Of Aquatic Macroinvertebrates To Watershed Level Harvesting And Thinning Of Streamside Management Zones, M. W. Griswold, R. T. Winn, Thomas Crisman, W. R. White

School of Geosciences Faculty and Staff Publications

Streamside Management Zones (SMZs) are meant to protect riparian habitat and the stream ecosystem. Benthic macroinvertebrates are recognized bioindicators of water quality in streams, typically occupying multiple trophic levels in these systems and providing food for vertebrates. Thus, it is important to understand the effects of harvest within and adjacent to the SMZ on macroinvertebrate assemblages. Benthic macroinvertebrates were sampled pre- and post-harvest from four firstorder streams draining the Dry Creek watershed in southwestern Georgia. A multi-habitat sampling procedure was used. Macroinvertebrates were identified and compared using biotic indices. Comparisons were made between streams within the pre-harvest period and between …


Service-Learning In Watershed-Based Initiatives: Keys To Education For Sustainability In Geography?, James Eflin, Amy L. Sheaffer Jan 2006

Service-Learning In Watershed-Based Initiatives: Keys To Education For Sustainability In Geography?, James Eflin, Amy L. Sheaffer

Service Learning, General

A call for combining the strengths of geographic education with environmental education to produce an 'education for sustainability' addresses local problems for sustainable development. A place-based approach encourages civic responsibility among students. Using service-learning to extend education beyond the classroom in this case study connected students with local clients in a watershed-based initiative. Theoretical underpinnings of service-learning for geographic education are discussed, and the case study is viewed from instructor, student, and client perspectives to identify successful outcomes and provide suggestions for those who might adopt service-learning for the first time.


From Soft Tissue To Homing Pigeons (Faith & Science Update), John T. Baldwin Jan 2006

From Soft Tissue To Homing Pigeons (Faith & Science Update), John T. Baldwin

Perspective Digest

No abstract provided.