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 3121 - 3150 of 3979

Full-Text Articles in Entire DC Network

Conservation Genetics Of Snowy Plovers (Charadrius Alexandrinus) In The Western Hemisphere: Population Genetic Structure And Delineation Of Subspecies, W. Chris Funk, Thomas D. Mullins, Susan M. Haig Jan 2007

Conservation Genetics Of Snowy Plovers (Charadrius Alexandrinus) In The Western Hemisphere: Population Genetic Structure And Delineation Of Subspecies, W. Chris Funk, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

We examined the genetic structure of snowy plovers (Charadrius alexandrinus) in North America, the Caribbean, and the west coast of South America to quantify variation within and among breeding areas and to test the validity of three previously recognized subspecies. Sequences (676 bp) from domains I and II of the mitochondrial control region were analyzed for 166 snowy plovers from 20 breeding areas. Variation was also examined at 10 microsatellite loci for 144 snowy plovers from 14 breeding areas. The mtDNA and microsatellite data provided strong evidence that the Puerto Rican breeding group is genetically divergent from sites …


Dune Fields: Mid-Latitudes, J. Sun, Daniel R. Muhs Jan 2007

Dune Fields: Mid-Latitudes, J. Sun, Daniel R. Muhs

United States Geological Survey: Staff Publications

Large dune fields, or sand seas, are landscapes often thought to be found only in deserts beneath the great, subtropical high-pressure zones, where subsiding air suppresses rainfall. Dune fields are also quite common in mid-latitude regions, to the north and south of subtropical deserts (Fig. 1). Two major characteristics distinguish many mid-latitude dune fields from the sand seas of lower latitudes. One difference is that many of those in mid-latitudes are in semiarid, rather than arid climates, and therefore are not presently active. In this article, ‘active’ refers to eolian sand bodies that are not covered with vegetation, and where …


Cenozoic Extensional Processes And Tectonics In The Northern Rocky Mountains: Southwest Montana And Eastern Idaho, Susanne U. Janecke Jan 2007

Cenozoic Extensional Processes And Tectonics In The Northern Rocky Mountains: Southwest Montana And Eastern Idaho, Susanne U. Janecke

Geosciences Faculty Publications

No abstract provided.


Biogeography And The Cambrian Radiation Of Arachnomorph Arthropods, Jonathan R. Hendricks, Bruce S. Lieberman Jan 2007

Biogeography And The Cambrian Radiation Of Arachnomorph Arthropods, Jonathan R. Hendricks, Bruce S. Lieberman

Faculty Publications

Biogeographic patterns in primarily Cambrian arachnomorph taxa are investigated using a recently constructed phylogenetic hypothesis in order to explore the biogeographic context of the Cambrian radiation. A modified version of Brooks Parsimony Analysis is employed to elucidate patterns of vicariance and geodispersal in taxa from six regions (Laurentia, Baltica, Siberia, Australia, Africa and China). Well resolved vicariance and geodispersal trees are very similar and reconstruct Laurentia and China as sister areas. This close area relationship between Laurentia and China provides extensive evidence for congruent vicariance and range expansion in Cambrian arachnomorphs, while data from trilobites do not show this pattern. …


Speleothems As Indicators Of Wet And Dry Periods, Ian John Fairchild, Emily Anne Mcmillan Jan 2007

Speleothems As Indicators Of Wet And Dry Periods, Ian John Fairchild, Emily Anne Mcmillan

International Journal of Speleology

Calcareous speleothems provide a record of dripwater composition which in turn is a function of climatic conditions. The historical focus of speleothem palaeoclimate studies has been on the derivation of palaeotemperatures through oxygen isotope studies. However, it is now realized that water availability is a more generally important control on their characteristics. Growth rate and growth morphology in principle should give rise to recognizable changes at low flow. However, accidental plumbing effects during aquifer evolution, can also lead to variations in water supply and it is not easy to distinguish these effects. In areas where there is a strong amount …


Gis-Based Integration Of Swat And Remm For Estimating Water Quality Benefits Of Riparian Buffers In Agricultural Watersheds, Y. Liu, Wanhong Yang, Xixi Wang Jan 2007

Gis-Based Integration Of Swat And Remm For Estimating Water Quality Benefits Of Riparian Buffers In Agricultural Watersheds, Y. Liu, Wanhong Yang, Xixi Wang

Civil & Environmental Engineering Faculty Publications

The Soil and Water Assessment Tool (SWAT) is a process-based, watershed-scale model with a hydrologic response unit (HRU) as the basic computation element, which makes it difficult to accurately represent riparian buffers using their physical parameters (e.g., vegetation structure). On the other hand, the field-scale Riparian Ecosystem Management Model (REMM) provides the opportunity to consider details of hydrologic processes within a riparian buffer zone. However, the runoff and its associated constituents from the upland area that is hydraulically connected to the riparian buffer zone must be provided as inputs into REMM. The rationale proposed here is that the integration of …


Shelf-Margin Delta Morphology As A Paleo Sea Level Indicator: Implications On Late Quaternary Relative Sea-Level Changes In The Northeast Gulf Of Mexico, Swati Ghoshal Jan 2007

Shelf-Margin Delta Morphology As A Paleo Sea Level Indicator: Implications On Late Quaternary Relative Sea-Level Changes In The Northeast Gulf Of Mexico, Swati Ghoshal

LSU Doctoral Dissertations

A new technique to determine relative sea level history at siliciclastic settings is proposed in this dissertation. The clinoform break (defined as the topset-foreset transition point) of the modern Mississippi River Delta shows a direct relationship with sea level elevation. The analysis of Holocene lobes 8 and 9 belonging to the St. Bernard delta complex of the Mississippi Delta suggests that delta clinoforms can be significantly modified by post-abandonment processes, and hence a detailed stratigraphic evaluation is necessary to determine whether the clinoform geometry is a result of wave erosion or any other post-abandonment processes. The strategy was tested on …


Bomb-Spike Dating Of A Mummified Baboon In Ludwig Cave, Namibia, Greg Hodgins, George A. Brook, Eugene Marais Jan 2007

Bomb-Spike Dating Of A Mummified Baboon In Ludwig Cave, Namibia, Greg Hodgins, George A. Brook, Eugene Marais

International Journal of Speleology

In 1982 a mummified adult female baboon was discovered on a ledge in Ludwig Cave in Namibia. A toe bone was removed for dating in July 1995. AMS radiocarbon dating of bone collagen, tendon, and skin indicates a post-modern age. Application of the atomic bomb-spike calibration curve suggests death in late 1977 and an age at death of around 19 years. Baboons roost in the cave and the mummified female, along with a mummified juvenile male discovered in 2002 and three rotting corpses discovered in 1995, were probably chased by other baboons or by leopards down a ca. 6 m …


The Polygenetic Caves Of Cuatro Ciénegas (Coahuila, Mexico): Morphology And Speleogenesis, Leonardo Piccini, Paolo Forti, Italo Giulivo, Marco Mecchia Jan 2007

The Polygenetic Caves Of Cuatro Ciénegas (Coahuila, Mexico): Morphology And Speleogenesis, Leonardo Piccini, Paolo Forti, Italo Giulivo, Marco Mecchia

International Journal of Speleology

The Cuatro Ciénegas area is renown worldwide for its thermal springs, which feed a unique ecosystem consisting of many pools, lakes and marshes. The pools also represent a very important water resource in a region characterized by scarce rainfalls. Field investigation has emphasized the role of karst in the hydrogeology of the area. Only few and restricted forms of surface karst are represented; caves are mainly relics of old speleogenetic phases of thermal and bathyphreatic water flow.


Glacial Deposits, Vol. 35, 2006-2007, Department Of Geography-Geology Jan 2007

Glacial Deposits, Vol. 35, 2006-2007, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology


Assessment Of Atrazine In A Rural Water Source: Rough River Lake, Kentucky, Scotty Sharp Dec 2006

Assessment Of Atrazine In A Rural Water Source: Rough River Lake, Kentucky, Scotty Sharp

Masters Theses & Specialist Projects

Atrazine [2-chloro- 4-(ethylamino)-6-(isopropylamino)-l,3,5-triazine], a widely used herbicide in US corn production, impacts quality of drinking water for many rural water supply systems. Four systems at Rough River Lake, Kentucky, have had high levels of atrazine in raw water and in some cases finished water that have exceeded the legal limit of 3 parts per billion (ppb). The Rough River Lake watershed is 1,700-km2, much of which is located in limestone karst. A hypothesis was developed stating that there would be higher concentrations of atrazine in the northeast section of the Rough River Watershed, located in Hardin County, due to the …


Modeling Soil Erosion In The Upper Green River, Ky, Narcisa Pricope Dec 2006

Modeling Soil Erosion In The Upper Green River, Ky, Narcisa Pricope

Masters Theses & Specialist Projects

Off-site soil erosion has tremendous impacts on the present state of most river systems throughout the United States, contributing sediments to channels mainly as nonpoint pollution resulting from land-use and agricultural practices and leading to sedimentation downstream and downwind, a decrease in the transport capacity of streams, increase in the risk of flooding, filling reservoirs, and eutrophication. A primary focus in examining the problems associated with soil erosion arid ultimately in proposing control measures should be on identifying the sources of the sediment. Therefore, a model that would be able to assess soil erosion needs to start by identifying the …


Flash Flooding In Eastern Kentucky: An Analysis Of The 3-4 August 2001 Event, Christina Henry Dec 2006

Flash Flooding In Eastern Kentucky: An Analysis Of The 3-4 August 2001 Event, Christina Henry

Masters Theses & Specialist Projects

Limited research exists concerning flash flooding in the United States. However, flash floods can occur anywhere and cause more fatalities than any other weather related natural disaster. Eastern Kentucky experienced an average of 41 flash floods per year (1993-2002), yet little research exists for this region. Therefore, this paper presents an analysis of the particularly devastating flash flood event of 3-4 August 2001, which resulted in $15 million worth of property damage and two deaths. Previous studies indicate that flash floods typically occur under relatively 'benign' conditions, the most common characteristics being a quasi-stationary system and high atmospheric moisture. The …


Identification, Characterization And Analysis Of Wrench Related Faulting In Southwestern Warren County, Kentucky, Joseph Islas Dec 2006

Identification, Characterization And Analysis Of Wrench Related Faulting In Southwestern Warren County, Kentucky, Joseph Islas

Masters Theses & Specialist Projects

Warren County, Kentucky is located south of the southern boundary of the Rough Creek Graben marked by the Pennyrile fault system. The Pennyrile fault system is a regional southwest-northeast trending fault system that extends into Kentucky from the Reelfoot rift zone. The Rough Creek fault system bounds the northern arm of the Rough Creek Graben and trends northwest-southeast also extending from the Reelfoot rift zone. The Rough Creek fault system is related to the Shawneetown fault system in southeastern Illinois and occupies the southern end of the Illinois Basin. The East Continent Rift Basin intersects the Rough Creek Graben near …


Geosciences Newsletter - 2006, Department Of Geosciences Dec 2006

Geosciences Newsletter - 2006, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 2, No. 2

  • Mohamed Sultan, Chairperson
  • Faculty News
  • Department News
  • Michigan Geological Repository for Research and Education (MGRRE)
  • Department Updates
  • Graduate Student News
  • Awards & Graduations
  • Alumni News
  • Outstanding Alumni Academy
  • Dedication Ceremony Michigan Geological Repository for Research and Education (MGRRE) New Faces in the Geosciences


Biomass Estimation And Classification Of Secondary Succession Using Radar And Optical Remote Sensing Data Based On Textural And Spectral Analysis In Amazonia, Ping Jiang Dec 2006

Biomass Estimation And Classification Of Secondary Succession Using Radar And Optical Remote Sensing Data Based On Textural And Spectral Analysis In Amazonia, Ping Jiang

All-Inclusive List of Electronic Theses and Dissertations

Deforestation that happened during past decades in the Amazon Basin has been potentially affecting the global climate and carbon-cycle by contributing a vast amount of carbon into the atmosphere. Above-ground biomass (AGB) estimation of secondary successional and mature forests using remote sensing technology has been attracting scientists' attention. Optical sensor data are sensitive to forest canopies only, and therefore have limitations in AGB estimation, especially for tropical forests with complex structures and abundant species. Radar signals have the ability to penetrate canopies to detect the sub-layers of forests, and therefore potentially have a better performance in AGB estimation. Based on …


A Linear Modulation Osl Study Of The Unstable Ultrafast Component In Samples From Glacial Lake Hitchcock, Massachusetts, Usa, R. J. Goble, Tammy M. Rittenour Dec 2006

A Linear Modulation Osl Study Of The Unstable Ultrafast Component In Samples From Glacial Lake Hitchcock, Massachusetts, Usa, R. J. Goble, Tammy M. Rittenour

Geosciences Faculty Publications

Optical ages were determined for samples from delta and sand dune deposits associated with Glacial Lake Hitchcock near Amherst, Massachusetts using the single aliquot regenerative-dose (SAR) optically stimulated luminescence (OSL) technique. However, a strong unstable ultrafast component caused initial rejection of data from a large proportion of aliquots. A linearly modulated blue OSL (LM-OSL) study was undertaken on the sample with the strongest ultrafast component, with the data modelled using the equation of Bulur et al. (2000) as 5 fast, medium and slow components, and 1 ultrafast component.

The ultrafast component dominates the LM–OSL, almost completely obscuring the fast component. …


On The Use Of Modis Evi To Assess Gross Primary Productivity Of North American Ecosystems, Daniel A. Sims, Abdullah Rahman, Vicente D. Cordova, Bassil Z. El-Masri, Dennis D. Baldocchi, Lawrence B. Flanagan, Allen H. Goldstein, David Y. Hollinger, Laurent Misson, Russell K. Monson, Walter C. Oechel, Hans P. Schmid, Steven C. Wofsy, Liukang Xu Dec 2006

On The Use Of Modis Evi To Assess Gross Primary Productivity Of North American Ecosystems, Daniel A. Sims, Abdullah Rahman, Vicente D. Cordova, Bassil Z. El-Masri, Dennis D. Baldocchi, Lawrence B. Flanagan, Allen H. Goldstein, David Y. Hollinger, Laurent Misson, Russell K. Monson, Walter C. Oechel, Hans P. Schmid, Steven C. Wofsy, Liukang Xu

School of Earth, Environmental, & Marine Sciences Faculty Publications

[1] Carbon flux models based on light use efficiency (LUE), such as the MOD17 algorithm, have proved difficult to parameterize because of uncertainties in the LUE term, which is usually estimated from meteorological variables available only at large spatial scales. In search of simpler models based entirely on remote‐sensing data, we examined direct relationships between the enhanced vegetation index (EVI) and gross primary productivity (GPP) measured at nine eddy covariance flux tower sites across North America. When data from the winter period of inactive photosynthesis were excluded, the overall relationship between EVI and tower GPP was better than that between …


Atmospheric Chemistry Of A 33–34 Hour Old Volcanic Cloud From Hekla Volcano (Iceland): Insights From Direct Sampling And The Application Of Chemical Box Modeling, William I. Rose, Genevieve A. Millard, Tamsin A. Mather, Donald E. Hunton, Bruce Anderson, Clive Oppenheimer, Brett F. Thornton, Terrence M. Gerlach, Albert A. Viggiano, Yutaka Kondo, Thomas M. Miller, John O. Ballenthin Oct 2006

Atmospheric Chemistry Of A 33–34 Hour Old Volcanic Cloud From Hekla Volcano (Iceland): Insights From Direct Sampling And The Application Of Chemical Box Modeling, William I. Rose, Genevieve A. Millard, Tamsin A. Mather, Donald E. Hunton, Bruce Anderson, Clive Oppenheimer, Brett F. Thornton, Terrence M. Gerlach, Albert A. Viggiano, Yutaka Kondo, Thomas M. Miller, John O. Ballenthin

Department of Geological and Mining Engineering and Sciences Publications

On 28 February 2000, a volcanic cloud from Hekla volcano, Iceland, was serendipitously sampled by a DC-8 research aircraft during the SAGE III Ozone Loss and Validation Experiment (SOLVE I). It was encountered at night at 10.4 km above sea level (in the lower stratosphere) and 33–34 hours after emission. The cloud is readily identified by abundant SO2 (≤1 ppmv), HCl (≤70 ppbv), HF (≤60 ppbv), and particles (which may have included fine silicate ash). We compare observed and modeled cloud compositions to understand its chemical evolution. Abundances of sulfur and halogen species indicate some oxidation of sulfur gases but …


Geogram 2006, David J. Keeling Editor, Wku Department Of Geography And Geology Oct 2006

Geogram 2006, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.


Earth News, V30, Fall 2006, Department Of Earth Science, University Of Northern Iowa. Oct 2006

Earth News, V30, Fall 2006, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Earth Science Staff Activities
--- Emeritus Faculty/Staff
--- The New Madrid Fault Field Trip
--- Richard Golz Estate Donates Items to Earth Science Department
--- Fall 2006 Quarry Open House Features Dedication
--- Special Alumni Profile - Aaron Spurr
--- Pre-College Students Invade Latham Hall
--- Earth Science Seminar Series
--- Majors in the Earth Science Department
--- Sigma Gamma Epsilon - Gamma Sigma Chapter
--- Student Internships
--- Student Research Presentations
--- Scholarship and Award Recipients
--- The Charles J. Hearst Scholarship
--- 2006 Earth Science Graduates
--- Gifts to the Department of Earth Science …


Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak Sep 2006

Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak

United States Geological Survey: Staff Publications

Deep-water (307–697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several centuries old. Bands were delaminated in KOH and analyzed for carbon and nitrogen stable isotopes. Carbon values ranged from _16.4‰ to _15.7‰; the oldest specimen displayed the largest range in values. Nitrogen values ranged from 7.7‰ to 8.6‰. …


Hydrochemistry In An Alpine Karst System, Sequoia And Kings Canyon National Parks, California, Joel Despain Aug 2006

Hydrochemistry In An Alpine Karst System, Sequoia And Kings Canyon National Parks, California, Joel Despain

Masters Theses & Specialist Projects

This study uses high-resolution, long-term conductivity, temperature, discharge, pH, and laboratory data from 2001 through 2003 from an alpine karst spring located at 2,500 m amsl in Sequoia National Park, California to reveal detailed chemical parameters of this karst system. The data show a system with a pronounced spring run-off, extended periods of base flow quiescence, storm responses tied to precipitation as rain or as snowfall, and clear diurnal and seasonal patterns of discharge. pH and spC values show an inverse relationship to discharge and temperature, which are generally in phase. Total inorganic carbon (TIC) and the fraction of mineral-derived …


Strategies For Reducing Mosquito-Borne Disease Vulnerability In Equine Populations: A Kentucky Case Study, Sara Dalton Aug 2006

Strategies For Reducing Mosquito-Borne Disease Vulnerability In Equine Populations: A Kentucky Case Study, Sara Dalton

Masters Theses & Specialist Projects

This research examined equine management practices that limit or contribute to the spread of West Nile virus and other mosquito-bome disease. I hypothesize that there is a relationship between equine management practices and outbreaks of mosquito-borne disease in horse populations. Improved and appropriate mosquito habitat management may limit the risk of mosquito-borne disease in humans and horses by helping to lower the mosquito populations. The study goals were to recognize equine management practices and mosquito prevention practices that foster outbreaks of mosquito-borne disease. This study used a questionnaire for county level analysis of equine management practices and the relationship to …


Agriculture Land Suitability Analysis Of Indiana: Integrating Soil, Climate, Topography, And Urban Expansion, Yiran Huang Aug 2006

Agriculture Land Suitability Analysis Of Indiana: Integrating Soil, Climate, Topography, And Urban Expansion, Yiran Huang

All-Inclusive List of Electronic Theses and Dissertations

This study was initiated to classify the land suitability of Indiana for agricultural use. It integrates environmental, economic, and social factors to analyze the agricultural land suitability of Indiana. Soil, topography, flood, climate, and urban factors were considered. Soil Rating for Plant Growth (SRPG) was used as a soil index in this model; it is calculated based on the STA TSGO database along with landscape attributes and climate. Standard Precipitation Index (SPI) was used as a climate index. Urban areas were defined from Tiger data and a buffer zone was used to estimate future sprawl. GIS overlay was used to …


The Impact Of Acid Mine Drainage On West Little Sugar Creek, Vigo Co., In, Jodie L. Gibson Aug 2006

The Impact Of Acid Mine Drainage On West Little Sugar Creek, Vigo Co., In, Jodie L. Gibson

All-Inclusive List of Electronic Theses and Dissertations

This study evaluates the degree and extent of contamination in West Little Sugar Creek by analyzing water chemistry in the stream during low and moderate flow conditions. West Little Sugar Creek is located in Vigo County, Indiana and has been severely impacted by AMD discharging from the abandoned Green Valley Mine site. Stream water is commonly acidic (as low as pH 2.4) with elevated concentrations of Fe and Al and elevated trace elements including Ni, Zn, Cu, Cd, Cr, Co, and others, many of which exceed local and/or national surface water quality standards. Amorphous Fe and Al precipitates also form …


Seaside, Oregon, Tsunami Pilot Study : Modernization Of Fema Flood Hazard Maps, Frank I. González, Eric L. Geist, Costas Synolakis, Diego Rodriguez Arcas, Douglas Bellomo, David Carlton, Thomas Horning, Bruce Jaffe, Jeff Johnson, Utku Kânoğlu, Harold O. Mofjeld, Jean Newman, Thomas Parsons, Robert Peters, Curt D. Peterson, George Priest, Vasily V. Titov, Angie J. Venturato, Joseph Weber, Florence L. Wong, Ahmet Yalçıner Aug 2006

Seaside, Oregon, Tsunami Pilot Study : Modernization Of Fema Flood Hazard Maps, Frank I. González, Eric L. Geist, Costas Synolakis, Diego Rodriguez Arcas, Douglas Bellomo, David Carlton, Thomas Horning, Bruce Jaffe, Jeff Johnson, Utku Kânoğlu, Harold O. Mofjeld, Jean Newman, Thomas Parsons, Robert Peters, Curt D. Peterson, George Priest, Vasily V. Titov, Angie J. Venturato, Joseph Weber, Florence L. Wong, Ahmet Yalçıner

Geology Faculty Publications and Presentations

FEMA Flood Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study (Chowdhury et al., 2005). Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Assessment (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines. The Seaside area was chosen because it is typical …


Large Wind Shift On The Great Plains During The Medieval Warm Period, Venkataramana Sridhar, David B. Loope, James B. Swinehart, Joseph A. Mason, Robert J. Oglesby, Clinton M. Rowe Jul 2006

Large Wind Shift On The Great Plains During The Medieval Warm Period, Venkataramana Sridhar, David B. Loope, James B. Swinehart, Joseph A. Mason, Robert J. Oglesby, Clinton M. Rowe

Department of Earth and Atmospheric Sciences: Faculty Publications

Spring-summer winds from the south move moist air from the Gulf of Mexico to the Great Plains. Rainfall in the growing season sustains prairie grasses that keep large dunes in the Nebraska Sand Hills immobile. Longitudinal dunes built during the Medieval Warm Period (800 to 1000 years before the present) record the last major period of sand mobility. These dunes are oriented NW-SE and are composed of cross-strata with bipolar dip directions. The trend and structure of the dunes record a drought that was initiated and sustained by a historically unprecedented shift of spring-summer atmospheric circulation over the Plains: Moist …


Geomorphic Impact And Rapid Subsequent Recovery From The 1996 Skeióarársandur Jökulhlaup, Iceland, Measured With Multi-Year Airborne Lidar, Laurence C. Smith, Yongwei Sheng, Francis J. Magilligan, Norman D. Smith, Basil Gomez, Leal A. K. Mertes, William B. Krabill, James B. Garvin Jul 2006

Geomorphic Impact And Rapid Subsequent Recovery From The 1996 Skeióarársandur Jökulhlaup, Iceland, Measured With Multi-Year Airborne Lidar, Laurence C. Smith, Yongwei Sheng, Francis J. Magilligan, Norman D. Smith, Basil Gomez, Leal A. K. Mertes, William B. Krabill, James B. Garvin

Department of Earth and Atmospheric Sciences: Faculty Publications

The November 1996 jökulhlaup that burst from the Vatnajökull ice cap onto Skeiðarársandur was the highest-magnitude flood ever measured on the largest active glacial outwash plain (sandur). Centimeter-scale elevation transects, measured from repeat-pass airborne laser altimetry missions flown in 1996 (pre-flood), 1997, and 2001, show that sediment deposition exceeded erosion across the central Skeiðarársandur and established an average net elevation gain of +22 cm for the event. Net elevation gains of +29 and +24 cm occurred in braided channels of the Gígjukvísl and Skeiðará rivers, respectively. Nearly half of these gains, however, were removed within 4 years, and the two …


A Multimetric Benthic Index For Georgia's Wadeable Streams, Amanda Lynn Middleton Jun 2006

A Multimetric Benthic Index For Georgia's Wadeable Streams, Amanda Lynn Middleton

Theses and Dissertations

Using an ecoregional approach, multimetric indices were developed to describe stream condition in each geographically distinct region of Georgia. Collected from predetermined reference and impaired condition streams, macroinvertebrate data were used to develop multimetric indices. Multimetric indices identified a range of stream conditions, as well as, the overall health of aquatic ecosystems. Based on multimetric indices, the Multimetric Rating System grouped streams according to overall stream condition. The Multimetric Rating System used multiple indices to describe various facets of stream condition. Therefore, it may be concluded that the Multimetric Rating System is a robust water management tool that may be …