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 2821 - 2850 of 3979

Full-Text Articles in Entire DC Network

The River Discontinuum: Applying Beaver Modifications To Baseline Conditions For Restoration Of Forested Headwaters, Denise Burchsted, Melinda Daniels, Robert Thorson, Jason Vokoun Dec 2010

The River Discontinuum: Applying Beaver Modifications To Baseline Conditions For Restoration Of Forested Headwaters, Denise Burchsted, Melinda Daniels, Robert Thorson, Jason Vokoun

Center for Integrative Geosciences

Billions of dollars are being spent in the United States to restore rivers to a desired, yet often unknown, reference condition. In lieu of a known reference, practitioners typically assume the paradigm of a connected watercourse. Geological and ecological processes, however, create patchy and discontinuous fluvial systems. One of these processes, dam building by North American beavers (Castor canadensis), generated discontinuities throughout precolonial river systems of northern North America. Under modern conditions, beaver dams create dynamic sequences of ponds and wet meadows among free-flowing segments. One beaver impoundment alone can exceed 1000 meters along the river, flood the valley laterally, …


The Effect Of Enso On Nebraska Winter Snowfall, Jonathan Burnham Dec 2010

The Effect Of Enso On Nebraska Winter Snowfall, Jonathan Burnham

Department of Environmental Studies: Undergraduate Student Theses

No abstract provided.


Characterization Of Watersheds On Fort Benning Military Reservation: Comparison Of Field Data To Watershed Parameters, Melinda Rosetta Stahl Dec 2010

Characterization Of Watersheds On Fort Benning Military Reservation: Comparison Of Field Data To Watershed Parameters, Melinda Rosetta Stahl

Theses and Dissertations

Sixteen watersheds located on Fort Benning Military Installation in Georgia were analyzed using both physically collected data and computer modeling data. Physical data collected included total suspended solids (TSS) and grain size analysis using the Wolman Pebble Count method. Computer modeling analyzed the watersheds using ArcGIS 9.3 for comparison to physical data. Land use, slope, and soil data were used in a modified revised universal soil loss equation (RUSLE) to create a soil erodibility index map. Wolman Pebble Count data showed that in half of the watersheds, 84% of the sampled grains were less than half a millimeter in size. …


Phosphorus Export From A Restored Wetland Ecosystem In Response To Natural And Experimental Hydrologic Fluctuations, Marcelo Ardón, Shaena Montanari, Jennifer L. Morse, Martin W. Doyle, Emily S. Bernhardt Dec 2010

Phosphorus Export From A Restored Wetland Ecosystem In Response To Natural And Experimental Hydrologic Fluctuations, Marcelo Ardón, Shaena Montanari, Jennifer L. Morse, Martin W. Doyle, Emily S. Bernhardt

Environmental Science and Management Faculty Publications and Presentations

Wetland restoration is a commonly used approach to reduce nutrient loading to freshwater and coastal ecosystems, with many wetland restoration efforts occurring in former agricultural fields. Restored wetlands are expected to be effective at retaining or removing both nitrogen and phosphorus (P), yet restoring wetland hydrology to former agricultural fields can lead to the release of legacy fertilizer P. Here, we examined P cycling and export following rewetting of the Timberlake Restoration Project, a 440 ha restored riverine wetland complex in the coastal plain of North Carolina. We also compared P cycling within the restored wetland to two minimally disturbed …


Geosciences Newsletter - 2010, Department Of Geosciences Nov 2010

Geosciences Newsletter - 2010, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 4, No. 1

  • Faculty Updates
  • Publications
  • MGRRE
  • Grants
  • Graduate News
  • Awards
  • Field Trips
  • Alumni
  • Advisory Board


Spatial Similarities And Differences Of Attributes Of Three Subwatersheds Within The Middle Smoky Hill River Watershed And Their Relationship To Instream Total Suspended Solids, Dustin Fross Nov 2010

Spatial Similarities And Differences Of Attributes Of Three Subwatersheds Within The Middle Smoky Hill River Watershed And Their Relationship To Instream Total Suspended Solids, Dustin Fross

Master's Theses or Doctor of Nursing Practice

The objective of this study was to spatially analyze the attributes of three subwatersheds, Hydrological Unit Code 12 (HUC 12), of the Middle Smoky Hill River Watershed in west-central Kansas and relate the variances of the attributes to the concentrations of total suspended solids (TSS) entering the Smoky Hill River during storm events. This was accomplished by comparing land cover, including cropland, grassland, and urban factors; agricultural practices, such as tillage methods, condition of terraces, and the presence of grass waterways; geomorphology, including soil types, topography, and visible erosion; and lastly, precipitation variance. The three HUC 12s that were studied …


Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski Nov 2010

Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski

EKU Faculty and Staff Scholarship

Heavy metal pollution remains a problem in natural waters, particularly for localities near plausible anthropogenic sources. We assayed the level of heavy metals in surface waters and within surface sediments of Wilgreen Lake, whose watershed drains industrial, urban, and residential areas near Richmond, Kentucky.

Water samples were treated according to Environmental Protection Agency (EPA) protocols and digested with trace-metal-grade nitric and hydrochloric acids. Sediment samples were collected with a grab sampler and digested using established EPA procedures with hydrogen peroxide and trace-metal-grade nitric acid. Both water samples and sediment samples were sent to Activation Laboratories for analysis, and were measured …


Patterns Of Heavy Metal Concentration In Core Sediments, Wilgreen Lake, Madison County, Kentucky, Clint Mcmaine, Walter S. Borowski Nov 2010

Patterns Of Heavy Metal Concentration In Core Sediments, Wilgreen Lake, Madison County, Kentucky, Clint Mcmaine, Walter S. Borowski

EKU Faculty and Staff Scholarship

Elevated levels of cadmium, copper, lead, and nickel were found within the waters of Wilgreen Lake during a preliminary survey in 2007. Accumulation of heavy metals in freshwater systems is a known problem. Heavy metals enter the lake in the dissolved phase or adsorbed onto sediment particles and may be linked to industries within the lake’s watershed. Under certain geochemical conditions such as anoxia, heavy metals may detach from sediment particles and diffuse into overlying lake waters, causing a renewed influx of heavy metals into the ecosystem. We hypothesize that heavy metals should decrease in concentration upcore as a result …


Geogram 2010, David J. Keeling Editor, Wku Department Of Geography And Geology Oct 2010

Geogram 2010, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.


Comparison Of Ice Core Dissolved Organic Matter From A Greenland Ice Core By Nanospray Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Joshua Jeremiah Shiloh Marsh Oct 2010

Comparison Of Ice Core Dissolved Organic Matter From A Greenland Ice Core By Nanospray Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Joshua Jeremiah Shiloh Marsh

Chemistry & Biochemistry Theses & Dissertations

Recent studies of ice cores have embarked on the task of determining the classes of dissolved organic matter (DOM) present in melt-water from the cores collected in numerous locations in the northern and southern hemispheres. This DOM originally derives from wet precipitation and is thought to reflect atmospheric organic matter derived from anthropogenic and non-anthropogenic sources. Because the amount of DOM is so low, previous studies have necessarily used large sample volumes (greater than 500 mL) to concentrate sufficient ice core DOM necessary for mass spectral analysis. Solid phase extraction (SPE) with C18 resins was followed by evaporative concentration …


Development Of Agroecology Based Garden System And Educational Program At Grand Valley State University, Kendall Gilbert, Edwin Joseph Oct 2010

Development Of Agroecology Based Garden System And Educational Program At Grand Valley State University, Kendall Gilbert, Edwin Joseph

Student Summer Scholars Manuscripts

This study was part of a twelve- week project to introduce agroecology growing principles and educational models at the Community Garden on the campus of Grand Valley State University in Allendale, Michigan. This project was set up to be a demonstration for the further development of the garden space as an area for agroecology focused education, extension, and outreach. To accomplish this, three areas of change became essential components to developing a garden space that can serve as a living laboratory, demonstration area, and outdoor classroom. The first project goal was to develop and create a demonstration garden plot that …


In Memoriam Aug 2010

In Memoriam

Studia UBB Geologia

No abstract provided.


An Intercomparison Of Regional Atmospheric Circulation And The Melt Season Loss Of Arctic Snow Cover And Sea Ice Extent Across The Land–Ocean Boundary, Angela C. Bliss Aug 2010

An Intercomparison Of Regional Atmospheric Circulation And The Melt Season Loss Of Arctic Snow Cover And Sea Ice Extent Across The Land–Ocean Boundary, Angela C. Bliss

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study is designed to compare the monthly continental snow cover and sea ice extent loss in the Arctic with regional atmospheric conditions including: mean sea level pressure, 925 hPa air temperature, and mean wind direction among others during the melt season (March-August) over the 29-year study period 1979-2007. Little research has gone into studying the concurrent variations in the annual loss of continental snow cover and sea ice extent across the land-ocean boundary, since these data are largely stored in incompatible formats. However, the analysis of these data, averaged spatially over three autonomous study regions located in Siberia, North …


Identification Of Geochemical Facies Through Major Ion Data And Additional Parameters From Shallow Groundwater Utilizing A Comparison Of Geomathematics And Traditional Methods In Las Vegas Valley, Nevada, Eric Dano Aug 2010

Identification Of Geochemical Facies Through Major Ion Data And Additional Parameters From Shallow Groundwater Utilizing A Comparison Of Geomathematics And Traditional Methods In Las Vegas Valley, Nevada, Eric Dano

UNLV Theses, Dissertations, Professional Papers, and Capstones

There has been little exploration to identify geochemical facies in shallow groundwater in the Las Vegas Valley in Clark County, Nevada. Identification of hydrochemical facies in Las Vegas Valley is important for assessing the extent and nature of a potential groundwater resource. The identification of facies could be complicated by the possibility that secondary recharge constitutes a hydrochemical facies of its own. To identify geochemical facies, groundwater samples for major ions, stable isotopes and some municipal tracers were collected from 35 wells in an established network of monitor wells. Wells were purged with a bailer or 12V pump and EC, …


Variations In Vulnerability To Climate Change In Southeast Asia, Kelsey Margaret Allard Jun 2010

Variations In Vulnerability To Climate Change In Southeast Asia, Kelsey Margaret Allard

Social Sciences

No abstract provided.


The Hydro-Ecology Of Everyday Life: Assessing The Social And Environmental Determinants Of Water Use In The Portland Region, Vivek Shandas May 2010

The Hydro-Ecology Of Everyday Life: Assessing The Social And Environmental Determinants Of Water Use In The Portland Region, Vivek Shandas

Systems Science Friday Noon Seminar Series

Driven in part by the imminent threats of population growth and climate destabilization, recent studies suggest that urban areas face severe water scarcity, with some areas in Australia and the United States already instituting moratoria on water use. While water managers traditionally avoid such crises by developing demand forecasts based on population estimates, technological developments, and weather predictions, their analysis are often at a regional scale with aggregate measures of water consumption. To date, there exists limited empirical evidence about how urban spatial structure and concomitant socio-demographic and temperature characteristics mutually interact to affect water demand at the scale of …


Analysis Of Fresh Water Resources At The Line Hole Well Field, San Salvador Island, The Bahamas, Scot Allan Russell Jr. May 2010

Analysis Of Fresh Water Resources At The Line Hole Well Field, San Salvador Island, The Bahamas, Scot Allan Russell Jr.

Masters Theses & Specialist Projects

A major economic constraint in the Bahamas, and other small carbonates islands world-wide, is the lack of fresh water resources. To combat these socio-economic problems on San Salvador Island I sought to gain a more detailed understanding of the extent, behavior, and controls on the island’s fresh-water lens. DC electrical resistivity tomography and time-series geochemical data are used to study the fresh water lens at the Line Hole well field. Electrical Resistivity profiles are used to image the extent of fresh water resources. Time-series geochemical data provide information on the behavior of the fresh water resources as a function of …


Talus Slope Processes In The Appalachian : An Analysis Of Rock Size And Shape On The Shawangunk Ridge, Northwestern New Jersey, Muhammad Hamidul Haque May 2010

Talus Slope Processes In The Appalachian : An Analysis Of Rock Size And Shape On The Shawangunk Ridge, Northwestern New Jersey, Muhammad Hamidul Haque

Theses, Dissertations and Culminating Projects

Sphericity, hardness, roundness, and size of talus boulders were analyzed to understand the mass wasting process on the Shawangunk Ridge in northwestern New Jersey. Similar studies have been conducted in other localities (e.g., Lassen Peak, California and Spitsbergen, Sweden) but few works were carried out in the eastern United States, particularly in the Appalachian region. During the Pleistocene, ice sheets advanced in North America, and glacial and periglacial (soil and rock affected by ice) environments existed throughout the Appalachians. Although the periglacial climate is not present in this region right now, rock falls are still active where weak joints are …


Variations In Winter Surface High Pressure In The Northern Hemisphere And Climatological Impacts Of Diminishing Arctic Sea Ice, Kristen D. Fox May 2010

Variations In Winter Surface High Pressure In The Northern Hemisphere And Climatological Impacts Of Diminishing Arctic Sea Ice, Kristen D. Fox

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study explores the role Arctic sea ice plays in determining mean sea level pressure and 1000 hPa temperatures during Northern Hemisphere winters while focusing on an extended period of October to March. This is accomplished by investigating two regions of the same size and comparable climatic zones and elevations in the Northern Hemisphere. A breakdown of 29 years of reanalysis data into average monthly values, anomalies, trends, and comparisons between regions serves as current data to compare with a computer model control run. Ensuring the control run accurately models current atmospheric patterns, altering the model inputs to have no …


Random Forests Applied As A Soil Spatial Predictive Model In Arid Utah, Alexander Knell Stum May 2010

Random Forests Applied As A Soil Spatial Predictive Model In Arid Utah, Alexander Knell Stum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Initial soil surveys are incomplete for large tracts of public land in the western USA. Digital soil mapping offers a quantitative approach as an alternative to traditional soil mapping. I sought to predict soil classes across an arid to semiarid watershed of western Utah by applying random forests (RF) and using environmental covariates derived from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and digital elevation models (DEM). Random forests are similar to classification and regression trees (CART). However, RF is doubly random. Many (e.g., 500) weak trees are grown (trained) independently because each tree is trained with a new randomly …


Forest Conservation In A Changing World: Natural Or Cultural? Example From The Western Carpathians Forests, Romania, Angelica N. Feurdean Apr 2010

Forest Conservation In A Changing World: Natural Or Cultural? Example From The Western Carpathians Forests, Romania, Angelica N. Feurdean

Studia UBB Geologia

In order to plan for the future management of some of the most biodiverse forests of Europe, it is essential that we understand under which condition they arose and the time and processes responsible for their variability. Here, I highlight the main findings from the palaeoecological (pollen and charcoal), archaeological and historical investigation comprising the last 6000 years, in the Apuseni Natural Park, NW Romania and discuss the effect of the past land use and forest management on these forests. I then ask what does it mean in term of conservation values if these forests are not natural but a …


Coastal Karren Features In Temperate Microtidal Settings: Spatial Organization And Temporal Evolution, Lluís Gómez-Pujol, Joan J. Fornós Apr 2010

Coastal Karren Features In Temperate Microtidal Settings: Spatial Organization And Temporal Evolution, Lluís Gómez-Pujol, Joan J. Fornós

Studia UBB Geologia

Basin pools are the diagnostic feature of Coastal Karren landscape at temperate settings. According to the size and connectivity parameters four morphological zones are identified along limestone coastal profiles. Each zone reflects the balance between the effects of physical and chemical weathering-erosion agents. Broadly, marine abrasion, bioerosion and biological driven solution show a larger influence seaward, whereas non-biological driven solution enhances its participation landward


Suspended Sediment Transport Dynamics And Sediment Yields In Relation To Watershed Characteristics, Upper Green River Basin, Kentucky, James Nii Aboh Otoo Apr 2010

Suspended Sediment Transport Dynamics And Sediment Yields In Relation To Watershed Characteristics, Upper Green River Basin, Kentucky, James Nii Aboh Otoo

Masters Theses & Specialist Projects

Sediment delivery is a major problem in the Green River, Kentucky, home of 71 of the state’s 103 known mussel species and 151 fish species. The river also provides water for many of its surrounding counties. This research focuses on how suspended sediment loads, grain size, and sediment concentration during runoff events are related to watershed characteristics.

The research characterized suspended sediment loads, grain size, and sediment concentration during runoff events and how they were related to watershed characteristics such as hydro-climatic regime, watershed size, geology and soils, topography and landuse conditions and land cover conditions. The study focused on …


Distribution Of Dioecious Eastern Red Cedar (Juniperus Virginiana) Along An Environmental Gradient In Ogallala, Ne, Taylor Sloey Apr 2010

Distribution Of Dioecious Eastern Red Cedar (Juniperus Virginiana) Along An Environmental Gradient In Ogallala, Ne, Taylor Sloey

Department of Environmental Studies: Undergraduate Student Theses

Abstract

The purpose of this research was to study the sex distribution and energy allocation of dioecious Eastern Red Cedars (Juniperus virginiana) along an environmental resource gradient. The trees surveyed were growing in a canyon located at the University of Nebraska’s Cedar Point Biological Research Station in Ogallala, Nebraska. Due to the geography of this canyon, environmental factors necessary for plant growth should vary depending on the tree’s location within the canyon. These factors include water availability, sun exposure, ground slope, and soil nitrogen content, all of which are necessary for carbon acquisition.

Juniperus virginiana is a dioecious conifer. Dioecious …


Baseline Rockfall Rates And Rockfall Protection In Virginia, Brian Bruckno Apr 2010

Baseline Rockfall Rates And Rockfall Protection In Virginia, Brian Bruckno

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Current approaches to rockfall hazard and risk mitigation have been dominated by a model in which rockfall is treated as a global slope stability phenomenon which is mainly triggered by precipitation, freeze-thaw, or root wedging. The methods implemented by many public agencies and private entities developed from this conceptualization. These methods, such as the Rockfall Hazard Rating System, Key Block and Key Group Analysis, and remote sensing using LIDAR or digital images, are best applied to the end-members of slopes, such as pure engineered soil or structurally simple and consistent rock slopes. Slopes exhibiting complex structure, slopes that cross formations …


A Catalog Of Felt Intensity Data For 570 Earthquakes In India From 1636 To 2009, Stacey Martin, Walter Szeliga Apr 2010

A Catalog Of Felt Intensity Data For 570 Earthquakes In India From 1636 To 2009, Stacey Martin, Walter Szeliga

Faculty Scholarship for the Cascadia Hazards Institute

Eight thousand three hundred thirty-nine intensity observations have been evaluated for earthquakes that occurred on the Indian subcontinent and surrounding plate boundaries from the seventeenth century to the present. They characterize 570 earthquakes, more than 90% of which occurred in the past two centuries. The electronic supplement to this article lists these data using European Macroseismic Scale (EMS-98) intensities with their geographic coordinates. We summarize these data graphically in the form of a spatially averaged intensity map for the subcontinent, a map that emphasizes the features of many previously published earthquake hazard maps for the Indian plate, but which more …


Analysis Of Streamflow In The St. Croix River: A Hydrologic Model, Stephanie A. Kleinschmidt Apr 2010

Analysis Of Streamflow In The St. Croix River: A Hydrologic Model, Stephanie A. Kleinschmidt

Geography Honors Projects

This project assesses how streamflow is affected by anthropogenic changes to the environment, looking specifically at the St. Croix River Basin. In 2004 the United States Geologic Survey (USGS) published a report on streamflow in the St. Croix River at two gaging stations: Danbury and St. Croix Falls. The streamflow at the upstream station near Danbury, Wisconsin remained stable over time, while an increase was observed at the station in St. Croix Falls, Wisconsin further downstream. In order to evaluate this disparity, this project utilizes a GIS hydrologic model to analyze the factors expected to be influencing the flow rate. …


Changing Depositional Environments In An Upper Ordovician Stratigraphic Sequence, Ashlock Formation, Madison County, Kentucky, Kevin G. Greff, Walter S. Borowski Apr 2010

Changing Depositional Environments In An Upper Ordovician Stratigraphic Sequence, Ashlock Formation, Madison County, Kentucky, Kevin G. Greff, Walter S. Borowski

EKU Faculty and Staff Scholarship

We investigate the sedimentology, stratigraphy, and depositional environments of a 7-meter, Upper Ordovician limestone sequence cropping out in Richmond, Madison County, Kentucky. The stratigraphic section lies within the Ashlock Formation with good lateral exposure stretching along 200 meters of a highway roadcut. We took approximately 20 samples from the measured section, focusing on representative samples and lithologic transitions. We use standard laboratory procedures in slabbing rock samples and making thin sections.

The Ashlock Formation here consists of alternating layers of limey mudstone and limestone (field units A through F). Megafossils - brachiopods, bryozoans, trilobites, gastropods, ostracodes, coralline algae, and bivalves …


Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez Feb 2010

Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez

US-Mexico Negotiations on Improved Colorado River Management: An Update (February 19)

Presenter: Mario López, Engineering and Technical Standards Manager, National Water Commission of México

53 slides


Modern And Late Holocene Wind Regimes Over The Great Plains (Central U.S.A.), Rebecca L. Schmeisser, David B. Loope, Joseph A. Mason Feb 2010

Modern And Late Holocene Wind Regimes Over The Great Plains (Central U.S.A.), Rebecca L. Schmeisser, David B. Loope, Joseph A. Mason

Department of Earth and Atmospheric Sciences: Faculty Publications

The Great Plains of the central United States contain numerous presently stabilized dune fields that were active during the late Holocene. The most recent period of reactivation occurred about 700–1000 years ago during the Medieval Climatic Anomaly, a period of frequent, severe drought recognized throughout the North American West. Dune orientations and internal bedding preserve information about paleowinds from this time period. We compared paleowind information with modern winds and potential sand transport analyzed from meteorological data. While both reconstructed paleowinds and modern winds include a strong northwesterly component over the northern to central portions of the Great Plains, a …