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Articles 331 - 360 of 1911

Full-Text Articles in Hydrology

Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele Jun 2018

Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele

International Journal of Speleology

The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and Cueva Los Mucolitos, both located in the northwest foothills of the main crater. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization used Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In addition, measurements of environmental parameters in the caves, …


Results Of Test-Hole Drilling For Observation Well Planning In The Lower Loup Natural Resources District, Spring 2017, Douglas R. Hallum P.G., Sue Olafsen Lackey, Steven S. Sibray May 2018

Results Of Test-Hole Drilling For Observation Well Planning In The Lower Loup Natural Resources District, Spring 2017, Douglas R. Hallum P.G., Sue Olafsen Lackey, Steven S. Sibray

Conservation and Survey Division: Faculty and Staff Publications

The High Plains Aquifer underlies much of Nebraska. It is the primary source of groundwater within the Lower Loup Natural Resources District (LLNRD) of central Nebraska. Water derived from the aquifer is an important natural resource for the area and supplies water for recreation, wildlife and agriculture, as well as domestic, municipal, and industrial uses. Falling spring water levels measured in existing observation and irrigation wells have raised concerns about possible changes in water availability, groundwater-surface water relationships and water quality in the area, prompting the LLNRD to propose test holes and the collection of additional groundwater data in the …


Preliminary Sedimentology And Stratigraphy Of The Enigmatic Middle Lake Beds Succession (Pleistocene?) In The Rukwa Rift Basin, Tanzania, Cassy Mtelela May 2018

Preliminary Sedimentology And Stratigraphy Of The Enigmatic Middle Lake Beds Succession (Pleistocene?) In The Rukwa Rift Basin, Tanzania, Cassy Mtelela

Tanzania Journal of Science

This paper presents sedimentology and stratigraphic overview of a series of previously unrecognized lithostratigraphic unit in the Rukwa Rift Basin, Tanzania. Based on the cross-cutting relationship and pilot detrital zircon geochronology, these isolated, enigmatic strata are herein informally termed the middle Lake Beds (mLB). Facies analysis reveals that the mLB units were deposited within a complex array of depositional environments, ranging from alluvial to fluvial channels, floodplains and shallow lakes.  The mLB are characterised herein as isolated outcrop exposures with uncertain age relationships, but which can be divided into five distinctive lithostratigraphic units herein identified as informal members (A-E). These …


Quantifying Factors That Influence Road Deicer Retention And Export In A Multi-Landuse Upstate New York Watershed, David Joseph Saba May 2018

Quantifying Factors That Influence Road Deicer Retention And Export In A Multi-Landuse Upstate New York Watershed, David Joseph Saba

Graduate Dissertations and Theses

Chloride contamination of streams and groundwater has become a prevalent issue throughout urbanizing areas in the last half century, particularly in northern latitudes where deicing salts are applied to roadways. This study determined how deicer impacted runoff disperses through sub-urban and urban areas on seasonal and multi-year scales. Chloride concentration changes were then modelled under varying pollutant loading scenarios through an integrated catchment model (INCA-Cl).

Six in-stream conductivity/stage/temperature sondes, recording at 15-minute intervals, were installed within the small (~9.6 km2) Fuler Hollow Creek multi-landuse watershed in Broome County NY and monitored over a 1-year period. Weekly grab samples were taken …


Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood May 2018

Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood

Graduate Theses/Dissertations

Springfield, MO is located on the Springfield Plateau physiographic province. The Springfield plateau contains a number of Mississippian aged units and is mainly capped by the Burlington-Keokuk Formation. The Burlington-Keokuk is a highly fossiliferous limestone with nodular and interbedded chert. Beneath the Burlington-Keokuk lies the Elsey, Reeds Spring, and Pierson Formations respectively which comprise the Springfield Plateau aquifer hydrostratigraphic unit. Within the Springfield Plateau aquifer, a well-developed karst system includes springs, sinkholes, and caves. The Springfield Plateau aquifer is the predominant source for springs and seeps in the Springfield area. The purpose of this study was to understand the differences …


Assessing Land Deformation And Sea Encroachment In The Nile Delta, Egypt, Esayas Gebremichael Apr 2018

Assessing Land Deformation And Sea Encroachment In The Nile Delta, Egypt, Esayas Gebremichael

Research and Creative Activities Poster Day

Persistent scatterer interferometric analyses were conducted on a stack of 84 Envisat ASAR scenes spanning 7 years (2004 to 2010) over the entire Nile Delta of Egypt and surroundings to monitor the ongoing spatial and temporal land deformation, identify the factors controlling the deformation, and model the interplay between sea level rise and land subsidence to identify areas and populations threatened by sea encroachment by the end of the 21st century. Findings include: (1) general patterns of subsidence in the northern delta, near-steady (none) subsidence in the southern delta, separated by a previously mapped flexure zone undergoing uplift; (2) high …


Modeling Climate Change Impacts On Water Balance Components Of The Mackinaw River Watershed, Central Illinois, Joseph Honings Apr 2018

Modeling Climate Change Impacts On Water Balance Components Of The Mackinaw River Watershed, Central Illinois, Joseph Honings

Theses and Dissertations

Understanding the response of water cycle dynamics to climate change and human activity is essential for best management of water resources. This study used the USDA Soil-Water Assessment Tool (SWAT) to measure and predict major water balance variables including stream discharge, potential aquifer recharge, and surface storage in a small-scale watershed (~2,930 km²) in Central Illinois. The watershed is predominantly tile-drained agricultural land, which controls the nutrient dynamics and hydrology. Two reservoirs, Evergreen Lake and Lake Bloomington, and the Mahomet Aquifer in the watershed are used for public water supply. The subject watershed has been very sensitive to recent droughts, …


Landscapes From The Waves—Marine Terraces Of California, Marjorie Schulz, Corey Lawrence, Daniel R. Muhs, Carol Prentice, Sam Flanagan Mar 2018

Landscapes From The Waves—Marine Terraces Of California, Marjorie Schulz, Corey Lawrence, Daniel R. Muhs, Carol Prentice, Sam Flanagan

United States Geological Survey: Publications

M any coastlines around the world have stair-step landforms, known as marine terraces. Marine terraces make up a large part of coastal California’s landscape—from San Diego to Crescent City. Find out how these landscapes form, why marine terraces are of interest to scientists, and where you can explore these landscapes.

Marine terraces result from the interaction of two geologic processes: uplift of the land surface and the natural rise and fall of sea level over hundreds of thousands of years. As sea level rises, waves move underwater sediment—sand and gravel—back and forth against bedrock, acting like sandpaper to hone bedrock …


Fossils On The Floor In The Nebraska State Capitol: A Coloring And Activities Book, Robert F. Diffendal Jr. Mar 2018

Fossils On The Floor In The Nebraska State Capitol: A Coloring And Activities Book, Robert F. Diffendal Jr.

Conservation and Survey Division: Faculty and Staff Publications

The Nebraska State Capitol is a wonderful place. This building is home to great treasures of art owned by the people of Nebraska. The floor of the Capitol Rotunda has beautiful works of art. Maybe you have seen this art. Small pieces of two kinds of rocks make pictures of people, their tools, the natural resources they used, and pictures of fossil animals and plants. These kinds of pictures are called mosaics [moe ZAY icks]. The animals and plants follow one another in a curved ribbon around the floor. In that ribbon of pictures are many kinds of fossil animals …


Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown Jan 2018

Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown

Faculty Publications

Diverse karst phenomena occur throughout the Gypsum Plain where the Castile Formation crops out over ~1800 km2 in West Texas and southeastern New Mexico. Hypergene karst is extensive and widespread, while traditional hypogene karst manifestations (both caves and intrastratal dissolution) occur in high frequency in the western outcrop region where surface denudation has been the greatest so as to induce surficial breaching. Unconfined hypogene karst occurrences have been recently identified, including two general variations: 1) artesian-like discharge features; and 2) venting structures. Artesian-like discharge features arise at surficially-breached hypogene caves and through high permeability regions on the margins of …


Review Of The Ends Of The World: Volcanic Apocalypses, Lethal Oceans, And Our Quest To Understand Earth's Past Mass Extinctions, By Peter Brannen, Robert F. Diffendal Jr. Jan 2018

Review Of The Ends Of The World: Volcanic Apocalypses, Lethal Oceans, And Our Quest To Understand Earth's Past Mass Extinctions, By Peter Brannen, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In his new best-selling book, Peter Brannen, award-winning science writer, takes you on a fascinating trip through the run-up to the end of the Cretaceous extinction event and the K-Pg (Cretaceous/Paleogene) boundary, formerly called the K-T (Cretaceous/Tertiary) boundary.

Brannen interviewed many scientists who studied these events and went on field trips with them to major Cretaceous sites and to those where earlier and later extinction events happened. He presents clear explanations of what is known and not known about all of these events in a largely error-free book. Brannen details the other four big extinction events in geologic history: the …


The Pothole Hydrology-Linked Systems Simulator (Phyliss)—Development And Application Of A Systems Model For Prairie-Pothole Wetlands, Owen P. Mckenna, David M. Mushet, Eric J. Scherff, Kyle I. Mclean, Christopher T. Mills Jan 2018

The Pothole Hydrology-Linked Systems Simulator (Phyliss)—Development And Application Of A Systems Model For Prairie-Pothole Wetlands, Owen P. Mckenna, David M. Mushet, Eric J. Scherff, Kyle I. Mclean, Christopher T. Mills

United States Geological Survey: Publications

The North American Prairie Pothole Region covers about 770,000 square kilometers of the United States and Canada (including parts of 5 States and 3 provinces: North Dakota, South Dakota, Montana, Minnesota, Iowa, Saskatchewan, Manitoba, and Alberta). The Laurentide Ice Sheet shaped the landscape of the region about 12,000 to 14,000 years ago. The retreat of the ice sheet left behind low-permeability glacial till and a landscape dotted with millions of depressions known today as prairie potholes. The wetlands that subsequently formed in these depressions, prairie-pothole wetlands, provide critical migratory-bird habitat and support dynamic aquatic communities. Extensive grasslands and productive agricultural …


Appendix 1. Testing The Influence Of Management Regime And Year On Vegetation Structure Variables On Two Grass Types On Federal Lands Managed Under An Adaptive-Management Framework By The U.S. Fish And Wildlife Service In North Dakota, South Dakota, Minnesota, And Montana, 2011–13, J.J Gannon, T.L. Shaffer, C.T. Moore Jan 2018

Appendix 1. Testing The Influence Of Management Regime And Year On Vegetation Structure Variables On Two Grass Types On Federal Lands Managed Under An Adaptive-Management Framework By The U.S. Fish And Wildlife Service In North Dakota, South Dakota, Minnesota, And Montana, 2011–13, J.J Gannon, T.L. Shaffer, C.T. Moore

United States Geological Survey: Publications

Generalized linear mixed model (assuming a beta distribution with a logit link) testing the influence of management regime and year on mean bare-ground cover (percent) on two grass types on Federal lands managed under an adaptive-management framework by the U.S. Fish and Wildlife Service (Gannon and others, 2013) in North Dakota, South Dakota, Minnesota, and Montana, 2011–13.


Assessing The Impact Of The Conservation Reserve Program On Honey Bee Health, Otto, C.R.V., O'Dell, S., Bryant, R.B., Euliss, N.H., Bush Jan 2018

Assessing The Impact Of The Conservation Reserve Program On Honey Bee Health, Otto, C.R.V., O'Dell, S., Bryant, R.B., Euliss, N.H., Bush

United States Geological Survey: Publications

Insect pollinators are critically important for maintaining U.S. food production and ecosystem health. The upper Midwest is home to more than 40 percent of all U.S. honey bee colonies and is considered by many beekeepers to be America’s last beekeeping refuge. Beekeepers come to this region because their honey bees require high-quality grassland and bee-friendly agricultural crops to make honey and to improve bee health. Agricultural grassland, such as those enrolled in the Conservation Reserve Program (CRP), support flowers that provide bees with the pollen and nectar they need. In 2014, the U.S. Department of Agriculture (USDA) and the U.S. …


Adaptive Management In Native Grasslands Managed By The U.S. Fish And Wildlife Service—Implications For Grassland Birds, Lawrence D. Igl, Welsey E. Newton, Todd A. Grant, Cami S. Dixon Jan 2018

Adaptive Management In Native Grasslands Managed By The U.S. Fish And Wildlife Service—Implications For Grassland Birds, Lawrence D. Igl, Welsey E. Newton, Todd A. Grant, Cami S. Dixon

United States Geological Survey: Publications

Burning and grazing are natural processes in native prairies that also serve as important tools in grassland management to conserve plant diversity, to limit encroachment of woody and invasive plants, and to maintain or improve prairies. Native prairies managed by the U.S. Fish and Wildlife Service (FWS) in the Prairie Pothole Region of the northern Great Plains have been extensively invaded by nonnative, cool-season species of grasses. These invasions were believed to reflect a common management history of long-term rest and little or no defoliation by natural processes (burning and grazing). To address the challenges associated with these invasive species, …


Combining Hydraulic Head Analysis With Airborne Electromagnetics To Detect And Map Impermeable Aquifer Boundaries, Jesse T. Korus Jan 2018

Combining Hydraulic Head Analysis With Airborne Electromagnetics To Detect And Map Impermeable Aquifer Boundaries, Jesse T. Korus

Conservation and Survey Division: Faculty and Staff Publications

Impermeable aquifer boundaries affect the flow of groundwater, transport of contaminants, and the drawdown of water levels in response to pumping. Hydraulic methods can detect the presence of such boundaries, but these methods are not suited for mapping complex, 3D geological bodies. Airborne electromagnetic (AEM) methods produce 3D geophysical images of the subsurface at depths relevant to most groundwater investigations. Interpreting a geophysical model requires supporting information, and hydraulic heads offer the most direct means of assessing the hydrostratigraphic function of interpreted geological units. This paper presents three examples of combined hydraulic and AEM analysis of impermeable boundaries in glacial …


The Groundwater Atlas Of Red Willow County, Nebraska, Dana Divine, Duane Eversoll, Leslie M. Howard Jan 2018

The Groundwater Atlas Of Red Willow County, Nebraska, Dana Divine, Duane Eversoll, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

The purpose of this groundwater atlas is to synthesize a wealth of hydrogeologic data for Red Willow County that has not been published in readily accessible formats previously. Many of the maps presented here are based on geologic information from registered wells and test holes that is publically available on-line, which becomes more valuable when compiled, analyzed, and discussed as a whole.

In Red Willow County, the aquifers are alluvial sand and gravel in the river and stream valleys and the High Plains aquifer beneath the uplands. The High Plains aquifer in Red Willow County consists primarily of the Ogallala …


Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton Jan 2018

Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton

Theses and Dissertations--Civil Engineering

Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. …


Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford Jan 2018

Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford

Theses and Dissertations--Earth and Environmental Sciences

Landslide characterization and hazard assessments require multidisciplinary approaches that connect geologic processes with geotechnical parameters. Field monitoring of hydrologic variables such as water content and water potential, coupled with geoelectrical measurements that can establish relationships used for geotechnical and landslide hazard investigations is deficient.

This study brings together different techniques to develop a methodology that connects geoelectrical measurements and shear strength. A field-based framework was established that includes (1) analysis of long-term soil moisture fluctuations within different landslides (2) establishment of constitutive and new equations that test the use of electrical conductivity to predict soil-water relationships and shear strength (3) …


Failure Of The Alexander Dam Embankment And Reconstruction Using Drainage Mitigation On Kauai, Hawaii, 1930-1932, Kerry D. Cato, J. David Rogers Jan 2018

Failure Of The Alexander Dam Embankment And Reconstruction Using Drainage Mitigation On Kauai, Hawaii, 1930-1932, Kerry D. Cato, J. David Rogers

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Alexander Dam is a hydraulic fill earth dam and the second-highest embankment dam in Hawaii, having been built in 1929-1932 on the south side of the Hawaiian island of Kauai to provide irrigation for McBryde Sugar Company Ltd. It was constructed across Wahiawa Stream mauka (Hawaiian for "stream that comes from the mountains," literally "toward the mountains"), upstream of Kalaheo, to store 800 million gallons (5 million m3) of water to irrigate sugarcane fields. The embankment dam was intended to have a maximum height of 125 ft (38 m), a crest length of 620 ft (189 m), and a maximum …


John Frank Stevens: Panama Canal Mastermind And Pioneering Railroad Pathfinder, J. David Rogers, Lawrence M. Magura Jan 2018

John Frank Stevens: Panama Canal Mastermind And Pioneering Railroad Pathfinder, J. David Rogers, Lawrence M. Magura

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

John Frank Stevens began his civil engineering career as a rodman on a survey crew in Maine in 1872. He soon moved to Minneapolis, where he apprenticed himself, eventually becoming Assistant City Engineer. In 1876 he began working for railroads in the western United States. In 1882 Stevens began working for a contractor laying tracks for the Canadian Pacific Railroad in Saskatchewan. The next spring he became assistant engineer of location for the Canadian Pacific, completing the first transcontinental line linking Montreal with Vancouver in 1888. In 1889 James Jerome Hill retained Stevens as chief pathfinder for the new Great …


Winter Rain Versus Snow In Headwater Catchments: Responses Of An Unconfined Pumice Aquifer, South-Central Oregon, Usa, Michael L. Cummings, David A. Eibert Jan 2018

Winter Rain Versus Snow In Headwater Catchments: Responses Of An Unconfined Pumice Aquifer, South-Central Oregon, Usa, Michael L. Cummings, David A. Eibert

Geology Faculty Publications and Presentations

Winter precipitation in two headwaters catchments (elevation ~1600 m) in the rain shadow of the Cascades volcanic arc in south-central Oregon normally falls as snow. However, in water year 2015, winter precipitation fell mainly as rain. An eight year study of the unconfined pumice aquifer allowed inter-annual comparison of groundwater recharge during the freshet and discharge during the growing season. During these water years precipitation ranged from 67% (WY2014) to 132% (WY2017) of the 30 year average, and included the rain dominated winter of WY2015 when precipitation during the water year was 98% of the 30 year average. Change in …


Qualitative And Quantitative Analysis Of Carbonate Waters In The Peters Mountain Region Of Monroe County, Wv, Emily A. Bausher Jan 2018

Qualitative And Quantitative Analysis Of Carbonate Waters In The Peters Mountain Region Of Monroe County, Wv, Emily A. Bausher

Graduate Theses, Dissertations, and Problem Reports (ETD)

Water in Monroe County, WV is used extensively for public and private supply and requires quantification, chemical analysis, and assessment for contamination susceptibility. Over 250 springs were previously identified in the eastern side of Monroe County on or near Peters Mountain; 14 were continuously monitored in this study. Springs were grouped based on geologic and spatial distribution: interbedded clastic-rock springs on the mountain flanks, carbonate springs in the valley, and a thermal spring associated with the St. Clair thrust fault. Clastic and carbonate springs have calcium-magnesium-bicarbonate chemistries, neutral pHs and high alkalinities; the thermal spring has calcium-magnesium-sulfate-carbonate chemistry, low pH, …


2017 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, H. Reiners-Hild Dec 2017

2017 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, H. Reiners-Hild

Conservation and Survey Division: Faculty and Staff Publications

Twenty participants completed the 2017 Water Leaders Academy bringing the total number of graduates to 101 since the inception of the program in 2011. Assessment of participants’ transformational leadership skills, champion of innovation skills, water knowledge and engagement, civic capacity, and entrepreneurial leadership behaviors showed a significant increase over the course of the year, from both participants’ and their raters’ perspectives. Feedback from participants was highly positive and constructive. Participant concerns were addressed, and only minor changes are planned for the 2018 Academy curriculum. Results of the program assessment indicate that the curriculum is meeting Academy objectives. Most importantly, Alumni …


An Lntegrated Approach (Remote Sensing, Hydrogeology, Geotechnical, And Geoinformatics) To Assess And Monitor Fossil Aquifers And Associated Land Deformation Over The Arabian Peninsula, Abdullah Ghurmullah Saeed Othman Dec 2017

An Lntegrated Approach (Remote Sensing, Hydrogeology, Geotechnical, And Geoinformatics) To Assess And Monitor Fossil Aquifers And Associated Land Deformation Over The Arabian Peninsula, Abdullah Ghurmullah Saeed Othman

Dissertations

Deformational features such as subsidence, sinkholes, fissures, settling and cracks in buildings and structures, and earthquakes are being reported from many of the world’s arid lands, in areas where fossil aquifers are being excessively exploited. Using the Lower Mega Aquifer System (LMAS) in Arabia as a test site, I applied an integrated approach (remote sensing, geodesy, GIS, geology, hydrogeology, and geotechnical) to identify nature, intensity, spatial distribution, and factors controlling the observed deformation in the central (Al-Qassim and Ha'il regions; area: 16×10⁴ km²) and the northern (Wadi As-Sirhan Basin; area: ~10.9×10⁴ km²) Arabia. A four -fold approach was adopted to …


Understanding Cigarette Butt Littering Behavior On A Public Beach: A Case Study Of Jekyll Island, Maranda R. Miller, Mark E. Burbach Dec 2017

Understanding Cigarette Butt Littering Behavior On A Public Beach: A Case Study Of Jekyll Island, Maranda R. Miller, Mark E. Burbach

Conservation and Survey Division: Faculty and Staff Publications

Conservation of natural resources and promotion of family-friendly tourism activities are vital to Jekyll Island. As it is stated in the Jekyll Island Authority (JIA) Master Plan “Jekyll Island is a unique, state-owned barrier island that balances conserving and preserving natural, historic, and cultural resources with providing accessible, affordable recreation, vacation, and education opportunities for the people of Georgia and beyond” (Jekyll Island Authority, 2014b, p. 4). The JIA has reported approximately 1 million people visit the island annually (Jekyll Island Authority, 2015). As such, tourism is instrumental to Jekyll Island’s economy, and that tourism contributes to the overall economy …


Aquifers Of Nebraska Ii: The Niobrara Aquifer, Dana Divine, Robert Matthew Joeckel, Sue Olafsen Lackey Dec 2017

Aquifers Of Nebraska Ii: The Niobrara Aquifer, Dana Divine, Robert Matthew Joeckel, Sue Olafsen Lackey

Conservation and Survey Division: Faculty and Staff Publications

The marine shale, chalk, marl, and chalky limestone of the Niobrara Formation directly underlie Quaternary sediments in 23 counties from south-central to northeastern Nebraska. Nevertheless, the formation serves as an aquifer only in and around Cedar, Madison, and Nuckolls counties. Niobrara aquifer wells mostly supply irrigation, domestic, and livestock needs. Two hundred of the approximately 230 active registered wells in Nebraska that are screened entirely in the Niobrara aquifer are in Cedar County and environs. About another 200 wells in this area are screened in both the Niobrara aquifer and overlying Quaternary sediments. Wells screened entirely in the Niobrara aquifer …


Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard Dec 2017

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …


A Geophysical Investigation Of Stratigraphy And Structure On St. Catherines Island, Georgia, Anne M. Delua Nov 2017

A Geophysical Investigation Of Stratigraphy And Structure On St. Catherines Island, Georgia, Anne M. Delua

Honors College Theses

Geophysical tools were used to investigate potential structural and stratigraphic pathways of the salt water intrusion that is affecting the surficial aquifer on St. Catherines Island, Georgia. Ground penetrating radar (GPR) is a geophysical tool that uses electromagnetic waves to view the subsurface. GPR is used for a variety of applications stratigraphically, biologically, and anthropogenically. GPR electromagnetic waves react to changes in density and composition and type and percentage of pore fluids in sediment and rock. GPR waves also react to interfaces including fractures and faults. GPR waves exhibit attenuation and decreased return signal in materials such as clay. Fresh …


Evidence Of Subglacial Brine Inflow And Wind-Induced Mixing From High Resolution Temperature Measurements In Lake Bonney, Antarctica, Jade Lawrence Nov 2017

Evidence Of Subglacial Brine Inflow And Wind-Induced Mixing From High Resolution Temperature Measurements In Lake Bonney, Antarctica, Jade Lawrence

LSU Master's Theses

Hypersaline brine beneath Taylor Glacier enters proglacial West Lobe Lake Bonney (WLB) subglacially as well as from Blood Falls, a surface discharge point at the Taylor Glacier terminus. The brine strongly influences the water column of WLB. Because of the extremely high salinities below the chemocline in WLB, density is determined almost entirely by salinity and temperature can be used as a passive tracer. Cold brine intrusions enter WLB at the glacier face and intrude in to the water column at the depth of neutral buoyancy, where they can be identified by anomalously cold temperatures at that depth. This study …