Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- Montclair State University (33)
- University of Nebraska - Lincoln (21)
- University of Nevada, Las Vegas (12)
- University of South Florida (12)
- University of Texas at El Paso (11)
-
- University of Kentucky (10)
- Old Dominion University (9)
- Stephen F. Austin State University (9)
- Western Kentucky University (9)
- Western University (8)
- City University of New York (CUNY) (7)
- Eastern Kentucky University (7)
- University of Arkansas, Fayetteville (7)
- Central Washington University (6)
- Chapman University (6)
- Indiana State University (6)
- University of New Mexico (6)
- California Polytechnic State University, San Luis Obispo (5)
- Missouri State University (5)
- University of San Diego (5)
- West Virginia University (5)
- Clemson University (4)
- Louisiana State University (4)
- University of Malaya (4)
- University of North Dakota (4)
- Western Michigan University (4)
- Dartmouth College (3)
- Wilfrid Laurier University (3)
- Bucknell University (2)
- California State University, San Bernardino (2)
- Keyword
-
- Geochemistry (25)
- Groundwater (13)
- Environmental forensics (11)
- Water quality (11)
- Geology (9)
-
- Coal (7)
- Isotopes (7)
- Kentucky (7)
- Sediment (7)
- Soil (7)
- Uranium (7)
- Zinc (7)
- Heavy metals (6)
- Lead (6)
- Polycyclic aromatic hydrocarbons (PAHs) (6)
- Salinity (6)
- Stable isotopes (6)
- Arsenic (5)
- Minerals (5)
- Wilgreen Lake (5)
- Contaminants (4)
- Contaminated sediments (4)
- Dust (4)
- Hydrogeology (4)
- Karst (4)
- Mines (4)
- Nitrate (4)
- PAHs (4)
- Polycyclic aromatic hydrocarbons (4)
- Pyrolysis-GC-MS (4)
- Publication Year
- Publication
-
- Department of Earth and Environmental Studies Faculty Scholarship and Creative Works (31)
- Open Access Theses & Dissertations (11)
- Electronic Theses and Dissertations (10)
- Earth Sciences Publications (8)
- EKU Faculty and Staff Scholarship (7)
-
- Masters Theses & Specialist Projects (7)
- All-Inclusive List of Electronic Theses and Dissertations (6)
- OES Theses and Dissertations (6)
- Theses and Dissertations--Earth and Environmental Sciences (6)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (6)
- All Master's Theses (5)
- Earth and Planetary Sciences ETDs (5)
- Graduate Theses, Dissertations, and Problem Reports (ETD) (5)
- Graduate Theses/Dissertations (5)
- International Journal of Speleology (5)
- United States Geological Survey: Staff Publications (5)
- Biology, Chemistry, and Environmental Sciences Faculty Articles and Research (4)
- EERC Brochures and Fact Sheets (4)
- Graduate Theses and Dissertations (4)
- Masters Theses (4)
- Publications (WR) (4)
- United States National Park Service: Publications (4)
- All Theses (3)
- Dartmouth Scholarship (3)
- Earth and Environmental Sciences Faculty Publications (3)
- Publications and Research (3)
- School of Natural Resources: Faculty Publications (3)
- Student Works (2020-2029) (3)
- Theses (3)
- Theses and Dissertations (Comprehensive) (3)
- Publication Type
- File Type
Articles 61 - 90 of 274
Full-Text Articles in Geochemistry
Distribution Of Particulate Organic Carbon – Fluxes And Inventories – In Growth-Faulted Coastal Wetlands, Samuel Joel Whitehead
Distribution Of Particulate Organic Carbon – Fluxes And Inventories – In Growth-Faulted Coastal Wetlands, Samuel Joel Whitehead
Theses and Dissertations--Earth and Environmental Sciences
Coastal wetlands along the Northern Gulf of Mexico (NGOMx) are critically important but threatened environments which provide significant and diverse economic, social, and environmental value. These environments are essential components to the global carbon cycle, serving as one of the most efficient terrestrial carbon sinks. Since onset of the Industrial Revolution increasing rates of coastal wetland loss have been documented due to a variety of anthropogenic activities, neotectonic processes, subsidence, and rising sea-levels. This research utilized an array of methods and sedimentological analyses to test the hypothesis that growth-fault induced changes at Earth’s surface affects the delivery to, and storage …
Downstream Dispersal Of Fine Tailings, Chat And Metals In Channel Sediment Of Big River, Old Lead Belt, Southeast Missouri, Jennifer Pace Witt
Downstream Dispersal Of Fine Tailings, Chat And Metals In Channel Sediment Of Big River, Old Lead Belt, Southeast Missouri, Jennifer Pace Witt
Graduate Theses/Dissertations
In St. François County, Missouri, compromised above-ground tailings piles and containment ponds from historical mining activities in the Old Lead Belt released considerable amounts of dolomitic, Pb- and Zn-contaminated waste sediments to the Big River, contributing to significant downstream floodplain and channel sediment contamination. Previous studies have documented the effects of heavy metals on Big River biota and water quality, as well as benthic habitat disruption resulting from the influx of small sediments. Few have considered the effects and future contamination risk of the coarse waste sediments (2-16 mm in diameter), locally called “chat”, which retain high Pb and Zn …
Mining-Contaminated Sediment And Metal Storage In Channel Deposits In Turkey Creek, Tri-State Mining District, Missouri And Kansas, Max Quinn Hillermann
Mining-Contaminated Sediment And Metal Storage In Channel Deposits In Turkey Creek, Tri-State Mining District, Missouri And Kansas, Max Quinn Hillermann
Graduate Theses/Dissertations
The Joplin subdistrict, within the Tri-State Mining District (TSMD), was a major producer of lead (Pb) and zinc (Zn) ore between the 1880s to 1920s. Metalliferous mining wastes are still stored in the channel deposits of local streams raising environmental and health concerns. This study quantifies the volume, sediment size, and metal concentrations in channel bed, bar, bench, and chute deposits to quantify the spatial variability of contaminated sediment storage in Turkey Creek (119 km2). Sample reaches (n=14) contained metal concentrations elevated above the Tri-State Mining District specific probable effects concentration at every site with mean concentrations in …
The Effects Of Channel Incision And Land Use On Surface-Water/Groundwater Interactions In The Teanaway River Basin, Washington, Usa, Joseph Petralia
The Effects Of Channel Incision And Land Use On Surface-Water/Groundwater Interactions In The Teanaway River Basin, Washington, Usa, Joseph Petralia
All Master's Theses
The Teanaway River basin, a major tributary to the Yakima River, is host to several restoration projects with the intention of returning the river channel to a more natural state and improving riparian habitat. These projects may also increase aquifer storage and potentially increase summertime streamflows. This study of the Teanaway Valley Family Farm, an 88-hectare parcel on the main-stem Teanaway River that was recently purchased by Washington Department of Fish and Wildlife, provides hydrogeologic data that will inform these restoration projects. Following the purchase of this land, ten wells were installed within and slightly above the floodplain in order …
Low Impact Sampling Of Speleothems – Reconciling Scientific Study With Cave Conservation, Claire L.V. Macgregor, John C. Hellstrom, Jon D. Woodhead, Russell N. Drysdale, Rolan S. Eberhard
Low Impact Sampling Of Speleothems – Reconciling Scientific Study With Cave Conservation, Claire L.V. Macgregor, John C. Hellstrom, Jon D. Woodhead, Russell N. Drysdale, Rolan S. Eberhard
International Journal of Speleology
Speleothems are increasingly valued as important paleoclimate archives and yet the removal of samples from caves can come at a cost to natural heritage, impacting delicate environments with limited mechanisms for repair. Conservation of cave environments is a key responsibility for scientists and, with this in mind, we are working to develop and implement techniques that allow us to extract valuable scientific data, with minimal impact. In this study, we demonstrate the utility of low-impact reconnaissance dating surveys on caves in southern Tasmania and southwest Western Australia as a precursor to the removal of stalagmites for paleoclimate reconstruction. Small flakes …
Impacts Of Oil And Gas Wastes On Landfill Leachate, Sewage Treatment Plants, And The Environment, Lauren Badertscher
Impacts Of Oil And Gas Wastes On Landfill Leachate, Sewage Treatment Plants, And The Environment, Lauren Badertscher
Electronic Theses and Dissertations
Between January 2011 and March 2021 oil and gas wells in Pennsylvania produced
305,637,795 barrels of liquid waste and 6,992,957 tons of solid waste with the majority from
Marcellus Shale unconventional wells. This waste is not considered hazardous and over 89% of
the solid waste generated by unconventional and conventional oil and gas extraction has been
disposed of in landfills over the past decade. This study examined trends in the quantity of waste
produced and methods of disposal. Landfills accepting this waste were identified and their
general method of leachate treatment, using onsite facilities or offsite at wastewater treatment
plants, …
Changes In Tropospheric Ozone Associated With Strong Earthquakes And Possible Mechanism, Feng Jing, Ramesh P. Singh
Changes In Tropospheric Ozone Associated With Strong Earthquakes And Possible Mechanism, Feng Jing, Ramesh P. Singh
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The index of ozone anomaly (IOA) has been proposed to detect changes in tropospheric ozone associated with strong earthquakes. The tropospheric ozone prior and after the 2008 Wenchuan earthquake has been analyzed using IOA. Atmospheric infrared sounder ozone volume mixing ratio (O3 VMR) at different pressure levels (600, 500, 400, 300, 200 hPa) for an 18-year period 2003–2020 has been considered to identify the unique behavior associated with the strong earthquakes. Our results show distinct enhancement in tropospheric ozone occurred 5 d (7 May 2008) prior to the main event and distributed along the Longmenshan fault zone. An enhancement in …
200— Chemical Analysis Of Slag From Standish, Ny, Maria Leonard, Dori Farthing
200— Chemical Analysis Of Slag From Standish, Ny, Maria Leonard, Dori Farthing
GREAT Day Posters
From 1883 to 1907, magnetite was smelted in Standish, NY. During this time, a large amount of slag, a byproduct of smelting, was created. The slag is now in a pile that covers ~13 acres in the northeastern region of the Adirondacks. The slag at the site has been classified into 6 broad types based on their physical properties. Exemplars of select types were crushed and analyzed by X-ray fluorescence spectroscopy (XRF). Both major elements and trace element data was collected for these samples. The XRF results indicate that all Standish slag is dominated by SiO2, CaO, and Fe2O3(t) regardless …
Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen
Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen
Civil and Environmental Engineering Theses and Dissertations
Heavy metals in the environment add to the global burden of pollution, negatively impacting public health and ecosystem resilience. This study included projects regarding uranium (U), lead (Pb), and rare earth elements (REE) in natural samples, due to their known toxicity, ubiquity, and relevance in context to recent pollution trends. The first project focused on testing the potential of using a hydroxyapatite product as a remediation solution for U-contaminated groundwater and soil at an EPA Superfund site. The results showed that the U was sequestered in a highly crystalline mineral form within the solids, guiding the EPA to specify the …
Coastal Watershed Monitoring And Management: Geomorphology, Geochemistry, And Hydrologic Modeling Of Los Peñasquitos Creek, Ca, Ravleen Khalsa-Basra
Coastal Watershed Monitoring And Management: Geomorphology, Geochemistry, And Hydrologic Modeling Of Los Peñasquitos Creek, Ca, Ravleen Khalsa-Basra
Theses
Rivers in semi-arid climates are directly influenced by local geographic and hydrologic conditions and impacted by modifications to hydrology via urbanization. Changes can influence erosion, morphology, habitat sustainability, and watershed health. In highly urbanized southern California coastal regions, these rare open spaces provide vital ecosystem services. Los Peñasquitos Creek in San Diego County is one such watershed. Using stream surveying and laboratory methods we quantified channel characteristics, grain size distribution, total metal concentration [M], organic carbon (%OC), and phosphate to longitudinally characterize the creek for improved management. Results identified three distinct reaches in the watershed (upper, middle, lower). Downstream, depth …
The 3H/3He Groundwater Age-Dating Method And Applications, Troy E. Gilmore, Mikaela L. Cherry, Didier Gastmans, Douglas Kip Solomon, Eric Christopher Humphrey
The 3H/3He Groundwater Age-Dating Method And Applications, Troy E. Gilmore, Mikaela L. Cherry, Didier Gastmans, Douglas Kip Solomon, Eric Christopher Humphrey
School of Natural Resources: Faculty Publications
Groundwater age-dating is an important tool for quantifying and managing water resources. Groundwater age is the elapsed time between recharge (at the land surface or water table) and the time when groundwater is sampled. If groundwater is sampled at the point of discharge from an aquifer, then the age represents the groundwater transit time. Groundwater that has recharged in recent decades is considered young groundwater. In many areas, the quality and quantity of young groundwater has been impacted by human activities and groundwater age-dating is useful for quantifying current and historical water and contaminant fluxes into and through aquifers. This …
Peralkaline Silicic Extrusive Rocks: Magma Genesis, Evolution, Plumbing Systems, And Eruption., Ray Macdonald, John C. White, Harvey E. Belkin
Peralkaline Silicic Extrusive Rocks: Magma Genesis, Evolution, Plumbing Systems, And Eruption., Ray Macdonald, John C. White, Harvey E. Belkin
EKU Faculty and Staff Scholarship
Peralkaline silicic extrusive rocks are an important component of the volcanological record. Here we review several aspects of their formation and evolution, including the tectonic settings in which they occur, their main petrological and geochemical features, the magmatic lineages along which they evolve, and the parameters (T, P, fO2, melt water contents) that control the lineages. Particular attention is paid to the composition of the extraordinary melts formed at the lowest temperatures. Various lines of evidence are presented to explain the silica-gaps in some lineages. The partial melting of continental crust and the role of crustal contamination …
Artisanal Mining Impacts In Urbanized Semi-Arid Environments: Lessons From Historic Arsenic Mining Near San Diego, California, James A. Wright
Artisanal Mining Impacts In Urbanized Semi-Arid Environments: Lessons From Historic Arsenic Mining Near San Diego, California, James A. Wright
Theses
Anomalously elevated arsenic concentrations occur at an abandoned artisanal mine site in an open space recreational park in urban San Diego County, California. Although mining at the site ceased 100 years ago little to no remediation efforts took place leaving shafts, adits, waste piles and derelict infrastructure accessible by inquisitive hikers and adventurers frequenting Black Mountain Open Space Park. This study evaluates the geochemical mechanisms of As transport downgradient from the mine and examines the contribution of both climate and urbanization on the restriction of As mobility. Sediment As concentrations reach 2,320 mg/kg (483 times background crustal concentrations; n=73) along …
Variations In Produced Water Chemistry And Relation To Regional Geology And Production In The Marcellus Shale, Northcentral West Virginia, Jonathan M. Brady
Variations In Produced Water Chemistry And Relation To Regional Geology And Production In The Marcellus Shale, Northcentral West Virginia, Jonathan M. Brady
Graduate Theses, Dissertations, and Problem Reports (ETD)
An investigation of 74 Marcellus Shale wells across northcentral West Virginia indicates changes in produced water chemistry and quantity can be related to geologic conditions based on well logs and core data. These changes are determined by reviewing multiple produced water analyses for individual wells for periods up to ten years. Results show variations among the areas in this study. From west to east across central Harrison County to central Taylor County, then north into Monongalia County, gamma-ray logs show increasing intensity, especially in the middle and lower Marcellus. XRD mineralogy from core data shows increasing clay content from west …
The Persistence Of Acid Mine Drainage At An East Texas Coal Mine, Sarah Zagurski
The Persistence Of Acid Mine Drainage At An East Texas Coal Mine, Sarah Zagurski
Electronic Theses and Dissertations
The objective of this study was to estimate the time it will take for acid forming materials (pyrite) to be weathered to a state of equilibrium and thus cease to produce acid in ground and surface waters within Oak Hill Mine. This was accomplished using an ex-situ kinetic leaching study incorporating a humidity cell in a controlled laboratory setting. Leaching was conducted on soil cores obtained from the vadose zone at Oak Hill Mine and the humidity cell was used to accelerate oxidation of the pyrite within the cores.
An in-situ field study was also conducted that monitored groundwater conditions …
Historical And Future Antarctic Precipitation Based On Cmip5 Models, Reanalysis Data And In Situ Measurements, Malcolm Tang Siong Yii
Historical And Future Antarctic Precipitation Based On Cmip5 Models, Reanalysis Data And In Situ Measurements, Malcolm Tang Siong Yii
Student Works (2020-2029)
The study of precipitation in Antarctica is one of the most studied research topics today. The reliability and accuracy of climate models in simulating Antarctic precipitation, however, are still debatable. Measuring precipitation in Antarctica poses many distinctive challenges. This work attempts to establish a comprehensive study of precipitation in Antarctica. The first part of the study assesses a year-long measurements from five precipitation instruments with reanalysis datatsets and satellite data. The tipping bucket gauges (TBGs) were observed to be less sensitive compared to laser-based sensors (LBSs). Case studies of the daily precipitation and seasonal precipitation measurements showed VPF-730 to be …
Trends In Water Quality Of Cave Pools At Timpanogos Cave National Monument, July 2008–September 2018, Rebecca Weissinger, Andy Armstrong, Kirsten Bahr, Chris Groves
Trends In Water Quality Of Cave Pools At Timpanogos Cave National Monument, July 2008–September 2018, Rebecca Weissinger, Andy Armstrong, Kirsten Bahr, Chris Groves
Crawford Hydrology Laboratory
No abstract provided.
Geochemical Characterization Of Base Metals In Stream Water And Sediments In The Caddo Lake Watershed, Cass, Harrison, And Marion Counties, Texas, Melinda S. Faulkner, Melanie L. Ertons, Joseph D. Watkins
Geochemical Characterization Of Base Metals In Stream Water And Sediments In The Caddo Lake Watershed, Cass, Harrison, And Marion Counties, Texas, Melinda S. Faulkner, Melanie L. Ertons, Joseph D. Watkins
Faculty Publications
The Caddo Lake watershed is located in northeastern Texas and encompasses much of Cass, Harrison, and Marion counties. The watershed is drained by major streams and tributaries flowing in an easterly direction over Eocene-aged rocks and sediments of the Wilcox and Claiborne groups, and empty into the western arm of Caddo Lake. Since 1995, Caddo Lake and some of its tributaries have been included on the State of Texas Clean Water Act 303(d) list by the Texas Commission on Environmental Quality (TCEQ) for impairment due to mercury content in edible tissue, depressed dissolved oxygen, base metal concentrations, and low pH …
The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan
The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan
Graduate Theses/Dissertations
The historic Tri-State Mining District (TSMD) of southwestern Missouri, southeastern Kansas, and northeastern Oklahoma has a history of lead and zinc mining that extended over a hundred years. During the district’s peak production period, the TSMD was one of the world’s largest producers of lead and zinc. The mining activities in the TSMD produced economic growth that supported the local communities and were essential to the victory of the Allied Forces during World War I and World War II. Beginning in the 1920s, the mining activities in the district slowly began to cease due to depletion of metal ores and …
Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates
Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates
LSU Master's Theses
Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …
Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson
Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson
LSU Master's Theses
Rivers and wetlands are a major source of terrestrial derived carbon for coastal ocean margins. Unfortunately, Louisiana’s wetlands are threatened by ongoing high rates of erosion, deterioration, and unprecedented rates of river water discharge that changes seasonally, leading to a net loss of terrestrial carbon into the northern Gulf of Mexico (nGOM). There exists a current lack of understanding about the distribution of dissolved inorganic carbon (DIC) and total alkalinity (TAlk) within the shallowest regions of the Louisiana shelf. Even less is known about how the transport of DIC alters seasonally with changes in river outflow and shelf currents. Quantifying …
Chemostratigraphy Of Carbonate Gravity Flows Of The Wolfcamp Formation In Crockett County, Midland Basin, Texas, Alex Blizzard, Julie Bloxson
Chemostratigraphy Of Carbonate Gravity Flows Of The Wolfcamp Formation In Crockett County, Midland Basin, Texas, Alex Blizzard, Julie Bloxson
Electronic Theses and Dissertations
Sediment gravity flows into deep-water environments are important stratigraphic traps in lithologically diverse reservoirs generating multiple plays for hydrocarbon exploration. These highly heterogeneous deposits can be studied by utilizing chemostratigraphy and higher-order sequence stratigraphy; being an accurate method for reservoir characterization. Studying these gravity flows along a carbonate platform’s slope can further expand an understanding of the stratigraphy that is filling adjacent basins. The application of elemental analyses can support in identifying mineralogy that impact reservoir quality, especially when conventional testing cannot be applied.
This study utilizes five cores containing the Wolfcamp Formation from the southeastern slope of the Central …
A Geochemical Perspective On The Hydrocarbon Compositional Variation Within East Malay Basin: Implication For Oil Exploration, Mohd Sharef Nurfadhila
A Geochemical Perspective On The Hydrocarbon Compositional Variation Within East Malay Basin: Implication For Oil Exploration, Mohd Sharef Nurfadhila
Student Works (2020-2029)
Malay Basin is a prospective basin which perceived to be matured basin in terms of hydrocarbon generating potential. Many significant oil discoveries made since 1970’s includes Seligi, Pulai, Tapis and Bekok oil fields. These fields have been producing until now. Despite its matured stage, there are still more oil discoveries in various parts of Malay Basin until now. Oil discoveries include light and high density oils with various challenges in oil development project. This dissertation focuses on oil fields in East Malay Basin particularly Lerek, Chermingat, Lawang and Serudon oil fields. The objectives of this research are to study the …
Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton
Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton
Civil and Environmental Engineering Theses and Dissertations
Access to safe potable water is a necessity for all. Groundwater is a commonly relied upon drinking water source for many areas around the world. This is especially true for communities in high density, rural settings. Such is the case for populations near Cox’s Bazaar, Bangladesh, and in the Bugesera region of Rwanda. Sediment and groundwater contamination, through toxic dissolved species, represents a significant public health risk to exposed populations. Tropical soils, such as the soil profiles in Bangladesh and Rwanda, often contain higher concentrations of heavy metals (Rieuwerts, 2007). Additionally, nitrate from fertilizers, are widely used on the soils …
Assessment Of Various Groundwater Recharge Methods In The Lower Kelantan River Basin, Malaysia, Hussin Nur Hayati
Assessment Of Various Groundwater Recharge Methods In The Lower Kelantan River Basin, Malaysia, Hussin Nur Hayati
Student Works (2020-2029)
Groundwater recharge is a natural process to replenish the aquifer system. Since 1930s the groundwater demand has risen as it has supported 70% of water supply in Lower Kelantan River Basin. However, a comprehensive study on groundwater recharge mechanism has never been reported. This study evaluated various methods to identify recharge flow processes using stable isotopes of deuterium (2H) and oxygen-18 (18O), tritium (3H), radon (222Rn) and hydrogeochemical (HC) and quantify recharge rate using chloride mass balance (CMB), water table fluctuation (WTF), temperature-depth profile (TDP) and groundwater modelling coupled with water balance GM(WB) followed by the construction of a conceptual …
Temporal Transport Dynamics Of The Amazon River Plume Revealed Using Radium Isotope Analysis, Elana J. Ames
Temporal Transport Dynamics Of The Amazon River Plume Revealed Using Radium Isotope Analysis, Elana J. Ames
Electronic Theses and Dissertations
The Amazon River is the largest river by discharge in the world. It carries terrestrial nutrients into the Western Tropical North Atlantic via a buoyant freshwater plume, conveying water hundreds to thousands of kilometers away and driving critical biogeochemical cycles near the coast. Factors controlling the delivery of nutrients offshore by the plume are complicated and interconnected, yet these nutrients impact the foundation of phytoplankton community structures across the entire plume ecosystem. To better understand the temporal dynamics of this massive, highly influential region, we employ naturally occurring radium isotopes (223Ra, 224Ra, 226Ra, and 228Ra) to analyze mixing and transport …
Geochemical Analyses Of Base Metals In Sediments And Stream Water Black Cypress Bayou, Marion County, Texas, Melanie L. Ertons
Geochemical Analyses Of Base Metals In Sediments And Stream Water Black Cypress Bayou, Marion County, Texas, Melanie L. Ertons
Undergraduate Research Conference
Black Cypress Bayou is a primary tributary of Caddo Lake watershed in eastern Texas. The watershed is underlain by Eocene-aged strata from the Wilcox and Claiborne groups, which represent transgressive/regressive shoreline fluctuations that deposited interbedded friable sandstones and mudstones. The Wilcox Group is of special interest because it contains lignite coal, which has a direct link to heavy metals in sediment and natural waters. Caddo Lake has been listed on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury in edible tissue since 1995 and Black Cypress Bayou has been listed for impaired waters due to …
Element Transport In A River-Lake Continuum Across Forest-Dominated Landscapes: A Case Study In Central Louisiana, Zhen Xu
LSU Doctoral Dissertations
Studying the biogeochemical connectivity between rivers and lakes can help us understand their ecological and environmental impacts within a drainage basin, which is especially true for forest watersheds that play a vital role in provisioning freshwater services to ecosystems and downstream communities. This dissertation research consists of three interconnected studies with the overarching goal of discerning the connectivity of elements in a river-lake continuum across forest-dominated landscapes. These studies utilized water samples and in situ measurements collected from the Little River-Catahoula Lake continuum in the subtropical Louisiana, USA at monthly intervals during 2015-2016 and 1978-2008 historical water quality, hydrological and …
Biotic And Abiotic Factors Influencing Arsenic Biogeochemistry And Toxicity In Fluvial Ecosystems: A Review, Laura Barral-Fraga, María Teresa Barral, Keeley L. Macneill, Diego Martiñá-Prieto, Soizic Morin, María Carolina Rodríguez-Castro, Baigal-Amar Tuulaikhuu, Helena Guasch
Biotic And Abiotic Factors Influencing Arsenic Biogeochemistry And Toxicity In Fluvial Ecosystems: A Review, Laura Barral-Fraga, María Teresa Barral, Keeley L. Macneill, Diego Martiñá-Prieto, Soizic Morin, María Carolina Rodríguez-Castro, Baigal-Amar Tuulaikhuu, Helena Guasch
School of Natural Resources: Faculty Publications
This review is focused on the biogeochemistry of arsenic in freshwaters and, especially, on the key role that benthic microalgae and prokaryotic communities from biofilms play together in through speciation, distribution, and cycling. These microorganisms incorporate the dominant iAs (inorganic arsenic) form and may transform it to other arsenic forms through metabolic or detoxifying processes. These transformations have a big impact on the environmental behavior of arsenic because different chemical forms exhibit differences in mobility and toxicity. Moreover, exposure to toxicants may alter the physiology and structure of biofilms, leading to changes in ecosystem function and trophic relations. In this …
Lunar Magnetic Field Models From Lunar Prospector And Selene/Kaguya Along‐Track Magnetic Field Gradients, Dhananjay Ravat, M. E. Purucker, N. Olsen
Lunar Magnetic Field Models From Lunar Prospector And Selene/Kaguya Along‐Track Magnetic Field Gradients, Dhananjay Ravat, M. E. Purucker, N. Olsen
Earth and Environmental Sciences Faculty Publications
We use L1‐norm model regularization of |Br | component at the surface on magnetic monopoles bases and along‐track magnetic field differences alone (without vector observations) to derive high quality global magnetic field models at the surface of the Moon. The practical advantages to this strategy are the following: monopoles are more stable at closer spacing in comparison to dipoles, improving spatial resolution; L1‐norm model regularization leads to sparse models which may be appropriate for the Moon which has regions of localized magnetic field features; and along‐track differences reduce the need for ad‐hoc external field noise reduction strategies. We examine also …