Other Earth Sciences Commons^™

Large-Scale Volcanism On The Terrestrial Planets, Keenan Ben Golder

Doctoral Dissertations

Evidence for mafic volcanism has been found on each planet in the inner Solar System. Lava flows on these planets range in size from 10s to 1000s of kilometers in extent. I investigated large-scale lava flows on Mercury, Earth, and Mars throughout the chapters in this dissertation. Each of these lava flows provides an avenue to study the emplacement and evolution of lava on various planets and under differing conditions, the factors that affect their overall extent, and potential source areas.

Chapter One investigates large-scale lava flows in the Cerberus region on Mars, specifically to understand their emplacement history, material …

Impact Of Cover Crop Species Diversity On Soil Nutrient Availability And Crop Productivity, Amanda Kramer

Masters Theses

Cover crops provide multiple environmental benefits that improve both soil and water quality; however, farmers only utilize them on approximately 5% of harvested U.S. cropland. Low adoption rates are attributed to yield impact concerns, seed and planting costs, and lack of advocacy. This study, which began in October 2019, assessed the effects of nitrogen rate and cover crop diversity on weed biomass, soil coverage, in-situ residue decomposition, soil nitrogen and phosphorus availability, and cash crop yield to better understand the costs and benefits of cover crop adoption at two locations in Tennessee (Milan and Spring Hill). Treatments were replicated 4 …

Precambrian Molar-Tooth Structure: Unraveling The Diagenesis Of Ancient Carbonates, Agustin Kriscautzky

Doctoral Dissertations

Molar-tooth structure (MTS) is an enigmatic carbonate fabric that occurs mainly within Proterozoic carbonate host rocks. It is composed of two distinct features: cracks of various morphologies and crack-filling calcite microspar. Although the origins of MTS remain unknown, most previous investigation has focused on the formation of the cracks and mechanisms involved in the void space generation, with less emphasis on the intriguing carbonate fill. In this study I have investigated molar-tooth bearing carbonates from regions that span both paleogeography and geologic time. Analysis at the microscopic scale, including traditional petrography, cathodoluminescence petrography, scanning electron microscopy, and micrometer-scale geochemical analyses …

Understanding Hydrogen Variations In Silicate Glasses As A Result Of Degassing: Fire-Fountaining On The Moon And Earth, Erin M. Recchuiti

Masters Theses

Volatiles, particularly hydrogen, play a key role in volcanic eruptions, especially explosive eruptions like fire-fountaining [e.g., Saal et al. 2002; Dixon 1997; Arndt & von Engelhardt 1987; Yoder 1976]. Discerning volatile abundance and behavior during ascent and eruption can aid in understanding the source melt and primary volatile content of planetary interiors. Volcanic glasses are samples closest to the primary melt, as they quench quickly enough to limit fractionation or crystallization. This is paramount for volatile studies, especially pertaining to water as its constituents are oxygen and hydrogen. Hydrogen is the most volatile element and one of the first to …

Future Energy: Opportunities & Challenges, Thomas W. Kerlin

Open Educational Resources and Course Materials

Future Energy: Opportunities & Challenges was originally published in 2013 by the International Society of Automation. Rights for this work have been reverted to the authors by the original publisher. The author has chosen to license this work with a Creative Commons Attribution 4.0 International license (see https://creativecommons.org/licenses/by/4.0/).

Click the blue Download link on this page to download the full book PDF. Individual chapters are also listed and available for download in the list below.

Table of Contents

Part I. GETTING STARTED

Chapter 1 – Introduction to the Energy Story

Chapter 2 – Fundamentals

Chapter 3 – Energy Production and …

Fire-Vegetation-Climate Interactions Across The Holocene On The U.S. Southeastern Coastal Plain, Mathew S. Boehm

Doctoral Dissertations

This dissertation research examined multiple proxy indicators in sediment cores from one lake and one wetland to reconstruct long-term relationships between fire, vegetation, and climate in the southeastern U.S.

At Lake Balboa (30.6992 N, 83.2031 W; 48 m elevation), a sinkhole pond located in southern Georgia, Bølling-Allerød conditions were sufficiently wet to maintain a shallow wetland at the site. Evidence for fire was minimal. Between 12,600 and 9200 cal yr BP, water availability declined, leading to a potential hiatus in sedimentation. During the early Holocene moisture availability increased, leading to greater primary productivity within and outside the lake, triggering an …

Conservation Agriculture As A Climate Change Mitigation Strategy In Zimbabwe, Deb O'Dell, Neal Eash, Bruce B. Hicks, Joel Oetting, Thomas J. Sauer, Dayton M. Lambert, Tarirai Muoni, Joanne Logan, James A. Zahn, John J. Goddard

Biosystems Engineering and Soil Science Publications and Other Works

There is a need to quantify agriculture’s potential to sequester carbon (C) to inform global approaches aimed at mitigating climate change effects. Many factors including climate, crop, soil management practices, and soil type can influence the contribution of agriculture to the global carbon cycle. The objective of this study was to investigate the C sequestration potential of conservation agriculture (CA) (defined by minimal soil disturbance, maintaining permanent soil cover, and crop rotations). This study used micrometeorological methods to measure carbon dioxide (CO₂) flux from several alternative CA practices in Harare, central Zimbabwe. Micrometeorological methods can detect differences in …

Testing The Temporal Stability Of The Climate Response Of Tree Species At Norris Dam State Park, Tennessee, U.S.A., Allison Elizabeth Ingram

Masters Theses

Temporal stability of the climate-tree growth relationship means that over time, tree species were responding to a specific climate variable and continue to respond to that variable into the present. The stability of this response is important to test prior to attempting to reconstruct past climate. In this study, I sampled oaks (white oak = Quercus alba L. and chestnut oak = Quercus montana Willd.) and pines (Virginia pine = Pinus virginiana Mill. and shortleaf pine = Pinus echinata Mill.) growing in Norris Dam State Park in eastern Tennessee and tested the temporal stability of these species and their potential …

Tennessee Tornado Frequency, Vulnerability, And Relation To A Large-Scale Climate Variability, Vincent Marshall Brown

Masters Theses

This work explores the climatologies of isolated tornadoes and tornado outbreaks across the state of Tennessee, a state that in some years experiences more tornadoes than states in the heart of Tornado Alley. Part one assesses tornado frequency characteristics and fatality statistics within 100 km of three major Tennessee cities (Nashville, Memphis, and Knoxville) between 1950 and 2013. Nashville reported the most tornadoes, (426) but Memphis reported the most fatalities. Knoxville and Nashville tornadoes occurred on fewer days, while Memphis tornadoes were spread across more tornado days. Spring was the most active season for tornadoes, but Memphis still experienced approximately …

Trends In Location Of Lifetime Maximum Intensity Of Tropical Cyclones In The North Atlantic And West Pacific Oceans, Sarah Ann Bleakney

Masters Theses

Tropical cyclones threaten coastal populations around the world each year. Thus, the climatology of tropical cyclones is an immediate research need, specifically to better understand their long-term patterns and elucidate their future in a changing climate. One important pattern that has recently been detected is the poleward shift of the lifetime maximum intensity (LMI) of tropical cyclones in the Northern Hemisphere. My study further assesses the recent spatial changes in the LMI of tropical cyclones in the Northern Atlantic and Western Pacific basins since 1964. I explored relationships between the intensity and location of LMI with respect to landfall location …

Europan Double Ridge Morphology As A Test For Hypothesized Models Of Formation, Ashley Caroline Dameron

Masters Theses

Double ridges on the Jovian satellite Europa consist of two ridges with a central trough. Several hypotheses exist describing their formation. Explosive cryovolcanism would result in granular ice depositing as two self-symmetric ridges flanking a central fracture, lying at or below the angle of repose (AOR). Cryo-sediments deposited by tidal squeezing and low-viscosity cryolavas emplaced by effusive cryovolcanism would likely have shallow slopes, although ridge symmetry is not expected. A second group of hypotheses involves brittle deformation of the crust, namely by diapirism, shear heating, and buckling of the lithosphere due to compression. Because these models involve uplifting vertical fractures, …

Establishing A Chronology Of Late Quaternary Glacial Advances In The Cordillera De Talamanca, Costa Rica, Rebecca Susan Potter

Masters Theses

Little research has focused on glacial events in the tropics. Providing an absolute glacial chronology in Costa Rica will build a foundation for future glacial chronologies and paleoclimate reconstructions in the highlands of Central America. Evidence of past glaciation, including moraines and glacial lakes, is preserved within formerly glaciated valleys in the Cordillera de Talamanca. Orvis and Horn (2000) constrained deglaciation ages of the most recent glacial event in the Cordillera de Talamanca based on radiocarbon dates of glacial lake sediments. Radiocarbon ages indicated complete deglaciation after 12.4 ka cal BP but before 9.7 ka cal BP (Orvis and Horn, …

Near-Infrared (2 – 4 Micron) Spectroscopy Of Near-Earth Asteroids: A Search For Oh/H2o On Small Planetary Bodies, Nathanael Richard Wigton

Masters Theses

Near-Earth asteroids (NEAs) are not expected to have H₂O [water] ice on their surfaces because a) most accreted dry and therefore never contained H₂O, and b) their relatively high surface temperatures should drive rapid H₂O ice sublimation. However, OH/H₂O has been detected on other anhydrous inner solar system objects, including the Moon and Vesta. Possible sources for OH/H₂O in the inner Solar System might include production via solar wind interactions, carbonaceous chondrite or cometary impact delivery, or native OH/H₂O molecules bound to phyllosilicates. As these processes are active …

Characterizing Groundwater Ch4 And 222rn In Relation To Hydraulic Fracturing And Other Environmental Processes In Letcher County, Ky, St. Thomas Majeau Ledoux

Masters Theses

Hydraulic fracturing of shale deposits has greatly increased the productivity of the natural gas industry by allowing it to exploit previously inaccessible reservoirs. However, previous research has demonstrated that this practice can contaminate shallow aquifers with CH₄ [methane] from deeper formations. This study compares concentrations and isotope compositions of CH₄ sampled from domestic groundwater wells in Letcher County, Kentucky in order to characterize its occurrence and origins in relation to neighboring hydraulically fractured natural gas wells. Additionally, this study tests the reliability of ²²²Rn [radon] as an alternative tracer to CH₄ in identifying processes of gas …

Crystallization Kinetics Of Olivine-Phyric Shergottites, Megan Elizabeth Ennis

Masters Theses

Petrographic and geochemical techniques applied to Martian meteorites can reveal their petrogenesis, and ultimately the magmatic evolution and thermal history of Mars. Two quantitative textural tools, crystal size distribution (CSD) and spatial distribution pattern (SDP) analysis, are utilized to describe the early crystallizing phases, olivine and pyroxene, of one olivine-phyric shergottite (EET 79001A, DaG 476, and Dho 019) from each sampling locality as inferred from Mars ejection ages. Qualitative observations of trace element zonation patterns (P, Cr, and Al) in olivine are used in conjunction with CSD and SDP to characterize the crystallization history of these samples. Previously reported CSDs …

Evaluating Predictability In The Community Earth System Model In Response To The Eruption Of Mount Pinatubo, Abigail Laurel Gaddis

Doctoral Dissertations

A central goal of climate research is to determine the perceptible effects of climate change on humans; in other words, the regional and decadal scale effects of carbon dioxide forcing. Identifying the most pronounced and long-lasting responses of climate variables to forcing is important for decadal prediction since forcing terms are a source of predictability on those time scales. Powerful volcanic eruptions provide a transient forcing on the climate system, creating a test bed for climate models. In this study, the Mount Pinatubo eruption is simulated in the Community Earth System Model, CESM1.0, for three model configurations: fully coupled T85 …

Testing A Novel Technique To Improve Aluminum-26 Accelerator Mass Spectrometry Measurements For Earth Science Applications, Meghan Sarah Janzen

Masters Theses

The measurement of cosmogenic ²⁶Al [aluminum-26] in geological samples by accelerator mass spectrometry (AMS) is typically conducted on Al₂O₃ [aluminum oxide] targets. However, Al₂O₃ is not an ideal source material because it does not form a prolific beam of Al^- [negative atomic aluminum ions] required for measuring low-levels of ²⁶Al. This thesis presents the performance of AlN [aluminum nitride], AlF₃ [aluminum fluoride] and mixed AlN + Al₂O₃ as novel alternative source materials for the analysis of ²⁶Al. A negative ion cesium sputtering source at the Holifield …

Characterizing Phyllosilicate Distribution, Abundance, And Origin On Mars, Christina Elizabeth Viviano

Doctoral Dissertations

Secondary phyllosilicates are hydrated minerals formed in the presence of liquid water. On Earth, their formation is often indicative of a neutral, water-rich environment, capable of supporting and preserving organic matter. Different phyllosilicate species may be produced in different pH levels and water-to-rock ratios. The identification of mineralogically diverse phyllosilicates in small, localized exposures on Mars provides a complex record of their formation processes. While discrete outcrops of phyllosilicates have been previously identified in high-resolution visible/near-infrared images of Mars, regional coverage of these phyllosilicate-rich areas at better resolution is limited. Furthermore, spectra of minerals in this wavelength range do not …

An Evaluation Of The History Of Aqueous Activity On Mars Through A Survey Of Select Hypothesized Martian Deltas And Paleolakes Via The Analysis Of Mineralogy, Morphology, And Thermophysical Properties, Andrea C.G. Hughes

Masters Theses

Aqueous deposits are an essential key to understanding the geologic/climatic history of water on Mars. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), High Resolution Imaging Science Experiment (HiRISE), and Thermal Emission Imaging System (THEMIS) have enabled studies of Martian fan deposits in unprecedented detail, including the identification of hydrated minerals (such as phyllosilicates, carbonates, and sulfates) and morphologies consistent with formation in an aqueous environment associated with Martian sedimentary deposits. In this study, twenty-six previously identified fan-shaped deposits (hypothesized as possible deltas) have been examined for hydrated minerals in the beds and distal regions of the deposits. Six deposits …

An Investigation Of Stratigraphic Evidence For An Abrupt Climatic Event 8200 Yr Bp In Valle De Las Morrenas, Costa Rica, Brian Thomas Watson

Masters Theses

Lago de las Morrenas 4 (9.498056° [degrees] N, 83.486111° [degrees] W, 3466 m elev.) is the lowest lake in a chain of glacial lakes located in the Valle de las Morrenas, a valley facing almost due north from Cerro Chirripó, the highest peak in the Cordillera de Talamanca in Costa Rica. Coarse resolution analyses of pollen, microscopic charcoal, and loss-on-ignition of a ca. 10,000 year sediment record from Lago de las Morrenas 4 was carried out to complement and extend previous research on the environmental history of the Chirripó highlands and to provide context for high-resolution sampling and analysis of …

The Relationships Of Streambank Angles And Shapes To Streambank Erosion Rates In The Little River Watershed, Tn, William Ryan Foster

Masters Theses

Sediment is a leading cause of water quality impairment throughout the United States. In the Little River watershed in eastern Tennessee, several tributaries have been classified as impaired due primarily to sedimentation. Researchers at The University of Tennessee, in collaboration with a group of local and state organizations, began monitoring Little River tributaries to better understand their sources of pollution. To investigate the rates and processes of streambank erosion, erosion-pin monitoring sites were established on 32 banks in the watershed. This thesis complements the erosion-pin monitoring efforts by determining bank characteristics and examining the relationships of streambank angles and shapes …

Past Fire Regimes Of Table Mountain Pine (Pinus Pungens L.) Stands In The Central Appalachian Mountains, Virginia, U.S.A., Georgina Deweese

Doctoral Dissertations

Table Mountain pine is an Appalachian endemic that occurs in a patchy distribution from Georgia to Pennsylvania and is prolific at sites with a history of fire disturbance. The purpose of this dissertation was to reconstruct the fire regimes of Table Mountain pine stands in the Jefferson National Forest, Virginia. Sections from firescarred Table Mountain pines were collected at four sites to analyze fire history, while increment cores and stand composition information were collected from macroplots within each fire history site to investigate the possible influence of fires that were more ecologically severe. Results show that fire was frequent before …

Allozyrne Variation Within And Between Populations Of Ruth's Golden Aster, Pityopsis Ruthii (Small) Small, Steven A. Sloan

Masters Theses

Genetic structure of the two known populations of Ruth's golden aster, Pityopsis ruthii (Small) Small, was determined. Pityopsis ruthii is a rare, endemic plant species restricted to exposed phyllite and graywacke rock outcrops in the flooding zones of the Hiwassee and Ocoee River drainages in Polk County, Tennessee. There are an estimated 10,000 to 15,000 P. ruthii plants on the Hiwassee and ~600 on the Ocoee River. Patterns of variation at three enzyme loci were examined. Two loci, Pgm-2 and Prx-1, were polymorphic in both river populations. Despite limited habitat and subsequent restricted ranges (~ 5 kmalong each river), populations …