Physical Sciences and Mathematics Commons^™

Assessing The Tree-Ring Oxygen Isotope Hurricane Proxy Along The Atlantic And Gulf Coastal Seaboards, Usa, Whitney L. Nelson

Doctoral Dissertations

A recent increase in hurricane activity has put coastal populations at risk. To better understand hurricane activity, it is necessary to look beyond the modern instrumental record, using proxy records to establish modes of past variability. The utility of a newly developed tree-ring oxygen isotope proxy is further assessed. I present oxygen isotope time series from three sites: Francis Marion and Sandy Island, South Carolina and Eglin Air Force Base, Florida. Proxy results are verified against the instrumental record of hurricane occurrence. The sites record similar percentages (45% for Francis Marion and Sandy Island, 63% for Eglin Air Force Base) …

Generating Genetic Resources For Phytophthora Capsici (L.) And Studying P. Capsici And Phytophthora Hybrids In Peru, Oscar Pietro Hurtado-Gonzales

Doctoral Dissertations

The genus Phytophthora includes more than 90 described species infecting over 1000 plant species. Population studies were conducted to investigate the survival and spread of P. capsici in the Peruvian coastal region. A total of 227 P. capsici isolates, recovered at widely distant localities from 2005-2007, were fingerprinted with AFLPs and SNP genotyping. A clonal population (PcPE-1) represented by 221 isolates was found to be distributed throughout the country. Atypical isolates of P. nicotianae were isolated from loquat trees in Peru and nuclear (internal transcribed spacer [ITS], the phenol acid carboxylase gene, and AFLPs) and mitochondrial genotyping (cytochrome oxidase gene …

Relationship Between Slug-Test And Effective Hydraulic Conductivities For 2-Dimensional Heterogeneous Aquifers, Richard Walker Donat

Masters Theses

Slug tests are one of the most common field tests used by hydrogeologists to evaluate the hydraulic conductivity of an aquifer system. Steady-state and transient (slug test) numerical simulations were run in 37, 2-dimensional randomized multifractal hydraulic conductivity fields. Each field consisted of 59,049 individual saturated hydraulic conductivity (K) values with varying numbers of hydrofacies and different degrees of spatial heterogeneity. The K_eff values were determined by examining the flux in and out of the steady-state numerical model. The K_slug values were determined by adding a slug of water to the center node of the field and evaluating …

Investigating The Petrogenesis Of The Basaltic Crust Of Asteroid 4 Vesta: A Combined Petrologic-Spectral Study Of The Unbrecciated Eucrites, Rhiannon Gwenllian Mayne

Doctoral Dissertations

The Dawn mission, which launched in September 2007, will orbit and analyze two of the largest asteroids, 4 Vesta and 1 Ceres. These small, proto-planetary bodies retain a record of the conditions and processes that occurred in the early history of the Solar System, and, as such, provide us with a tool to understand its formation and evolution. Additional information can also be gleaned from the meteorite samples derived from such objects. This dissertation aims to increase understanding of the formation of the basaltic crust of the asteroid Vesta, and the lithologic variety that exists within it, by studying the …

Determination Of Mineral Abundances In Ordinary Chondrites Using Powder X-Ray Diffraction: Applications To Parent Body Processes And Asteroid Spectroscopy, Tasha L. Dunn

Doctoral Dissertations

The ordinary chondrites, the most abundant group of meteorites, are divided into three chemical groups (H, L, and LL), which are distinguished based on variations in bulk composition and iron content. Although ordinary chondrites are relatively abundant, our understanding of their formation has been hampered by an inability to accurately measure the abundances of minerals that they contain. Here I use power x-ray diffraction (XRD) to quantify the modal abundances of 48 unbrecciated ordinary chondrite falls, which represent the complete petrologic range of equilibrated ordinary chondrites (types 4-6).

Although the degree of metamorphism varies within each ordinary chondrite group, many …

Ground Penetrating Radar Investigations On The Relationship Between Horizontal Sub-Wavelength ‘Thin-Layer’ Bedrock Fractures And Reflection Amplitudes, Kevin E. Burns

Masters Theses

Several theoretical equations that predict sub-wavelength ‘thin-layer’ reflection amplitudes are compared to the results of a series of controlled ground penetrating radar surveys using 1 GHz transducers over a physical model of a horizontal bedrock fracture. Two large plastic (UHMW-PE) blocks, separated by one or more stacked inserts (polyethylene; ~0.1 mm thick) for a total of 101 surveys, generate a modeled fracture with an aperture ranging from 0-300 mm. All existing theoretical reflection coefficient equations fail to predict observed reflection amplitude oscillations in the data when the fracture aperture is less than 1/48 of a wavelength. The only theoretical formulation …

Amino Acid Analysis Of Marine Sediments, Hauraki Gulf, New Zealand, Tabbatha A. Cavendish

Masters Theses

Amino acid compositions, bulk organic carbon, total nitrogen, and total organic matter were measured for eight sediment samples from the Hauraki Gulf, New Zealand, in order to assess the source and fate of organic matter in a shallow marine environment. Samples were collected from near-shore and off-shore shore sites, as well as from a site receiving freshwater input from multiple rivers. A comparison of carbon, nitrogen, and amino acid compositions of samples between 1 cm depth (Uhle 2004) and 5 cm depth was used to assess changes in organic matter composition through time. Amino acid analyses in particular should be …

Tectonometamorphic Evolution Of The Eastern Blue Ridge: Differentiating Multiple Paleozoic Orogenic Pulses In The Glenville And Big Ridge Quadrangles, Southwestern North Carolina, Donald W. Stahr

Masters Theses

New field and analytical data collected in the eastern Blue Ridge (EBR) of southwestern North Carolina reveal a complex, polyphase thermotectonic history, and delimit the timing of previously unrecognized orogenic pulses in a portion of the southern Appalachian orogenic core. Detailed geologic mapping of the Glenville and Big Ridge 7.5’ quadrangles delineated the location of the Chattahoochee fault, a tectonic boundary separating the western Tugaloo terrane from distinct central Blue Ridge terranes.

Zircon geochronologic data for two EBR granitoids in the map area indicate emplacement occurred at ~335 Ma, making these plutons among the youngest recognized in the EBR. Bulk-rock …

Utk Geography Newsletter 8 (2008), Department Of Geography

UTK Geography Newsletter

No abstract provided.