Physical Sciences and Mathematics Commons^™

Improved 2d And 3d Resistivity Surveys Using Buried Electrodes And Optimized Arrays: The Multi-Electrode Resistivity Implant Technique (Merit), Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

This thesis presents a novel resistivity method called Multi-Electrode resistivity technique (MERIT) that is used for high resolution imaging of complex geologic features at depth and near the edges of survey lines. The MERIT electrodes are especially shaped and designed to be self-driven using a robust-direct push technique. Measurements are taken using optimized arrays that are generated using a modified version of the “Compare-R” optimization algorithm. This work focused on both two-dimensional (MERIT2D) and three-dimensional (MERIT3D) applications of the buried array and show the relevance of the additional information gained by the addition of deep electrodes especially in sites with …

An Iterative Approach To Ground Penetrating Radar At The Maya Site Of Pacbitun, Belize, Sheldon Skaggs, Terry G. Powis, Clara R. Rucker, George Micheletti

Publications and Research

Ground penetrating radar (GPR) surveys provide distinct advantages for archaeological prospection in ancient, complex, urban Maya sites, particularly where dense foliage or modern debris may preclude other remote sensing or geophysical techniques. Unidirectional GPR surveys using a 500 MHz shielded antenna were performed at the Middle Preclassic Maya site of Pacbitun, Belize. The survey in 2012 identified numerous linear and circular anomalies between 1 m and 2 m deep. Based on these anomalies, one 1 m × 4 m unit and three smaller units were excavated in 2013. These test units revealed a curved plaster surface not previously found at …

Basal Characteristics Of The Main Sticky Spot On The Ice Plain Of Whillans Ice Stream, Antarctica, Tarun Luthra, Sridhar Anandakrishnan, J. Paul Winberry, Richard B. Alley, Nicholas Holschuh

Geological Sciences Faculty Scholarship

Understanding the processes that affect streaming ice flow and the mass balance of glaciers and ice sheets requires sound knowledge of their subglacial environments. Previous studies have shown that an extensive deformable subglacial sediment layer favors fast ice-stream flow. However, areas of high basal drag, termed sticky spots, are of particular interest because they inhibit the fast flow of the overriding ice. The stick-slip behavior of Whillans Ice Stream (WIS) is perhaps the most conspicuous manifestation of a subglacial sticky spot. We present new ice-thickness and seismic-reflection measurements collected over the main sticky spot in the ice plain of WIS, …

Integrated Geophysical Methods In Investigation Of Claiborne Aquifer Hydrostratigraphy, Jackson Purchase, Kentucky, Marie Cooper

Theses and Dissertations--Earth and Environmental Sciences

Increased groundwater withdrawals associated with agricultural irrigation in the Jackson Purchase have prompted questions related to groundwater availability and sustainability. Key factors in addressing these questions are understanding the extent and variation in thickness of the local hydrostratigraphic system, which is the upper part of the Mississippi Embayment aquifer system. Correlations of 70 gamma-ray well logs, and 49 resistivity logs were made across parts of the Jackson Purchase in Fulton and Hickman Counties in order to delineate the upper Claiborne aquifer and middle Claiborne confining unit. Commercial software (i.e. Petra 3.8.3) was used to generate cross sections, structure and isopach …

A Geophysical Investigation At The Potrillo Maar, Manuel Moncada Gutierrez

Open Access Theses & Dissertations

The Potrillo Volcanic Field (PVF) is a unique geological site located in Doña Ana County the southernmost part of New Mexico, and part of northern part of Chihuahua, Mexico. The main feature of the southern PVF is Potrillo Maar. This maar-volcano straddles the international boundary between United States and Mexico and lies within the southern part of the Rio Grande Rift. The Potrillo Maar was formed about 20,000 years ago in three major events that formed basalt lava flows and ejecta deposits that consist of crustal and mantle xenoliths.

The purpose of this Thesis is to determine the area of …

Insights Into Volcanic Processes Using Seismic Data Techniques, Ezer Patlan

Open Access Theses & Dissertations

We present in this study numbers of technique to understand the volcanic processes using seismology. The types of techniques we used are earthquake location (double difference travel-time, cross-correlation tremor technique, and time reversal), stresses (b-values, focal mechanism), and tomography imagery (ambient noise tomography). The areas of study we focus on are in two different tectonic settings. The East Africa Rift System at Kenya, studying four volcanoes: Menengai Caldera, Silali, Paka, and Korosi volcanoes. The other area of study is located in a subduction zone in Central America, Salvador at San Miguel volcano.

In this study we aim to calculate accurate …

Application Of Time-Frequency Analysis To Characterize Gas Shadows From The Clinton Interval In Ohio Seismic Reflection Data, Fangzhou Yan

Browse all Theses and Dissertations

The Smoothed Pseudo Wigner-Ville Distribution (SPWVD) is one method to simultaneously resolve time series in both time and frequency domains, allowing determination of frequency variation with time in non-stationary signals. Also, SPWVD reduces the cross-term interference. This analysis was applied to stacked, migrated seismic reflection data from Ohio to characterize gas shadows produced by known and potential gas reservoirs in the Clinton interval. In northeast Ohio, the Clinton interval is identified as occurring immediately beneath the Dayton Limestone, which is known as the driller’s Packer Shell in the subsurface. The analysis was first applied to a seismic reflection line acquired …

Seismic Reflection Profiling Near Middletown, Ohio And Interpretation Of Precambrian Deformational Settings, David Joseph Peterman

Browse all Theses and Dissertations

The reprocessing of four vibroseis seismic reflection lines at the AK Steel facility in Middletown, Ohio, provides new insight on the age, deposition, and structural deformation of the pre-Mount Simon sedimentary sequence below Butler and Warren Counties. Processing was focused on the pre-Mt. Simon reflections to reveal gently west-southwest dipping reflectors that make a slight angular unconformity with the overlying Paleozoic sedimentary strata. This pre-Mount Simon sedimentary sequence has been encountered in several wells from western Ohio, Indiana, and northern Kentucky and has been identified as the Middle Run Formation. Examination of the weak and discontinuous seismic character of the …

Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion

All Master's Theses

Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± …

Spatial Scaling Of Crustal And Lithospheric Deformation In The Western United States, Cody W. Bomberger

Graduate Student Theses, Dissertations, & Professional Papers

Deformation of continental lithosphere can extend great distances laterally from tectonic plate boundaries. This extent has been used to argue for a variety of constitutive laws for continental materials, based on the underlying principles in continuum mechanics that identify a relationship between characteristic spatial scale and material properties. Although the relationship between observed deformation and material models is always non-unique, quantifying one or more characteristic scales of deformation in a region can rule out some models of how the lithosphere deforms. In the western United States active deformation occurs at the plate boundary between North America and either the Pacific …