Master of Science (MS), Wright State University, 2012, Earth and Environmental Sciences

In northeastern Ohio, an interval of interbedded sandstone and shale between the Queenston Shale and the Dayton Formation (both in the Silurian System) has long been referred to as the “Clinton interval”. The Clinton interval has produced oil and gas for over a century, but has been converted locally to gas storage. Within the Clinton interval, reservoirs are commonly compartmentalized, in part because the sandstones are discontinuous but also because fractures enhance permeability in portions of otherwise continuous sandstones. The goal of this study is to characterize the Clinton interval within the Gabor gas storage field of Dominion East Ohio near Canton, Ohio, using existing geophysical well logs and recently acquired 2D vibroseis reflection data (courtesy of Precision Geophysical). Gamma ray logs were used to construct isopach, net sand maps and cross-sections throughout the study area. The entire Clinton interval ranges between 85 and 116 ft thick and contains significantly less clean sand with less continuity than the Stark-Summit field to the east. The White Clinton ranges between 15-48 ft thick and contains a greater amount of clean sand compared to the Red and Stray Clinton. The Red Clinton ranges between 20-66 ft thick in the Gabor field and tends to have fairly continuous thick sandstone bodies towards the top and becomes more shaly at the base. The uppermost subunit, the Stray Clinton ranges between 18-50 ft thick and contains the least amount of sand but has thin sand beds that show possible continuity throughout the field. The new 2D vibroseis seismic lines reveal variations within the Clinton interval expressed as laterally varying interference of seismic wavelets apparently associated with changes in the composition and thickness of sandstone and shale layers. Variable area displays of the seismic data reveal specific areas with large attenuation of seismic energy that also appear as bright spots in displays of various seismic attributes. These fe (open full item for complete abstract)

Committee: Ernest Hauser PhD (Committee Chair); Doyle Watts PhD (Committee Member); David Dominic PhD (Committee Member) Subjects: Geological; Geology; Geophysical; Geophysics

Master of Science (MS), Wright State University, 2012, Earth and Environmental Sciences

In this study, fault trace-lengths of normal faults are measured in southern Sedna Planitia, Venus between 27° to 32° latitude and 336° to 343° longitude where smooth, lowland plains transition into highland regions which are broken by basin and range style tectonics. The fault trace-lengths are plotted on a cumulative number verses length plot (CNL) and fit with a power function, exponential function, and logarithmic function to determine which function best describes the trace-length distribution. A power function is the best fit with a scaling exponent of 1.73. This result is compared to previous studies of fault trace-lengths on Venus, Mars, and Earth where fault trace-lengths have been fit by power functions on CNL plots. The scaling exponent found in this study is closest to the scaling exponent found in the Gulf of Corinth, Greece. Fault density is the same across the study area. The normal faults in the study area show a small amount of strain and interaction within the fault system as part of a growth regime. This helps to separate it from previous studies on Venus and explain the tectonic transition across the study area.

Committee: Christopher Barton PhD (Advisor); Doyle Watts PhD (Committee Member); Christopher Scholz PhD (Committee Member); David Dominic PhD (Committee Member) Subjects: Geology; Geophysics; Planetology

Master of Science (MS), Wright State University, 2023, Earth and Environmental Sciences

Estimating sediment thickness and bedrock surface geometry is critical for many hydrogeologic studies. The horizontal-to-vertical spectral ratio (HVSR), a passive seismic method is a unique, non-invasive technique for speedily estimating bedrock depth. To record ambient seismic noise, the H/V method employs a single broadband three-component seismometer. A field assessment was conducted on the Wright State University Campus in Dayton, Ohio, to determine the depth (z) and elevation of the bedrock. Data were collected at 60 different locations. A known value for the depth of bedrock on campus was determined using the log from a local water well available from the Ohio Department of Natural Resources. Using this depth and the observed fundamental resonant frequency (f0) the shear wave velocity (Vs) of the glacial drift above bedrock was calculated, which was then used to determine the depth of bedrock and its elevation in relation to the fundamental resonant frequency (f0). The HVSR results generally produced distinct, easily discernible resonance frequency peaks which together with the Vs constrained at the local borehole allowed the depth to bedrock and thereby bedrock elevation to be mapped across campus. The interpreted depth and elevation of the bedrock surface are comparable with previous surveys on campus.

Committee: Ernest C. Hauser Ph.D. (Advisor); Doyle R. Watts Ph.D. (Committee Member); Abinash Agrawal Ph.D. (Committee Member) Subjects: Environmental Education; Environmental Engineering; Environmental Geology; Environmental Science; Environmental Studies; Geophysics

Master of Science (MS), Wright State University, 2022, Earth and Environmental Sciences

Azimuthal resistivity surveys coupled with an electromagnetic survey were completed at Sycamore Farms with the goal of investigating bedrock fracturing at the site. Previous work on this subject matter was completed at the site using similar geophysical tools, however, this study utilizes a unique method of azimuthal resistivity and higher resolution electromagnetic data. 72 azimuthal surveys were completed, and the electromagnetic survey covered all fields in which azimuthal surveys were completed. The results from the two methods were compared to identify zones of bedrock fracturing. Although correlation between the two data sets was limited it was found that the electromagnetic data were able to help explain anomalous readings that were not associated with bedrock fracturing. By identifying these areas and removing corresponding azimuthal survey results that were impacted a clearer, more homogenous nature of bedrock fracturing was achieved at the site.

Committee: Ernest Hauser Ph.D. (Committee Chair); Abinash Agrawal Ph.D. (Committee Member); Doyle Watts Ph.D. (Committee Member) Subjects: Earth; Geology; Geophysics

Master of Science, The Ohio State University, 2021, Earth Sciences

Natural gas hydrates exist in the shallow subseafloor throughout the Gulf of Mexico, though many systems have not been described in detail. Using publicly available seismic and well log data, I constrain potential gas hydrate accumulations. Seventeen unique seismic surveys were analyzed to identify and classify regions with bottom-simulating reflections (BSRs). BSRs represent free gas at the base of gas hydrate stability (BGHS) and can be identified in seismic data through their opposite polarity and sub-parallel orientation to the seafloor. Identifying these seismic events is a first step in prospecting for gas hydrate systems. In this thesis, twenty-six BSR systems were classified across the Northern Gulf of Mexico in the East Breaks, Garden Banks and Green Canyon Federal protraction areas, with an additional six previously published BSR systems classified. Each system is classified based on BSR type, which is classified as continuous, discontinuous, or clustered, BSR size including small (<8 km²), medium (8-16 km²), and large (>16 km²), and the BSR environment which includes structural, venting, and stratigraphic. In addition, proximal geologic features and hydrate indicators were also documented. A novel approach to classify each system and determine trends for BSRs in the Gulf of Mexico is employed using a ternary diagram. The results indicate that a majority of BSR systems have two-or-more BSR types, with the combination of continuous and discontinuous being the most prevalent. The BSR size ranges from a low of 1.49 km2 in Green Canyon-2 to a high of 49.6 km2 in Orca Basin. BSRs most commonly occur in stratigraphic environments, where gas may form through microbial methanogenesis. Notable relationships between BSR type and environment were interpreted on the ternary diagram, such as clustered BSRs occurring in structural environments and venting environments primarily containing continuous BSRs. These results aim to narrow down where BSRs are occurring in this (open full item for complete abstract)

Committee: Ann Cook (Advisor); Derek Sawyer (Committee Member); Demián Gomez (Committee Member) Subjects: Geology; Geophysics

Master of Science (MS), Wright State University, 2021, Earth and Environmental Sciences

Amplitude anomalies in pre-stack seismic data have widely been used in the oil and gas industry as a risk analysis tool when exploring for hydrocarbons. AVO analysis is most often applied to poorly consolidated Tertiary rocks due to the compressibility of these strata when natural gas and porosity are present. In contrast, well-lithified carbonate rocks are less prone to producing a pre-stack amplitude response due to the rigidity of their frame. Pre-stack seismic data of a 2-D seismic profile were conditioned and interpreted to identify amplitude variation with offset (AVO) attributes corresponding to the presence of hydrocarbons within the North Vernon Limestone (NVL) interval in the Illinois Basin. The seismic data were acquired over the Glen Ayr oil field in Vigo County, Indiana, and in the Old Hill oil field in Clay County, Indiana prior to wells being drilled. Production in both fields is from porous dolomites draped by tight limestone or dolomites over a Silurian reef complex We show that with appropriate pre-stack data conditioning subtle AVO responses in Illinois Basin carbonates may indicate the presence of hydrocarbons. Seismic line CM-46-12 (Clay) and CM-27-14 (Vigo) were both analyzed using AVO attributes to identify anomalous zones that may relate to the presence of hydrocarbons. Seismic Line CM-27-14 was further interpreted using pre-stack inversion to provide additional information pertaining to the reservoir rock properties. The results on both seismic lines show strong, negative AVO gradients along the NVL interval, whereas nonproductive intervals exhibit either positive or no amplitude gradient. Pre-stack inversion of lime CM-27-14 shows high impedance zones which are consistent with the presence of tight dolomite atop the reef structure. Low-impedance, low VP/VS ratio zones correlate to the hydrocarbon bearing porosity zones of the NVL interval.

Committee: Ernest C. Hauser Ph.D. (Committee Chair); Paul McColgan Ph.D. (Committee Co-Chair); Doyle R. Watts Ph.D. (Committee Member) Subjects: Geology; Geophysics

Master of Science, The Ohio State University, 2021, Earth Sciences

The Chandeleur Slide is a large submarine landslide on the Gulf of Mexico seafloor in approximately 1100 meters of water, 200 km southeast of New Orleans, LA. This part of the Mississippi Fan received high sedimentation throughout the Pleistocene, causing high pore fluid pressure and abundant slope failures, though few as large as the Chandeleur. Given its proximity to major coastal cities, oil and gas infrastructure, and its large size, I examine the Chandeleur Slide to: (1) map the location and thickness of the displaced sediment, (2) understand what led to the initial slope failure, (3) decipher if this was a fast-moving or slow-moving event, and (4) consider potential hazard implications a slide like the Chandeleur represents for seafloor infrastructures and tsunami risks to coastal communities surrounding the Gulf of Mexico. I interpreted publicly available 2D and 3D multichannel seismic surveys and high-resolution bathymetry data to reveal several flow paths generally due south/southeast, and a slow-moving sediment mass with a translational-rotational behavior. The Chandeleur Slide includes extensional faulting in the headscarp area and compressional structures in the northern-most toe confined by a natural ramp-like structure. Beneath the Chandeleur Slide, I observe an upward-migrating salt body that has compressed a regional sand-rich unit (the Blue Unit). I interpret that the upward-migrating salt led to overpressure within Blue Unit sand layers, facilitating the initial failure of the Chandeleur. After failure, the Chandeleur Slide transported a large volume of sediment southward but was blocked by antecedent topographic highs that deflected much of the sediment to the south/southwest. The initial failure was followed by retrogressive headwall retreat northward, which created the prominent scarp on the seafloor. In total, the Chandeleur Slide comprises an area just over 1000 km2 and contains about 300 km3 of failed sediment.

Committee: Derek Sawyer Dr. (Advisor); Ann Cook Dr. (Committee Member); Daniel Pradel Dr. (Committee Member) Subjects: Earth; Environmental Geology; Geographic Information Science; Geological; Geology; Geomorphology; Geophysics; Geotechnology; Marine Geology

MS, University of Cincinnati, 2021, Arts and Sciences: Geology

Interactions between surface water and groundwater (hyporheic exchange) influence water quality and control numerous physical, chemical, and biological processes. Despite its importance, hyporheic exchange and the associated dynamics of solute mixing are often difficult to characterize due to spatial (e.g., sedimentary heterogeneity) and temporal (e.g., river stage fluctuation) variabilities. This study coupled geophysical techniques with physical and chemical sediment analyses to quantify hyporheic exchange dynamics in a compound bar deposit within a gravel-dominated river system in southwestern Ohio. Electromagnetic induction (EMI) was used to quantify variability in electrical conductivity within the compound bar. A zone of high electrical conductivity was clearly identified as a fine-grained cross-bar channel fill. Differences in the physical and geochemical characteristics of such channel fills play an important role in hyporheic flow dynamics and nutrient processing. EMI informed locations of electrode placement for time-lapse electrical resistivity imaging surveys to examine changes in electrical resistivity driven by hyporheic exchange, revealing preferential flow paths through high-permeability sediments. Grain size analyses confirmed interpretations of geophysical data, and loss on ignition and x-ray fluorescence identified more favorable locations for enhanced geochemical and microbial activity as cross-bar channel fills identified through EMI measurements. These findings provide fundamental insights into hyporheic exchange, and the technical framework presented in this study has implications for improving future studies of hyporheic dynamics and numerical model development through more accurate representation of geomorphologic features and sediment heterogeneity.

Committee: Reza Soltanian Ph.D. (Committee Chair); Dimitrios Ntarlagiannis Ph.D. (Committee Member); Daniel Sturmer Ph.D. (Committee Member); Corey Wallace Ph.D. (Committee Member) Subjects: Geology

Master of Science (MS), Ohio University, 2019, Geological Sciences (Arts and Sciences)

The overall dimensions and internal structures of potential Earth-sized rocky exoplanets are modeled based on the relative photospheric abundances of Mg, Si, and Fe in their host stars. The modeling assumes that the planet has these same relative abundances and that all iron resides in a liquid core surrounded by a magnesiosilicate mantle comprising enstatite orthopyroxene and forsterite olivine or their high-pressure transformation products. The Mg/Si ratio sets the olivine/orthopyroxene fractions of the upper mantle and the Mg-perovskite/MgO fractions of the lower mantle. The amounts of volatile elements are not considered aside from the oxygen required by the silicate and oxide minerals. The planets are assumed to have formed under conditions where silicon remained in condensed form during accretion and volatile elements such as hydrogen, nitrogen and carbon did not. The core mass fraction is determined from the amount of Fe relative to Mg, Si, and O. Following the approaches of Valencia et al. (2006) and Sotin et al. (2007), the self-compression of a planet is modeled using published experimental observations or theoretical calculations of densities, bulk moduli, and thermal expansion coefficients of the silicate and iron components. Assuming a specific planet mass and an initial estimate of radius, compression is calculated from the surface downward in increments of 1-km layers, taking into account reconstructive phase changes as pressure and temperature increase. The core-mantle boundary is reached when the underlying (i.e., remaining) mass equals the core mass fraction of the planet. The self-compression is modeled iteratively, varying planet radius until the gravitational acceleration at the center converges to zero. In this research, effort is made to avoid using potentially Earth-unique assumptions regarding the core mass fraction of the planet, or the partitioning of iron into mantle silicates, instead relying primarily on data from obs (open full item for complete abstract)

Committee: Keith Milam (Advisor); Douglas Green (Other) Subjects: Geological; Geophysics

MS, Kent State University, 2018, College of Arts and Sciences / Department of Earth Sciences

This study uses previously obtained marine geophysical data for the proposed Galsi pipeline route from Algeria to Sardinia to analyze the buried salt distribution and calculate the amounts of fault displacements associated with halokinesis. Crossing the convergent African/Nubian–European plate boundary, the southern section of the proposed pipeline route traverses' continental shelves and slopes of Algeria and Sardinia, as well as the Algerian abyssal plain of the Western Mediterranean. Deeply buried Messinian-age salt is present throughout this area. With its low compressibility, salt is less dense and, therefore, more buoyant than the clastic overburden sediment, and thus tends to flow and form diapiric structures. Salt diapirs rise and push on overlying sediments, steepening slopes and causing faults to form. Fault displacements above diapiric structures were compared near the compressive plate boundary with those within passive margin environments. Measured offsets from seismic profiles of different resolutions are associated in this study with predicted sediment age at depth of each offset. The offsets were then used to calculate an average rate of movement along faults of 1.5 cm/ky. The highest rates along faults associated with halokinesis are along the Cagliari slope near Sardinia (2.5 to 2.7 cm/ky) and near the convergent plate boundary (2.3 cm/ky). In addition to faulting, one of the major threats to underwater pipelines can be submarine landslides. Due to decreased frictional resistance to sliding because of pore pressure, submarine landslides can occur at very low slope angles and can spread for much greater distances than terrestrial slope failures. Utilizing the same marine geophysical surveys and geotechnical data, analysis of the frequency and aerial extent of underwater failure events in this area can be linked, partially, to the distribution and nature of Messinian-age evaporites and the influence of salt tectonics (halokinesis). Turb (open full item for complete abstract)

Committee: Abdul Shakoor Dr. (Advisor); Daniel Holm Dr. (Committee Member); Christopher Rowan Dr. (Committee Member); William Johnson (Committee Member) Subjects: Geology

Master of Science (MS), Bowling Green State University, 2017, Geology

The length of a day on Earth (abbreviated LOD) is not exactly 24 hours. There is a small excess LOD that varies on timescales ranging from a few days to thousands of years, generally on the order of milliseconds. One characteristic of LOD variations is a sinusoidal component with a period of ~6 years. The cause of the ~6-year signal is unknown, but is generally suspected to be exchanges of angular momentum between the mantle and the core. This study aimed to test the hypothesis that the ~6-year LOD signal is due to coupling between the mantle and fluid outer core. The flow of the core's fluid deforms the base of the mantle, leading to redistribution of Earth's mass (causing changes in the gravitational field) and deformation of the overlying crust. Surface deformation data from a global network of high-precision Global Positioning System (GPS) stations was analyzed, and the component that acts on the ~6-year timescale was isolated and inverted for the core's flow. Resulting angular momentum changes were computed for the outer core and compared to the LOD signal to search for evidence of core-mantle coupling. Outer core angular momentum changes obtained from GPS deformation data exhibit evidence of the suspected core-mantle coupling, but this result is sensitive to inversion parameters. Changes in the gravitational field were also modeled and found to be smaller than the errors in the currently available data.

Committee: Yuning Fu PhD (Advisor); Richard Gross PhD (Committee Member); Marco Nardone PhD (Committee Member); Margaret Yacobucci PhD (Committee Member) Subjects: Geology; Geophysics

Master of Science, The Ohio State University, 2017, Earth Sciences

The interplay of tectonics and climate is recorded in the sedimentary strata within the Victoria Land Basin, McMurdo Sound, Antarctica. Patterns of Cenozoic sedimentation are documented from interpretation of seismic reflection profiles calibrated by drillhole data in McMurdo Sound. These patterns provide enhanced constraints on the evolution of the coupled Transantarctic Mountains-West Antarctic Rift System and on ice sheet advance/retreat through multiple climate cycles. Revised seismic mapping through McMurdo Sound has been completed, utilizing the seismic stratigraphic framework first established by Fielding et al. (2006) and new reflectors marking unconformities identified from the AND-2A core (Levy et al., 2016). Correlations between the two frameworks update age constraints for the initiation of the Terror Rift, which was previously interpreted to have begun ~13 Ma based on age assignments made by Wilson et al. (2012) in the AND-1B core. New observations indicate the Terror Rift could have initiated as early as ~20 Ma, and was well underway by ~18 Ma, taking into account interval thickness patterns and new age assignments for reflector surfaces. The new age framework for seismic reflectors also raises the possibility of down-to-the-east normal faults underneath Hut Point Peninsula, in order to reconcile ~13 Ma and younger ages in the AND-1B core with McMurdo Sound seismic stratigraphy. Seismic facies correlated to the AND-2A core were mapped throughout McMurdo Sound. The strongest control on these facies was Miocene water depth. Facies patterns suggest that the shelf-slope-basin geometry within McMurdo Sound did not shift laterally throughout the Miocene, and was very similar to the present morphology. The mapped extent of erosion features indicates that grounded ice did not extend from the south throughout McMurdo Sound until ~14.4 Ma. Prior to that point, erosion was limited to the western shelf as ice extended eastward from TAM outlet glaciers. U (open full item for complete abstract)

Committee: Terry Wilson (Advisor); Lawrence Krissek (Committee Member); Derek Sawyer (Committee Member) Subjects: Geological; Geology; Geophysical; Geophysics

Master of Science (MS), Wright State University, 2017, Earth and Environmental Sciences

Constraining the composition, structure, and origin of basement provinces, deep assemblages of Precambrian rocks, is largely dependent on deep boreholes and geophysical techniques. This is especially true for the eastern U.S. midcontinent. Here, I employ regional 2-D seismic reflection, Bouguer gravity, and aeromagnetic data to interpret the upper crust below west-central Indiana. Seismic reflection data were donated to Wright State University in 2015. Geopotential data are available through the USGS and affiliates. These geophysical data, together, are analyzed in a regional geologic context. Three distinct seismic stratigraphic sequences are observed on 2-D sections. The first, uppermost sequence, typified by continuous, high-amplitude, stratified reflections is constrained by boreholes and previous seismic investigations as the Paleozoic sedimentary sequence that masks the midcontinent basement. The Cambrian Mt. Simon Sandstone constitutes the base of this unit, which is underlain by the second, poorly reflective, westward-thinning sequence. Weak internal reflections create an apparent angular unconformity with the base of the Mt. Simon and appear concordant with reflections of the basal seismic package. This unit, termed the Wilbur sequence, compares well with the seismic character of the Middle Run Formation of western Ohio and Kentucky. A third, well-reflective sequence is observed at the base of the record. Stratal geometries, such as onlap and stratigraphic terminations, are locally observable on regional east-west profiles. A positive Bouguer anomaly appears associated with the apparent structural closure of this sequence, herein termed the Quincy, below northeast Owen County. Geophysical signatures of the Quincy suggest a depositional origin, composed of low-magnetic igneous rocks (rhyolites) sourced from midcontinent volcanic centers and clastic sediments from collapsed calderas. These data facilitate two alternative hypotheses. The pattern seen in (open full item for complete abstract)

Committee: Ernest Hauser Ph.D. (Advisor); Doyle Watts Ph.D. (Committee Member); David Dominic Ph.D. (Committee Member) Subjects: Geology; Geophysics

Master of Science (MS), Wright State University, 2017, Earth and Environmental Sciences

The Henry Kinsey family was among the first to settle in the Dayton, Ohio, region in the early 19th century. Henry, and his wife Eva, were buried near what is known as the deer keeper's lodge, a small building where the deer keeper lived, on the modern-day Dayton Veterans Affairs hospital grounds. In the time since they have been buried, the location of their gravesites has been lost. The main purpose of this thesis is to locate and map their graves using multiple geophysical methods. A secondary purpose is to compare the effectiveness of each geophysical method. Three geophysical methods were used in this work: magnetics, electromagnetics, and ground penetrating radar. The magnetics survey was conducted using two Geometrics 857 proton precession magnetometers in a gradiometer configuration. The results of the magnetic survey show that there is a large magnetic anomaly running through the center of the survey area, likely an old utilities pipe. The data also show a significant anomaly coinciding with a surface artifact site, which is most likely the structure that stood next to the Kinsey family graves. The electromagnetics survey was conducted using a GSSI EMP-400 Profiler which utilized three frequencies simultaneously: 5kHz, 9kHz, and 15kHz. The electromagnetic data revealed a large anomaly through the center of the survey area, similar to the magnetics survey results. The data also showed a slight anomaly under the artifact site, although without the strength and clarity of the magnetics survey. The ground penetrating radar survey used a GSSI SIR-3000 system with a 400 MHz bistatic antenna. This survey yielded the best results, showing the extent of the artifact site in the subsurface. A small 3D survey was conducted over a unique anomaly that is a potential grave location. The GPR data would have shown even more, however, there are numerous trees within the survey area and their roots severely inferred with the GPR data. Based upon the data c (open full item for complete abstract)

Committee: Ernest Hauser Ph.D. (Committee Chair); Doyle Watts Ph.D. (Committee Member); David Dominic Ph.D. (Committee Member) Subjects: Geology; Geophysics

Doctor of Philosophy, The Ohio State University, 1982, Graduate School

Committee: Not Provided (Other) Subjects: Education

Master of Science (MS), Wright State University, 2016, Earth and Environmental Sciences

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 from the East Dominion Ohio Gas Storage field that contained an example of a gas shadow. This analysis demonstrated that all frequencies were attenuated at otherwise continuous reflectors immediately beneath a portion of the Clinton interval fully charged with natural gas. There was no enhancement of low frequencies such as described in low frequency shadows from the Gulf of Mexico. This analysis was applied to other seismic lines acquired in areas where natural gas is produced from the Clinton interval and areas of possible natural gas attenuation were identified. In this work, low frequencies are not enhanced beneath the potential gas reservoir. To be successful, this method requires that continuous reflectors occur beneath the target horizon. Simple attenuation of signal from a continuous reflector may be a new direct indicator of natural gas on seismic reflection data from Ohio and other Paleozoic basins.

Committee: Doyle Watts Ph.D. (Advisor); David Dominic Ph.D. (Committee Member); Ernest Hauser Ph.D. (Committee Member) Subjects: Earth; Geophysics

Master of Science (MS), Wright State University, 2016, Earth and Environmental Sciences

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 reflections from the Middle Run Formation on these AK Steel lines suggests that the Middle Run Basin here is apparently deep and sits above strong, continuous reflectors that are parallel to the overlying reflections from within the Middle Run. However, the gentle dip of the Middle Run exhibited at the AK Steel location contrasts greatly with the Middle Run Formation and deeper rocks to the east, as observed in the Warren County Line ODNR-1-88. There the Middle Run Formation exhibits a moderate apparent east-dip below an angular unconformity with the overlying Mt. Simon Sandstone, and the Middle Run Formation has been erosionally removed at the western end of the Warren County seismic line. The structures exhibited by these seismic lines suggest the likely presence of a fault between the AK Steel lines and the ODNR-1-88 line, with the thicker Middle Run sequence and gently dipping reflections on the AK Steel lines being best explained by preservation in a downthrown block, followed by subsequent erosion. The structural pattern of these lines suggest this fault is a Grenville reverse fault. The age and setting of the Middle Run Formation has been a subject of controversy. However, recent workers have provided new evidence that suggests that the Middle Run Formation fro (open full item for complete abstract)

Committee: Ernest Hauser Ph.D. (Advisor); Doyle Watts Ph.D. (Advisor); David Dominic Ph.D. (Committee Member) Subjects: Geological; Geology; Geophysical; Geophysics

Master of Science (MS), Wright State University, 2015, Earth and Environmental Sciences

An experiment was conducted to constrain the HVSR (Horizontal to Vertical Spectral Ratio) or H/V spectral ratio method at a glaciated site in northeast Ohio. Multiple methods were used to determine the shear wave velocity (Vs) and depth (h) to bedrock in relation to the fundamental resonant frequency (fo) determined from 3-component seismic data, as defined by the relationship f0=Vs/4h. The shear wave velocity structure was determined at three sites using MASW (Multi-channel Analysis of Surface Waves) and shear wave refraction methods, and the fundamental resonant frequency was passively observed using 3-component Guralp broadband seismometers. The Vs and bedrock depth results from both refraction and MASW produced comparable calculated theoretical f0 to that observed by the 3-component broadband seismometers. However, the bedrock depth and glacial drift Vs results were consistently lower for refraction than for MASW. Part of the calculations used with the generalized reciprocal method (GRM) method could yield bedrock depths that are underestimated proportionally with the Vs. Notably, the MASW results appear to be improved by combining overtones of multiple source offsets. The average Vs from the MASW and refraction surveys of this study were each used to calculate bedrock depth using the f0 observed for a suite of 73 seismometers previously deployed across the surrounding area as part of another study. Maps of these calculated bedrock depths correlate with the major dipping trends indicated by the water and gas wells in the area. At the site where the closest comparison could be made, the MASW determined Vs yielded a depth to bedrock that was significantly closer to the measured bedrock depth than the refraction determined Vs. This study suggests that an average shear wave velocity for glacial drift determined from a few MASW surveys in a region is sufficient to determine a viable average Vs to convert an array of 3-component f0 observations to pr (open full item for complete abstract)

Committee: Ernest Hauser Ph.D. (Advisor); Doyle Watts Ph.D. (Committee Member); David Dominic Ph.D. (Committee Member) Subjects: Geophysical; Geophysics

Master of Science (MS), Wright State University, 2015, Earth and Environmental Sciences

This thesis investigates how well ground vibrations can be detected at ladar or radar wavelengths and how the atmosphere may impact the observation of such activity. First understanding atmospheric hindrances at each of these wavelengths is helpful to prioritize by those yielding best transmission results. A prerequisite to the outdoor field experiment performed for this study involves analyzing atmospheric effects characterization at six probable wavelengths using the Laser Environmental Effects Definition and Reference tool (LEEDR) developed by the Air Force Institute of Technology's (AFIT) Center for Directed Energy (CDE). These wavelengths, selected from the shortwave infrared and microwave portions of the electromagnetic (EM) spectrum, are assessed to determine which provides optimal path transmission results allowing a sensor platform at an altitude of 1525 meters to sense induced ground vibrations. Selecting an altitude just above the typical atmospheric boundary layer (BL) allows further investigation of precipitation and cloud impacts on potential path transmission. The objective of performing the outdoor field experiment is to induce surface vibrations tracked by a 12 channel geophone spread linked to a seismograph at various locations along a horizontal path to determine if the signal can be detected by a 35 GHz radar. The contributory goal of this research is to realize new ways of monitoring otherwise invisible illegal or terrorist-like activities for the security of this nation. Additionally, the use of LEEDR could allow the atmospheric effects measured in the microwave part of the spectrum to be scaled for various platform altitudes and applied for atmospheric correction in other parts of the spectrum such as the visible, near-infrared, infrared, or submillimeter ranges. Experimental results indicate a 35 GHz radar is optimal and capable of detecting ground vibrations across short ranges when using a retro-reflector. How well seismic activity can (open full item for complete abstract)

Committee: Ernest Hauser Ph.D. (Committee Chair); Steven Fiorino Ph.D. (Committee Member); Douglas Petkie Ph.D. (Committee Member) Subjects: Atmosphere; Atmospheric Sciences; Electromagnetism; Energy; Environmental Geology; Environmental Science; Environmental Studies; Experiments; Geology; Geophysical; Geophysics; Physics; Remote Sensing

Master of Science, University of Akron, 2014, Geology-Geophysics

Reprocessing of the URSEIS explosive source seismic reflection data from the Trans and East Uralian Zones provides new geophysical evidence of a remnant subduction zone preserved in the upper mantle. A ~70 km long, ~4 km thick, east-dipping reflector is observed between 60-120 km depth. This reflector is interpreted to represent eclogized oceanic crust that was subducted below the Trans-Uralian Arc and is entrained in the upper mantle. Evidence of a remnant subduction zone has clear implications for constraining theories of tectonic evolution in the Southern Urals. Above the subducted plate, a horizontal, ~50 km long sill-like structure is observed between 70-90 km depth. This reflector, termed the Alexandrovka Reflection Sequence (ARS) is likely composed of garnet-jadeitic pyroxenite or recrystallized eclogite based on its coefficient of reflection of 0.13. Between 120-170 km depth, a discontinuous, west-dipping series of reflections termed the Nikolaevka Reflection Sequence (NRS) is observed. The NRS may represent a second, more recent, west-dipping remnant subducted slab. Alternatively, the NRS reflections may represent recrystallized eclogite and pyroxenite melt from deeper sources in the asthenosphere. Reprocessing steps differed somewhat from the original processing, resulting in an enhanced image of the east-dipping subducted plate. The image of the subducted plate was enhanced by a bandpass filter of 3-12 Hz with 5 Hz ramps on each end, and automatic gain control using windows of 10 seconds. Without this technique, observation of the east-dipping subducted slab would not have been possible.

Committee: David Steer Dr. (Advisor); LaVerne Friberg Dr. (Committee Member); Caleb Holyoke III Dr. (Committee Member) Subjects: Geological; Geology; Geophysical; Geophysics