Physical Sciences and Mathematics Commons^™

A Bayesian Framework For Estimating Seismic Wave Arrival Time, Hua Zhong

Graduate Theses and Dissertations

Because earthquakes have a large impact on human society, statistical methods for better studying earthquakes are required. One characteristic of earthquakes is the arrival time of seismic waves at a seismic signal sensor. Once we can estimate the earthquake arrival time accurately, the earthquake location can be triangulated, and assistance can be sent to that area correctly. This study presents a Bayesian framework to predict the arrival time of seismic waves with associated uncertainty. We use a change point framework to model the different conditions before and after the seismic wave arrives. To evaluate the performance of the model, we …

Volcanic Electrification: A Multiparametric Case Study Of Sakurajima Volcano, Japan, Cassandra M. Smith

USF Tampa Graduate Theses and Dissertations

Electrical activity at volcanoes has been recently recognized as a potential new remote sensing technique for plume-forming eruptions. Volcanic electrical activity takes place in the conduit and plume and therefore has the benefit of being a direct indicator of surface activity. This is unlike seismic signals, which indicate magma/gas movement underground, and infrasound signals, which indicate a surface explosion but not necessarily the formation of an ash plume. There are two distinct types of volcanic electrical discharges: volcanic lightning and continual radio frequency (CRF) impulses. This dissertation explores the relationships between these two electrical signals and other commonly monitored volcanic …

Utilizing Geophysical Attributes To Investigate The Architecture Of A Pinnacle Reef Complex, Michigan Basin, Usa, Austin M. Johnson

Masters Theses

The Silurian Niagaran Pinnacle Reefs of the Michigan Basin retain their relevance after primary recovery of hydrocarbons and are excellent candidates for carbon dioxide sequestration, natural gas storage, and enhanced oil recovery. Due to the nature of carbonate rocks, these reef complexes are heterogeneous and lateral interpolation between observations in wells, is ambiguous. Ambiguity has led to large uncertainty and disagreement regarding reef architectures and their internal facies distributions. Previous models of these reef complexes have relied almost entirely on well logs and conventional core. This study focused on integrating 3D seismic reflection data to reduce uncertainty when delineating the …

Geophysical Analysis Of The Midcontinent Rift’S Subsurface Structure In Southeastern Nebraska, Patrick Szopinski

Honors Theses

The Midcontinent Rift System (MCRS) is a 1.1 billion-year-old failed rift system that spans much of the North American continental interior. The MCRS is exposed at Lake Superior and is buried in the subsurface along its southwest-extending arm through southeastern Nebraska. Due to the presence of buried volcanic rocks, the MCRS has characteristic highly-pronounced potential field anomalies (gravity and magnetic). Despite these large anomalies, not much is known about the subsurface faulting associated with the rift zone in the Midwest. The goal of this project is to attempt to use integrated analysis of collected geophysical data from multiple methods to …

Reflector Dip Trends In Seismic Sh-Wave Imaging Of A Modern Lower Mississippi River Point Bar, Adam Gostic

LSU Master's Theses

Various studies of ancient point bars have noted that a relationship can be observed between the dip angle and grain size of point bar lateral accretion deposits, with the most mud-rich deposits tending to exhibit the greatest dip. No analysis and only cursory explanations for this relationship have been provided. Additionally, buried mid-channel bars are absent from typical models of point bar architecture.

We successfully image the architecture of late-stage point bar deposits with a near surface 2D seismic SH-wave reflection survey and generate an SH-wave velocity model of the subsurface in the study area in order to interpret the …

New Insights On Messinian Evaporites Based On Field And Seismic Interpretations In The Neogene Antalya Basin, Sw Turkey, Sali̇ha Dündar, Baki̇ Erdoğan Varol

Turkish Journal of Earth Sciences

In situ/primary Messinian upper evaporite is absent in the onland (onshore) sections of the Aksu and Manavgat subbasins (Antalya Basin), where gypsum blocks, gypsum conglomerate, and laminated gypsum beds mixed with siliciclastic materials are collectively present in the uppermost Messinian-?lowermost Pliocene succession. The metric-size resedimented evaporite blocks, mainly derived from selenite-dominated marginal/upper evaporite, were deposited time-equivalent to the lower-middle parts of the reefal Gebiz limestone in the Aksu subbasin. Resedimented bedded evaporites were accumulated after siliciclastic-dominated (fluvio-deltaic) sedimentation of the Taşlık Formation in the Manavgat subbasin (nearby Antalya city). Some bedded/?resedimented gypsums were defined within the Gebiz limestone and the …

Seismic Structure Of Tanaga Island, Alaska, Kevin F. (Kevin Francis) Lally

WWU Graduate School Collection

Tanaga Island is located in the Central Aleutian Islands and includes four stratovolcanoes: Sajaka, Tanaga, and East Tanaga in the northwest, and Takawangha in the central part of the island. Of these volcanoes, only Tanaga has a record of historical eruptive activity (in 1914). Over 3,000 earthquakes have been recorded beneath the island and the surrounding offshore region since the six-station seismic network was emplaced in 2003. The origin of these earthquakes is not completely understood, and to arrive at this understanding, more accurate hypocenter locations and power spectra need to be determined. A better analyses including improved locations of …

Quantifying The Seismic Vulnerability Of Bridges In Low To Moderate Seismicity Regions, John Edward Lens

Graduate College Dissertations and Theses

The U.S. Congressional Research Service issued a report for Congress in May 2016, entitled” Earthquake Risk and U.S. Highway Infrastructure: Frequently Asked Questions” which highlighted the absence of a national database on the status of seismic vulnerability of bridges or other infrastructure, and thus no estimate of costs to retrofit vulnerable bridges. Low to moderate seismicity regions exist in each of the continental United States, with over 30 states having mostly or entirely low-to-moderate seismicity. Resources at state transportation agencies and municipalities are focused on higher seismicity regions, creating a gap in quantifying the system-wide seismic vulnerability despite an overall …

Reprocessing And Comparison Of The 2 Hz And 10 Hz Vertical Component Seismic Data Of The Blackfoot 3c-2d Survey, Mete Sarikaya

Masters Theses

"The Blackfoot seismic 3C-2D data were obtained from the Consortium for Research in Elastic Wave Exploration Seismology (CREWES) Project in 1995. The seismic data acquisition was performed in the Blackfoot Field, which is around 15 km southeast of Strathmore, Alberta. The 4 Hz and 10 Hz vertical component data are reprocessed to increase the quality and resolution of the seismic images. The Glauconitic sand reservoir at approximately 1.1 s, and a strong reflection about at 1.5 s are the focuses of the study.

The processing procedure includes different parameters and methods to obtain the best seismic sections of 2 Hz …