Geophysics and Seismology Commons^™

Integrated Geophysical Approach Using Electrical Resistivity Tomography And Multichannel Analysis Of Surface Wave In Assessing Wilson Spring Development, Ibrahim E. Ahmed

Doctoral Dissertations

"This research investigated fractured zones leading to preferential flow paths of Wilson Spring. In this context, electrical resistivity tomography (ERT) data and multi-channel analyses of surface waves (MASW) data were acquired at studied site with the purpose of mapping a variable depth to top of bedrock and geological structures.

Interpretation of the boreholes, MASW, and ERT data indicated that a depth to top of rock does vary significantly at the studied site due to many solution-widened fractures. Multiple near-vertical solution-widened fractures were mapped in the studied site based on the interpretation of the ERT data. The mapped solution-widened fractures appear …

The Martian Surface Radiation Environment- A Comparison Of Models And Msl/Rad Measurements, Daniel Matthiä, Bent Ehresmann, Henning Lohf, Jan Köhler, Cary Zeitlin, Jan Appel, John W. Wilson

Mathematics & Statistics Faculty Publications

Context: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models.

Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation …

Kinds Of Volcanoes, John J. Renton, Thomas Repine

Readings and Notes

By definition, a volcano is a conical structure that builds around a volcanic vent. A volcanic vent is an opening from which molten rock and gases erupt. According to the definition, there is no size requirement. There are volcanoes that you can span with your legs while on the other hand, there is Mt. Fiji.

Targeted Reflection-Waveform Inversion Of Experimental Ground-Penetrating Radar Data For Quantification Of Oil Spills Under Sea Ice, John H. Bradford, Esther L. Babcock, Hans-Peter Marshall, David F. Dickins

Geosciences Faculty Publications and Presentations

Rapid spill detection and mapping are needed with increasing levels of oil exploration and production in the Arctic. Previous work has found that ground-penetrating radar (GPR) is effective for qualitative identification of oil spills under, and encapsulated within, sea ice. Quantifying the spill distribution will aid effective spill response. To this end, we have developed a targeted GPR reflection-waveform inversion algorithm to quantify the geometry of oil spills under and within sea ice. With known electric properties of the ice and oil, we have inverted for oil thickness and variations in ice thickness. We have tested the algorithm with data …

A Synthetic Study To Assess The Applicability Of Full-Waveform Inversion To Infer Snow Stratigraphy From Upward-Looking Ground-Penetrating Radar Data, Lino Schmid, Jürg Schweizer, John Bradford, Hansruedi Maurer

CGISS Publications and Presentations

Snow stratigraphy and liquid water content are key contributing factors to avalanche formation. Upward-looking ground penetrating radar (upGPR) systems allow nondestructive monitoring of the snowpack, but deriving density and liquid water content profiles is not yet possible based on the direct analysis of the reflection response. We have investigated the feasibility of deducing these quantities using full-waveform inversion (FWI) techniques applied to upGPR data. For that purpose, we have developed a frequency-domain FWI algorithm in which we additionally took advantage of time-domain features such as the arrival times of reflected waves. Our results indicated that FWI applied to upGPR data …

Re-Assessment Of Lithostratigraphy, Biostratigraphy, And Volcanic Activity Of The Late Paleozoic Intra-Sudetic, Krkonoše-Piedmont And Mnichovo Hradiště Basins (Czech Republic) Based On New U-Pb Ca-Id-Tims Ages, Stanislav Opluštil, Mark Schmitz, Václav Kachlík, Stanislav Štamberg

Geosciences Faculty Publications and Presentations

Five U-Pb CA-ID-TIMS high-precision ages were obtained from single zircon crystals separated from tuffs or ignimbrites embedded in Pennsylvanian to Asselian sediments of the Intra-Sudetic, Krkonoše-Piedmont and the adjacent part of the Mnichovo Hradiště basins. The new radioisotopic data are used for extrapolation of ages of dated lithostratigraphic units. The existing borehole network in the Late Paleozoic continental basins of central and western Bohemia and in the Sudetic area, and similarity of their stratigraphically equivalent strata including some common lacustrine horizons allow a detailed lithostratigraphical correlation between these two areas. This in turn, allows combining our new radioisotopic data with …

Assessing The Sensitivity Of The Non-Hydrostatic Regional Climate Model To Boundary Conditions And Convective Schemes Over The Philippines, Gemma T. Narisma, Faye T. Cruz, Hidetaka Sasaki

Physics Faculty Publications

Regional climate models have been useful in climate studies and in downscaling climate projections from global climate models, especially for areas characterized by complex topography and coastline features, such as the Philippines. However, several factors may affect model skill, such as uncertainties related to the boundary conditions and model configuration. This study evaluates the performance of the non-hydrostatic regional climate model (NHRCM) over the Philippines. Present-day climate simulations at 50 km resolution are conducted using two sets of boundary conditions (ECMWF ERA-Interim and the NCEP/NCAR Reanalysis Project NNRP1), as well as two convective parameterization schemes in the model (Grell and …

Earthquake Hazard Mitigation In The New Madrid Seismic Zone: Science And Public Policy, Alice M. Orton, Zhenming Wang, Lanmin Wang, Edward W. Woolery

Report of Investigations--KGS

In the central United States, earthquake sources that are not well defined, long earthquake recurrence intervals, and uncertain ground-motion attenuation models have contributed to an overstatement of seismic hazard for the New Madrid Seismic Zone on the national seismic hazard maps published by the U.S. Geological Survey. A series of informal interviews in western Kentucky with local businesspersons, public officials, and other professionals in occupations associated with seismic-hazard mitigation discussed seismic-mitigation policies in relation to depressed local economy. Scientific and relative economic analysis was then performed using scenario earthquake models developed with the Federal Emergency management Agency's Hazus-MH software. The …

Earthquakes And Seismology, John J. Renton, Thomas Repine

Readings and Notes

The great majority of earthquakes are caused by the movement of faults. Two terms are used to determine the location of an earthquake, focus and epicenter. The focus of an earthquake is the point along a fault where the rocks slipped and released the energy previously stored during the elastic phase of deformation. Because faults represent brittle deformation, the highest frequency of earthquakes occurs at Earth's surface and decreases with depth as rocks become less brittle and more plastic. The deepest earthquake foci occur at depths of about 640 km. ( 400 mi.) which is the deepest penetration of subducting …

Earthquakes, John J. Renton, Thomas Repine

Readings and Notes

For centuries, earth scientists have known where the major earthquakes occurred. They also knew they occurred in the same locales as the most violent volcanoes, a fact that led to centuries of arguments as to which was the cause of the other. Now we know that they are not cause and effect; they are both associated with the convergent plate margins. During the mid-1900s, another major zone of both volcanic and earthquake activity was discovered, namely the divergent margins, the most important site being the oceanic ridges. Since then, we have also come to understand the occurrence of volcanic activity …

Egg On Hegranes: Geophysical Prospection, Coring, & Test Excavations—Report 2016, John M. Steinberg, Brian N. Damiata, Rita S. Shepard, Kathryn Anne Catlin, John W. Schoenfelder

Andrew Fiske Memorial Center for Archaeological Research Publications

This report describes the 2016 archaeological work at the farm of Egg is in the southernmost part of Hegranes, North Iceland.

Contribution Of Shallow Geology To Hydrocarbon Seep Formation In Green Canyon Block 600, Samantha Lynn Lucker

Electronic Theses and Dissertations

The Green Canyon Federal Protraction area in the Gulf of Mexico is rich in hydrocarbons. The movement of the Sigsbee salt escarpment in green canyon has resulted in a complex bathymetric profile and extensive shallow faulting that has allomigration of hydrocarbons to the surface creating cold seep sites. Green Canyon block 600 (gc600) contains multiple naturally occurring, active hydrocarbon seeps. Multi-beam bathymetry, backscatter, and polarity preserving chirp data were collected for gc600 to study the development of these naturally occurring seeps. Using these data, the structure and sedimentation of the first fifty meters can be studied in relation to the …

Hegranesþing On Hegranes: Geophysical Prospection Interim Report 2013 – 2015, Brian N. Damiata, John M. Steinberg, John W. Schoenfelder, Douglas J. Bolender

Andrew Fiske Memorial Center for Archaeological Research Publications

Geophysical surveys were conducted at Hegranesþing on Hegranes in North Icelad during the summers of 2013 and 2015.

Site Characteristics, Instrumentation, And Recordings Of The Central United States Seismic Observatory, Edward W. Woolery, Zhenming Wang, N. Seth Carpenter

Report of Investigations--KGS

The Central United States Seismic Observatory is a vertical seismic array in southwestern Kentucky within the New Madrid Seismic Zone. It is intended to record the effects of local geology, including thick sediment overburden, on seismic-wave propagation, particularly strong ground motion. The three-borehole array is composed of seismic sensors placed on the surface, in the bedrock, and at various depths within the 585-m-thick sediment overburden. The array's deep borehole also provides a unique opportunity to describe the geology and geophysically measure the complete Late Cretaceous through Quaternary stratigraphy in the northern Mississippi Embayment.

Based on the surface and borehole geophysical …

Nonlinear Inversion Strategies Applied To Source Characterization And 3d Earthquake Tomography In Volcanic Environments: A Case Study At Pacaya Volcano, Guatemala, Federica Lanza

Dissertations, Master's Theses and Master's Reports

Full-waveform moment tensor inversion of volcanic seismic signals and travel-time 3D tomography of local earthquakes have been widely used to explore source processes related to magma transport as well as to image the location and size of magma storage systems. However, the inversion solutions and the associated reliability estimates are non-unique and bear intrinsic uncertainties due to simplifying assumptions about the source, inaccuracies in the velocity models, dependence on network configuration, and other a priori constraints imposed by the modeler.

This work addresses the non-uniqueness and uncertainties of the model results by introducing non-linear inversion techniques that allow sampling the …

Use Of Laboratory Geophysical And Geotechnical Investigation Methods To Characterize Gypsum Rich Soils, Raghava A. Bhamidipati

Theses and Dissertations--Civil Engineering

Gypsum rich soils are found in many parts of the world, particularly in arid and semi-arid regions. Most gypsum occurs in the form of evaporites, which are minerals that precipitate out of water due to a high rate of evaporation and a high mineral concentration. Gypsum rich soils make good foundation material under dry conditions but pose major engineering hazards when exposed to water. Gypsum acts as a weak cementing material and has a moderate solubility of about 2.5 g/liter. The dissolution of gypsum causes the soils to undergo unpredictable collapse settlement leading to severe structural damages. The damages incur …

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 …

Development Of A Semi-Automated Methodology For Discriminating Between Natural And Manmade Seismic Events Using The Oiink Seismic Array, Paul Rodriguez Asihama

Theses and Dissertations--Earth and Environmental Sciences

Broadband waveforms from the Ozark, Indiana, Illinois, Kentucky temporary seismic array OIINK, a Flexible Array in the EarthScope project, were used to develop routines to identify and remove mine blast events from a database of local events and preserve the infrequent, small, natural earthquakes. The approach taken was to first create a database of all seismic events that were detected by the OIINK Seismic Array. False-detections, events detected from outside of the project area (approx. 302 thousand square km), and known (i.e. cataloged) local earthquake were also removed. The remaining in the database were local unknown events. During the Phase …

Seismic Reflection, Well Log, And Gravity Analysis Of The Thrace Basin, Northwestern Turkey, Murat Kuvanc

Graduate Theses/Dissertations

The Thrace basin is located between the Paleogene the Istranca and Rhdope massifs in the northwestern part of Turkey. Sediments in the Thrace basin accumulated during the early Eocene to the late Miocene, and the basin includes normal and strike-slip faults that were mainly formed in the Miocene. The hydrocarbon potential of the Thrace basin has been investigated by analyzing seismic reflection, well log, and gravity data since the 1930s; the basin has a huge gas reservoir potential and contains the first gas production field in Turkey. To determine the geologic and geophysics features of a portion of the basin …

Comparisons Of Seismic Interferometry By Cross Correlation, Deconvolution, And Cross Coherence, Haitao Cao

Dissertations, Master's Theses and Master's Reports

Ambient noise seismic interferometry (ANSI) has been applied widely for geophysical investigations including earthquake tomography, civil engineering and seismic exploration purposes. Comparing this approach with the traditional active seismic survey, the application of ANSI is cost effective, environmentally friendly and easily repeatable. Conventional seismic interferometry by cross correlating wavefields recorded at different receivers has already obtained fruitful results.

Even though the application of seismic interferometry (SI) by cross correlation has been successful, different methods for the processing workflow such as cross coherence and deconvolution have been conducted in an effort to improve the resolution. While these three methods have been …