Geophysics and Seismology Commons^™

Subsurface Planetary Investigation Techniques And Their Role For Assessing Subsurface Planetary Composition, Ahmed Elshafie

Graduate Theses and Dissertations

Subsurface planetary investigation techniques are of high interest and importance for the scientific community. Not only they can enhance our knowledge of the history of planetary formation but also can lead to information about its future. Whether the investigation is being conducted remotely using imagers, radars or physically using penetrometers or drills, a pre-existed knowledge of the mechanical and electrical properties of the subsurface regolith should be acquired for better data interpretation and analysis. Therefore, the main objective of this work is to investigate the mechanical and electrical properties of planetary analogs, understand their role for assessing the subsurface structure …

A Feasibility Study Of Time-Lapse Seismic Monitoring Of Co2 Sequestration In A Layered Basalt Reservoir, Murari Khatiwada, Ludmila Adam, Michael Morrison, Kasper Van Wijk

CGISS Publications and Presentations

We investigate the potential of scattered seismic waves to remotely sense geological sequestration of CO₂ in basalt. Numerical studies in horizontally layered models suggest that strong scattering quickly complicates the wave fields, but also provides a sensitive tool to monitor physical changes in and around the reservoir. These results go hand-in-hand with recent laboratory work and rock-physics modeling that has shown significant changes in the seismic properties of a reservoir undergoing CO₂ sequestration, due to fluid substitution and mineral precipitation.

The Influence Of Non-Equilibrium Pressure On Rotating Flows, Irfan Rashid Zardadkhan

Mechanical & Aerospace Engineering Theses & Dissertations

This study was undertaken to investigate the influence of pressure relaxation on steady, incompressible flows with strong streamline curvature. In the early part of this dissertation research, the significance of non-equilibrium pressure forces in controlling the structure of a steady, two dimensional axial vortex was demonstrated. In order to extend the study of pressure relaxation influences on more complex rotating flows, this dissertation has examined other rotating flow features that can be associated with hurricanes, tornadoes and dust devils. To model these flows, modified boundary layer equations were developed for a fluid column rotating near a solid plane including the …

Modeling, Visualizing, And Understanding Complex Tectonic Structures On The Surface And In The Sub-Surface, Steven Wild

Physics Theses & Dissertations

Plate tectonics is a relatively new theory with many details of plate dynamics which remain to be worked out. Moving plates can interact by divergence, lateral sliding, convergence, or collision. At a convergent plate boundary, a lithospheric slab of oceanic crust and upper mantle is subducted at a trench and dips down under a magmatic arc — either oceanic or continental. Textbooks show a static view of convergent boundaries but plate dynamics require that subduction zones and magmatic arcs must migrate with time. Therefore I develop animated models to help convey this motion. Also, convergent plate boundaries cannot continue along …

Gravity Anomalies Along The East Scotia Ridge: Constraining The Relative Importance Of Magmatic And Tectonic Controls On Crustal Accretion, Briton Lee Nicholson

OES Theses and Dissertations

Similar to regions such as the Lau Basin and the Caribbean Sea, the eastern Scotia Sea is a geologically complex area that involves multiple plate boundary types. This study uses bathymetry and gravity data to infer upper mantle geodynamics in the eastern Scotia Sea region. Beneath this region is an intermediate-rate back-arc spreading center known as the East Scotia Ridge (ESR) that forms the boundary between the Scotia and Sandwich plates. To the east of the ESR are the South Sandwich island arc and the South Sandwich Trench. The ESR is a relatively young feature, with spreading estimated to have …

Investigation Of Stress Changes At Mount St. Helens, Washington, And Receiver Functions At The Katmai Volcanic Group, Alaska, With An Additional Section On The Assessment Of Spreadsheet-Based Modules., Heather L. Lehto

USF Tampa Graduate Theses and Dissertations

Forecasting eruptions using volcano seismology is a subject that affects the lives and property of millions of people around the world. However, there is still much to learn about the inner workings of volcanoes and how this relates to the chance of eruption. This dissertation attempts to increase the breadth of knowledge aimed at helping to understand when a volcano is likely to erupt and how large that eruption might be. Chapters 2 and 3 focus on a technique that uses changes in the local stress field beneath a volcano to determine the source of these changes and help forecast …

Plains Co2 Reduction (Pcor) Partnership Atlas, Wesley D. Peck, Tera D. Buckley, Earl P. Battle, Megan M. Grove, Joyce M. Riske, Charles D. Gorecki, Edward N. Steadman, John A. Harju

EERC Maps and Infographics

The Plains CO₂ Reduction (PCOR) Partnership Atlas provides a regional profile of CO₂ sources and potential CO₂ storage locations across the PCOR Partnership region. The fourth edition provides an update-to-date look at PCOR Partnership activities, including regional characterization and full-scale demonstration activities. Additional background information on carbon capture, utilization, and storage (CCUS) is included to give a better understanding of how CCUS addresses concerns about climate change while allowing future energy needs to be met.

Scanning For Velocity Anomalies In The Crust And Mantle With Diffractions From The Core-Mantle Boundary, Elmer Ruigrok, T. Dylan Mikesell, Kasper Van Wijk

CGISS Publications and Presentations

A novel method, based on differential arrival times of diffractions from the core-mantle boundary, swiftly scans for seismic velocity anomalies in the crust and mantle below an array of seismometers. The method is applied to data from the USArray and the large-scale structural features in the western United States are resolved. High lateral resolution is achieved, but structure is averaged over depth. As such, this method is complementary to surface-wave and tomographic body-wave methods, where averaging takes place in the lateral sense. Processing and data-volume requirements involved are minimal. Therefore, this method can be applied during the early stages of …

The Emergence And Future Of Near-Surface Geophysics, William E. Doll, Richard D. Miller, John Bradford

CGISS Publications and Presentations

Over the past 30 years, geophysical methods have assumed a much more prominent and integral role in many investigations where subsurface features have environmental and engineering importance. In fact, the field once referred to as "environmental and engineering geophysics" has broadened to include other applications (e.g., archeology, forensics), and is now commonly referred to more generally as "near-surface geophysics." It is difficult to precisely define near-surface geophysics, and the definition will likely depend on whom you ask. However, we define it as the use of geophysical methods to investigate the zone between the surface and hundreds of meters into the …

Estimates Of The Density Contrast At Earth’S Inner-Core Boundary Beneath Central Mexico, Wade Kelley

Physics

Seismograms recorded in the western United States from a Guatemalan earthquake are examined for matching pairs of PKiKP and PcP waveforms for use in estimating the density contrast at earth’s inner-core boundary via a PKiKP/PcP amplitude ratio analysis. Examination of waveforms from the SN, SC, TA, US and CI arrays finds 68 visually identifiable PKiKP and PcP pairs from which 17 were judged to be of sufficient quality (low signal-to-noise ratio) for use in the PKiKP/PcP amplitude ratio analysis. The epicentral distance range of the selected data spans epicentral distances from 22 – 37 degrees inside of which stations are …

Three-Dimensional Stochastic Estimation Of Porosity Distribution: Benefits Of Using Ground-Penetrating Radar Velocity Tomograms In Simulated-Annealing-Based Or Bayesian Sequential Simulation Approaches, Baptiste Dafflon, Warren Barrash

CGISS Publications and Presentations

Estimation of the three-dimensional (3-D) distribution of hydrologic properties and related uncertainty is a key for improved predictions of hydrologic processes in the subsurface. However it is difficult to gain high-quality and high-density hydrologic information from the subsurface. In this regard a promising strategy is to use high-resolution geophysical data (that are relatively sensitive to variations of a hydrologic parameter of interest) to supplement direct hydrologic information from measurements in wells (e.g., logs, vertical profiles) and then generate stochastic simulations of the distribution of the hydrologic property conditioned on the hydrologic and geophysical data. In this study we develop and …

Sedimentology And Geochronology Of Holocene Paleochannel Features In The Lower Ohio River Valley, Indiana, Kathryn G. De Rego, C. Russell Stafford, Mark Cantin

Symposium 2012

Rivers condition human settlement strategy by determining both the location of aquatic resources and the stability of the landscape. Therefore, understanding where the river was and how quickly it migrated in the past aids in predicting buried site potential. This study investigates the sedimentology and geochronology of paleochannel deposits along the Lower Ohio River floodplain. A series of low, wide swales are prominent features in a series of bottoms in a ~40 km section of the river valley downstream from the Falls of the Ohio. Previous studies in Knob Creek Bottom indicate that one of these paleochannel swales was active …

Monitoring Glacier Surface Seismicity In Time And Space Using Rayleigh Waves, T. D. Mikesell, Kasper Van Wijk, Matthew M. Haney, John H. Bradford, Hans-Peter Marshall, Joel T. Harper

CGISS Publications and Presentations

Sliding glaciers and brittle ice failure generate seismic body and surface wave energy characteristic to the source mechanism. Here we analyze continuous seismic recordings from an array of nine short-period passive seismometers located on Bench Glacier, Alaska (USA) (61.033°N, 145.687°W). We focus on the arrival-time and amplitude information of the dominant Rayleigh wave phase. Over a 46-hour period we detect thousands of events using a cross-correlation based event identification method. Travel-time inversion of a subset of events (7% of the total) defines an active crevasse, propagating more than 200 meters in three hours. From the Rayleigh wave amplitudes, we estimate …

A Field Proof-Of-Concept Of Aquifer Imaging Using 3-D Transient Hydraulic Tomography With Modular, Temporarily-Emplaced Equipment, Michael Cardiff, Warren Barrash, Peter K. Kitanidis

CGISS Publications and Presentations

Hydraulic tomography is a field scale aquifer characterization method capable of estimating 3-D heterogeneous parameter distributions, and is directly sensitive to hydraulic conductivity (K), thus providing a useful data source for improving flow and transport models. We present results from a proof-of-concept field and modeling study in which we apply 3-D transient hydraulic tomography (3DTHT) to the relatively high-K and moderately heterogeneous unconfined aquifer at the Boise Hydrogeophysical Research Site. Short-duration (20 min) partially penetrating pumping tests, for which observed responses do not reach steady state, are used as the aquifer stimulation. To collect field data, we utilize a system …

Subsurface Characterization Using Head-Wave Artifacts In Seismic Interferometry, Thomas Dylan Mikesell

Boise State University Theses and Dissertations

Seismologists continually work to improve images of the Earth's interior. One new approach is seismic interferometry, which involves cross-correlating the seismic wave field recorded at two receivers to generate data as if one of the receivers was a source. Over the past decade, seismic interferometry has become an established technique to estimate the surface-wave part of the impulse response between two receivers; however, practical limitations in the source-energy distribution have made body-wave recovery difficult and causes spurious energy in the estimated impulse response. Rather than suppress such spurious energy, it can be useful to analyze coherent spurious events to help …

Non-Destructively Mapping The In-Situ Hydrologic Properties Of Snow, Firn, And Glacial Ice With Georadar, Joel Matthew Brown

Boise State University Theses and Dissertations

Ground penetrating radar (GPR) is a useful tool for studying the in-situ properties of glacial ice, firn, and snowpacks. The main focus of this dissertation is improving and expanding methods employed when collecting, processing, and understanding GPR data collected in the Cryosphere, or the snow and ice covered areas of the earth. The data used herein were collected on the Greenland Ice Sheet (GrIS) and on seasonal snowpacks of Western Montana, USA. This document has three sub-topics.

The first sub-topic is comparing the spatial variability of GPR data to the spatial variability of core data collected in two locations within …

Seismic Detection Of A Low-Velocity Layer Atop The 410-Km Discontinuity: Verification Of An Electromagnetically Detected Layer Of Partial-Melt Atop The 410-Km Discontinuity Beneath Se Arizona, Dwight W. Townsend

Physics

No abstract provided.

Bulk Rock Composition And Geochemistry Of Olivine-Hosted Melt Inclusions In The Grey Porri Tuff And Selected Lavas Of The Monte Dei Porri Volcano, Salina, Aeolian Islands, Southern Italy., Angela L. Doherty, Robert J. Bodnar, Benedetto De Vivo, Wendy A. Bohrson, Harvey E. Belkin, Antonia Messina, Robert J. Tracy

All Faculty Scholarship for the College of the Sciences

The Aeolian Islands are an arcuate chain of submarine seamounts and volcanic islands, lying just north of Sicily in southern Italy. The second largest of the islands, Salina, exhibits a wide range of compositional variation in its erupted products, from basaltic lavas to rhyolitic pumice. The Monte dei Porri eruptions occurred between 60 ka and 30 ka, following a period of approximately 60,000 years of repose. The bulk rock composition of the Monte dei Porri products range from basaltic-andesite scoria to andesitic pumice in the Grey Porri Tuff (GPT), with the Monte dei Porri lavas having basaltic-andesite compositions. The typical …

Paleomagnetism Of The Knight Island Ophiolite, Prince William Sound, Alaska, Steven M. Espinosa^, Terry L. Pavlis*

COURI Symposium Abstracts, Spring 2012

No abstract provided.

Continued Mapping Of Unmarked Graves In The Mescalero Apache Indian Reservation, Ashley Galusina Nauer^, Alan C. Espino^, Alejandro Rios^, Laura Serpa*

COURI Symposium Abstracts, Spring 2012

No abstract provided.