Geophysics and Seismology Commons^™

Estimating Subsurface Anisotropy: Combining Waveform Tomography And Simulated Annealing, Michael Victor Afanasiev

Electronic Thesis and Dissertation Repository

Crosshole seismic tomography has been used by Vale to provide geophysical images of mineralized massive sulphides in the Eastern Deeps deposit at Voisey's Bay. High resolution seismic images are presented by applying acoustic waveform tomography to these data. In waveform tomography, an initial model is required which predicts the first arrival traveltimes to within a half-cycle of the lowest frequency in the data. Because seismic velocity anisotropy can be significant, the initial model must quantify the anisotropy, as well as the velocity, in order to meet the half-cycle criterion.

In our case study, difficulties were encountered in generating an accurate …

Calculation Of A Synthetic Gather Using The Aki-Richards Approximation To The Zoeppritz Equations, Graham Ganssle

University of New Orleans Theses and Dissertations

A synthetic seismic gather showing amplitude versus offset can be analyzed by the interpretive geophysicist to predict rock properties useful in oil exploration. Reflection coefficients derived from measured well log data are convolved with a Ricker wavelet to create a synthetic seismic trace. The Zoeppritz equations describe the propagation of an acoustic wave across an interface between two viscous media of different acoustic impedances with respect to increasing offset angle. The Aki-Richards linear approximation is used to create a synthetic seismic gather with offset angles up to fifty degrees. This gather is compared to a synthetic gather created using commercially …

Megathrust Splay Fault Geometry In Prince William Sound, Alaska, Shaun Patrick Finn

Boise State University Theses and Dissertations

I present marine seismic reflection results from Prince William Sound, Alaska that document the location of active faults related to the subduction zone processes.

Subduction zones along convergent margins experience large earthquakes, magnitude >8, with recurrence intervals on the order of centuries. Smaller magnitude earthquakes with shorter recurrence intervals are probable along the same subduction zone fault zones. Convergent margin earthquakes also are associated with high uplift rates and tsunami generation, yet the location and uplift history of most tsunamigenic faults are unknown. In this thesis, I present the processed results of high resolution marine seismic reflection data of Prince …

Contextualizing The Tipton-Haynes State Historic Site (40wg59): Understanding Landscape Change At An Upland South Farmstead., Daniel Whitaker Howard Brock

Masters Theses

This thesis focuses on a contextual archaeological approach to investigate the historic landscape of the Tipton-Haynes State Historic Site. Tipton-Haynes is a late eighteenth- through twentieth-century upland south farmstead located in Johnson City, TN. Home to two prominent Tennessee families and occupied until acquired by the state in the 1960s, the site has experienced many alterations to the landscape over time. The analysis presented views the landscape as material culture investigated through a multidisciplinary approach including historic research, architectural survey, geophysical survey, dendrochronology, and archaeology. To make sense of the complex nature of the Tipton-Haynes site, multiple methods were used …

Stratigraphic Variations In The Carboniferous Section Across The Arkansas-Oklahoma State Line Arch, Tyler Dean Engelhardt

Graduate Theses and Dissertations

The State Line Arch is represented by a structural high that trends through the study area in a loose alignment with the Arkansas-Oklahoma state line. Evidence of the arch extending further to the north includes a structural high and stratigraphic variation at an outcrop on Highway 59 near Evansville Mountain in Crawford County, Arkansas. The exact timing of the formation of the arch remains undetermined, but upper Devonian thinning at the top of the arch indicates the structure is pre-Mississippian. The reason for the development of the arch is poorly understood, but evidence linking Mississippian-aged Waulsortian mounds to Precambrian Spavinaw …

Glacial Shortcut Of Arctic Sea-Ice Transport, Michael Stärz, Xun Gong, Rüdiger Stein, Dennis A. Darby, Frank Kauker, Gerrit Lohmann

OES Faculty Publications

Due to the lack of data, the extent, thickness and drift patterns of sea ice and icebergs in the glacial Arctic remains poorly constrained. Earlier studies are contradictory proposing either a cessation of the marine cryosphere or an ice drift system operating like present-day. Here we examine the marine Arctic cryosphere during the Last Glacial Maximum (LGM) using a high-resolution, regional ocean-sea ice model. Whereas modern sea ice in the western Arctic Basin can circulate in the Beaufort Gyre for decades, our model studies present an extreme shortcut of glacial ice drift. In more detail, our results show a clockwise …

Azimuthal Seismic First-Arrival Tomography As A Proxy For Hydraulically Conductive Subsurface Fracture Networks, Matthew Brooks Edmunds

Masters Theses

The Oak Ridge Field Research Center (ORFRC) was established by the Environmental Sciences Division (ESD) at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, TN, in order to study the various biogeochemical processes involved in the remediation as well as natural attenuation of a large contaminant plume that is extant in the vicinity of the ORIFRC. A part of this work has been to characterize the movement of this groundwater/contaminant plume with the use of azimuthal seismic first-arrival tomography (ASFT).

Within the general area of the ORIFRC, a 0-2 m layer of generally isotropic anthropogenic fill and unconsolidated soil …

Strategies For Visco-Acoustic Waveform Inversion In The Laplace-Fourier Domain, With Application To The Nankai Subduction Zone, Rie Kamei

Electronic Thesis and Dissertation Repository

Waveform inversion is a non-linear and ill-posed inverse problem, with the objective of utilizing the full information content of recorded seismic waveforms. A Laplace-Fourier domain implementation allows a natural `multiscale' approach that mitigates the non-linearity and ill-posedness by inverting low-frequency, early arrival data in the initial stages of inversion. High-frequency components, and late arrivals are incorporated at a later stage. This allows the development of robust inversion strategies capable of handling large wide-angle crustal surveys, leading to reliable, high-resolution velocity and attenuation models of crustal structures. I apply waveform inversion to extract a P-wave velocity model of the active megasplay …

Variability Of Pennsylvanian-Permian Carbonate Associations And Implications For Nw Pangea Palaeogeography, East-Central British Columbia, Canada, K. D. Zubin-Stathopoulos, B. Beauchamp, V. I. Davydov, C. M. Henderson

Geosciences Faculty Publications and Presentations

Different stages of Pennsylvanian-Permian carbonate sedimentation in east-central British Columbia record a complex history of changing environments influenced by evolving palaeogeography and climate. Newly recognized tectonically controlled features affected the distribution and variability of carbonate associations, providing new interpretations for this portion of the west coast of Pangea. Both a heterozoan (cool water) and photozoan (warm-water) association were identified on either side of a palaeogeographic high here informally termed “Tipinahokan Peninsula”. Cool water carbonates were located outboard, or to the west of this high, an area influenced by upwelling waters. Inboard of this high, a warm, protected sea developed, here …

A Modified Delay-Time Method For Statics Estimation With The Virtual Refraction, T. Dylan Mikesell, Kasper Van Wijk, Elmer Ruigrok, Andrew Lamb, Thomas E. Blum

CGISS Publications and Presentations

Topography and near-surface heterogeneities lead to traveltime perturbations in surface land-seismic experiments. Usually, these perturbations are estimated and removed prior to further processing of the data. A common technique to estimate these perturbations is the delay-time method. We have developed the “modified delay-time method,” wherein we isolate the arrival times of the virtual refraction and estimate receiver-side delay times. The virtual refraction is a spurious arrival found in wavefields estimated by seismic interferometry. The new method removes the source term from the delay-time equation, is more robust in the presence of noise, and extends the lateral aperture compared to the …

Nearest Neighbor Methods Applied To Dune Field Organization: The Coral Pink Sand Dunes, Kane County, Utah, Usa, David Wilkins, Richard Ford

David E. Wilkins

Dune fields have recently come to be recognized as self-organizing systems that can be seen progressing from states of disorganization or randomness to uniformity. Dune systems can be highly sensitive to changes in factors, such as climate and sediment transport, that determine system state. Changes in climate and sediment state can take time to work their way through a dune system; this, in turn, leads to spatial heterogeneity in dune field organization. Using the Coral Pink Sand Dunes in southern Utah as a model, this study tests nearest neighbor analysis adapted as a method to objectively identify and characterize differences …

Palaeolake Shoreline Sequencing Using Ground Penetrating Radar: Lake Alvord, Oregon, And Nevada, David Wilkins, William Clement

David E. Wilkins

Field, map, and aerial photoreconnaissance in the Lake Alvord basin has focused on identifying late Pleistocene depositional shoreline features (e.g., tombolos, spits, barriers). Features in different areas of the basin are well defined, and their spatial extents are easily mapped; however, absolute---or even relative-ages of shoreline features are not clear. Ground penetrating radar (GPR) was used to distinguish between intermediate and highstand stage shorelines during what is thought to have been the latest Pleistocene, threshold-controlled lake cycle. Radar transects of 280 and 600 m imaged a spit and a baymouth barrier at sites in the northeastern quadrant of the basin …

Technique Design To Increase In-Situ Electrical Connections In A Cubic Anvil Press, Marie April Burford

Electronic Thesis and Dissertation Repository

An experimental technique designed to increase in-situ electrical connections in a cubic anvil press has been developed. Two encompassing cell designs (extruded gasket and pre-formed gasket) were tested with several electrical barrier methods: PVD coatings, G-10/FR-4 and Canvas Electrical (C. E.) phenolic, Teflon and Al ceramic tubing.

Many variations of techniques were attempted and each (n)^th attempt was founded on the experience from/observation of the results obtained with the (n-1)^thtechnique variation. Eighteen pressure cell configurations were designed and tested. The cells with self-extruded gaskets were unsuccessful due to the destructive nature of the extruding gaskets on the …

Extension Of The Spatial Autocorrelation (Spac) Method To Mixed-Component Correlations Of Surface Waves, Matthew M. Haney, T. Dylan Mikesell, Kasper Van Wijk, Hisashi Nakahara

CGISS Publications and Presentations

Using ambient seismic noise for imaging subsurface structure dates back to the development of the spatial autocorrelation (SPAC) method in the 1950s. We present a theoretical analysis of the SPAC method for multicomponent recordings of surface waves to determine the complete 3 × 3 matrix of correlations between all pairs of three-component motions, called the correlation matrix. In the case of isotropic incidence, when either Rayleigh or Love waves arrive from all directions with equal power, the only non-zero off-diagonal terms in the matrix are the vertical–radial (ZR) and radial–vertical (RZ) correlations in the presence of Rayleigh waves. Such combinations …

Geogram 2012, David J. Keeling, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

Northern Thailand Geothermal Resources And Development: A Review And 2012 Update, Fongsaward Suvagondha Singharajwarapan, Spencer H. Wood, Natthaporn Prommakorn, Lara Owens

Spencer H. Wood

Northern Thailand has 16 hot spring systems with surface temperatures near or greater than 80°C with potential for binary plant power generation. Presently only Fang system generates power from wells flowing a total of 8.3 1/s of 116°C water to a 300 kW single module Ormat binary plant. Current production is 150-250 KW, which potentially can be increased by constructing new wells and increasing flow by pumping. Of the other 15 systems, 4 are in national parks and not considered for development. Several of the hot springs systems have silica geothermometry >130°C suggesting significant undeveloped resources exist in northern Thailand. …

Northern Thailand Geothermal Resources And Development: A Review And 2012 Update, Fongsaward Suvagondha Singharajwarapan, Spencer H. Wood, Natthaporn Prommakorn, Lara Owens

Geosciences Faculty Publications and Presentations

Northern Thailand has 16 hot spring systems with surface temperatures near or greater than 80°C with potential for binary plant power generation. Presently only Fang system generates power from wells flowing a total of 8.3 1/s of 116°C water to a 300 kW single module Ormat binary plant. Current production is 150-250 KW, which potentially can be increased by constructing new wells and increasing flow by pumping. Of the other 15 systems, 4 are in national parks and not considered for development. Several of the hot springs systems have silica geothermometry >130°C suggesting significant undeveloped resources exist in northern Thailand. …

Collaborative Research: Dynamics At The Base Of A Pseudotachylyte-Bearing Fault System, Scott E. Johnson, Peter O. Koons

University of Maine Office of Research Administration: Grant Reports

A concerted effort through EarthScope is currently underway to better understand seismicity along the San Andreas Fault, which poses serious threats to society from large-magnitude earthquakes. The San Andreas Fault Observatory at Depth features an instrumented drill hole, allowing characterization of the rocks, fluids, kinematics, and stress orientations and magnitudes within the fault zone to depths of approximately 3 km. These studies are designed partly to investigate the strength of the San Andreas Fault, which is critical for seismic forecasting. In conjunction with these studies it is important that we locate and study appropriate exhumed examples of similar faults at …

Probing Local Wind And Temperature Structure Using Infrasound From Volcan Villarrica (Chile), Jeffrey B. Johnson, J. Anderson, O. Marcillo, S. Arrowsmith

Geosciences Faculty Publications and Presentations

We use the continuous and intense (∼10⁷ W) infrasound produced by Volcan Villarrica (Chile) to invert for the local dynamic wind and temperature structure of the atmosphere. Infrasound arrays deployed in March 2011 at the summit (2826 m) and on the NNW flank (∼8 km distant at 825 m) were used to track infrasound propagation times and signal power. We model an atmosphere with vertically varying temperature and horizontal winds and use propagation times (ranging from 23 to 24 s) to invert for horizontal slowness (2.75–2.94 s/km) and average effective sound speeds (328–346 m/s) for NNW propagating infrasound. The …

An Investigation Into Earthquake Ground Motion Characteristics In Japan With Emphasis On The 2011 M9.0 Tohoku Earthquake, Hadi Ghofrani

Electronic Thesis and Dissertation Repository

In this integrated study, ground-motion characteristics of one of the most devastating earthquakes in history, the 11^th March 2011 Tohoku-oki earthquake (moment magnitude (M) 9.0), are investigated. The investigation centers on developing empirical and simulated-based ground-motion prediction models for this earthquake. These models allow prediction of expected ground motions from large interface (mega-thrust) earthquakes and estimation of their variability due to variability in input parameters, specifically source characteristics (e.g. slip distributions), propagation path, and site effects.

This research work can be divided into two main parts. In the first part, the influence of regional geologic structure, in …

Hydrologic Data Assimilation With A Hillslope-Scale-Resolving Model And L Band Radar Observations: Synthetic Experiments With The Ensemble Kalman Filter, Alejandro N. Flores, Rafael L. Bras, Dara Entekhabi

Geosciences Faculty Publications and Presentations

Soil moisture information is critical for applications like landslide susceptibility analysis and military trafficability assessment. Existing technologies cannot observe soil moisture at spatial scales of hillslopes (e.g., 10⁰ to 10² m) and over large areas (e.g., 10² to 10⁵ km²) with sufficiently high temporal coverage (e.g., days). Physics-based hydrologic models can simulate soil moisture at the necessary spatial and temporal scales, albeit with error. We develop and test a data assimilation framework based on the ensemble Kalman filter for constraining uncertain simulated high-resolution soil moisture fields to anticipated remote sensing products, specifically NASA's Soil …

Interseismic Strain Accumulation Along The Western Boundary Of The Indian Subcontinent, Walter Szeliga, Roger Bilham, Din Mohammad Kakar, Sarosh H. Lodi

All Faculty Scholarship for the College of the Sciences

Despite an overall sinistral slip rate of ≈3 cm/yr, few major earthquakes have occurred in the past 200 years along the Chaman fault system, the western boundary of the India Plate with the Eurasia Plate. GPS and InSAR data reported here indicate sinistral shear velocities of 8–17 mm/yr across the westernmost branches of the fault system, suggesting that a significant fraction of the plate boundary slip is distributed in the fold and fault belt to the east. At its southernmost on‐land segment (≈26°N), near the triple junction between the Arabia, Eurasia, and India Plates, we find the velocity across the …

Exploration Of Charge Carriers In Obsidian, Ryan Nordvik, Friedemann Freund

STAR Program Research Presentations

This research effort is part of an ongoing investigation into stress-activated positive hole charge carriers in common igneous and high-grade metamorphic rocks. The findings have already revealed potential early earthquake detection mechanisms and caused a re-think on the processes that could conceivably contribute to the formation of and evolution of life. Positive holes are defect electrons in the oxygen anion sub-lattice of silicate minerals that have demonstrated some intriguing capabilities: flowing out of a stressed rock volume; causing oxidation reactions at the rock-water interface and ionization at the rock-air interface; and traveling great distances. This research seeks to determine if …

Statistical Clustering Of Microseismic Event Spectra To Identify Subsurface Structure, Deborah Kay Fagan

Boise State University Theses and Dissertations

Understanding subsurface structure by studying microseismicity influences a wide range of activities, including energy extraction, aquifer storage, carbon sequestration, and seismic hazard assessment. Identifying individual fractures in a larger fault system is key to characterizing, understanding, and potentially mitigating risks of natural or induced seismicity.

A year-long study associated with a carbon dioxide (CO₂) sequestration project was conducted at the Aneth oil field in southeast Utah to record microseismicity at a single downhole geophone array. A previous analysis located events by first identifying event multiplets consisting of highly correlated time-domain waveforms on receivers shallower than the depth of …

Monitoring Co2 Sequestration In Basalt With Elastic Waves, Larry Thomas Otheim

Boise State University Theses and Dissertations

The continued burning of fossil fuels as a source of energy is contributing to greater concentrations of carbon dioxide (CO₂) in the atmosphere. Increased levels of CO₂ in the atmosphere have been linked to an increase of global mean surface temperature. To mitigate the continued release of CO₂, projects to capture this gas at large point sources and sequester it in geologic formations are in place. Carbon dioxide sequestration in basalts promises permanent trapping of the fluid as these rocks react with carbonic acid and precipitate carbonate minerals. It is important to monitor the injection …

Evaluation Of Use Of Em38-Mk2 As A Tool To Understand Field Scale Changes In Soil Properties, Sudershan Gangrade

All Theses

Sustainable water resources management requires tools to help farmers identify variations in soil hydraulic characteristics so that precision irrigation schemes can be developed to optimize water use. In this study we use electromagnetic induction (EMI) to evaluate whether changes in the apparent electrical conductivity (σ_a) of agricultural fields can be related to hydrologic processes. Field work for this study was completed at three different sites - 1) in different agricultural fields located in a watershed near Salri, Madhya Pradesh, India, 2) over an agricultural field located near Clemson University, SC, and 3) at a flood plain wetland restoration site near …

Characterization Of Wetting Front Geometry And Fluid Migration In The Vadose Zone Using Surface Time-Lapse Seismic First-Arrival Tomography, Rachel Elizabeth Storniolo

Masters Theses

Characterizing and quantifying vadose zone parameters and processes are critical for assessing environmental, agricultural, and engineering problems. The shallow subsurface is essential to the geologic and hydrologic cycles because it supports agriculture and ecosystems, influences water resources, and acts as a repository for contaminants. Fluid migration in the vadose zone is dependent on a number of soil characteristics (e.g. soil type and saturation). Quantifying parameters is often the primary goal of hydrological fluid-flow investigations; however, the values calculated can be misrepresentative of the subsurface due to anisotropic features. Hydraulic conductivity (K), the most common quantitative parameter used to describe fluid …

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 …

Determining The Motion And Location Of The Frenchman Mountain Fault, Las Vegas, Nevada: A Paired Basin Analysis And Structural Analysis, Laura Margaret Eaton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding the evolution of large-scale fault systems remains a challenge to geologists and is of critical importance in understanding the dynamics of larger plate tectonic interactions. I mapped the southwestern Frenchman Mountain Fault (FMF), conducted a basin analysis of units in the footwall of the fault, and measured kinematic indicators along the fault zone in order to constrain fault offset, magnitude, and timing in an attempt to further our understanding of these systems.

My findings include: 1) the presence of vertical and sub-vertical slickenlines on southwest dipping fault surfaces indicative of normal sense offset; 2) relatively little lateral variation in …

Paleoseismic Study Of The Stewart Valley And Northern Pahrump Segments Of The Stateline Fault System, Nevada, Jonathan Carter

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Stateline fault system (SFS) is a ~200 km long zone of dextral faults running NW along the NV/CA border from Primm, Nevada to Amargosa Valley in the western Central Basin and Range province (CBR). Because of size and proximity, the SFS poses a hazard to the 2.5 million people, most of who live within 10 km, in Pahrump, Nevada and within 40 km, in Las Vegas, Nevada. The goals of this thesis are to (1) understand if the SFS is accommodating faulting slip change in the CBR; (2) test the along strike continuity of the SFS in Pahrump and …