Geophysics and Seismology Commons^™

Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke

Department of Earth, Environment and Sustainability Faculty Publications

Located in central Elko County, the Welcome and adjacent part of the Wells quadrangles expose a remarkable array of critical relationships for understanding the geologic history of the State of Nevada and the interior of the southwestern U.S. Cordillera. Covering the northern end of the East Humboldt Range and adjacent Clover Valley and Clover Hill, this map includes the northern terminus of the Ruby Mountains-East Humboldt Range metamorphic core complex. The oldest rocks in the State of Nevada (the gneiss complex of Angel Lake), and Nevada’s only exposures of Archean rock, form the core of a multikilometer scale, southward-closing recumbent …

Theoretical Foundation Of Cyclostationary Eof Analysis For Geophysical And Climatic Variables: Concepts And Examples, Kwang-Yul Kim, Benjamin Hamlington, Hanna Na

CCPO Publications

Natural variability is an essential component of observations of all geophysical and climate variables. In principal component analysis (PCA), also called empirical orthogonal function (EOF) analysis, a set of orthogonal eigenfunctions is found from a spatial covariance function. These empirical basis functions often lend useful insights into physical processes in the data and serve as a useful tool for developing statistical methods. The underlying assumption in PCA is the stationarity of the data analyzed; that is, the covariance function does not depend on the origin of time. The stationarity assumption is often not justifiable for geophysical and climate variables even …

Pressure-Temperature-Time Constraints For Exhumation Of Ultrahigh-Pressure Metamorphic Rocks, North Qaidam Terrane, Western China, Brittany Kristine Fagin

All Master's Theses

Ultrahigh-pressure rocks of a Paleozoic continental suture zone are exposed in the southeastern North Qaidam terrane (Dulan region). Garnetite sample D119 contains minor Czo+Qtz+Chl+Ttn; rutile inclusions in titanite suggest that titanite replaced rutile during decompression. Pressure-temperature estimates of sample D119 are 16.1-18.4 kbar and 485-520 °C. Sample D130B is a mafic band in calc-silicate gneiss, with garnet porphyroblasts in a fine-grained Hbl-Cpx-Pl-Qtz symplectite that is interpreted as former omphacite. D130B symplectite pressure-temperature estimates are 7.7-9.4 kbar and 623-708 °C. Titanite U-Pb ages of 419.7±3.1 Ma and 415.9±4.2 Ma are interpreted to date retrogression of D119 and D130B, respectively. Average exhumation …

Palynological Interpretations Of Deep Sea Drilling Projects Cores In The Gulf Of Mexico And Bahamian Platform, Adam Patrick Barron

Masters Theses

"One hundred drill core samples were from Deep Sea Drilling Project (DSDP) Sites 94, 98, and 540 were investigated for their palynological contents (pollen, spores, acritarchs, dinoflagellate cysts, and dispersed organic matter) to infer the paleoenvironmental and paleoceanographic history of the Gulf of Mexico and the Bahamian Platform during the middle Eocene to middle Miocene interval. At Sites 94 and 540, abundant dinoflagellate cysts (chiefly Operculodinium centrocarpum, Lingulodinium machaerophorum, Impagidinium sp., Nematosphaeropsis sp., and Spiniferites spp.) were used as paleoenvironmental indicators. Two alternating palynofacies assemblages were identified from dispersed organic matter analysis: terrestrially influenced assemblage A and marine dominated assemblage …

Fault Interpretation And Reservoir Characterization Of The Farewell Formation Within Kerry Field, Taranaki Basin, New Zealand, Waleed Deefallah M Alotaby

Masters Theses

"The Kerry Field, located in the southern offshore Taranaki Basin, is a large liquid-rich gas accumulation with a thin (20 m) oil rim. The field was discovered by the New Zealand Oil & Gas in 1986 (well Kupe South-1). The gas and oil are trapped within a 9.2 km² fault-dependent three-way dip closure in the Paleocene Farewell Formation reservoir. Pressure, volume, and temperature (PVT) data indicate that the gas and oil columns in the field are in equilibrium with one another and are saturated at current reservoir conditions.

The Farewell Formation is the uppermost formation of the Kapuni Group …

Seismic Structural Investigation And Reservoir Characterization Of The Moki Formation In Maar Field, Taranaki Basin, New Zealand, Mohammed Dhaifallah M Alotaibi

Masters Theses

"The Maari Field is a large oil field located in the southern part of the Taranaki Basin, New Zealand. The field is bounded by two major structures, the Eastern Mobile Belt and Western Stable Platform. The Maari Field produces 40,000 BOPD (Barrels of Oil per Day) from five wells from reservoirs in the Moki Formation. The Miocene Moki Formation was deposited as part of the Wai-iti Group and consists of sandstone interbedded with siltstone and claystone. The sandstone of the Moki Formation is characterized by a submarine fan. It is distributed along the southern and central Taranaki shelf. Three-dimensional seismic …

A Geochemical Investigation Of Co₂ Sequestration And Site Characterization At Two Missouri Locations, Robert Allen Swain

Masters Theses

"The feasibility of sequestering CO₂ in saline aquifers of Lamotte Formation sandstone was investigated at wells located near Thomas Hill power plant, Moberly, MO and Sioux City Power Plant in Florissant, MO. Governing factors of using aquifers for CO₂ disposal include water salinity, potential for carbonic acid buffering, rate of precipitation of carbonate minerals following CO₂ introduction into the host aquifer, and the integrity of the Davis and Derby-DoeRun shale as a trap rock to prevent migration of the CO₂ phase and carbonic acid into the overlying potable Ozark Aquifer.

Both in situ and laboratory methods …

Development Of 3-D Shear Wave Models Using A Multi-Objective Optimization Scheme, Lennox Emmanuel Thompson

Open Access Theses & Dissertations

Evidence of geologic activity still occurring in Rio Grande Rift (RGR) includes quaternary faulting, seismicity, and widening at a small rate. We map the crustal thickness and seismic velocity ratio to create crustal model cross sections that highlights the regional extension of the Southern Rio Grande Rift (SRGR). Specifically, we compute receiver functions and receiver function stacks for 147 USArray and previously collected data, and interpolate the crustal and velocity results using a kriging interpolation scheme. By incorporating gravity, magnetics, receiver functions, velocity models, and the interpretation of seismic reflection/refraction data, we produce a constrained crustal model that characterizes the …

Optimization Schemes For The Inversion Of Bouguer Gravity Anomalies, Azucena Zamora

Open Access Theses & Dissertations

Data sets obtained from measurable physical properties of the Earth structure have helped advance the understanding of its tectonic and structural processes and constitute key elements for resource prospecting. 2-Dimensional (2-D) and 3-D models obtained from the inversion of geophysical data sets are widely used to represent the structural composition of the Earth based on physical properties such as density, seismic wave velocities, magnetic susceptibility, conductivity, and resistivity. The inversion of each one of these data sets provides structural models whose consistency depends on the data collection process, methodology, and overall assumptions made in their individual mathematical processes. Although sampling …

Dynamic Triggering In The Coso Geothermal Field, 2004-2013, Richard A. Alfaro-Diaz

Open Access Theses & Dissertations

We take advantage of EarthScope’s USArray Transportable Array (TA), regional seismic networks to investigate 154 M ≥ 7 earthquakes over a ten-year period (2004- 2013), in search of remotely triggered seismicity within the continental United States. We conduct an automated search to detect high frequency signals (which may indicate triggering of small local earthquakes) using a time window of 5 hours before and after each mainshock. The automated detection applies a short-term average (STA) to long-term-average (LTA) algorithms, to create a catalogue of detections. Using the catalog we search for an increase in detection rates after each main-shock. Sharp increases …

Lithospheric Structure And Stress Field Orientations In The Northern Libya And East-Central Mediterranean Region, Abdusalam Ali Agail

Open Access Theses & Dissertations

This thesis is a combination of three studies including tomography using surface wave group velocities, stress orientations from focal mechanisms, and receiver functions. The study area covers northern Libya and the east central Mediterranean region. I utilized new data from the Libyan National Seismic Network to better understand the crustal thickness and stress orientation of northern Libya as well as the east central Mediterranean region. In the first study, I conducted surface wave group velocity tomography implementing the Gaussian beam method for obtaining 2-D velocity variations assuming an isotropic model. I constructed surface wave group velocity maps over a range …

Crustal Structure Beneath The Eastern Nepal Himalayas And Southern Tibet From Receiver Function Analysis, Arjun Sharma Neupane

Open Access Theses & Dissertations

The Himalayas are the results of continental collision between the Indian plate and the Eurasian plate and serve as a natural site to study the physical causes and process of mountain building. The crustal structure beneath the Himalayas has been subject to numerous geophysical studies and the variation in the velocity structure across the Himalayan region suggests significant differences in the crustal structure between the southern and northern portion in that region. In this research, a P receiver function analysis has been conducted on data collected for 14 years (2000-2014) from 211 different stations in Eastern Nepal and Southern Tibet, …

Receiver Function Analysis To Study Crustal Structure Of The Northern Nepal And Tibetan Plateau, Mohan Pant

Open Access Theses & Dissertations

The teleseismic P-waveform receiver function analysis is a commonly used technique in earthquake seismology to study the crustal structure beneath a broadband seismic station. To understand the structure of the Northern Nepal and Tibetan plateau different studies have used the receiver function method to estimate the Moho depth and Vp/Vs ratio. The value suggested was ~ 30 km in the south and the ~ 75 km in the north. Other studies have used teleseismic body wave data to perform the travel time residuals to model the lithosphere structure. In our study, we analyzed data from 261 seismic stations to establish …

A Tectonic Analysis On The Central Region Of The Himalaya Collision Zone Using Double Difference Tomography, Chanel Perez

Open Access Theses & Dissertations

The Himalaya mountain range remains the only place on Earth undergoing continuous effects from the continental-continental collision between India and Asia. Because of this, the Himalayas have been subjected to extensive deformation and transpression, and contain five major shear zones. Extensive seismic analysis of the region, however, is lacking due to sparse seismograph coverage and complexity of the crustal structure. I examined seismic event data from two temporary seismic networks deployed in the central Himalaya, the HIMNT deployment from 2001-2003, and the Bhutan deployment from 2002-2003. Using this data I develop a 3-D earth model for the region using double-difference …

Geophysical Explorations On And Near The Ismenion Hill, Thebes, Greece, 2011, Robert W. Jacob, Stephanie Larson, Kevin Daly, Emily Bitely

Faculty Journal Articles

Το άρθρο αυτό παρουσιάζει τις πρώτες κοινές έρευνες στη Θήβα, στην περιοχή του ναού του Απόλλωνος Ισμηνίου, που κρίθηκαν επιβεβλημένες, πριν από την υποβολή μιας ολοκληρωμένης και τεκμηριωμένης πρότασης Συνεργασίας, για τη διενέργεια εργασιών πεδίου και πιό συγκεκριμένα ανασκαφών. Οι έρευνες αυτές έλαβαν χώρα το καλοκαίρι του 2011, μετά από ευγενική πρόσκληση του Διευθυντή τότε ένατης Εφορείας, Καθηγητή κυρίου Βασίλειου Αραβαντινού, που χρονολογείται το 2010. Σκοπός μας ήταν ωα αναλάβουμε μαζί την προσπάυεια διερεύνησης τοπογραφικών και αρχαιολογικών ζητημάτων, σχετικών με την παλαιά ανασκαφή του Ισμηνίου και τη νεώτερη του Ηρακλείου των Θηβών.

Characterization Of Seismicity At Volcán Barú, Panama: May 2013 Through April 2014, Chet J. Hopp

Dissertations, Master's Theses and Master's Reports - Open

Volcán Barú, in the western province of Chiriquí, is Panama's youngest and most active volcano. Although Barú has experienced no historic eruptions there have been four eruptive episodes in the last 1600 years, the most recent occurring 400-500 years ago (Sherrod et al., 2007). In addition, there have been four reported earthquake swarms in the last 100 years. The most recent swarm occurred in May of 2006, prompting a USGS hazard assessment (Sherrod et al., 2007). In order to characterize local seismicity and provide a reference for future monitoring efforts, we established a seismic network that operated from May 2013 …

Mineral And Geochemical Attributes Of The Midcontinent Rift Sequence; An Application For Deep Carbon Dioxide Sequestration, Alsedik Mohamed Ali Abousif

Doctoral Dissertations

"The potential for using the Oronto Group of the Midcontinent Rift (MCR) Sequence for CO₂ sequestration has been disparaged because of low porosity-permeability characteristics, which are largely a result of extensive calcite cementation. This study investigated the potential for using the MCR as a target for CO₂ sequestration by examining reactions involving detrital host-rock minerals at high pressure-temperature conditions that could provide dissolved Ca²⁺, Mg²⁺, and Fe²⁺, and then precipitating these cations as carbonate minerals. The effect of carbonic acid on cement dissolution was also evaluated with respect to enhancing porosity and …

Shear Wave Splitting Analysis Beneath Tien Shan: Geodynamic Implications Of Complex Anisotropy, Solomon Gerra Cherie

Doctoral Dissertations

"In spite of numerous studies, the mechanisms for the crustal shortening, mountain formation and associated tectonism leading to complex or simply seismic anisotropy formation beneath the Tien Shan Orogenic Belt is still debated. The most popular hypotheses suggested for the existence of seismic anisotropy are small-scale mantle convection, regional scale resistive basal shear and APM induced asthenospheric flow. Here, we used shear-wave splitting (SWS) measurements with good azimuthal coverage to provide additional constraints on the various models proposed by previous studies. One of the most effective approaches utilized to constrain convective mantle flow patterns is the splitting of P-to-S converted …

Origin And Stratigraphic Architecture Of The Middle Permian Lower And Upper Quanzijie Low-Order Cycles, Bogda Mountains, Nw China, Jonathan Obrist-Farner

Doctoral Dissertations

"This study is carried out in the Bogda Mountains, NW China, and aims to provide a detailed sedimentary, stratigraphic, environmental, and paleoclimatic reconstruction in the paleo-mid-latitude along the east coast of Pangea. The Middle Permian lower and upper Quanzijie low-order cycles (QZJ LCs) provide a nearly complete sedimentary record in an area were little is known. In the first part of this work, the previously-established QZJ LC is divided into two LCs on the basis of regional stratigraphic correlation and major changes in depositional environments and tectonic and climatic processes. The newly-established lower QZJ LC is mainly composed of meandering …

Seismological Investigation Of The Okavango Rift, Botswana, Youqiang Yu

Doctoral Dissertations

The mechanisms of rifting have been intensively investigated using geological and geophysical techniques beneath mature rift zones. However, current understanding on the earliest stages of rifting is seriously limited. Here we employ recently archived data from 17 broadband seismic stations traversing northern Botswana to conduct the first shear wave splitting and mantle transition zone (MTZ) studies within the Okavango Rift Zone (ORZ). The ORZ is an incipient continental rift situated at the terminal of the southwestern branch of the East African Rift System. The resulting normal MTZ thickness and consistently rift-parallel fast polarizations imply an absence of significant thermal anomalies …

Ground-Coupled Air Waves: A Seismological Case Study Of The Explosion Quakes Of The 2007 Eruption Of Pavlof Volcano, Alaska, Cassandra Marie Smith

USF Tampa Graduate Theses and Dissertations

An abnormally high number of explosion quakes were noted during the monitoring effort for the 2007 eruption of Pavlof Volcano on the Alaskan Peninsula. In this study we manually counted the explosion quakes from their characteristic ground-coupled air waves. This study makes an effort at better quantifying the number of explosion quakes and how the characteristic ground-coupled air waves are affected by wind direction and wind speed. Additionally this study investigates how the ground coupled air waves might be used in a monitoring or analysis effort by calculating energy release and gas mass release. Over 3.2x10⁴ quakes were recorded. …

Glaciological Applications Of Terrestrial Radar Interferometry, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

Terrestrial Radar Interferometry (TRI) is a relatively new ground-based technique that combines the precision and spatial resolution of satellite interferometry with the temporal resolution of GPS. Although TRI has been applied to a variety of fields including bridge and landslide monitoring, it is ideal for studies of the highly-dynamic terminal zones of marine-terminating glaciers, some of which are known to have variable velocities related to calving and/or ocean-forced melting. My TRI instrument is the Gamma Portable Radar Interferometer, which operates at 17.2 GHz (1.74 cm wavelength), has two receiving antennas for DEM (digital elevation model) generation, and images the scenes …

Deterministic And Stochastic Inversion Techniques Used To Predict Porosity: A Case Study From F3-Block, Hao Wu

Dissertations, Master's Theses and Master's Reports

Within large-scale sigmoidal bedding of the F3-block in the shallow zone there appear to be some indicators of hydrocarbon deposits. In order to characterize target zone in the sigmoidal bedding, I combine the analysis of inverted results of post-stack seismic data with rock-physics relationships developed from well log data to predict the porosity, which ranges from 20% to 33%, for different system tracts in this area. The methods used in this study include conventional deterministic inversion and novel stochastic inversion. Through a rock physics analysis of the density, velocity and gamma-ray logs in two wells, I constructed relationships between the …

Mapping Thunder Sources By Inverting Acoustic And Electromagnetic Observations, J. F. Anderson, J. B. Johnson, R. O. Arechiga, R. J. Thomas

Geosciences Faculty Publications and Presentations

We present a new method of locating current flow in lightning strikes by inversion of thunder recordings constrained by Lightning Mapping Array observations. First, radio frequency (RF) pulses are connected to reconstruct conductive channels created by leaders. Then, acoustic signals that would be produced by current flow through each channel are forward modeled. The recorded thunder is considered to consist of a weighted superposition of these acoustic signals. We calculate the posterior distribution of acoustic source energy for each channel with a Markov Chain Monte Carlo inversion that fits power envelopes of modeled and recorded thunder; these results show which …

Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez

Geology Faculty Publications and Presentations

The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr–Coulomb failure stress were probably too small to …

Urban Seismology For Groundwater Characterization In A Developing Country: Challenges And Rewards, John H. Bradford, Kyle Lindsay, Steve Silliman, Nicaise Yalo, Moussa Boukari

Geosciences Faculty Publications and Presentations

The coastal city of Cotonou in the developing country of Bénin, West Africa, is a large population center that is facing a serious threat to the sustainability of its freshwater supply. The city relies on the Godomey aquifer for domestic water, but the aquifer is undergoing saltwater intrusion. This problem is likely to worsen without significant steps to improve management of the water supply. Aquifer continuity and saltwater flow paths are poorly understood, but that information is critical to ensure sustainable access to freshwater in this growing urban center. In January 2012, a two-year geophysical investigation was begun with the …

Quantifying The Basal Conditions Of A Mountain Glacier Using A Targeted Full-Waveform Inversion: Bench Glacier, Alaska, Usa, E. Babcock, J. Bradford

Geosciences Faculty Publications and Presentations

Glacier dynamics are inextricably linked to the basal conditions of glaciers. Seismic reflection methods can image the glacier bed under certain conditions. However, where a seismically thin layer of material is present at the bed, traditional analyses may fail to fully characterize bed properties. We use a targeted full-waveform inversion algorithm to quantify the basal-layer parameters of a mountain glacier: thickness (d), P-wave velocity (α) and density (ρ). We simultaneously invert for the seismic quality factor (Q) of the bulk glacier ice. The inversion seeks to minimize the difference between the data …

Seeing Below The Surface With Electrical Resistivity Tomography: Exploring The Deepest Reaches Of Arkansas' Tallest Prehistoric Mounds, James Robert Zimmer-Dauphinee

Graduate Theses and Dissertations

Despite decades of research and over a century of public interest, the most prominent features at Toltec Mounds Archeological State Park, Mound A and Mound B, remain virtually unexamined by modern archaeological techniques, and poorly understood. The tremendous scale and importance of these mounds makes most standard research methods difficult if not impossible. Electrical Resistivity Tomography, a geophysical technique rarely used in North America, was employed to survey both Mound A and Mound B, resulting in models of the subsurface that provide insights into the construction, modification and condition of the mounds.

Development And Application Of Tools For Avalanche Forecasting, Avalanche Detection, And Snowpack Characterization, Scott Christopher Havens

Boise State University Theses and Dissertations

Avalanche formation is a complex interaction between the snowpack, weather, and terrain. However, detailed observations typically can only be made at a single point and must be extrapolated over the slope or regional scale. This study aims to provide avalanche forecasters with tools to evaluate the snowpack, avalanche hazard, and avalanche occurrence when manual observations are not feasible.

Avalanches that occur within the new storm snow are a prevalent problem for the avalanche forecasters with the Idaho Transportation Department (ITD) along Highway 21. We have implemented a real time SNOw Slope Stability (SNOSS) model that provides an index to the …

Refraction Microtremor Analysis Of Areas Surrounding California State University San Bernardino, Malcolm D. Thomas

Electronic Theses, Projects, and Dissertations

The San Andreas Fault stretches for over 800 miles through California. Along the foothills of the San Bernardino Mountains, areas in close proximity to the San Andreas Fault Zone may be subject to site amplification of ground motion caused by seismic activity via wave propagation through the subsurface. These seismic hazards are being addressed via the Alquist-Priolo Earthquake Faulting Zone Act and the National Earthquake Hazards Reduction Program (NEHRP). Shear wave velocity of the subsurface has served as a proxy for ground motion amplification and is therefore a useful parameter to help analyze and reduce seismic hazards. Low shear wave …