Earth Sciences Commons^™

Unusual Patterns Of Seismicity During Eruptive And Non-Eruptive Periods At The Persistently Restless Telica Volcano, Nicaragua, Melanie Rodgers

USF Tampa Graduate Theses and Dissertations

Telica Volcano, Nicaragua, is a persistently restless volcano with high rates of seismicity that can vary from less than ten events to over a thousand events per day. Low-frequency (LF) events dominate the seismic catalogue and seismicity rates at Telica show little clear correlation with periods of eruption. As such, traditional methods of forecasting of volcanic activity based on increases in seismicity and recognition of LF activity are not applicable. A single seismic station has been operating at Telica since 1993, and in 2010 we installed a broadband seismic and continuous GPS network (TESAND network) at Telica. In this study …

Appendix C—Deformation Models For Ucerf3, Tom Parsons, Kaj M. Johnson, Peter Bird, Jayne Bormann, Timothy E. Dawson, Edward H. Field, William C. Hammond, Thomas A. Herring, Robert Mccaffrey, Zheng-Kang Shen, Wayne R. Thatcher, Ray J. Weldon Ii, Yuehua Zeng

Geology Faculty Publications and Presentations

This document describes efforts to best characterize seismogenic deformation in and near California. The rate of hazardous earthquakes in California is expected to be proportional to deformation rates; in particular, the rates at which faults slip. Fault slip rates are determined from offsets of geologic and geomorphic features of measured age and by modeling geodetically determined surface displacement rates. Extensive use of geodesy in the form of Global Positioning System (GPS) observations is a new feature brought into the Working Group on California Earthquake Probabilities (WGCEP) forecasts for the Uniform California Earthquake Rupture Forecast, version 3 (UCERF3) model. Geodetic measurements …

Balanced Cross Section Of The Northeast Of Adiyaman, Turkey, Mustafa Tuncer

Masters Theses

"Deformation during closure of an ocean basin and continent-continent collision in southeast Anatolia Turkey during the Late Cretaceous to Middle Miocene was investigated by construction of a geologic map, structural cross-section and retrodeformed palinspastically restored cross-section. The area of study is a N-S transect across the Bitlis Suture Zone of Northeast of Adiyaman. The study area is situated in the southeast Anatolian orogenic belt which includes, from south to north, the Arabian platform, the zone of Imbrication, and the zone of Nappes. A geologic map of this region was prepared in order to construct balanced and restored cross sections from …

Validation Of A 'Displacement Tomography' Inversion Method For Modeling Sheet Intrusions, Sarah J. Menassian

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

The study of volcano deformation data can provide information on magma processes and help assess the potential for future eruptions. In employing inverse deformation modeling on these data, we attempt to characterize the geometry, location and volume/pressure change of a deformation source. Techniques currently used to model sheet intrusions (e.g., dikes and sills) often require significant a priori assumptions about source geometry and can require testing a large number of parameters. Moreover, surface deformations are a non-linear function of the source geometry and location. This requires the use of Monte Carlo inversion techniques which leads to long computation times. Recently, …

A Structural Analysis Of The El Kasr Structure In The Western Desert Of Egypt, Trevor Charles Ellis

Masters Theses

"The El Kasr structure was studied in order to investigate the origins and evolution of the enigmatic Desert Eyes structures of the Western Desert due to its accessibility and uniqueness among the structures. The El Kasr structure, an elongate structural basin with low limb dips, is unique among the "Desert Eyes" structures in that it: 1) occurs in isolation in otherwise horizontal sedimentary rock, 2) the long dimension of the basin is oriented NNW, 3) it is closely spatially associated with the less common NNW fault zones, and 4) is composite in nature. The structure was investigated using remote sensing …

Estimating Variations In Locking Depth For The Mojave Segment Of The San Andreas Fault Over The Past 1500 Years From Paleoseismic Stress Drop, Teira Solis

Open Access Theses & Dissertations

The most fundamental model for characterizing earthquake occurrence [Reid, 1910] assumes a constant stress accumulation rate on a locked fault segment, which eventually fails at a threshold stress level. While this model provides a conceptual framework for investigating the conditions that prepare a fault for failure, there is little evidence that faults rupture periodically or at a uniform threshold stress. Moreover, this model fails to explain the large differences in earthquake recurrence intervals and paleoseismic slip for segments of major fault systems: why do some faults rupture on the order of 10's of years, while others require 100's of years …

Propagation Of Interval And Probabilistic Uncertainty In Cyberinfrastructure-Related Data Processing And Data Fusion, Christian Servin

Open Access Theses & Dissertations

Data uncertainty affects the results of data processing. So, it is necessary to find out how the data uncertainty propagates into the uncertainty of the results of data processing. This problem is especially important when cyberinfrastructure enables us to process large amounts of heterogeneous data. In the ideal world, we should have an accurate description of data uncertainty, and well-justified efficient algorithms to propagate this uncertainty. In practice, we are often not yet in this ideal situation: the description of uncertainty is often only approximate, and the algorithms for uncertainty propagation are often not well-justified and not very computationally efficient. …

Contribution Of The Pacific Decadal Oscillation To Global Mean Sea Level Trends, B. D. Hamlington, R. R. Leben, M. W. Strassburg, R. S. Nerem, K-Y. Kim

CCPO Publications

Understanding and explaining the trend in global mean sea level (GMSL) have important implications for future projections of sea level rise. While measurements from satellite altimetry have provided accurate estimates of GMSL, the modern altimetry record has only now reached 20 years in length, making it difficult to assess the contribution of decadal to multidecadal climate signals to the global trend. Here, we use a sea level reconstruction to study the 20 year trends in sea level since 1950. In particular, we show that the Pacific Decadal Oscillation (PDO) contributes significantly to the 20 year trends in GMSL. We estimate …

Optimized Correlation Of Geophysical And Geotechnical Methods In Sinkhole Investigations: Emphasizing On Spatial Variations In West-Central Florida, Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

Abstract

Sinkholes and sinkhole-related features in West-Central Florida (WCF) are commonly identified using geotechnical investigations such as standard penetration test (SPT) borings and geophysical methods such as ground penetrating radar (GPR) and electrical resistivity tomography (ERT). Geophysical investigation results can be used to locate drilling and field testing sites while geotechnical investigation can be used to ground truth geophysical results. Both methods can yield complementary information. Geotechnical investigations give important information about the type of soil, groundwater level and presence of low-density soils or voids at the test location, while geophysical investigations like GPR surveys have better spatial coverage and …

Deciphering Deposits: Using Ground Penetrating Radar And Numerical Modeling To Characterize The Emplacement Mechanisms And Associated Energetics Of Scoria Cone Eruption And Construction, Leah Michelle Courtland

USF Tampa Graduate Theses and Dissertations

Our understanding of tephra depositional processes is significantly improved by high-resolution ground-penetrating radar (GPR) data collected at Cerro Negro volcano, Nicaragua. The data reveal three depositional regimes: (1) a near-vent region on the cone itself, where 10 GPR radargrams collected on the western flank show quantifiable differences between facies formed from low energy normal Strombolian and higher energy violent Strombolian processes, indicating imaging of scoria cone deposits may be useful in distinguishing eruptive style in older cones where the proximal to distal tephra blanket has eroded away; (2) a proximal zone in which horizons identified in crosswind profiles collected at …

3d Seismic Data Interpretation Of Boonsville Field, Texas, Aamer Ali Alhakeem

Masters Theses

"The Boonsville field is one of the largest gas fields in the US located in the Fort Worth Basin, north central Texas. The highest potential reservoirs reside in the Bend Conglomerate deposited during the Pennsylvanian. The Boonsville data set is prepared by the Bureau of Economic Geology at the University of Texas, Austin, as part of the secondary gas recovery program. The Boonsville field seismic data set covers an area of 5.5 mi². It includes 38 wells data. The Bend Conglomerate is deposited in fluvio-deltaic transaction. It is subdivided into many genetic sequences which include depositions of sandy conglomerate representing …

Properties Of The Thundercloud Discharges Responsible For Terrestrial Gamma-Ray Flashes, Joseph R. Dwyer, Ningyu Liu, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

The source of terrestrial gamma-ray flashes (TGFs) has been an active area of research since their discovery by Compton Gamma-Ray Observatory/Burst and Transient Source Experiment in 1994. These intense bursts of gamma rays originate within thunderclouds via the rapid production of relativistic runaway electrons, accelerated by thundercloud/lightning electric fields to multi-MeV energies. Recent studies have shown that electrical discharges within thunderclouds caused by these runaway electrons can generate currents that rival those of lightning and so could serve as an alternative discharge path for thunderclouds. In particular, the discharges responsible for TGFs produce some of the largest amplitude VLF-LF radio …

Formation Of Sprite Streamers At Subbreakdown Conditions From Ionospheric Inhomogeneities Resembling Observed Sprite Halo Structures, Burcu C. Kosar, Ningyu Liu, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

Modeling results of sprite streamer formation from large ionospheric inhomogeneities or patches (several tens to hundreds of meter wide) indicate that positive streamers can be initiated at subbreakdown conditions from the inhomogeneities with a density comparable to sprite halo densities. For spherical patches with a given radius, the minimum density required for streamer initiation decreases with increasing ambient field. For a given density, the minimum size of the inhomogeneity decreases with increasing ambient field. The modeling results on the associated optical emissions show that a luminous spherical-like cap appears around the lower tip of the ionization patch before streamer initiation, …

Palynology Of Acid-Saline Lakes Of Western Australiabiostratigraphy And Paleoenvironmental Reconstruction, Carlos A. Sanchez Botero

Doctoral Dissertations

"Lakes are excellent repositories of fossils and sedimentary features that provide clues to past climatic and geologic events. Sediments from four cores drilled in Lake Aerodrome (LA1-09, LA2-09) and Lake Brown (LB1-09, LB2-09), two of the hundreds of ephemeral lakes in southern Western Australia, were analyzed for their palynological contents to understand the geologic and climatic evolution of the depositional basin. Palynofacies assemblages defined by statistical analyses of dispersed organic matter suggested differences in the depositional conditions and probable correlations between Lake Aerodrome cores. Detailed identifications and quantification of organic-walled microfossils yielded two palynomorph assemblages that reflect a climatic turnover: …

Geochemical And Isotopic Characterization Of Lead In Fugitive Dust From Unsurfaced Roads In Missouri, Emitt C. Witt

Doctoral Dissertations

"Eighteen unsurfaced roadways in Missouri's rural Ozark region were sampled to characterize the differences in trace element and isotopic chemistry to determine if there is a human health concern with inhaling and/or ingestion of fugitive dust generated by a moving vehicle. Road reaches were selected to represent those in similar rural areas with and without the presence of mining activity--13 roads were selected in the Viburnum Trend (VT) resource mining area and five were located to the southwest of the mining areas. Samples were collected using a novel cyclonic fugitive dust sampler (patent pending) that collects a composite sample from …

Integrated Geological And Geophysical Studies Of The Indio Mountains And Hueco Bolson, West Texas, Pawan Budhathoki

Open Access Theses & Dissertations

This Dissertation consists of two different projects. The first project describes the results of an outcrop based sequence stratigraphic study of the Albian Cox Sandstone in the Indio Mountains of west Texas. The depositional environment of the Cox Sandstone ranges from shallow marine to the coastal plain deposited in four sequences where sequence 1 and sequence 2 consists of transgressive system tracts (TST) followed by highstand system tracts (HST). The highstand system tract (HST) is missing in sequence 3 and the transgressive systems tract is missing in sequence 4. The Cox changes in thickness from 320 m in the northern …

Seismic Reflection Exploration Of Geothermal Reservoir Atnaval Air Station (Nas) Fallon, Nevada, Alay Ghebremariam Gebregiorgis

Open Access Theses & Dissertations

The Primary objective of this study is to increase geologic and tectonic understanding of the geothermal resources at the Naval Air Station (NAS) Fallon, Nevada. The seismic reflection method is employed to study faults, fractures and other tectonic structures in the subsurface in order to identify geothermal drill targets. The efficiency of geothermal systems is strongly dependent on water circulation. Discrete faults may be permeable and provide pathways for water flow depending on the fracture density. It is therefore desirable to detect and map faults and fracture zones and characterize their physical properties when evaluating a geothermal prospect.

The seismic …

A Block Operator Splitting Method For Heterogeneous Multiscale Poroelasticity, Paul M. Delgado

Open Access Theses & Dissertations

Traditional models of poroelastic deformation in porous media assume relatively homogeneous material properties such that macroscopic constitutive relations lead to accurate results. Many realistic applications involve heterogeneous material properties whose oscillatory nature require multiscale methods to balance accuracy and efficiency in computation.

The current study develops a multiscale method for poroelastic deformation based on a fixed point iteration based operator splitting method and a heterogeneous multiscale method using finite volume and direct stiffness methods. To characterize the convergence

of the operator splitting method, we use a numerical root finding algorithm to determine a threshold surface in a non-dimensional parameter space …

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

LSU 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 …

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 …

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 …

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 …

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

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

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 …

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. …

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 …

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 …