Geophysics and Seismology Commons^™

Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion

All Master's Theses

Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± …

Assessing The Impact Of Vertical Land Motion On Twentieth Century Global Mean Sea Level Estimates, B. D. Hamlington, P. Thompson, W. C. Hammond, G. Blewitt, R. D. Ray

CCPO Publications

Near-global and continuous measurements from satellite altimetry have provided accurate estimates of global mean sea level in the past two decades. Extending these estimates further into the past is a challenge using the historical tide gauge records. Not only is sampling nonuniform in both space and time, but tide gauges are also affected by vertical land motion (VLM) that creates a relative sea level change not representative of ocean variability. To allow for comparisons to the satellite altimetry estimated global mean sea level (GMSL), typically the tide gauges are corrected using glacial isostatic adjustment (GIA) models. This approach, however, does …

Influence Of The Weathered Layer On Retrieving Body Wave Using Passive Siesmic Interferometry, Boming Wu

Dissertations, Master's Theses and Master's Reports

Passive seismic interferometry (SI) is an increasingly popular seismic method due to its cost-efficient advantage because it does not need an active source. Techniques in using SI to retrieve surface waves are relatively well established, but using SI to retrieve body waves is still under development by many authors. These geophysicists have proved that many factors, such as average duration of the natural sources, the number of natural sources that occurred during recording time, source distribution, etc., influence the quality of body waves retrieved. In this research, I focus on how to make use of the attenuation property of weathered …

Petrophysical And Empirical And Theoretical Rock Physics Modeling For The Moki Formation In Two Fields In The Taranaki Basin, New Zealand, Deniz Yener

Dissertations, Master's Theses and Master's Reports

This work consists of conventional petrophysical analysis and sonic response determination from empirical relations, rock physics modelling, and fluid substitution for six wells in the Moki formation of New Zealand’s Taranaki Basin. The project composed of three parts encompassing conventional log analysis, rock-physics modeling using empirical and theoretical approaches, and finally rock-physics modeling for shaley sands using semi-empirical adaptations to Gassmann fluid substitution. Finally, comparisons are made between results for the different wells, based on their depths and mineralogy.

The first part of this study is presented as a petrophysical analysis, including crossplot analysis, conventional 3-mineral identification approach, and determination …

Cave Detection Using Seismic Methods At Madison Blue Spring State Park, Madison County, Florida, Charles Breithaupt

Dissertations, Master's Theses and Master's Reports

Locating caves and quantifying their geometries has significant importance in aquifer characterization, sinkhole mitigation, and contaminant transport monitoring. Several geophysical methods have been used for cave detection with limited success, but no reliable solution has been found. New developments in seismic techniques, however, show promising results indicating that cave voids may be more accurately detected.

We evaluated the capability of several seismic techniques to detect caves by collecting new seismic data over a known conduit connected to Madison Blue Spring, in northern Florida. These analyses validated the abilities of diffracted surface waves to detect water-filled caves by viewing these data …

Enhancement Of Margrave Deconvolution And Q Estimation In Highly Attenuating Media Using The Modified S-Transform, Adnan Djeffal

Dissertations, Master's Theses and Master's Reports

We evaluate the performance of the Margrave deconvolution and spectral ratio methods using the Gabor, S-, and modified S transforms in highly attenuating media, where the quality factor changes with depth dramatically. Our results substantiate that the modified S-transform deconvolution is more robust in terms of generating fewer artifacts and providing better estimates of reflectivities than the Gabor transform. The results also show that using the modified S-transform in the spectral ratio method produces better Q estimates than the S-transform and the Fourier transform that is conventionally used in the spectral ratio method. This improvement in the estimates of reflectivities …

Reservoir Characterization Through Pre-Stack Seismic Analysis And Inversion In The Thrace Basin, Northwest Turkey, Emre Doguturk

Dissertations, Master's Theses and Master's Reports

This study analyzes hydrocarbon reservoirs by using Amplitude-Versus-Offset (AVO) analysis and different inversion methods to investigate hydrocarbon reservoir in the Thrace Basin which is located in northwest Turkey.

A 3D seismic survey containing prestack data was provided by Turkish Petroleum Corporation as true amplitude NMO corrected 3D gathers.

The quality of this land data was poor for AVO applications, and steps were taken to make it useful. Radon filtering proved to be extremely useful for this purpose. Although application of this filter affected the AVO characteristics differently depending on the parameters selected for the filter, relative AVO characteristics remained useful …

Preliminary Seismic Coda Wave Attenuation Study Of Pacaya Volcano, Guatemala, Maximilian Guettinger

Dissertations, Master's Theses and Master's Reports

Pacaya volcano is a basaltic complex in the Central American Volcanic Arc in Guatemala. Pacaya has been in an open vent condition since 1961. During January 2015 we deployed 19 short period seismometer stations on Pacaya at distances less than 1.5 kilometers from the summit. The resulting data consisted of tremor and thousands of discrete events associated with ongoing outgassing. Where possible, individual events were identified and located. They were found to be high in the edifice near the vent. We used the decaying codas of these events to model the attenuation structure of the Pacaya edifice, following the energy …

3d Structural And Stratigraphic Architecture Of The Northwest Santa Barbara Basin And Implications For Submarine Landslide Generation, Alexis Wright

Dissertations and Theses

Multiple submarine landslides have been previously documented on the north flank of the Santa Barbara Channel, and such failures are considered to be capable of generating local tsunamis hazards to the Santa Barbara region. 2D seismic-reflection datasets provide a general view of regional framework geology, including faulting and folding associated with north-south compression. However, better understanding of the relationships between faults, folds, stratigraphic architecture, and submarine landslides can be obtained with 3D seismic datasets. In this study we use an industry 3D seismic-reflection volume that encompasses the slope and shelfbreak surrounding the Gaviota submarine landslide (3.8 km2) to investigate structural …

An Integrated Geophysical Survey Of Kilbourne Hole, Southern New Mexico: Implications For Near Surface Exploration Of Mars And The Moon, Nisa Maksim

Open Access Theses & Dissertations

Features such as the Home Plate plateau on Mars, a suspected remnant of an ancient phreatomagmatic eruption, can reveal important information about paleohydrologic conditions. The eruption intensity of a phreatomagmatic volcano is controlled mainly by the quantity of water and magma, the internal geometry of the volcano, and the depth of the interaction zone between magma and water. In order to understand the paleohydrologic conditions at the time of eruption, we must understand all the factors that influenced the phreatomagmatic event. I conducted an integrated geophysical survey, which are magnetic and gravity surveys, and a ground-penetrating radar (GPR) surveys at …

Seismic Modeling, Rock Physics, Avo And Seismic Attribute Analysis For Illuminating Sandstone Facies Of The Late Ordovic Ian Mamuniyat Reservoir, R-Field, Murzuq Basin-Libya, Yousf Milad Abushalah

Open Access Theses & Dissertations

The Late Ordovician Mamuniyat Formation is the main hydrocarbon reservoir in the R-Field in Murzuq Basin, SW Libya. The Lower Mamuniyat, which is the only unit that was encountered in the study area, is composed of sandstone facies called Clean Mamuniyat and shaly sandstone facies called Dirty Mamuniyat. One major problem with the development of the R-Field is the difficulty of distinguishing the two units so this project was aimed to develop better methods for distinguishing between the two units of the Lower Mamuniyat. The other problem is to distinguish the transgressive shaly facies of the Bir Tlacsin, which has …

Evidence Of Active Rifts In The Southwest United States Using Geophysical Inversion Of Seismic Data, Sergio H. Celis

Open Access Theses & Dissertations

A continental rift represents a zone where the lithosphere has become thinner due to extensional forces associated with plate tectonics. Many of these rifts are still active, such as the East Africa rift, while others appear to be failed rifts. I build upon recent results of crustal structure for the southern section of the Rio Grande Rift using seismic data collected by USArray stations, and extend the analysis into the states of New Mexico, Oklahoma, Arkansas, and Louisiana to investigate the differences between active and failed rifts in the state of Texas. I collect two geophysical data sets, including receiver …

3-D Structure Of Colombia From 1-D Constrained Joint Inversion Of Receiver Functions And Surface Wave Dispersion, Nick Talavera

Open Access Theses & Dissertations

The country, Colombia, resides at the northwest corner of the South America with seismicity and volcanism due to the intersections of the Nazca, South America and Caribbean tectonic plates (Figure 1). The boundaries of the South America plate, on which Colombia lies, borders between 60 to 200 kilometers from its coasts. A dense spot of seismicity known as the Bucaramanga Nest has had many theories to explain its existence. Two tectonic microplates suspected in this region have not been well understood. With many mysteries of the behavior of the tectonic plates beneath Colombia, using new methods may shed light on …

A Geophysical Investigation At The Potrillo Maar, Manuel Moncada Gutierrez

Open Access Theses & Dissertations

The Potrillo Volcanic Field (PVF) is a unique geological site located in Doña Ana County the southernmost part of New Mexico, and part of northern part of Chihuahua, Mexico. The main feature of the southern PVF is Potrillo Maar. This maar-volcano straddles the international boundary between United States and Mexico and lies within the southern part of the Rio Grande Rift. The Potrillo Maar was formed about 20,000 years ago in three major events that formed basalt lava flows and ejecta deposits that consist of crustal and mantle xenoliths.

The purpose of this Thesis is to determine the area of …

Insights Into Volcanic Processes Using Seismic Data Techniques, Ezer Patlan

Open Access Theses & Dissertations

We present in this study numbers of technique to understand the volcanic processes using seismology. The types of techniques we used are earthquake location (double difference travel-time, cross-correlation tremor technique, and time reversal), stresses (b-values, focal mechanism), and tomography imagery (ambient noise tomography). The areas of study we focus on are in two different tectonic settings. The East Africa Rift System at Kenya, studying four volcanoes: Menengai Caldera, Silali, Paka, and Korosi volcanoes. The other area of study is located in a subduction zone in Central America, Salvador at San Miguel volcano.

In this study we aim to calculate accurate …

Geophysical Constraints On The Hueco And Mesilla Bolsons: Structure And Geometry, Victor Manuel Avila

Open Access Theses & Dissertations

The Hueco and Mesilla Bolsons are part of the intramountain basins of the Rio Grande Rift system. These bolsons are the primary source of groundwater for the El Paso-Ciudad Juarez metropolitan area and contain faults that show evidence of repeated earthquakes during the Quaternary. The region is also associated with has low-level (M<4) seismicity. The collection and analysis of precision gravity data, coupled with information from water wells, multichannel analysis of surface waves (MASW) studies and previously published seismic reflection lines, have been used to examine the structure and faulting within these bolson. This study reveals that the Hueco and Mesilla Bolsons are very different structurally. The southern Mesilla Bolson contains about 500 m of sediment. Faults are difficult to trace and have less than 50-100 m of displacement across them. The southernmost bolson contains numerous Tertiary intrusions and the thickness of Cretaceous bedrock appears to decrease from south to north, possibly delineating the edge of Laramide age deformation within the bolson. The northern Hueco Bolson contains 1800 to 2500 m of basin fill. Displacement along the East Franklin Mountains fault (EFMF), a fault with evidence for repeated earthquakes within the past 64,000 years, is about 1500 m, and displacement on intrabasin faults is 200-300 m. Several intrabasin faults appear to control the saline to freshwater contact within the bolson. The EFMF may extend over 30 km south of the end of its mapped trace at the end of the Franklin Mountains and a number of intrabasin faults also extend south into the urbanized regions of the study area. The EFMF and other basin structures appear to be offset or disrupted at the speculated edge of Laramide deformation that lies beneath the bolson. Horizontal Gradient Methods (HGM) were applied to the gravity data and were successful for tracing faults and older Laramide features within the Hueco Bolson beneath the urbanized regions of the cities. HGM were not as successful at tracing faults within the Mesilla Bolson, however they were helpful for tracing the subsurface extent of igneous intrusions including the Mt. Cristo Rey, River, Three Sisters, and the Westerner outcrops. Some of these features appear linked at depth by a series of dikes and faults. MASW data were used to determine the average shear wave velocity in the upper 30m (Vs 30) at ~70 sites within the Hueco Bolson. These observations were combined with similar data collected previously in Juarez to produce regional velocity and site classification maps. The results show low velocities are found close to the river within fluvial deposits with higher velocities close to the Franklin Mountains where bedrock is close to the surface and higher velocities in upland regions of northeast El Paso were soils appear to be more highly cemented. These data will be used in conjunction with information on bolson geometries to model the expected effects of strong ground motion from earthquakes in the El Paso-Ciudad Juarez region.

Dynamics Of Plume-Triple Junction Interaction: Results From A Series Of Three-Dimensional Numerical Models And Implications For The Formation Of Oceanic Plateaus, Mladen Dordevic, Jennifer Georgen

OES Faculty Publications

Mantle plumes rising in the vicinity of mid-ocean ridges often generate anomalies in melt production and seafloor depth. This study investigates the dynamical interactions between a mantle plume and a ridge-ridge-ridge triple junction, using a parameter space approach and a suite of steady state, three-dimensional finite element numerical models. The top domain boundary is composed of three diverging plates, with each assigned half-spreading rates with respect to a fixed triple junction point. The bottom boundary is kept at a constant temperature of 1350°C except where a two-dimensional, Gaussian-shaped thermal anomaly simulating a plume is imposed. Models vary plume diameter, plume …

The Mantle Transition Zone Beneath South America From Stacking Of P-To-S Receiver Functions, B. A. Goetze

Masters Theses

"The Mantle Transition Zone (MTZ) beneath South America is investigated with stacking of Receiver Functions (RFs) of converted P-to-S phases from the velocity discontinuities at 410 km (d410) and 660 km (d660). A total of 785 seismic stations provided 22,235 high quality RFs, allowing 1,717 MTZ thickness measurements in circular bins of 2⁰ radius. An apparent MTZ structure is derived using the IASP91 reference model, where the d410 mean depth is 409.1 km and the d660 is 661.5 km, and the mean MTZ thickness is 251.8 km. This model presents coherent depressions and uplifts of the discontinuities matching well known …

Reprocessing And Structural Interpretation Of Multichannel Seismic Reflection Data From Penobscot, Nova Scotia, Fulya Gizem Yagci

Masters Theses

"Penobscot area is located in the Scotian Basin, which was occurred as a result of extension in the eastern North America border. 2-D data set that was utilized for the study consists of three multichannel seismic profiles that were collected from Penobscot Parcel 8. The main purpose of the study was to enhance signal-to-noise ratio of the seismic reflection sections suppressing high frequency noise and multiples, and removing diffractions. In addition, while the resolution of the sections were enhanced, determining the correct processing techniques and parameters for better results was the another important criteria.

The processing steps included deconvolution, minimum …

Periclinal Folding In Ozark Plateau: A Record Of Local Karst Collapse Or Regional Tectonic Forces?, Chao Liu

Masters Theses

"The Ordovician Rubidoux Formation of the Ozark Plateau, Missouri is typically identified as mechanically competent sub-horizontal beds of medium grained sandstone. North of Licking, MO, the Rubidoux Formation was deformed into a series of dome-and-basin shaped buckle folds, exposed in road cuts over a distance of ~10 km. Such folds are highly unusual within the Ozark Plateau and their origin remains controversial. Three major hypotheses have been proposed based on field observations and stereographic analysis. Given the pervasive distribution of karst collapse throughout Missouri, one hypothesis to explain these folds is that the Roubidoux Formation sagged into collapsed caverns. A …