Geophysics and Seismology Commons^™

Plate Boundary Trench Retreat And Dextral Shear Drive Intracontinental Fault-Slip Histories: Neogene Dextral Faulting Across The Gabbs Valley And Gillis Ranges, Central Walker Lane, Nevada, Jeffrey Lee, Andrew K. R. Hoxey, Andrew Calvert, Peter Dubyoski

All Faculty Scholarship for the College of the Sciences

The spatial-temporal evolution of intracontinental faults and the forces that drive their style, orientation, and timing are central to understanding tectonic processes. Intracontinental NW-striking dextral faults in the Gabbs Valley–Gillis Ranges (hereafter referred to as the GVGR), Nevada, define a structural domain known as the eastern Central Walker Lane located east of the western margin of the North American plate. To consider how changes in boundary type along the western margin of the North American plate influenced both the initiation and continued dextral fault slip to the present day in the GVGR, we combine our new detailed geologic mapping, structural …

Geospatial Analyses Of Seismic Hazards And Risk Perception In Libya, Somaia Suwihli

Graduate Theses and Dissertations

Libya is not considered a highly active seismic region. However, several earthquakes of magnitude >5.0 have occurred there. This dissertation analyzes the seismicity of Libya in order to better understand earthquake hazards, related geomorphic features, and the current evolution of Libyan perceptions of seismic risk. The first article developed a baseline of past and current seismic inventory in Libya, which represented an assessment of Libya seismic hazard by translating, analyzing, and compiling historical sources and archaeological data. This study shows that Libya has experienced earthquakes in varying degrees since ancient times. Through the spatial and temporal distribution of earthquakes from …

Changing Mantle Sources And The Effects Of Crustal Passage On The Steens Basalt, Se Oregon: Chemical And Isotopic Constraints, Nicole E. Moore, A. L. Grunder, Wendy A. Bohrson, Richard W. Carlson, I. N. Bindeman

Geological Sciences Faculty Scholarship

Continental flood basalts are more prone to compositional modification from passage through thicker and (or) more felsic crust in comparison to their oceanic counterparts. The Steens Basalt in southeast Oregon (~17 Ma) is among the oldest and most mafic members of the Columbia River Basalt Group and provides a record of the early stages of flood basalt volcanism. We evaluate the balance of mantle sources in time during the onset of Columbia River Basalt Group magmatism and assess the effect of crustal passage using stratigraphically controlled Sr, Nd, Pb, Hf, Os, and O isotopic compositions, as well as whole rock …

Crystal Queer: Fracturing The Binaries Of Matter, Creation, And Landscape, Sarah Knight

Graduate School of Art Theses

In this thesis, I compile a series of fragments consisting an analysis of my artwork in the gendered contexts of landscape, self-identity, mythology, and philosophy. I develop my concept of a “queer mark” in my art that serves as a form of queering, a disruption of visual and conceptual cohesion. I form a picture of how our contemporary selves are influenced by our gendered understanding of the landscape through the analysis of philosophical, artistic, and mythological concepts of creation. I see my sculptures as an atlas to an alternative means of understanding identity, a queering of these historical and exclusionary …

An Analysis Of The Reactivation Potential Of A Deep-Seated Landslide In The Oregon Coast Range Under Varying Hydrologic Conditions With Seismic Triggering, Emily E. Smoot

Anthós

Landslides can occur in many locations across the world and have the potential to be extremely destructive if failures occur near populated areas. Failures are most likely to occur on slopes that have already experienced numerous failures. This means they are a considerable hazard, and the risk involved with building in areas that have previously experienced landslides should be adequately understood. This study examines the reactivation potential of a deep-seated landslide located in the Oregon Coast Range. The analysis of this landslide included creating a map of the surface morphology and computing the factor of safety for the deposit using …

Evolution And Stratigraphic Architecture Of Tidal Point Bars With And Without Fluvial Input: Influence Of Variable Flow Regimes On Sediment And Facies Distribution, And Lateral Accretion, Pricilla Souza

LSU New Orleans Theses and Dissertations

Tide-influenced point bars represent a significant proportion of shallow-marine deposits, commonly developed along meandering channels in most backbarrier and estuarine systems. However, sedimentological studies to characterize this type of deposit are still emerging. They often present very heterogeneous internal architectures which development is controlled by the complex flow patterns operating in tidal environments. The study of the sedimentological and morphological characteristics of these features provides better understanding of the hydrodynamic processes that shape coastal systems and control their evolution as well as it contributes to better reservoir potential prediction and production strategy optimization, as tidal point bars may represent hydrocarbon …

The Shelf To Basin Transition And Tectonostratigraphy Of The Atoka Formation (Lower Pennsylvanian) In The Arkoma Basin, Northwest Arkansas, Travis Gibson White

Graduate Theses and Dissertations

The east-to-west oriented Arkoma Basin is a peripheral foreland basin or depositional trough that developed during the Carboniferous Period. This formation covers an aerial extent of approximately 33,800 square miles and spans from west-central Arkansas into southeastern Oklahoma (McGilvery, Manger, and Zachry, 2016; Perry, 1995). The Atoka Formation, deposited during the early Pennsylvanian, is the largest Paleozoic formation by aerial extent in the state of Arkansas and is located within and comprises the bulk of Arkoma Basin sediments (McFarland, 2004; Nance, 2018). This formation has been informally divided into three divisions, the lower, middle, and upper, based on their stratigraphic …

Integrating Geochronologic And Instrumental Approaches Across The Bengal Basin, Elizabeth L. Chamberlain, Steven L. Goodbred, Richard Hale, Michael S. Steckler, Jakob Willinga, Carol Wilson

OES Faculty Publications

Constraining time is of critical importance to evaluating the rates and relative contributions of processes driving landscape change in sedimentary basins. The geomorphic character of the field setting guides the application of geochronologic or instrumental tools to this problem, because the viability of methods can be highly influenced by geomorphic attributes. For example, sediment yield and the linked potential for organic preservation may govern the usefulness of radiocarbon dating. Similarly, the rate of sediment transport from source to sink may determine the maturity and/or light exposure of mineral grains arriving in the delta and thus the feasibility of luminescence dating. …

Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski

Engagement & Service-Learning Summit

No abstract provided.

Snowmelt Detection On Alpine Glaciers Using Synthetic Aperture Radar Time Series, Corey Scher

Dissertations and Theses

Hindu Kush Himalayan (HKH) glaciers serve as some of the most sensitive indicators of changes in global climate. These glaciers shape the hydrologic dynamics of river systems supplying freshwater to over 2 billion people throughout Asia and regulate the geochemistry of sensitive aquatic alpine ecosystems. As snowmelt onsets sooner, lasts longer, and snowfields retreat due to increases in global temperature, the hydrologic dynamics of catchments draining HKH threaten to change the availability of surface freshwater resources for nearly one fifth of the global population, disturb sensitive aquatic habitat, and precipitate hazards associated with glacier wasting. Informed planning and decision-making around …

Assessing Ground Penetrating Radar’S Ability To Image Subsurface Characteristics Of Icy Debris Fans In Alaska And New Zealand, Robert W. Jacob, Jeffrey M. Trop, R. Craig Kochel

Faculty Journal Articles

Icy debris fans have recently been described as fan shaped depositional landforms associated with (or formed during) deglaciation, however, the subsurface characteristics remain essentially undocumented. We used ground penetrating radar (GPR) to non-invasively investigate the subsurface characteristics of icy debris fans (IDFs) at McCarthy Glacier, Alaska, USA and at La Perouse Glacier, South Island of New Zealand. IDFs are largely unexplored paraglacial landforms in deglaciating alpine regions at the mouths of bedrock catchments between valley glaciers and icecaps. IDFs receive deposits of mainly ice and minor lithic material through different mass-flow processes, chiefly ice avalanche and to a lesser extent …

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 x10 …

Holocene Formation And Evolution Of Horn Island, Mississippi, Usa, Nina Gal

Master's Theses

Horn Island, one of the most stable barriers along the Mississippi-Alabama chain, provides critical habitat, helps regulate estuarine conditions in the Mississippi Sound, and reduces wave energy and storm surge for the mainland. This study integrates 2,200 km of high-resolution geophysics, 35 sediment cores, and 15 radiocarbon ages to better understand the formation and evolution of the island in response to sea-level rise, storms, and antecedent geology. The Biloxi and Pascagoula incised valleys converge at Horn Island and have played a profound role in the evolution of the system. Within the incised valleys, numerous shallow paleochannels between 4 and 9 …

Changes To Subaqueous Delta Bathymetry Following A High River Flow Event, Wax Lake Delta, Usa, Amanda Rose Whaling

Graduate Theses and Dissertations

I report changes to the subaqueous bathymetry of the Wax Lake Delta (WLD) located in coastal Louisiana with the purpose of quantifying the two- and three-dimensional evolution of the entire delta front. The spatial distribution and volume of erosion and deposition were determined by differencing two Digital Elevation Models (DEMs) collected 16 months apart, including the 2nd largest high flow event (flood) in the WLD’s recorded history. The difference map showed 6.41×10^6 m^3 ± 3.70% of sediment were deposited and 1.19×10^7 m^3 ± 2.71% were eroded yielding 5.46×10^6 m^3 ± 7.32% of net erosion in the survey area (~75.9 km^2). …

Assessing Ground Penetrating Radar's Ability To Image Subsurface Characteristics Of Icy Debris Fans In Alaska And New Zealand, Robert W. Jacob, Jeffrey M. Trop, R. Craig Kochel

Faculty Journal Articles

Icy debris fans have recently been described as fan shaped depositional landforms associated with (or formed during) deglaciation, however, the subsurface characteristics remain essentially undocumented. We used ground penetrating radar (GPR) to non-invasively investigate the subsurface characteristics of icy debris fans (IDFs) at McCarthy Glacier, Alaska, USA and at La Perouse Glacier, South Island of New Zealand. IDFs are largely unexplored paraglacial landforms in deglaciating alpine regions at the mouths of bedrock catchments between valley glaciers and icecaps. IDFs receive deposits of mainly ice and minor lithic material through different mass-flow processes, chiefly ice avalanche and to a lesser extent …

Analysis Of Fluvial Scroll Bar Development With Surface Wave Inversion: False River, Louisiana, Blake Odom

LSU Master's Theses

The development of ridge-and-swale scroll bar topography of meandering river point bars is not well understood. We hypothesize that scroll bars formed during lateral accretion by the landward migration of transverse bars. To explore this, we relate the scroll bar topography to the internal sedimentary structure. We acquire, invert, and interpolate three pseudo-2D shear wave velocity profiles in two regions of the False River point bar, a Mississippi river oxbow lake in Pointe Coupee Parish Louisiana. Prior studies provide electrical conductivity well logs and cores as well as SH seismic reflection images along the same seismic surveys. LiDAR elevation data …

Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range, Justin T. Wilgus

Earth and Planetary Sciences ETDs

Metamorphic core complexes (MCC) are distinctive uplifts that expose deeply exhumed and deformed crustal rocks due to localized extensional deformation. Consequently, their detailed structure provide a window into deep crustal mechanics. The North American Cordillera contains numerous MCC, one of which is the Ruby Mountains core complex (RMCC) located in the highly extended northern Basin and Range. To constrain the extent to which anisotropy below the RMCC deviates from the regional Basin and Range average and test the depth dependence of crustal anisotropy we conduct a radial anisotropy investigation below the RMCC and surrounding northern Basin and Range. Data from …

The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta

International Journal of Speleology

The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif …

Geomorphology Of Icy Debris Fans: Delivery Of Ice And Sediment To Valley Glaciers Decoupled From Icecaps, R. Craig Kochel, Jeffrey M. Trop, Robert W. Jacob

Faculty Journal Articles

The pace and volume of mass flow processes contributing ice and sediment to icy debris fans (IDFs) were documented at sites in Alaska and New Zealand by integrating field observations, drone and time-lapse imagery, ground penetrating radar, and terrestrial laser scanning. Largely unstudied, IDFs are supraglacial landforms at the mouths of bedrock catchments between valley glaciers and icecaps. Time-lapse imagery recorded 300–2300 events reaching 15 fans during intervals from nine months to two years. Field observations noted hundreds of deposits trapped within catchments weekly that were later remobilized onto fans. Deposits were mapped on images taken three to four times …

Regional Stress Regime Study Of East Texas Based On Orientation Of Fractures In The Weches Formation, Cory D. Ellison

Electronic Theses and Dissertations

Fractures in the Weches Formation in a roughly 50 mile radius around Nacogdoches, Texas were documented and analyzed using data obtained at various outcrops. This data was used to infer information about the regional stress regime based on the direction of maximum/minimum horizontal stresses (SHmax / SHmin) that formed the fractures. This is based on the principle that systematic, steeply dipping, mode I joints propagate in the direction of SHmax and normal to the direction of SHmin. Joints in the Weches Formation are typically iron filled and are predominantly opening mode, indicated by crack-seal formation, steep dip (700 – 900) …

Evidence Of The 1762 Arakan And Prior Earthquakes In The Northern Sunda Subduction, Dhiman Ranjan Mondal

Dissertations, Theses, and Capstone Projects

The objective of this dissertation is to understand the seismic hazard associated with Arakan segment of the northern Sunda subduction along SE Bangladesh. In order to do that, it is necessary to document geologic evidence for the 1762 Arakan earthquake and prior events, to help estimate the recurrence interval (repeat time) for that earthquake. Historical records described that the 1762 earthquake caused extensive damage along the Arakan segment of the Sunda subduction system. But the geologic evidence for the earthquake farther north is necessary to better understand its associated seismic hazard to the densely populated nation of Bangladesh. This dissertation …

Onshore-Offshore Velocity Models North Of The Mendocino Triple Junction In Northern California, Alan Jacquez

Open Access Theses & Dissertations

The Mendocino Triple Junction (MTJ) marks the boundary where the Gorda plate, North American Plate, and Pacific Plate meet, separating the Cascadia subduction zone to the North from transform tectonics of the San Andreas plate boundary. This actively deforming region experiences high seismic activity and young geological features. Here we examine offshore and onshore seismic wide-angle reflection and refraction data north of the MTJ crossing the Cascadia subduction zone from offshore northern California to the Western edge of the Sierra Nevada. We image subsurface structures in this region by creating P-wave velocity models using datasets collected in 1993 to 1994 …

Assessing The Use Of Tsunami Simulations As A Tool To Predict Source Magnitudes And Locations Of Paleoearthquakes In Chile, Rebeca Isabel Becerra

All Master's Theses

A long-term goal of paleotsunami studies is the ability to predict paleoearthquake parameters based on tsunami deposits found on land. Chile provides an exemplary location for testing methods of making these predictions because the historical record includes 41 major earthquakes as far back as 1562 AD, and there are many known paleotsunami deposits throughout the region. Using these records as a comparison tool, I evaluated simulated tsunami wave heights and inundation extent with the tsunami model GeoClaw for nine hypothetical tsunamigenic large earthquakes (M_w 8.6, 8.8, and 9.0) in south-central Chile with epicenters at -35.1º, -38.8º, and -42.9º. As …

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …

3d Seismic Interpretation Of A Plio-Pleistocene Mass Transport Deposit In The Deepwater Taranaki Basin Of New Zealand, Francisco Jose Rusconi

Graduate Theses and Dissertations

A series of Plio-Pleistocene mass transport deposits (MTD) have been identified in the deepwater Taranaki Basin, in New Zealand, using the Romney 3D seismic survey, which covers an area of approximately 2000 km2. One of these MTDs has been chosen for description and interpretation based on high confidence mapping of its boundary surfaces. The deposit exhibits an array of interesting features similar to those documented by researchers elsewhere plus a unique basal feature unlike those previously observed. The basal shear surface exhibits erosional features such as grooves, “monkey fingers”, and glide tracks. Internally, the MTD is typically characterized by low …

How Dredge Pits Evolve Over Time: A Look At Their Geomorphologic Evolution And Infilling Processes, Patrick Robichaux

LSU Master's Theses

As coastal environments become more susceptible to land loss through accelerating sea level rise and subsidence, new restoration methods harnessing borrowed sediment are more valuable than ever. Mud-capped dredge pits (MCDPs) are a relatively new source of restoration-quality sediment that has only recently been utilized for beach and barrier island restorations in Louisiana. Because MCDPs have been in use for less than two decades in only a handful sites, little is understood about their evolution over decadal timescales. To improve our understanding of MCDPs after they are dredged, we have conducted a suite of geophysical surveys including bathymetry, sidescan sonar, …

The Uppermost Mantle Seismic Velocity And Viscosity Structure Of Central West Antarctica, J. P. O'Donnell, K. Selway, A. A. Nyblade, R. A. Brazier, D. A. Wiens, S. Anandakrishnan, R. C. Aster, Audrey D. Huerta, T. Wilson, J. Paul Winberry

All Faculty Scholarship for the College of the Sciences

Accurately monitoring and predicting the evolution of the West Antarctic Ice Sheet via secular changes in the Earth's gravity field requires knowledge of the underlying upper mantle viscosity structure. Published seismic models show the West Antarctic lithosphere to be ∼70–100 km thick and underlain by a low velocity zone extending to at least ∼200 km. Mantle viscosity is dependent on factors including temperature, grain size, the hydrogen content of olivine, the presence of partial melt and applied stress. As seismic wave propagation is particularly sensitive to thermal variations, seismic velocity provides a means of gauging mantle temperature. In 2012, a …

Integrated Approach For Sinkhole Evaluation And Evolution Prediction In The Central Ebro Basin (Ne Spain), Oscar Pueyo Anchuela, Andrés Pocoví Juan, Antonio M. Casas Sainz, Javier Gracia Abadias, Carlos L. Liesa Carrera

International Journal of Speleology

Evaluation of karst hazards benefits from the integration of different techniques, methodologies and approaches. Each one presents a different signature and is sensitive to certain indicators related to karst hazards. In some cases, detailed analysis permits the evaluation of representativeness either from isolated approaches or by means of integrated analyses. In this study, we present the evaluation of an area with high density of karstic collapses at different evolutionary stages through the integration of surficial, historical, geomorphological and geophysical data in order to finally define the evolutionary model for karst activity development. The obtained dataset permits to identify different steps …

Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, Francis C. Okocha

Electronic Theses and Dissertations

Salt domes are important geological structures because they are potential major hydrocarbon traps and have a profound effect on overlying strata in the subsurface. Over five hundred salt domes have been located on the United States Gulf Coast region, including the Hastings Salt Dome. Hastings Oil Field is located about 40.2 km (25 miles) southeast of Houston, Texas. The Hasting oil field was discovered in 1934 and it was considered the largest oil reserve on the Gulf Coast. Its peak production of 75,000 BOPD (barrels of oil per day) was recorded in 1977 and it had a cumulative production of …

Characterizing Subsurface Void Spaces And Water Distribution And Flow Patterns In Cave Hill Karst Using Resistivity, Jacob A. Gochenour

Senior Honors Projects, 2010-2019

Describing the distribution of groundwater is essential in understanding the evolution of geomorphologic features in karst topography. Electrical resistivity allows us to find a model of subsurface distribution of resistivity that enables the visual recognition of groundwater and void spaces. The purpose of this research is to implement electrical resistivity to describe the spatial relationship of groundwater and karstic features at Grand Caverns National Natural Landmark, Grottoes, Virginia. Two locations of interest, a karstic swale and sinkhole area, were identified for the deployment of electrical resistivity. Both, dipole-dipole and Schlumberger arrays were collected for each deployment. A total of ten …