Geophysics and Seismology Commons^™

New Constraints On The Stratigraphic Architecture And Evolution Of Mississippi River Delta Lobe Activity: Barataria Basin, Southeastern La, Wilke Coleman

LSU New Orleans Theses and Dissertations

Barataria Basin is a shallow water, interdistributary estuary that has evolved in response to dynamic depositional regimes governed by distributary avulsion and reworking of sediments by coastal processes. In the Mississippi River delta plain, the migratory nature of the River has produced an evolving landscape constructed through episodes of regressive and transgressive sedimentation. These processes produce unique depositional signatures in the stratigraphic record, however the transgressive component of the delta cycle often results in obliteration of the regressive phase. This study uses a modern suite of geophysical and sediment core data to construct a revised geologic framework in Barataria Basin, …

Α-Quartz Plastic Strength Investigation Via Diffraction Experiments On Novaculite Using A D-Dia And Elastic Plastic Self-Consistent Interpretation, Denali Jivanjee Medina

UNLV Theses, Dissertations, Professional Papers, and Capstones

The plastic response of experimentally deformed quartz provides insight into the strength of ductile shear zones that has implications for tectonic, lithospheric, and ore deposit models. We present a suite of 15 uniaxial deformation experiments on Arkansas novaculite conducted in a DDIA apparatus with in-situ synchrotron x-rays. Experimental temperatures range from 25 C to 1334 C with pressures between 1.39 GPa and 3.1 GPa, and strain rates between 1x10-5 s-1 and 9x10-6 s-1. Macroscopic sample strain ranges from 3% to 24%. d-spacings from the (101), (110), (200), (201), and (112) lattice planes were measured, producing lattice strain up to ~5%. …

Multi-Scale Thermal Mapping Of Submarine Groundwater Discharge In Coastal Ecosystems Of A Volcanic Area, Ebony L. Williams, Christopher B. Kratt, Raymond S. Rodolfo, Mark R. Lapus, Ryan R. Lardizabal, Aya S. Bangun, Amber T. Nguyen, Scott W. Tyler, M. Bayani Cardenas

Environmental Science Faculty Publications

Submarine groundwater discharge (SGD) in volcanic areas commonly exhibits high temperatures, concentrations of metals and CO2, and acidity, all of which could affect sensitive coastal ecosystems. Identifying and quantifying volcanic SGD is crucial yet challenging because the SGD might be both discrete, through fractured volcanic rock, and diffuse. At a volcanic area in the Philippines, the novel combination of satellite and drone-based thermal infrared remote sensing, ground-based fiber-optic distributed temperature sensing, and in situ thermal profiling in coastal sediment identified the multi-scale nature of SGD and quantified fluxes. We identified SGD across ∼30 km of coastline. The different approaches revealed …

A Python Pipeline For Rapid Inversion Of Gravity Data Aimed At Early Career Researchers: Application To The Lost River Fault, Idaho, Bradford C. Mack

USF Tampa Graduate Theses and Dissertations

Gravity data and modeling can be used to create a 3D view of basin and fault geometries, a valuable tool for seismic hazard assessment. Additionally, access to a high-speed, easy-to-use modeling workflow will enable more researchers to supplement their work with a new method and allow students to be exposed to modeling earlier in their academic careers. The primary goals of this work are to create a widely usable 3D gravity and basin model, to create an introduction to modeling teaching module for undergraduate geology students, and to apply the model to the northernmost two segments of the Lost River …

Impact Of Young Biocrust On Dryland Surface Albedo, Rhynhardt Mudde, Rebekah Magness, Raul Roman, Nicole Pietrasiak

Undergraduate Research Symposium Posters

More than 40% of the Earth’s surface is covered by drylands. Due to limited availability of water, less surface area is covered by vascular plants. Instead, this space is occupied by microbial communities that exist in close contact with mineral soil, creating a living aggregate on the upper soil layer and are known collectively as biological soil crusts or “biocrusts”. Biocrusts play a vital role in ecosystem functioning in drylands specifically through their influence on hydrological processes (e.g., water retention, infiltration). However, the impact of biocrusts on evaporation is not well understood. Biocrusts have been reported to either increase or …

Statistical Methods For Interpreting Spatial And Temporal Heterogeneity Of Martian Tropical Water Ice Informed By Properties Of Crater Ejecta Types, Jamie D. Riggs, Michelle R. Kirchoff

College of Population Health Faculty Papers

The martian tropical water ice spatial and temporal distribution was characterized using impact crater ejecta type, location, size, and age in one of two epochs, (Formula presented.) Ga and (Formula presented.) Ga, using statistical models designed for spatial and temporal correlation structures. The indicator thought to identify the presence of ice is craters with layered ejecta, while the indicator thought to identify no ice is craters with radial ejecta. These indicators imply the location (longitude and latitude) and, potentially, depth (crater diameter as a proxy) of ice, and when the ice was present. The spatial and temporal distribution of layered …

Ambient Noise Tomography Of The Southern M9.2 1964 Great Alaska Earthquake Rupture Area, Joshua Ojuoluwa Osasona

Earth and Planetary Sciences ETDs

We used data from a densely spaced node array to investigate seismic velocity structure within the southern rupture area of the M9.2 1964 Great Alaska earthquake. The node array was deployed along a ~50 km section of the road system on Kodiak Island as part of the Alaska Amphibious Community Seismic Experiment (AACSE). The full ~400-node array was active for 25 days in May-June 2019. We extracted Rayleigh wave dispersion curves from ambient noise cross-correlations between station pairs in the node array to compute phase velocity maps from 2-8 s periods. Using these phase velocity maps, we performed a Bayesian …

Sea Surface Temperatures, The Gulf Of Mexico Loop Current, Hurricane Ian, And Their Junction, Alexander K. Nickerson

USF Tampa Graduate Theses and Dissertations

In the first chapter, a climatology was created for the deep Gulf of Mexico, West Florida Shelf, and Tampa Bay. These climatologies were compared to each other and to global temperatures. Seasonal variability is shown to be a product of bathymetry as well as latitude. In Chapter Two, using the self-organizing map neural network, patterns of the Gulf of Mexico Loop Current were analyzed to establish phases with necessary and sufficient conditions for translation from one phase to the next. Two separate patterns of evolution were established from these analyses, and empirical arguments are used to confirm the findings from …

Using Convolutional Neural Network To Determine Time Window For Analyzing Local Shear-Wave Splitting Measurements, Yanwei Zhang, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The time window for analyzing local shear-wave splitting (SWS) phases significantly affects the quality of measurements, revealing a noteworthy domain influence. In this study, an approach using convolutional neural network (CNN) is applied to determine the end of time window (e), which has a similar idea of the phase-picking CNNs. The start of time window is 0.5 s before e. Our data set contains 803 human-labeled measurements, recorded from three stations located in Ridgecrest, California. These measurements are foreshocks and aftershocks of an M 7.1 earthquake on 6 July 2019. After 21 times shifting on each measurement, 90% of the …

A Comparative Study Of Cave System Calcium Isotope Ratios: Implications For Quantitative Reconstruction Of Paleorainfall From Speleothems, Cameron B. De Wet, Elizabeth M. Griffith, Andrea Erhardt, Jessica L. Oster

Earth and Environmental Sciences Faculty Publications

Variations in speleothem calcium isotope ratios (δ44Ca) are thought to be uniquely controlled by prior carbonate precipitation (PCP) above a drip site and, when calibrated with modern data, show promise as a semi‐quantitative proxy for paleorainfall. However, few monitoring studies have focused on δ44Ca in modern cave systems. We present a multi‐year comparative study of δ44Ca, carbon isotopes (δ13C), and trace elemental ratios from cave drip waters, modern calcite, and host rocks from two cave systems in California—White Moon Cave (WMC) and Lake Shasta Caverns (LSC). Drip water and calcite δ44Ca from both caves indicate PCP‐ driven enrichment, and we …

Low-Impact Geophysical Research Near Richardton, North Dakota, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about a multi-year research project that explores a lower-cost, less invasive geophysical survey technique. Part of the Red Trail Energy carbon capture and storage research effort.

Seismic Resilience Of Timber Homes, Melia R. Costa

College of Engineering Summer Undergraduate Research Program

The vast majority of residential buildings in California are wood-frame structures. A home is typically a very large investment for families, and damage to the home can be detrimental to a family’s economic success. Thus, reducing the economic impacts of an earthquake on residential timber housing is crucial. A full scale, two-story section of a residential timber house is in construction in the Parson’s Geotechnical and Earthquake Engineering Laboratory on the Cal Poly campus in San Luis Obispo, California. Once built it will be put through earthquake simulation tests on a shake table with various magnitudes of seismic activity. Next, …

Detection Of Seismic Microwave Radiation Anomalies In Snow-Covered Mountainous Terrain: Insights From Two Recent Earthquakes In The Pamir–Tien Shan Region, Feng Jing, Meng Jiang, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

When earthquakes occur in high-mountain areas during the winter season, the epicentral region is often covered by a snow layer, which can be either thin or thick. The presence of snow and/or ice layers affects the detection of thermal anomalies associated with seismic signals. Taking into account the penetration capabilities of microwaves, microwave brightness temperature data were analyzed by using the index of microwave radiation anomaly to study the response of the epicentral region associated with two recent strong earthquakes in Central Asia, which occurred in snow-covered mountainous areas. Increased microwave radiation was observed within one week prior to the …

The Aimag Project: Using Machine Learning To Predict Crustal Magnetic Anomaly Values, Xavier Gobble, Marlie Mollett, Dr. Dawn King, Dr. Cory Reed, Erin Knese

Undergraduate Research Symposium

A detailed model of the Earth’s total magnetic field is important for acquiring the means for GPS-alternative, magnetic anomaly-based navigation. The Earth’s total magnetic field is an amalgam of 5 mechanisms: the geodynamo generated by the rotation of the Earth’s molten iron core, the fields induced by the flows of electric current in the atmosphere and oceans, the disturbance of the ionosphere by solar wind, and local anomalies attributable to ferromagnetic minerals present in the crust; the lattermost compose the crustal magnetic field. The EMAG2v3 dataset comprises a compilation of satellite, shipborne, and airborne magnetic measurements differenced from the Comprehensive …

Temporal Dynamics Of Coastal Sediment Characteristics: A Comparative Study On Pre- And Post-2004 Tsunami Event Along The Nagoor - Poompuhar Stretch, Tamil Nadu, Yamini S

Theses and Dissertations

Tsunamis represent some of the most devastating natural events for coastal regions, as exemplified by the 26th December 2004 Great Indonesian Earthquake triggered a massive tsunami across the Bay of Bengal and Indian Ocean, causing extensive destruction in various countries, including India. This study addresses a significant gap in the literature by focusing on the detailed sedimentological aspects of coastal dynamics. Specifically, it examines the pre-tsunami (December 2004), post-tsunami (January 2005), and recent (December 2022) sediment characteristics along a 35 km stretch of the Coromandel coast from Poompuhar to Nagoor.

Eight stations were selected for sampling: Poompuhar, Chinnankudi, Kuttyandiyur, Chandrapadi, …

Crustal Structure And Evolution Of The Queen Charlotte Plate Boundary, Collin C. Brandl

Earth and Planetary Sciences ETDs

There are many outstanding questions in plate tectonics that remain unanswered because large regions of the Earth are unexplored, both at the surface and in the subsurface. In this dissertation, I processed and analyzed active source seismic reflection data from the historically understudied Queen Charlotte transform plate boundary. Using this dataset, I found that the southern segment of the plate boundary has active underthrusting, is analogous to subduction zone crustal slivers, and is a site of early subduction initiation. Along the entire plate boundary, I constrained the near-surface thermal gradient using the stability of gas hydrate, finding that it is …

Structural Characterization Of The Puma Diapir, Gulf Of Mexico Basin, Rodrigo Velasquez

Electronic Theses and Dissertations

The Gulf of Mexico (GOM) Basin has been a significant target for oil and gas since the 1990s and continues today as a leading exploration target. This super basin is home to an estimated 200 BBOE (Billon barrels of oil equivalent), with current production totaling 60 BBOE for both USA and Mexico. Even though the overall depositional evolution of the GOM has allowed for the key elements for petroleum accumulations to be met, a complex structural framework is present. This framework results from the asymmetric spreading of the North American Plate from the Yucatan block crating the GOM basin we …

Palynostratigraphy And Bayesian Age Stratigraphic Model Of New Ca-Id-Tims Zircon Ages From The Walloon Coal Measures, Surat Basin, Australia, K. Sobczak, J. Cooling, T. Crossingham, H. G. Holl, M. Reilly, J. Esterle, J. L. Crowley, C. Hannaford, M. T. Mohr, Z. Hamerli, S. Hurter

Geosciences Faculty Publications and Presentations

The Surat Basin hosts significant coal and coal seam gas resources. New high-precision CA-TIMS U/Pb zircon ages from tuffs and Bayesian age stratigraphic models are combined with palynology from fine-grained sedimentary rocks and zircon trace elements to provide further chronostratigraphic and biostratigraphic constrains on the Walloon Coal Measures in the eastern margin of the Surat Basin and infer the palaeoenvironment and tectonic setting. The tuff ages range from 165.88 ± 0.11 Ma to 158.84 ± 0.05 Ma, with those from the stratigraphically lower Taroom Coal Measures ranging from 165.88 ± 0.11 to 163.05 ± 0.08 Ma and Juandah Coal Measures …

Exploring Intraplate Seismicity In The Midwest, Alexa Fernández

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Intraplate seismicity represents a notable occurrence within the stable North American Craton. This research explores the potential sources of stresses that could reactivate older faults and influence seismic activity within this region. Among these sources, the enduring impact of the last glacial period is considered, which includes continued glacial isostatic adjustments (GIA). During GIA the lithosphere rebounds due to the retreating ice, and the forebulge caused by far-field flexure in response to the glacial load, collapses. This results in significant faulting, fracturing, and seismic activity associated with the deglaciation phase. The adjustment of the lithosphere manifests as both near surface …

Exploring Overbank Sediment Deposition Variation In Heavily Modified Floodplains Of The Lower Mississippi River: A Sedimentological And Geophysical Analysis, Seth Fradella

Master's Theses

Since the 1930s, the Lower Mississippi River (LMR) has experienced large-scale modifications to the channel profile and surrounding floodplains through dams, dikes, revetments, dredging, and channel cutoffs. Although these changes have improved navigation and reduced flood risk, unanticipated changes to the major flood return period, individual flood severity and duration, and sediment regime have become increasingly apparent and sometimes problematic, such as the 2011 and 2018-2020 floods. Flood control levees along the LMR have reduced the natural floodplain area by 70-90%, resulting in heavily restricted overbank storage capacity of water and sediment. For the same flood events in recent history, …