Geology Commons^™

Advancements In Modern Seismic Monitoring: Integrating Novel And Traditional Methods For Earthquake Detection, Characterization, And Structural Imaging, Marc Adrian Garcia

Open Access Theses & Dissertations

Modern seismic monitoring has been transformed by machine-learning methods that detect and locate earthquakes at scales manual analysis cannot reach. This dissertation develops, validates, and applies such workflows across three settings that span the range of modern monitoring problems: a major subduction-zone aftershock sequence, the tectonic questions that sequence can answer, and an urban region without any local monitoring at all. First, I construct a high-resolution catalog for the aftershock sequence of the September 8, 2017, Mw 8.2 Tehuantepec, Mexico earthquake, by integrating deep-learning phase detection with established location and relocation methods. The resulting catalog of 11,374 relocated earthquakes is …

Stratigraphic Analysis Of The Buda Limestone With Implications On Hydrocarbon Production Constraints, Madison And Houston County, Texas, Jeffrey C. Bridges

Electronic Theses and Dissertations

The Fort Trinidad and Alabama Ferry fields located in eastern Madison and southern Houston County, Texas, have produced approximately 100 million barrels of oil equivalent to date, with approximately 65% of this being oil. However, there has been considerable variation in production within this Cretaceous carbonate play of the Fort Trinidad field, despite similar well completions and perforated intervals. The Buda Limestone, a key producing formation in the Cretaceous interval, is described as under-pressurized and often has lost circulation problems during drilling due to sub-pressure vertical fractures. Within the producing interval, the mechanisms for water production versus oil production are …

The Role Of Heterogeneity In Earthquake Rupture Dynamics: Insights From Friction Experiments On A 1-Meter Laboratory Fault, Alejandro Aguilar

All Graduate Theses and Dissertations, Fall 2023 to Present

Tectonic faults are made of many kinds of rocks and minerals, creating natural weak and strong zones along faults where earthquakes occur. These differences can affect how faults move, including whether slip occurs slowly and quietly or suddenly and destructively during an earthquake. However, it is not fully understood how these variations influence when earthquakes start, how fast they spread, and whether they stop or grow into large ruptures. This research studies how different fault materials interact during earthquake slip. Using a large laboratory machine that simulates fault movement under realistic conditions, we recreate earthquake processes and closely measure how …

Reading The Martian Surface: Impact Crater Distributions And Geochemical Signatures In Gale Crater As Recorded By The Curiosity Rover, Megan E. Hoffman

Earth and Planetary Sciences ETDs

The Curiosity rover has been exploring Gale crater, a large impact basin near the Mars equator since 2012. This mission has greatly improved our ability to explore the surface of Mars with a suite of geologic tools and cameras and has revealed that Mars likely once resembled present-day Earth. In this dissertation, I utilize measurements and data taken by Curiosity to analyze the distribution and preservation of small impact craters at meter scales, I quantify the formation characteristics of a small impact crater cluster, and I examine the presence of barium in a geologic unit with high-Si to constrain sediment …

Mapping Along-Strike Changes In Shallow Subduction Zone Geometry At The Alaska Subduction Zone Using Seismic Reflection And Tectono-Geomorphic Analysis, Madelyn K. Hurd

Earth and Planetary Sciences ETDs

The Alaska subduction zone, where the oceanic Pacific plate subducts beneath the continental North American plate at a rate of 60-66 mm/yr, has hosted more >M8 earthquakes over the last century than any other subduction zone globally. The largest of these, the 1964 M9.2 Alaska earthquake, ruptured 800 km of the margin, including a high slip patch near the trench offshore Kodiak Island. The 1964 rupture area may have overlapped with the 1938 M8.3 Semidi earthquake rupture zone that lies to the west. Slip propagation near the subduction trench during large earthquakes can control tsunamigenesis, and differences in wedge geometry …

Mining Legacy And Wildfires: Interfacial Reactions Affecting Metal Mobility, Eresay Alcantar-Velasquez

Earth and Planetary Sciences ETDs

We identified water labile interfacial reactions between laboratory burned pinewood ash and mine waste solids that influence metal mobilization. The Upper Gallinas Creek Watershed in New Mexico is affected by wildfires and mining legacy. Pinewood and mine waste sediments were sampled from the area, and the pinewood was burned at 350°C to simulate medium burn intensity ignition. Rapid desorption and gradual dissolution of Mn and Fe was detected by ICP-MS as pH decreased over time. After reacting 18 MΩ ultra-pure water with a mixture of pinewood ash and mine waste sediments Fe (143%) and Mn (89.2%) concentrations increased over time. …

Hydrus Modeling Of A Sahelian Agroforestry System: An Investigation Of Local Water Balance, Nicole A. Butler

Master's Theses

Effects of drought can devastate agricultural productivity in the West African Sahel. Climate complexities, such as lower-than-average rainfall and high winds, can lead to crop failure and low yields, thereby creating food security issues. Agriculture in the Sahel is primarily rainfed, and the rain is becoming increasingly unpredictable due to the changing climate. The method of intercropping groundnut (Arachis hypogea) and pearl millet (Pennisetum glaucum) with the shrub species Piliostigma reticulatum can combat the effects of climate change and restore degraded soil. Intercropping can increase water availability and crop yield when compared to crops grown in the absence of shrubs. …

Minerals Rock!: Improving Audience Engagement And Interest In Stem Through Enhancement Of The In-Person And Online Mineral Collection At Ursinus College, Juliette Lyons

Environment and Sustainability Summer Fellows

Museums are a vital source of educational resources for the general public. They provide information on a variety of topics and disciplines and encourage visitors to be excited about and engaged in learning something new. As we work to comprehend key topics such as climate change, it is especially important for the broader public to better understand science, including geology. While the geological collection at Ursinus, Pieces of Earth’s History, is not in a museum, implementing methods that museums use can improve the reception of the collection. Through the application of research gathered through articles, journals, books, and talking with …

Toward The Significance Of Crevasse Orientation In Low And High Crevassed Regions On The Kennicott Glacier, Alaska, Usa, Claire A. Sturm

DePaul Discoveries

Supraglacial landforms serve as potential indicators of underlying bedrock morphology and glacier dynamics. The distribution and morphology of crevasses are closely associated with stress fields and ice-flow regimes, representing processes of stable glaciers, in contrast to their reduced occurrence in stagnant or receding ice masses. The orientation and density of crevasses influence a glacier’s ability to absorb solar energy, as they facilitate movement of meltwater down to subglacial rivers. Beyond the meltwater acting as a lubricant for basal sliding, the slope of the bedrock further impacts the local velocity and ice deformation of a glacier. The study of ice-fracturing mechanics …

Block Kinematics, Interseismic Coupling And Fault Slip Rates In The Aegean Region From Gps And Earthquake Slip Vector Data: 1. Upper Plate Structures, Konstantinos Chousianitis, Sotiris Sboras, Volkan Özbey, Robert Mccaffrey, Semih Ergintav

Geology Faculty Publications and Presentations

We represent the active deformation of the Aegean region with an elastic‐kinematic block model composed of a finite number of rotating crustal blocks whose boundaries coincide with major active structures. A total of 832 GPS velocities and 146 earthquake slip vectors were inverted to provide estimates of block rotations and interseismic locking on block‐bounding faults so as to best reproduce the observed deformation field. Our regional model allowed us to derive a self‐consistent set of geodetic slip rates for upper plate faults and the Hellenic subduction system, the results of which are presented in a companion paper, and to determine …

Elemental Analysis Of Upper Devonian To Lower Mississippian Organic-Rich Mudstone Cores From Kentucky By Portable X-Ray Fluorescence (Pxrf), Alex M. Washburn

KGS Research Data Set

This dataset contains high-density portable X-ray fluorescence (pXRF) elemental analyses of 1,867 m (6,125 ft) of Upper Devonian to Lower Mississippian organic-rich mudstone cores from Kentucky. Analyses were collected from cores across the Illinois Basin, Cincinnati Arch, and Appalachian Basin to support regional evaluation of elemental variability, chemostratigraphy, and redox-sensitive trace-metal enrichment in Devonian–Mississippian mudstone successions. All measurements were conducted using a Bruker Tracer 5 pXRF analyzer with the factory “Mudrock Air” calibration, using analytical settings optimized for both low-atomic-number elements and transition metals/redox-sensitive trace elements. Reference materials SARM-41 and SGR-1 were analyzed throughout the analytical sequence to monitor instrument …

Glacier Elevation Difference Data For The Conterminous U.S., Andrew G. Fountain, Bryce Allen Glenn, Christopher Mcneil, Brian Menounos

Geology Faculty Datasets

Historic and recent elevation data for the glaciers in the conterminous US were differenced to estimate glacier mass and volume change.

Historic glacier elevations were obtained from the USGS National Elevation Dataset (https://doi.org/10.15760/geology-data.04), a digitized product from the USGS 1:24,000 paper topographic maps that included the glacier extent (Gesch, 2007). Recent glacier elevations were derived from aerial lidar and from satellite radar. The lidar data were largely obtained from the USGS 3D Elevation Program (Stoker and Miller, 2022; US Geological Survey, 2024), and filtered by acquisition date using only those data collected between mid-summer and early autumn. The …

Chaotropic And Kosmotropic Effects Of Brines On Protein Structure: Habitability Across The Solar System, Shelby Dawn Osborne

Graduate Theses and Dissertations

Salts exhibit unique and specific effects on biomolecular structure depending on the physical nature of the salt (ion density, formation of hydration shells, direct binding to protein). This thesis implements biochemical, thermodynamic, and computational methods to investigate how the nature of the salt effects protein structure, which aids in defining the habitability of various brine solutions. By using simple proteins and solar system relevant salts, we inspect the physical reactions of proteins to these saltwater environments to understand which salts stabilize or destabilize protein structure. Several methods of experimentation are utilized to provide an understanding of the interaction relevant to …

The Geologic History Of The Chehalis Forearc Basin, Washington State, Usa, R. L. Moe, J. Bershaw, L. M. Staisch, A. R. Streig

Geology Faculty Publications and Presentations

The Chehalis basin is located between the Cascade arc and the Coast Range in southwest Washington State. It consists of sedimentary and volcanic rocks deposited throughout the Cenozoic and is underlain by the Siletzia terrane, a thick, large igneous province accreted in the Eocene. Here, we constrain evolution of the Chehalis basin depocenter using isochore maps derived from isostatic gravity anomalies, borehole data, and stratigraphy for several time periods: the Eocene (47.6–36.8 Ma), the Oligocene (36.8–20 Ma), and the Neogene (20–0 Ma). Our results suggest that local subsidence is driven by deformation on faults that bound and intersect the basin. …

Block Kinematics, Interseismic Coupling And Fault Slip Rates In The Aegean Region From Gps And Earthquake Slip Vector Data: 2. Hellenic Subduction System, Konstantinos Chousianitis, Volkan Özbey, Sotiris Sboras, Robert Mccaffrey, Semih Ergintav

Geology Faculty Publications and Presentations

The Hellenic subduction system is the primary locus of Nubia‐Eurasia convergence, yet thedistribution of strain accumulation along it is still debated. Here, we invert 832 geodetic velocities and 146earthquake slip vectors to assess the spatial variability of interseismic locking and provide new constraints onthe rate of slip deficit accumulation. We find that the subduction interface beneath southwestern Peloponneseand across the area from offshore south Peloponnese to offshore southwest of western Crete hosts three patchesof low to moderate locking (0%–40%) at 10–50 km depth whose slip rate deficits account for ∼15–30% of thetotal plate convergence. The offshore weakly locked patches show …

Hydrogeochemical Characterization Of Groundwater In Fractured Crystalline Basement Aquifers In Dodoma, Central Tanzania: Implications On Water Quality For Domestic And Irrigation Applications, George J. Ishabairu, Simon R. Melchioly, Charles H. Kasanzu, Gabriel D. Mulibo

Tanzania Journal of Science

Assessment of groundwater hydrogeochemistry characteristics of aquifers plays a vital role in establishing water quality status and its suitability for human and industrial use. The main objective of this research was to carry out hydrogeochemical characterization of groundwater and assess its impacts on water quality and spatial variability of groundwater geochemistry in Dodoma, Tanzania. The methods used include groundwater sampling, laboratory analysis to determine physico- chemical parameters and data processing to classify the groundwater hydrochemical facies. The results show that the average value for pH is 7.2, for electrical conductivity (EC) is 1108 µS/cm and for total dissolved solids (TDS) …

An Overlooked Terrestrial Archive: Freshwater Cements And Hydroclimate Signals In Quaternary Glaciogenic Deposits, Owen F. Mccaffrey, Ian Z. Winkelstern, Tara A. Kneeshaw, Melinda C. Higley

University Faculty Publications and Creative Works

Quaternary glaciogenic deposits, which serve as vital groundwater aquifers, are often partially cemented with carbonate minerals, but the timing of emplacement of these cements and their geochemical conditions of formation remain understudied. Here, we integrated petrography, δ¹⁸O, Mg/Ca, and clumped isotope (Δ₄₇) data from two calcitecemented outcrops in western Michigan (USA) to investigate the origin of glacial sediment cements. The two sites have contrasting topographic and textural settings reflecting distinct formation conditions. The elevated Wabasis Lake deposit records sequential phreatic-to-vadose cementation, while the Cherry Valley Sands site, very close to the modern water table, shows a …

An Overlooked Terrestrial Archive: Freshwater Cements And Hydroclimate Signals In Quaternary Glaciogenic Deposits, Owen F. Mccaffrey, Ian Z. Winkelstern, Tara A. Kneeshaw, Melinda C. Higley

University Faculty Publications and Creative Works

Quaternary glaciogenic deposits, which serve as vital groundwater aquifers, are often partially cemented with carbonate minerals, but the timing of emplacement of these cements and their geochemical conditions of formation remain understudied. Here, we integrated petrography, δ¹⁸O, Mg/Ca, and clumped isotope (Δ₄₇) data from two calcitecemented outcrops in western Michigan (USA) to investigate the origin of glacial sediment cements. The two sites have contrasting topographic and textural settings reflecting distinct formation conditions. The elevated Wabasis Lake deposit records sequential phreatic-to-vadose cementation, while the Cherry Valley Sands site, very close to the modern water table, shows a …

Morphodynamic Evolution Of Midnight Pass, West-Central Florida, Sydney C. Scott

USF Tampa Graduate Theses and Dissertations

This study takes advantage of a rare opportunity provided by the reopening of Midnight Pass due to two consecutive hurricanes in 2024, to examine the morphologic evolution of a newly reopened inlet and subsequent beach-inlet interactions. Historical aerial photos since the 1940s were collected and analyzed to understand the last closure of Midnight Pass, and to gain knowledge on the future of the newly reopened inlet. Time-series topography and bathymetry survey of the beach-inlet system were conducted bimonthly to quarterly for the first year and a half after the reopening, with the goals of quantifying the morphologic changes and understanding …

Interseismic Creep Along The Enriquillo–Plantain Garden Fault, Haiti, Estimated From Insar, Rishabh Dutta, Jeremy L. Maurer, Yi Chieh Lee

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Enriquillo–Plantain Garden fault zone (EPGFZ) is a major left-lateral strike-slip fault in southern Haiti hosting several recent destructive earthquakes, including the 2021 MW 7.1 Nippes event with primary thrust-slip. To investigate how strain is accommodated in the vicinity of the 2021 event, we analyzed Sentinel-1 interferometric synthetic aperture radar (InSAR) data from 2017 to 2021 using a PS + DS (persistent + distributed scatterers) InSAR time-series approach to overcome decorrelation in this highly vegetated region. We reveal interseismic creep along the EPGF and adjacent Grand'Anse–Sud border faults, with pure strike-slip mechanism and rates up to 9 mm/yr. We suggest …