Geology Commons^™

What Controls Ice Shelf Isotopic Variability? Local And Global Processes Preserved Within Ice Cores Across The Larsen C Ice Shelf, Antarctica, Orion Laurene Schomber

USF Tampa Graduate Theses and Dissertations

The Antarctic Peninsula (AP) is one of the foremost indicators of anthropogenic global warming as it interacts with both atmospheric and oceanic processes. Although ice shelves across the AP have undergone increased rates of disintegration over the last 30 years, limited in-situ measurements have been investigated. Assessment of three short (~30 m) firn cores (J108, J208, and J409) across the Larsen C ice shelf (LCIS) provide insight into local, regional, and global processes. Average core densities and isotopic variability (δ¹⁸O and δ²H) fall within expected ranges for all cores, indicating signal preservation through firn. However, isotopic maxima in J108 and …

Phosphorus: From The Origins Of Life To The Origin Of An Industry, Joshua Abbatiello

USF Tampa Graduate Theses and Dissertations

The element phosphorus is a key biogenic element that is often the limiting reagent for life. Phosphorus is quickly bound by metal divalent cations making it virtually insoluble and inert in water (forming the phosphate mineral apatite). Due to this, it becomes imperative to understand alternative pathways to increase biogenically available phosphorus in environments. To that end, this dissertation involved examining olivine as an alternative source of phosphorus to apatite, analyzing a novel grain of iron silicide found via lightning reduction in a fulgurite, and finally sought to understand the impact of phosphate mining through phosphogypsum stacks. Olivine is a …

Sea Turtle Nesting On Nourished Beaches With Different Construction Designs: A Case Study In Southeast Florida, Usa., Lara Novalvos Hernandez

USF Tampa Graduate Theses and Dissertations

This study examines the influences of different beach nourishment designs and subsequent post-nourishment profile adjustments on loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles nest survival and reproductive success. Data on time-series post-nourishment beach-profile changes, positions and elevations of turtle tracks and nest/false-crawl apices, and sea turtle nest hatch/emergence success were collected on five high density nesting beaches along the east coast of Florida: Melbourne Beach, Jensen Beach, Jupiter Island Beach, Juno Beach, and South Hutchinson Island Beach. The field data collection was conducted in 2018, 2019, 2021, and 2022 with the main goal of documenting and comparing turtle …

Quantifying Wellbore Effects During Co2 Sequestration In A Saline Aquifer, Uzoma Johnpaul Ajugwe

USF Tampa Graduate Theses and Dissertations

Carbon capture and storage (CCS) is a strategy for mitigating climate change by reducing greenhouse gas emissions from large stationary sources like fossil-fuel-fired power stations. One method of CCS involves carbon dioxide (CO2) sequestration in deep saline aquifers, where supercritical CO2 is injected into an aquifer. The success of such projects depends on accurate predictions of CO2 behavior within the subsurface, which are obtained through numerical simulations.

TOUGHREACT, a renowned simulation tool, models subsurface fluid flow, geochemical interactions, and solute transport, providing insights into the feasibility of CO2 sequestration projects. A critical aspect of these simulations is the apportioning of …

New Petrographic And Geochemical Constraints On Pre-Eruptive Storage Conditions And Their Control On Eruptive Styles In Martinique’S Recent Volcanic Systems, Abigail Martens

USF Tampa Graduate Theses and Dissertations

This dissertation investigates the volcanic systems of Martinique Island, focusing on magma storage conditions, magmatic evolution, and eruption dynamics. Chapter 3 presents a petrographic analysis of volcanic rocks from the island’s old, intermediate, and recent arcs, examining the evolution of plagioclase textures and the increasing abundance of other mineral phases, such as pyroxene, amphibole, olivine, and quartz, which provide insights into changing magmatic conditions. The main research is divided into two projects. Chapter 4 addresses the pre-eruptive storage conditions (pressure and temperature) of magmas beneath recent (<5 Ma) volcanic complexes (Morne Jacob, Piton du Carbet, Trois Îlets, Mt. Conil, and Mt. Pelée), exploring magma evolution, crystallization, and the role of lower crustal injections and flank collapses in triggering eruptions. Results reveal variable magma storage depths (<6 km), with significant temperature and pressure variations, indicating complex magmatic systems. Chapter 5 focuses on the Roches-Genty ignimbrite in southwestern Martinique, investigating its stratigraphy, geochemistry, and age using field mapping, grain size analysis, and 40Ar/39Ar dating. The study identifies two distinct sub-Plinian eruptive phases associated with the Dizac ignimbrite, with ages of 3.37 ± 0.14 Ma and 2.10 ± 0.26 Ma, providing insights into past explosive volcanic activity. Geochemical analysis confirms an andesitic composition, similar to regional volcanic systems. This dissertation enhances understanding of Martinique’s volcanic history, providing valuable insights into magmatic processes and eruption dynamics, with implications for volcanic hazard assessments in the Lesser Antilles.

Characterizing Lava Flow Morphology And Lava Flow Dynamics: A High-Resolution Lidar And Structure From Motion Study Of The Hell’S Half Acre Lava Flow, Idaho, Rachel T. Bakowski

USF Tampa Graduate Theses and Dissertations

Basaltic lava flow eruptions can impact vast areas, profoundly altering the landscape. Although many past eruptions have gone unobserved by scientists, they often leave behind substantial deposits that preserve key elements of the eruption’s history. By studying lava textures and the overall structure of lava flows, we can reconstruct the specific conditions that occurred during the eruption and contributed to the final morphology of the lava flows. Hell’s Half Acre is a large, well-preserved basaltic lava flow in the Eastern Snake River Plain, containing a variety of significant geological features resulting from its distinctive eruption history. This thesis examines a …

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 …

Revealing Grounding Zone And Subglacial Processes At Cosgrove Ice Shelf: Seafloor Analogs For The Modern Antarctic Ice Sheet, Rosemary E. Burkhalter-Castro

USF Tampa Graduate Theses and Dissertations

The future loss of ice in West Antarctica is one of the biggest uncertainties in projections of global sea level rise. The West Antarctic Ice Sheet (WAIS), home to Cosgrove Ice Shelf (CIS), contains enough ice to raise global sea level by more than three meters if it collapsed completely. Accurately predicting how much sea level change may occur from a future collapse of WAIS is of particular interest to low-lying, heavily populated coastal areas such as Florida. For this reason, it is important to understand the processes underpinning rapid changes and retreat at marine-terminating glaciers in the Amundsen Sea. …

The Application Of Multi-Isotope Analysis To Assist In Geoprofiling Unidentified Decedents Within Florida, Liotta D. Noche-Dowdy

USF Tampa Graduate Theses and Dissertations

The biochemistry of human tissues can provide information for geoprofiling (geographic birthplace or migration patterns) of an unidentified decedent. Utilizing isotope analyses (both stable and radiogenic) from teeth, bone, nails, and/or hair reveals specific isotopic information that correlates to diverse geographic regions reflecting an individual’s birthplace and migration patterns. Isotope analysis of enamel and bone has been employed in bioarchaeology for decades to reconstruct the diet, health, and migration patterns of past populations. Isotope ratios measured from enamel can then be compared to isotope ratios measured from bone of the individual to track patterns of migration. The enamel from the …

Development Of Decision-Support Tools For Water Resources Management In Coupled Human-Natural Systems, Edgar J. Guerrón Orejuela

USF Tampa Graduate Theses and Dissertations

Water is an indispensable resource for all forms of life. Water is a cornerstone for economic development, public health, and social well-being. However, increasing water demand and challenges posed by climate change, pollution, population growth, and land use change underscore the urgent need for effective water management strategies. To address these complexities and ensure the sustainable use of water resources, it is imperative to adopt science-based decision-support tools. These tools leverage data, models, and analytical techniques to provide valuable insights and recommendations that guide decision-makers in formulating evidence-based policies and practices.

Effective water management requires a comprehensive understanding of the …

Local Seismic Investigations In Arizona: Analysis Of A Low-To-Moderate-Magnitude Aftershock Sequence And A Pilot Study Of Monsoon-Driven Flash Floods, Kathryn Margo Dorn

USF Tampa Graduate Theses and Dissertations

Arizona encompasses a strikingly diverse array of geological terranes and physiographic terrain and consequently experiences a wide range of tectonic and meteorological phenomena, many of which generate distinctive seismic signals. For much of the past century, however, the state has largely lacked the style of dense seismic networks now prevalent in some regions of neighboring California, allowing myriad low-magnitude earthquakes and other subtle seismic sources to elude detection and characterization. In this dissertation, I utilize the high-resolution data of two temporary local seismic networks to investigate two such sources – the primarily low-magnitude but prolific aftershock sequence of the 29 …

Resolving Antarctic Margin Paleoceanography For Two Different Timescales And Archives, Theresa M. King

USF Tampa Graduate Theses and Dissertations

Recent decades have seen increased rates of ice mass loss from Antarctic ice sheets, through thinning of many ice shelves around the periphery of the continent. The most vulnerable are the glacial systems that are marine-terminating and grounded below sea level, a characteristic that exposes these systems to sea level rise and warming oceans. Enhanced basal melting under the influence of warm ocean water masses can lead to thinning and retreat of glaciers, and ultimately to the acceleration of grounded ice loss. To contextualize current ice mass loss and contribute to accurate model projections for future retreat scenarios, it is …

Beach Processes Controlling Erosional Hotspots And Their Influences On Beach Nourishment Performances: A Case Study Along West-Central Florida Barrier Island Beaches, Sophia Gutierrez

USF Tampa Graduate Theses and Dissertations

This study examines the long-term performance of repeated beach nourishment over an approximately 35-year period at two barrier islands, Sand Key and Treasure Island along the west-central Florida coast, USA. Five cycles of beach nourishment on Sand Key and six on Treasure Island were conducted during the study period. Three erosional hotspots were identified along a combined 14-km stretch of the nourished beach. The processes that cause the erosional hotspot were examined through numerical modeling of nearshore wave and current fields.

The most recent three nourishments since 2006 were monitored systematically by this study. Beach profiles were surveyed bimonthly to …

Investigating The Causes Of Lake Level Variability On A Modern Carbonate Platform, Natalie M. Salazar

USF Tampa Graduate Theses and Dissertations

Lakes on carbonate islands are known to reduce freshwater lens volumes and alter freshwater lens distribution; however, the magnitude and controlling factors between lake and freshwater lens interactions remain poorly understood. Since freshwater lenses are thin and can be fragmented by lakes in small carbonate islands, it is important to understand the magnitude of exchange between lakes and the freshwater lens to understand potential groundwater depletion. This study utilized high temporal resolution water levels and meteorological data to quantify monthly water budgets for seven lakes on San Salvador Island, The Bahamas. The monthly water budgets accounted for rainfall, potential evaporation, …

Determining The P-Wave Velocity Structure In The Near-Surface Of Nw Miami, Florida, Using Quarry Blasts, Elham Moslemi

USF Tampa Graduate Theses and Dissertations

The fact that Florida is an earthquake-free region has caused seismologists to pay less attention to it. Few earthquakes in this state mean it is not a usual practice to study the propagation of seismic waves. However, utilizing data from quarry blasts, we studied wave propagation in this region. The primary objective of the project is to investigate the near-surface P-wave velocity structure and factors that may affect it. We also analyzed the amplitude of signals versus distance and blast size. A network of up to 10 Raspberry Shake instruments around the NW Miami-Lakes mining area was deployed where four …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Water Chemistry Variability In Peacock Springs Cave System And Spring Basin: Impacts On Continuous Monitoring Of Karst Aquifers, Mahnoor Kamal

USF Tampa Graduate Theses and Dissertations

The Upper Floridan Aquifer (UFA) is a highly transmissive and heterogeneous karst aquifer that makes it acutely susceptible to pollution. Rapid and extensive water quality changes in nutrients at springs draining the UFA have prompted intensive monitoring at several priority springs, including continuous and discrete water quality sampling. Springs, however, are a discrete discharge point of an often-expansive phreatic cave network that can intersect different land uses and thus drain distinct geographic areas of a springshed. The extensive network contains convergent passages from deep and shallow aquifer regions and may contribute to varying water chemistry across passages resulting in water …

Mining Multibeam Transit Data For Deep Ocean Polymetallic Nodules: Case Study In Se Pacific Ocean, Mark E. Mussett

USF Tampa Graduate Theses and Dissertations

Occurrences of nodules on the seafloor represent benthic habitats and present potential deposits of economically important metals. Better understanding their extent throughout Earth’s oceans will aid in resource management and determining different factors which influence their formative factors and respective local characteristics. Multibeam bathymetry and backscatter data, along with auxiliary data suggest an area of seafloor near the Foundation Seamount chain in the southern Pacific Ocean, centered around -36.84° latitude, -119.75° longitude, contains a previously uncharted polymetallic nodule occurrence. Our analysis of Simrad EM12 DUAL (12 kHz) multibeam data, collected during a 1997 transit, shows an area of strong backscatter …

Flow Generation And Propagation From Headwater Wetlands To Downstream Waters, Leanne Marie Stepchinski

USF Tampa Graduate Theses and Dissertations

Headwater wetlands are connected to one another and to downstream waters by dynamic hydrologic flowpaths, functioning as integrated hydrologic networks at the watershed scale. Headwater wetlands perform a variety of hydrologic lag, sink, and source functions, including flow generation and propagation, thereby contributing to the natural flow regimes of downgradient waters. The functions of individual wetlands and their contributions to hydrologic connectivity and subsequently to the natural flow regime have been widely studied and are well understood. Comparatively, the functions and hydrologic connectivity within wetland complexes as a whole and their collective subsequent contributions to the natural flow regime of …

Ice-Core Reveals Flavors Of Hydroclimate Extremes In The American Southwest, Laura Calabrò

USF Tampa Graduate Theses and Dissertations

A small number of caves and lava tubes worldwide host perennial ice deposits, which occur at elevations well below those of mountain glaciers and in areas outside the permafrost climatic belt, where no surface glaciation exists. These settings make any of the ice deposits in caves or lava tubes particularly susceptible to the current warming trend, leading to the imminent loss of some untapped cryospheric paleoenvironmental archives.

The present work is the result of a paleoclimate study based on ice deposits accumulated within lava tubes in El Malpais National Monument (ELMA, western New Mexico). The ice cores span from 7,000 …

Applications Of Seismic And Geodetic Data To Earthquake Hazard Research, Mahsa Afra

USF Tampa Graduate Theses and Dissertations

Being a part of a seismically active zone, including large and crowded cities such asTehran, Qazvin and Semnan, Central Alborz experiences many local earthquakes. Knowl- edge of crustal velocity structure in this area is thus necessary considering its economical and political importance, a large concentration of population, and relatively poor construc- tion practice which increases the earthquake risks in this region. In second chapter of this thesis, we aim at obtaining the 3D crustal velocity structure of the Central Alborz region in northern Iran using local earthquake tomography. We also validate anomalies inferred from our velocity model using an independent …

A Seismic Investigation Of Uturuncu Volcano And The Lazufre Volcanic Complex, Heather L. Mcfarlin

USF Tampa Graduate Theses and Dissertations

The following dissertation is a study of three seismological techniques used to determine the geophysical properties of two large, inflating magma bodies in the upper crust in South America: one under Uturuncu volcano and one beneath Lastarria and Cordon del Azufre volcanoes. First, I use the method of teleseismic receiver functions to image the top and bottom of the magma body beneath Uturuncu volcano. Depths to the top of this body vary between 6 and 12 km below sea level, while depths to the bottom vary between 13 and 22 km below sea level, with the thickness ranging from 6 …

Volcano And Tectonic Hazard Modeling Using Interdisciplinary Geophysical And Geodetic Methods, Mitchell Scott Hastings

USF Tampa Graduate Theses and Dissertations

Volcanic and tectonic hazards such as volcanic eruptions, earthquakes and tsunamis present risks to about ~45% of the global population. They have caused at least 1.5 trillion dollars in damages worldwide since the start of the 20th century, and the costs are accelerating as population increases. In this dissertation, new data are combined with existing information and novel modeling approaches to quantify volcanic, earthquake and tsunami hazards.

The Blackfoot Reservoir Volcanic Field (BRVF) is a bimodal volcanic field on southeastern margin of the Eastern Snake River Plain in Idaho. In the BRVF, gravity anomalies reveal two shallow silicic intrusions that …

Functional Morphology And Taphonomy Of Ordovician–Silurian Diploporan Echinoderms, Stephen Ashley Hill

USF Tampa Graduate Theses and Dissertations

Diploporan echinoderms were one of the most speciose groups of stemmed echinoderms during the Ordovician. Despite this widespread abundance, the fossil record of diploporan fauna consists primarily of incomplete specimens, with complete specimens being rare. While the theca, or body, is more commonly preserved, the feeding appendages and the attachment structures (i.e. stems or holdfasts) are seldomly preserved. Insight into these features is highly valuable to the understanding the paleoecology, like the feeding and respiratory strategies, of these enigmatic creatures.

One group of diploporan echinoderms which does have an extensive fossil record, is the Holocystites Fauna, primarily known from the …

Ice Deposits In Lava Tubes From West-Central New Mexico As Archives Of Past Volcanic Eruptions And Climate Change, Quinton Z. Vitelli-Hawkins

USF Tampa Graduate Theses and Dissertations

The Southwest of the United States is currently in a megadrought phase. Recent studies have shown that three of the most severe droughts of the last two millennia have occurred in the last 120 years, while geo-archaeological evidence suggests there were five megadroughts just from 150 to 950 CE. To try to better understand the causes of the droughts across the Southwest, a 110-cm long ice core was drilled from an ice deposit in a lava tube (Cave 29) from El Malpais National Monument in west-central New Mexico. The δ18O values in the ice core (ranging from −11.78 to −3.54‰) …

A Technique-Based Approach To Structure-From-Motion: Applications To Human-Coastal Environments, Robert Van Alphen

USF Tampa Graduate Theses and Dissertations

Photogrammetry is a method by which physical information can be extracted from thecorrespondence of 2-dimensional images. In the geosciences, Structure-from-Motion (SfM) photogrammetry is a technique that has seen considerable interest in the past decade of research. Here I present three case studies of various scope and methodologies which can inform the use of SfM in the geosciences. First, I discuss the theoretical and algorithmic basis of SfM photogrammetry and its uses thus far in the geosciences. Chapters two through four show specific studies which highlight several approaches to SfM and the data which can be produced. Chapter five then concludes …

Determining Depth Of Closure Based On Time-Series Beach Profiles And Empirical Formulas: A Case Study Along The Florida Coast, Elizabeth Royer

USF Tampa Graduate Theses and Dissertations

Depth of closure (DOC) is defined as the most landward depth seaward of which there is no significant change in bed elevation and no significant net sediment exchange between the nearshore and the offshore over a certain period of time, such as 5 to 20 years. DOC is an essential parameter used in beach and shore protection, sediment management, and many other aspects of coastal studies. Taking advantage of advancements in wave hindcast and bathymetry measurement in the past 20 years (2000-2019), this study determined the DOC at 12 locations along the Florida coast, including three from the northwest Gulf …

Characterizing Explosive Volcanic Eruptions Using Tephra Fall Deposit Data, Robert Constantinescu

USF Tampa Graduate Theses and Dissertations

This dissertation addresses the estimation of the magnitudes and intensities of explosive volcanic eruptions using tephra fall deposits and numerical modeling. Tephra fall deposits retain information about eruption dynamics. Volcanologists sample tephra fall deposits and measure the thickness, extent and grain size distribution to estimate the erupted volume and plume height of explosive eruptions. These terms are known as eruption source parameters. These parameters are used to classify the intensity and magnitude of the eruption on a scale such as the Volcanic Explosivity Index (VEI). Accurate estimation of the intensity and magnitude of explosive eruptions is a crucial factor in …

Factors Controlling Longshore Variations Of Beach Changes Induced By Hurricane Hermine Along Pinellas County Beaches, West-Central Florida, Wenhan Zhai

USF Tampa Graduate Theses and Dissertations

Hurricane Hermine, 2016, impacted the coast of west-central Florida and generated high waves superimposed on elevated wave levels which caused significant beach erosion. A total of 122 profiles, spaced about 300 m apart, were surveyed 2 weeks before and one week after the storm to examine the beach changes along three barrier islands along the coast of west-central Florida. including Sand Key, Treasure Island and Long Key. In order to investigates the longshore variations of beach/nearshore changes induced by storm, several parameters were defined and calculated including beach volume changes, berm height, beach width, foreshore slope, as well as sandbar …

Soil Accretion And Mass Accumulation In A Scrub And Fringe Mangrove Forest In Biscayne Bay, Florida, Jessica A. Jacobs

USF Tampa Graduate Theses and Dissertations

This study estimated soil accretion and mass (organic carbon (OC), total nitrogen (TN), and total soil) accumulation in a scrub and fringe mangrove forest in Biscayne Bay, FL, to assess how forests of different morphologies (scrub vs. fringe) have kept pace with recently accelerating rates of sea-level rise. Accretion rates (AR) were estimated using the Constant Initial Concentration (CIC) model of lead-210 deposition and it was determined that the scrub forest has accreted at 1.3 ± 0.2 mm yr-1 over 75 years and the fringe forest at 2.8 ± 0.4 mm yr-1 over 92 years. The fringe forest estimate met …