Physical Sciences and Mathematics Commons^™

The Effects Of Fractures On The Occurrence And Distribution Of Arsenic In The Upper Floridan Aquifer During Aquifer Storage And Recovery, William Charles Hutchings

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Aquifer storage and recovery (ASR) is used world-wide to supplement available water supplies by storing surplus water in aquifers and recovering it during periods of drought and increased demand. The use of ASR as an option for increasing available municipal irrigation and fresh water supplies is threatened as a result of the mobilization of arsenic in some aquifers during ASR. Arsenic is liberated from arsenic-bearing sulfide minerals as a result of the mixing of oxidizing injected water with reducing insitu groundwater. Fracture networks can have significant influence on the migration and distribution of arsenic in the Upper Floridan Aquifer …

Assessment Of Student Achievement In Introductory Physical Geology: A Three -Year Study On Delivery Method And Term Length, Marianne O'Neal Caldwell

USF Tampa Graduate Theses and Dissertations

Physical Geology is a popular general education course at Hillsborough Community College (HCC) as at many other colleges and universities. Unlike many science courses, most students taking Physical Geology are not majoring in a STEM (Science, Technology, Engineering, and Mathematics) discipline. Typically most students enrolled in Physical Geology are majoring in business, education, or pursuing a general A.A degree for transfer to a four-year university. The class is likely to be one of the few, if not the only, physical science classes that many of these students will take in their academic career. Therefore, this class takes on increased importance, …

A Geochemical Analysis Of Fulgurites: From The Inner Glass To The Outer Crust, Michael L. Joseph

USF Tampa Graduate Theses and Dissertations

Cloud-to-ground lightning strikes produce natural glasses on the surface of the Earth, called fulgurites. These natural glasses are tubular in shape with a central void surrounded by an inner glass, and the inner glass is surrounded by an outer crust or toasted region. Previous studies report different kinds of melts existing in several different types of fulgurites; however, little to no chemical data has been collected that tracks chemical variations from the inner glass to the outer crust of a fulgurite. This study uses microprobe and laser ablation inductively coupled plasma mass spectrometer analytical techniques to collect transects of chemical …

Sediment Transport And Distribution Over Continental Shelves: A Glimpse At Two Different River-Influenced Systems, The Cariaco Basin And The Amazon Shelf., Laura Lorenzoni

USF Tampa Graduate Theses and Dissertations

The aim of this dissertation was to understand lithogenic suspended sediment transport mechanisms and distribution in two river-influenced margins: The Cariaco Basin, Venezuela, and the Amazon Shelf, Brazil. Lithogenic sediment input in the Cariaco Basin is controlled by small mountainous rivers (SMR), while in the Amazon Shelf it is dominated by the Amazon River, the largest river in the world in terms of freshwater discharge (~20% of global riverine discharge). Optical transmissometer measurements were coupled with particulate organic matter (POM) observations to understand changes in the geochemical composition of suspended sediment and spatial/temporal distributions over the two regions of interest. …

Production Of Bioactive Secondary Metabolites By Florida Harmful Bloom Dinoflagellates Karenia Brevis And Pyrodinium Bahamense, Cheska Burleson

USF Tampa Graduate Theses and Dissertations

Despite the critical role algae serve as primary producers, increases or accumulation of certain algae may result in Harmful Algal Blooms (HABs). Algal toxins from these blooms contribute significantly to incidences of food borne illness, and evidence suggests HABs are expanding in frequency and distribution. Mitigation of these HABs without knowledge of the ecological purpose and biochemical regulation of their toxins is highly unlikely. The production, function, and potential of secondary metabolites produced by the dinoflagellates Karenia brevis and Pyrodinium bahamense, were investigated.

Brevetoxins were demonstrated by two different methods to localize within the cytosol of Karenia brevis. …

Investigation Of Stress Changes At Mount St. Helens, Washington, And Receiver Functions At The Katmai Volcanic Group, Alaska, With An Additional Section On The Assessment Of Spreadsheet-Based Modules., Heather L. Lehto

USF Tampa Graduate Theses and Dissertations

Forecasting eruptions using volcano seismology is a subject that affects the lives and property of millions of people around the world. However, there is still much to learn about the inner workings of volcanoes and how this relates to the chance of eruption. This dissertation attempts to increase the breadth of knowledge aimed at helping to understand when a volcano is likely to erupt and how large that eruption might be. Chapters 2 and 3 focus on a technique that uses changes in the local stress field beneath a volcano to determine the source of these changes and help forecast …

Assessment Of The Oxbow Morphology Of The Caloosahatchee River And Its Evolution Over Time: A Case Study In South Florida, Chloe Delhomme

USF Tampa Graduate Theses and Dissertations

The Caloosahatchee River, located in Southern Florida, was originally a meandering and relatively shallow river. During the 1920s, the Caloosahatchee River was channelized and became the C-43 canal. The channelization has significantly impacted the river ecosystem, particularly the oxbows. The oxbows are the U-shaped water bodies on each side of the river channel, which are the remnant bends of the original river. To understand how anthropogenic influence affects hydrologic systems, the proposed case study was designed to assess the geomorphic changes of the oxbows of the Caloosahatchee River, Florida. Understanding and documenting the evolution of river morphology is becoming increasingly …

Paleobiological Assessment Of Controls Underlying Long-Term Diversity Dynamics, Andrés L. Cárdenas

USF Tampa Graduate Theses and Dissertations

Deciphering the factors underlying both long-term patterns of diversity and taxonomic turnover rates (i.e., extinction, and origination) has been one of Paleobiology's major foci for the past three decades. The importance of documenting these components is that they will expand our ability to interpret and model the evolutionary processes underlying those trends, highlight the evolutionary impact of historical events, and contribute to the formulation of robust predictions about the future of global diversity in response to the current anthropologically driven environmental changes. Accordingly, the first part of this study examines the possible occurrence of global marine evolutionary environmental controls into …

Temporal And Spatial Analysis Of Monogenetic Volcanic Fields, Koji Kiyosugi

USF Tampa Graduate Theses and Dissertations

Achieving an understanding of the nature of monogenetic volcanic fields depends on identification of the spatial and temporal patterns of volcanism in these fields, and their relationships to structures mapped in the shallow crust and inferred in the deep crust and mantle through interpretation of geochemical, radiometric and geophysical data.

We investigate the spatial and temporal distributions of volcanism in the Abu Monogenetic Volcano Group, Southwest Japan. E-W elongated volcano distribution, which is identified by a nonparametric kernel method, is found to be consistent with the spatial extent of P-wave velocity anomalies in the lower crust and upper mantle, supporting …

Vent-Fault Spatial Study Of Selected Volcanic Fields Of Southwestern North America And Mexico, Michelle Leonard

USF Tampa Graduate Theses and Dissertations

Of fundamental concern in volcanic hazard and risk assessment studies of volcanic systems is what role crustal structures might play in the ascent of magma through the crust. What are the processes that govern the spatial distribution and timing of eruptions, especially in populated areas or near sensitive facilities? Many studies have drawn the conclusion that faults play a critical role as easily–exploitable crustal weaknesses along which magma can ascend. Great care must be used when assuming a causative relationship between patterns of vents and faults especially when such relationships may be incorporated into hazard assessment models or other forecasting …

Natural And Anthropogenic Influences On The Morphodynamics Of Sandy And Mixed Sand And Gravel Beaches, Tiffany Roberts

USF Tampa Graduate Theses and Dissertations

Beaches and coastal environments are dynamic, constantly shaped and reshaped by natural processes and anthropogenic modifications. The morphodynamics and influence of natural and anthropogenic factors of two different coasts at various temporal and spatial scales are discussed.

To quantify the performance of several beach nourishment projects at annual temporal and kilometer spatial scales on three adjacent microtidal low-wave energy barrier islands in west-central Florida, a total of 5,200 beach and nearshore-profiles spaced at 300 m were surveyed monthly to bi-monthly from 2006-2010. Beach nourishment performance is most significantly influenced by the interruption of longshore sediment transport by complex tidal-inlet processes. …

On The Spatial And Temporal Variability Of Upwelling In The Southern Caribbean Sea And Its Influence On The Ecology Of Phytoplankton And Of The Spanish Sardine (Sardinella Aurita), Digna Tibisay Rueda-Roa

USF Tampa Graduate Theses and Dissertations

The Southern Caribbean Sea experiences a strong upwelling process along the coast from about 61°W to 75.5°W and 10-13°N. In this dissertation three aspects of this upwelling system are examined: (A) A mid-year secondary upwelling that was previously observed in the southeastern Caribbean Sea between June-July, when land based stations show a decrease in wind speed. The presence and effects of this upwelling along the whole southern Caribbean upwelling system were evaluated, as well as the relative forcing contribution of alongshore winds (Ekman Transport, ET) and wind-curl (Ekman Pumping, EP). (B) Stronger upwelling occurs in two particular regions, namely the …

Shelf-Scale Mapping Of Fish Distribution Using Active And Passive Acoustics, Carrie Christy Wall

USF Tampa Graduate Theses and Dissertations

Fish sound production has been associated with courtship and spawning behavior. Acoustic recordings of fish sounds can be used to identify distribution and behavior. Passive acoustic monitoring (PAM) can record large amounts of acoustic data in a specific area for days to years. These data can be collected in remote locations under potentially unsafe seas throughout a 24-hour period providing datasets unattainable using observer-based methods. However, the instruments must withstand the caustic ocean environment and be retrieved to obtain the recorded data. This can prove difficult due to the risk of PAMs being lost, stolen or damaged, especially in highly …

Mapping And Assessing Urban Impervious Areas Using Multiple Endmember Spectral Mixture Analysis: A Case Study In The City Of Tampa, Florida, Fenqing Weng

USF Tampa Graduate Theses and Dissertations

The advance in remote sensing technology helps people more easily assess urban growth. In this study, the utility of multiple endmember spectral mixture analysis (MESMA) is examined in a sub-pixel analysis of Landsat Thematic Mapper (TM) imagery to map urban physical components in Tampa, FL. The three physical components of urban land cover (LC): impervious surface, vegetation and soil, were compared using the proposed MESMA with a traditional spectral mixture analysis (SMA). MESMA decomposes each pixel to address the heterogeneity of urban LC characteristic by allowing the number and types of endmembers to vary on a per pixel basis. This …

Something Is Askew In Florida's Water: Arguing For A Better Descriptive Statistic For Positively Skewed Water-Quality Data, Amie October West

USF Tampa Graduate Theses and Dissertations

ABSTRACT

It may be of no surprise that water quality data is right-skewed, but what appears to be overlooked by some is that the arithmetic mean and standard deviation most often fail as measures of central tendency in skewed data. When using the arithmetic mean and arithmetic standard deviation with nutrient data, one standard deviation about the arithmetic mean can capture nearly all of the data and extend into negative values. Representing nutrient data this way can be misleading to viewers who are using the statistics, and making assumptions, to understand the characteristics of those waters. Through an in-depth statistical …

Variability In Hydrology And Ecosystem Properties And Their Role In Regulating Soil Organic Matter Stability In Wetlands Of West-Central Florida, Sharon Jean Feit

USF Tampa Graduate Theses and Dissertations

Soil organic matter (SOM) provides many ecosystem services that are necessary for continued ecosystem function. The accumulation of SOM in an ecosystem is a function of its persistence time which can range from days to thousands of years. Ecosystem properties including dominant vegetation type, soil texture, and soil moisture in various habitats can regulate the persistence time of SOM.

Wetlands, because of their associated ecosystem properties, promote SOM accumulation, but little has been done to determine the ecosystem properties that regulate its persistence over time. In west-central Florida, urbanization and increased water demands have suppressed water tables in isolated wetland …

Stable Isotope Analysis Of Busycon Sinistrum To Determine Fort Walton-Period Seasonality At St. Joseph Bay, Northwest Florida, Ryan Michael Harke

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Recent archaeological investigations indicate that coastal Fort Walton cultures in the St. Joseph Bay region of northwest Florida emphasized marine and estuarine foraging. These late prehistoric (A.D. 1000-1500) peoples collected fish, shellfish, and other aquatic resources. At the Richardson's Hammock site (8Gu10), radiocarbon-dated to about A.D. 1300, as at dozens of other shell middens around this salty bay, large gastropods were a major subsistence component. This adaptation is in sharp contrast with that of contemporaneous inland Fort Walton societies, who relied on maize agriculture. It is unknown whether coastal groups represent separate hunter-gatherer-fisher populations or seasonal migrations by inland …

Remote Sensing Of Whitings In The Bahamas, Ryan Allen Lloyd

USF Tampa Graduate Theses and Dissertations

Whitings on both the Great Bahama Bank (GBB) and Little Bahama Bank (LBB) were evaluated using data collected from 2000-2010 by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites. A semi-objective method was developed to classify whiting patches from other look-alike features using the recently developed Floating Algae Index (FAI) algorithm, an empirical cloud masking algorithm, and a gradient analysis from the 250-m resolution MODIS data. A total of 1,500 images with minimal cloud cover was used to calculate long-term and seasonal trends as well as an average daily coverage for both banks. Annual and …