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Articles 5281 - 5310 of 29939
Full-Text Articles in Geology
Examining The Expression Patterns Of Desulfotalea Psychrophila Dsrab Operon And Pit At Subfreezing Temperatures And Different Concentrations Of Sulfate Salts As A Model For Mars And Icy Worlds Survival And Colonization, Sergio Luis Mosquera Mora
Examining The Expression Patterns Of Desulfotalea Psychrophila Dsrab Operon And Pit At Subfreezing Temperatures And Different Concentrations Of Sulfate Salts As A Model For Mars And Icy Worlds Survival And Colonization, Sergio Luis Mosquera Mora
Graduate Theses and Dissertations
Since ancient times, Humanity has been fascinated with the idea of what lies beyond the borders of our planet. Fortunately, the combined efforts of many nations have made it possible to send unmanned spacecraft to orbit planets located close to Earth. These missions have the principal goal to collect data that could help us understand the basic environmental conditions that persist on those planets, or for evidence of past or present life. Equally important, landers and rovers have been successfully deployed to start the in-situ exploration of many planets of the Solar System. Among them, Mars has been extensively studied …
Water Sourcing Strategies Of Desert Vegetation In Varying Soil Textures With Vegetation Competition: A Stable Isotope Analysis, Martha Elizabeth Gardea
Water Sourcing Strategies Of Desert Vegetation In Varying Soil Textures With Vegetation Competition: A Stable Isotope Analysis, Martha Elizabeth Gardea
Open Access Theses & Dissertations
Recent studies have suggested an ecohydrological separation of water exists in the northern Chihuahuan Desert, where vegetation types, rainfall regimes, and location in the terrain seem to determine the type of water (e.g. isotopically depleted or enriched in 18O and 2H) plants are able to source and use throughout their growing cycle. That work found evidence of creosote (Larrea tridentata) and mesquite (Prosopis glandulosa) using tightly bound soil water at both a site on an ephemeral channel and a site in higher elevated flat area because the isotopic signature of plant water at the beginning of the study did not …
Coastal Geomorphic Response To Sea-Level Rise, Storms, And Antecedent Geology: Examples From The Northern Gulf Of Mexico, Clayton Dike
Coastal Geomorphic Response To Sea-Level Rise, Storms, And Antecedent Geology: Examples From The Northern Gulf Of Mexico, Clayton Dike
Dissertations
Sea-level rise and tropical cyclone activity are threatening coastlines around the world. Past geologic coastal responses can be used to inform future scenarios. This three-part study examines the response of coastal systems to sea-level rise, storms, sediment supply, and antecedent geology over the past ~ 140 ka.
The first study is of the Bay St. Louis, Mississippi, coastal system along the northern Gulf of Mexico incorporating sediment supply, subsidence, and antecedent topography paired with an examination of geologic response to sea-level fall and rise. I used core and geophysical data that resolve incised valleys and other subsurface deposits from ~ …
Hydroclimate Variability In Central America During The Holocene Inferred From Lacustrine Sediments In Lake Izabal, Eastern Guatemala, Edward Fernando Duarte
Hydroclimate Variability In Central America During The Holocene Inferred From Lacustrine Sediments In Lake Izabal, Eastern Guatemala, Edward Fernando Duarte
Doctoral Dissertations
"Holocene hydroclimate reconstructions have contributed to our understanding of the mechanisms controlling precipitation in Central America. Recent hydroclimate proxy records from the region, however, have revealed considerable spatiotemporal complexity in precipitation variability. This complexity is hypothesized to result from the interaction between multiple oceanic-atmospheric processes that converge in the region. This project analyzed three sediment cores from Lake Izabal, eastern lowland Guatemala, with the goal of understanding changes in precipitation, lake productivity, and lake water chemistry during the Holocene. Our proxy results indicate that precipitation in the region increased from the early to the middle Holocene, when Lake Izabal became …
Structural Interpretation Of An Alkaline-Carbonatite Complex Using Gravity And Magnetic Methods At Magnet Cove, Arkansas, Chelsea Morgan Amaral
Structural Interpretation Of An Alkaline-Carbonatite Complex Using Gravity And Magnetic Methods At Magnet Cove, Arkansas, Chelsea Morgan Amaral
Graduate Theses and Dissertations
The Magnet Cove alkaline-carbonatite complex in the Ouachita Mountains of south-central Arkansas could be a valuable resource for rare earth elements, though it has not yet been thoroughly studied using geophysical methods, and existing geophysical models simplify its diverse nature. Prior to this study, the subsurface structure and extent of the Magnet Cove complex was poorly understood and, in general, the process of emplacement of alkaline carbonatite complexes worldwide is also not fully understood. The Magnet Cove complex hosts an extensive variety of rare rock types and mineral resources that contrast significantly to the sedimentary rocks into which they have …
Understanding Martian Salts And Their Implications For Liquid Water, Rachel Slank
Understanding Martian Salts And Their Implications For Liquid Water, Rachel Slank
Graduate Theses and Dissertations
Water is one of the key components for life as we know it. The existence of salts on Mars has been a large contributing factor to the possibility of habitability, due to their ability to allow liquid water to remain stable at colder temperatures. Salts, including perchlorates, chlorates, and chlorides, have been detected by multiple landers, rovers, and orbiters, and are now believed to be ubiquitous on Mars. One of the pathways to liquid brine solutions is through deliquescence. Deliquescence is the transition from a solid salt crystal into an aqueous solution when exposed to a humid atmosphere. This research …
Evaluation Of The Geothermal Potential Of The Camas Prairie, South-Central Idaho, Connor J. Smith
Evaluation Of The Geothermal Potential Of The Camas Prairie, South-Central Idaho, Connor J. Smith
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The area studied in this thesis was assessed based on the analysis of a water sample collected from the exploratory well USU Camas-1. The water sample was characterized and compared to other water samples collected and analyzed during a previous phase of this project according to its water chemistry.
Lithologic, geophysical, and temperature logs were also used to assess the study area. The depth sensitive data was analyzed to determine the characteristics of the formation as they relate to the favorable parameters of a geothermal resource, those being permeability of the subsurface, heat, and the presence of a clay seal. …
Evidence For An Early Saginaw Lobe Ice Retreat And Drainage Adjustments Across Southern Michigan, Usa, Nathan Erber
Evidence For An Early Saginaw Lobe Ice Retreat And Drainage Adjustments Across Southern Michigan, Usa, Nathan Erber
Dissertations
The Saginaw lobe of the Laurentide Ice Sheet (LIS), flowed out of Saginaw Bay, across Lower Michigan and into northern Indiana. As it retreated, the Saginaw lobe deposited the Sturgis moraine, a recessional moraine of the lobe in southern Michigan. Positioned to the west and east of the Saginaw lobe were the Lake Michigan and Huron-Erie lobes, respectively. These lobes retreated across the region asynchronously, with the Saginaw lobe retreating first. The asynchronous behavior of the lobes allowed for the Lake Michigan and Huron-Erie lobes to overprint and alter landscapes once occupied by the Saginaw lobe ice.
The Kalamazoo moraine, …
Source And Parental Melts Of Poikilitic Shergottites: Implications For Martian Magmatism, Evan W. O'Neal
Source And Parental Melts Of Poikilitic Shergottites: Implications For Martian Magmatism, Evan W. O'Neal
UNLV Theses, Dissertations, Professional Papers, and Capstones
Martian poikilitic shergottite meteorites are cumulate rocks that can be used to understand melt evolution on Mars from the bottom of the crust (~10 kbar) all the way up to near-surface shallow depths (~1 kbar). There is a general lack of knowledge regarding shergottites including, parental magma compositions, crystallization ages, and the location of the enriched geochemical source of the shergottites in the martian mantle. Through a comprehensive petrographic and geochemical study, we have attempted to better understand poikilitic shergottite formation and the evolution of the martian interior during the Amazonian period (~3 Ga – present day). We studied a …
The Application Of Detrital Zircon Geochronology, Pressure-Temperature Modeling, Monazite Petrochronology, And Quartz-In-Garnet Elastic Geobarometry To The Tectonic Evolution Of The Funeral Mountains And Related Metamorphic Core Complexes, Suzanne Renae Mulligan
UNLV Theses, Dissertations, Professional Papers, and Capstones
This dissertation investigates and applies different techniques for studying mid-crustal metamorphic rocks including detrital zircon geochronology, monazite petrochronology, thermodynamic pressure-temperature modeling, and elastic geobarometry. The first chapter reconstructs stratigraphy in deformed metamorphic rocks from the Funeral Mountains metamorphic core complex in Death Valley, California, and the Bullfrog Hills, Nevada, using U-Pb detrital zircon (DZ) geochronology. This study documents another successful application of stratigraphic techniques applied to metamorphic rocks and migmatites. DZ geochronology identified Pahrump Group metasediments in rocks that were previously interpreted to be Paleoproterozoic basement gneisses, providing insights into the distribution of Rodinia rift basins. This analysis has shown …
The Diatom Dark Ages: Identification Of Mid-Cretaceous Arctic Platform Diatoms From The Basal Transgression Of The Kanguk Formation, Devon Island, Nunavut, Canada, Megan Heins
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
The lower part of the mid-Cretaceous Kanguk Formation (Lower Turonian interval) contains an important paleontological record crucial to the characterization of a poorly known interval of fossil marine diatoms history. Kanguk Formation mudstones are exposed in a ~200 m-thick section on Devon Island, Nunavut, Canadian High Arctic. Diatoms at this location are well-preserved due to shallow burial on this Arctic Platform site. The rock sequence was protected from glacial erosion that removed much of the Cretaceous record by being down-faulted in a linear graben. Study of these well-preserved fossil diatoms allows for a documentation of the assemblage, identification of potentially …
Spatial Stream Modeling Of Louisiana Waterthrush (Parkesia Motacilla) Foraging Substrate And Aquatic Prey In A Watershed Undergoing Shale Gas Development, Mack W. Frantz, Petra B. Wood, Steven C. Latta
Spatial Stream Modeling Of Louisiana Waterthrush (Parkesia Motacilla) Foraging Substrate And Aquatic Prey In A Watershed Undergoing Shale Gas Development, Mack W. Frantz, Petra B. Wood, Steven C. Latta
United States Geological Survey: Staff Publications
We demonstrate the use of spatial stream network models (SSNMs) to explore relationships between a semiaquatic bioindicator songbird, Louisiana Waterthrush (Parkesia motacilla), and stream monitoring and benthic macroinvertebrate data in an area undergoing shale gas development. SSNMs allowed us to account for spatial autocorrelation inherent to these environmental data types and stream properties that traditional modeling approaches cannot capture to elucidate factors that affect waterthrush foraging locations. We monitored waterthrush along 58.1 km of 1st- and 2nd-order headwater stream tributaries (n = 14) in northwestern West Virginia over a two year period (2013–2014), sampled benthic macroinvertebrates in waterthrush …
Functional Morphology And Taphonomy Of Ordovician–Silurian Diploporan Echinoderms, Stephen Ashley Hill
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 …
Single-Crystal Elasticity Of Clinopyroxenes And The Viscosity Of Kimberlite Magma Under High Pressure-Temperature Conditions, Ming Hao
Earth and Planetary Sciences ETDs
Clinopyroxene is not only an important mineral phase in the pyrolitic upper mantle, but also one of the dominated mineral phases in the subducted or delaminated eclogitic materials in the deep Earth. Identifying and locating these eclogitic materials requires the knowledge of the thermoelastic properties of clinopyroxene under high pressure-temperature conditions. In this dissertation, we have measured the single-crystal elastic properties of jadeite and omphacite, which are major clinopyroxene phases in the eclogitic materials, up to 18 GPa 700 K by Brillouin spectroscopy and utilized these data to identify the eclogitic heterogeneities in the mantle.
We also measured the viscosity …
Sulfuric Acid Speleogenesis And Surface Landform Evolution Along The Vienna Basin Transfer Fault: Plavecký Karst, Slovakia, Pavel Bella, Helena Hercman, Šimon Kdýr, Petr Mikysek, Petr Pruner, Juraj Littva, Jozef Minár, Michal Gradzinski, Wojciech Wróblewski, Marek Velšmid, Pavel Bosak
Sulfuric Acid Speleogenesis And Surface Landform Evolution Along The Vienna Basin Transfer Fault: Plavecký Karst, Slovakia, Pavel Bella, Helena Hercman, Šimon Kdýr, Petr Mikysek, Petr Pruner, Juraj Littva, Jozef Minár, Michal Gradzinski, Wojciech Wróblewski, Marek Velšmid, Pavel Bosak
International Journal of Speleology
Hypogene caves in the Plavecký hradný vrch Hill (Western Slovakia, Central Europe) were formed by waters ascending along faults in fractured Triassic carbonates related to the horst-graben structure at the contact of the Malé Karpaty Mountains and the NE part of the Vienna Basin. The Plavecká jaskyňa and Pec caves mostly contain horizontal passages and chambers with flat corrosion bedrock floors, fissure discharge feeders, wall water-table notches, replacement pockets, as well as a few other speleogens associated with sulfuric acid speleogenesis. The low-temperature sulfuric acid development phases of the Plavecká Jaskyňa are also indicated by the presence of sulfate minerals …
Science Of The Total Environment, Benjamin Linhoff
Science Of The Total Environment, Benjamin Linhoff
United States Geological Survey: Staff Publications
Recently, the subsoils of ephemeral stream(arroyos) floodplains in the northern Chihuahuan Desert were discovered to contain large naturally occurring NO3− reservoirs (floodplain:~38,000 kg NO3-N/ha; background:~60 kg NO3-N/ha). These reservoirs may be mobilized through land use change or natural stream channel migration which makes differentiating between anthropogenic and natural groundwaterNO3−sources challenging. In this study, the fate and sources of NO3− were investigated in an area with multiple NO3− sources such as accidental sewer line releases and sewage lagoons aswell as natural reservoirs of subsoil NO3−. …
Titaniferous-Vanadiferous, Magnetite-Ilmenite Mineralization In A Mafic Suite Within The Chhotanagpur Gneissic Complex, Bihar, India, Ashmeer Mohammad, Anup K. Prasad, Kehe-U Wetsah, Mohammad Azad, Vivek Aryan, Hesham El-Askary
Titaniferous-Vanadiferous, Magnetite-Ilmenite Mineralization In A Mafic Suite Within The Chhotanagpur Gneissic Complex, Bihar, India, Ashmeer Mohammad, Anup K. Prasad, Kehe-U Wetsah, Mohammad Azad, Vivek Aryan, Hesham El-Askary
Mathematics, Physics, and Computer Science Faculty Articles and Research
Titanium or vanadium metals or their alloys are important industrial metals/alloys. Because these resources are in short supply, the investigation of potential titaniferous-vanadiferous deposits needs special attention to bridge the supply-demand gap. The study integrates geological, geochemical, remote sensing, and geophysical data for assessing the potentiality of titaniferous-vanadiferous, magnetite-ilmenite mineralization in and around the Sudamakund and Paharpur areas, Gaya and Jehanabad districts, Bihar, India, and delineation of specific targets for detailed exploration. Field visits for large scale mapping on (1:12,500 scale) were used to conduct a reconnaissance survey for magnetite-ilmenite mineralization in parts of toposheet number 72G/04 in the Gaya …
Spatial Variations In The Stress Field Near The Wilmington Blind-Thrust, An Earthquake Source Beneath Los Angeles, California, Justin Kain
LSU Master's Theses
A newly identified blind-thrust fault in the southern Los Angeles basin may have substantial implications for earthquakes in the region. A previous study suggests that the Wilmington blind-thrust may link up with nearby faults to produce a multisegment (Mw 6.6–7.4) earthquake rupture. These estimates are based on the joint rupturing of the Wilmington blind-thrust, Compton, Newport Inglewood, and the Huntington Beach fault segments (~85 km total length). However, stress heterogeneity near these faults may limit the size and intensity of earthquakes when incorporated into earthquake hazard modeling. This study presents a detailed model of the stress field in this …
Assessing Impact Of Unconventional Oil And Gas Development On Groundwater Quality In The Northern Appalachian Region With Mixed Land Uses, Favour C. Epuna
Assessing Impact Of Unconventional Oil And Gas Development On Groundwater Quality In The Northern Appalachian Region With Mixed Land Uses, Favour C. Epuna
Theses - ALL
Over the past decade, the rapid growth of unconventional oil and gas development (UOGD) has raised public concerns about its potential impact on groundwater quality. High methane and salt levels in groundwater have been the most widely cited UOGD-related impairments. The attribution of these contaminants to UOGD is usually complex, especially in regions with mixed land uses. Here, we compiled a large hydrogeochemistry dataset containing 13 geochemical analytes for 17,794 groundwater samples from the rural northern Appalachia, i.e., 19 counties located on the boundary between Pennsylvania (PA; UOGD is permitted) and New York (NY; UOGD is banned). With this dataset, …
Differentiating Pleistocene Alloformations In The South Carolina Coastal Plain Through Lithologic, Textural, Mineralogical, And Cluster Analyses, Charles Andrew Wykel
Differentiating Pleistocene Alloformations In The South Carolina Coastal Plain Through Lithologic, Textural, Mineralogical, And Cluster Analyses, Charles Andrew Wykel
Theses and Dissertations
Currently, there is no textural or mineralogic basis for identifying and differentiating Pleistocene strand deposits in the South Carolina (SC) Lower Coastal Plain (LCP). Historically, geologic mapping of the SC coastal plain uses geomorphologic and biostratigraphic techniques for identifying and mapping LCP surficial strand deposits. While useful, both approaches have problems. The aim of this study is to develop a cost-effective approach to differentiate and identify strand deposits of different Pleistocene alloformations occurring in the SC LCP. To accomplish this task, four strand samples were taken from the Ten Mile Hill, the Ladson, and Wicomico alloformations in Horry County, SC. …
Studying Redox Conditions Of Devonian And Neoproterozoic Oceans Using I/Ca Proxy From Bulk Carbonate Rocks, Ruliang He
Studying Redox Conditions Of Devonian And Neoproterozoic Oceans Using I/Ca Proxy From Bulk Carbonate Rocks, Ruliang He
Dissertations - ALL
Iodine is an important trace element in biogeochemical and redox reactions. It has a nearly consistent concentration of ~0.46 μmol/L in the seawater and the inorganic speciation (IO3− and I−) of iodine is primarily controlled by redox conditions in water columns. Iodate (IO3−), not iodide (I−), is the only species that can be incorporated into carbonate minerals. Therefore, I/Ca ratio from carbonate rocks can be used to constrain the redox condition in the water column over a range of time scale. This dissertation contains three chapters that utilizes I/Ca ratio from bulk carbonate rocks to reconstruct ocean redox changes during …
An Assessment Of The Performance Of The Earthscope Automated Receiver Survey: A User’S Guide To Ears., Erin L. Taxon
An Assessment Of The Performance Of The Earthscope Automated Receiver Survey: A User’S Guide To Ears., Erin L. Taxon
Theses and Dissertations
An Assessment of the Performance of the EarthScope Automatic Receiver Survey: A User's Guide to EARS.
With the advent of digital seismic recording, the ability to process and interpret large quantities of seismic data has become increasingly vital. EarthScope Automated Receiver Survey, EARS, was launched in 2005 to estimate bulk crustal properties in real time, at all broadband seismograph stations, globally. EARS utilizes the receiver function HK stacking method to estimate a station’s crustal thickness (H) and ratio of P wave velocity (Vp) and S wave velocity (Vs), known as Vp/Vs (K). Receiver function analysis observes the arrival times …
Evaluation Of Natural Radioactivity And Radiation Hazards Of Soils Around Petroleum Products Marketing Company Using Gamma Ray Spectrometry, Dayo A. Ayeni, Festus M. Adebiyi
Evaluation Of Natural Radioactivity And Radiation Hazards Of Soils Around Petroleum Products Marketing Company Using Gamma Ray Spectrometry, Dayo A. Ayeni, Festus M. Adebiyi
Tanzania Journal of Science
This study aimed at evaluating natural radioactivity and radiation hazards of soils around a petroleum product marketing company due to anthropogenic influences using gamma ray spectrometry. Top soils (5 cm deep) were collected from diverse locations inside the premises of the Company using standard analytical technique, while control samples were acquired at approximately 200 m from the study area. Mean activity concentrations of the radionuclides in the test soils were 89.36 Bq/kg for 40K, 92.1 Bq/kg for 238U and 10.95 Bq/kg for 232Th, which are more than that of control samples with statistically significant differences. Assessment of the radiological levels …
Charcoal Whirlwinds And Post-Fire Observations In Serengeti National Park Savannahs, Colin J. Courtney Mustaphi, Heleen C. Vos, Rob Marchant, Colin Beale
Charcoal Whirlwinds And Post-Fire Observations In Serengeti National Park Savannahs, Colin J. Courtney Mustaphi, Heleen C. Vos, Rob Marchant, Colin Beale
Tanzania Journal of Science
Whirlwinds and visible dust devils occur over semi-arid ecosystems and entrain particles from the ground surface. Fires produce abundant charcoal across savannahs and the resulting blackened surfaces create a large albedo contrast. Whirlwinds have been observed associated with active fires; yet, there are few published observations on post-fire landscapes. Spatiotemporal patterns of whirlwinds have been documented for a limited number of regions and have not been made for the ecosystems of eastern Africa. From field-based sightings in the Serengeti National Park, Tanzania, we report on whirlwinds over burned savannah patches that entrained large quantities of charcoal to produce black coloured …
Characterization Of Clay And Granite Dust Blends As Novel Materials For Energy Storage And Diffuser In Constructing Flat-Plate Solar Collector, Tajudeen Kolawole Ajiboye, Mustapha Olawale Fabiyi, Ndagi Mustapha, Sulaiman Abdulkareem
Characterization Of Clay And Granite Dust Blends As Novel Materials For Energy Storage And Diffuser In Constructing Flat-Plate Solar Collector, Tajudeen Kolawole Ajiboye, Mustapha Olawale Fabiyi, Ndagi Mustapha, Sulaiman Abdulkareem
Tanzania Journal of Science
Sun is the main source of solar energy, and the energy it releases to the Earth’s surface in one hour is more than what the whole planet consumes in a year. This present work is about characterizing novel material that can be used as energy storage and diffuser in constructing flat plate solar collector. Materials used are clay and granite dust obtained from Okelele and Kulende Quarry sites, both in Ilorin, Kwara State, Nigeria. The materials were sun-dried; the clay crushed before the two materials were sieved into different particle sizes. They were thereafter blended into different ratios and then …
Sedimentary Characteristics And Associated Carbon And Nutrients Of Overbank Sediments Deposited During The 2018, 2019, And 2020 Floods In Embanked Floodplains Along The Lower Mississippi River Near Natchez, Mississippi, Rachel Kelk
Master's Theses
The Lower Mississippi River (LMR) experienced major floods in 2018, 2019, and 2020. Sediment deposition in the embanked floodplains during floods represent important storage and sequestration opportunities for carbon and nutrients from ~40% of the continental USA. This research aims to compare depositional thicknesses, organic matter (OM), carbon (C), nitrogen (N), phosphorous (P) concentrations, and grain sizes in floodplain sediments deposited by the combined 2018-19 floods to the 2020 flood along the LMR near Natchez, Mississippi. Greater depositional thicknesses in 2018-19 are best explained by their combined flood durations; the 2019 flood was the longest in recorded history. Slightly higher …
Ice Deposits In Lava Tubes From West-Central New Mexico As Archives Of Past Volcanic Eruptions And Climate Change, Quinton Z. Vitelli-Hawkins
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‰) …
Observational Constraints On The 520 Km Mantle Discontinuity, Mantle Transition Zone Anisotropy, And Local Seismicity At Mount St. Helens, Han Zhang
Earth and Planetary Sciences ETDs
Seismology provides valuable observational constraints to thermal and compositional states at inaccessible depths via understanding how elastic wave propagating through them. While many of fundament questions regarding solid Earth structures have been addressed during its more than 100 years history, some details remain unfilled and carefully designed approaches are needed to complete the pictures. This dissertation contributes observational constraints on three topics with newly developed methods. 1) We detected a controversial mantle discontinuity at about 520 km and concluded a mean mantle composition close to the Pyrolite model based on its seismic properties. 2) We isolated anisotropic effects in mantle …
Population Genetics Reveals Bidirectional Fish Movement Across The Continental Divide Via An Interbasin Water Transfer, Audrey C. Harris, Sara J. Oyler-Mccance, Jennifer A. Fike, Matthew P. Fairchild, Christopher M. Kennedy, Harry J. Crockett, Dana L. Winkelman, Yoichiro Kanno
Population Genetics Reveals Bidirectional Fish Movement Across The Continental Divide Via An Interbasin Water Transfer, Audrey C. Harris, Sara J. Oyler-Mccance, Jennifer A. Fike, Matthew P. Fairchild, Christopher M. Kennedy, Harry J. Crockett, Dana L. Winkelman, Yoichiro Kanno
United States Geological Survey: Staff Publications
Interbasin water transfers are becoming an increasingly common tool to satisfy municipal and agricultural water demand, but their impacts on movement and gene flow of aquatic organisms are poorly understood. The Grand Ditch is an interbasin water transfer that diverts water from tributaries of the upper Colorado River on the west side of the Continental Divide to the upper Cache la Poudre River on the east side of the Continental Divide. We used single nucleotide polymorphisms to characterize population genetic structure in cutthroat trout (Oncorhynchus clarkii) and determine if fish utilize the Grand Ditch as a movement corridor. …
A Technique-Based Approach To Structure-From-Motion: Applications To Human-Coastal Environments, Robert Van Alphen
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 …