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Articles 8851 - 8880 of 59525
Full-Text Articles in Earth Sciences
New Insights Into The Tectonic Framework & Geologic Features Of The Bengal Basin, Bangladesh, Shahriar Bin Shahid
New Insights Into The Tectonic Framework & Geologic Features Of The Bengal Basin, Bangladesh, Shahriar Bin Shahid
Masters Theses & Specialist Projects
In this research, high-resolution SRTM-based NASA Digital Elevation Models (DEM) data and published literature have used to gain new insights regarding South-east Asian surficial geology, fluvial geomorphology, and tectonics, focusing on the Bengal Basin. Seismic databased discovery of shallow, down-warping and >30 km thick Indian crust challenges prior knowledge of crustal origin, which was thought to be oceanic rather than continental in origin due to high-angle subduction. Furthermore, the collapse of the Indian passive margin beneath the Shillong Plateau may have formed a 20 km thick Surma Basin on top and has led to substantial earthquake risks. To update the …
Verification Of Astm Centrifugation Equations For Soil Suction Determination, Esteban Maclein Miranda Pinzon
Verification Of Astm Centrifugation Equations For Soil Suction Determination, Esteban Maclein Miranda Pinzon
Graduate Theses and Dissertations
The unit correction constant (B) in the ASTM D6836 standard needs to be evaluated. The B-value was proposed to be 0.00548 instead of 0.00553. This apparent discrepancy led to an investigation comparing the predicted and measured suction values for high air entry (HAE) ceramic disks. A Beckman-Coulter Model J6-MI six-bay centrifuge and a WP4C Dewpoint Potentiameter were used in the testing program. HAE ceramic disks rated with bubbling pressures of 3-bar and 5-bar were used as analogue soil specimens. The HAE ceramic disks were spun in the small-scale centrifuge to apply prescribed suction amounts and then placed in the WP4C …
Experimental And Theoretical Studies Of Fluid-Solid Coupling Processes Of Tight Rock Media, Tao Zhang
Experimental And Theoretical Studies Of Fluid-Solid Coupling Processes Of Tight Rock Media, Tao Zhang
Earth & Environmental Sciences Dissertations - Archive
This study covers the application of continuum mechanics in the realm of rock work in geological studies. Continuum mechanics encompasses two major branches: fluid mechanics that deals with fluid behavior, and solid mechanics pertaining to the behavior of rock media. The research focuses on comprehending the mechanical behavior of rocks as a continuous mass, offering a comprehensive perspective for analyzing geological structures, fluid flow, and rock mechanics. Under the framework of continuum mechanics applied to rock media, following the sequence of the rock/solid properties, fluid flow properties, and the fluid-solid coupling behavior, this dissertation is divided into four sections, each …
Volatile Cycling And Metasomatism In Flat-Slab Subduction Zones Of The Central Andes, Coleman Hiett
Volatile Cycling And Metasomatism In Flat-Slab Subduction Zones Of The Central Andes, Coleman Hiett
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Flat-slab subduction, where an oceanic plate subducts horizontally below a continental margin for hundreds of kilometers, is an enigmatic but prevalent tectonic configuration in which chemical cycling and alteration of the continental plate is poorly constrained. Geochemical investigations in regions of modern and ancient flat-slab subduction in the Central Andes afford an opportunity to study this process. Certain elements naturally occur with varying number of neutrons in their nuclei (isotopes), and measurements of isotope ratios within geologic materials inform on chemical sources and geologic processes. This research leverages stable isotope analyses and other geochemical tools to investigate volatiles and other …
Urban Vulnerability Analysis Based On Micro-Geographic Unit With Multi-Source Data—Case Study In Urumqi, Xinjiang, China, Jianghua Zheng, Danlin Yu, Chuqiao Han, Zhe Wang
Urban Vulnerability Analysis Based On Micro-Geographic Unit With Multi-Source Data—Case Study In Urumqi, Xinjiang, China, Jianghua Zheng, Danlin Yu, Chuqiao Han, Zhe Wang
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
This study introduces a novel approach to urban public safety analysis inspired by a streetscape analysis commonly applied in urban criminology, leveraging the concept of micro-geographical units to account for urban spatial heterogeneity. Recognizing the intrinsic uniformity within these smaller, distinct environments of a city, the methodology represents a shift from large-scale regional studies to a more localized and precise exploration of urban vulnerability. The research objectives focus on three key aspects: first, establishing a framework for identifying and dividing cities into micro-geographical units; second, determining the type and nature of data that effectively illustrate the potential vulnerability of these …
Liquid Flow And Gas Diffusion In Natural Rocks: Experimental And Simulation Studies, Xuewei Ning
Liquid Flow And Gas Diffusion In Natural Rocks: Experimental And Simulation Studies, Xuewei Ning
Earth & Environmental Sciences Dissertations - Archive
Natural rocks, as key components in energy and environmental geosciences, play crucial roles in groundwater extraction, geological storage of high-level nuclear waste, geothermal energy mining, and petroleum exploration in both conventional and unconventional reservoirs. Unconventional reservoirs, specifically the tight shale formations, have seen a significant usage in petroleum production in recent decades, largely due to advances in fracturing stimulation techniques which counter the inherently low permeability and connectivity of shale reservoirs by expanding natural fractures and creating artificial ones for an enhanced petroleum production. However, the low mobility (liquid flow and gas diffusion) of stored fluids in naturally fractured formations …
The Temporal Evolution Of Subduction Initiation In The Samail Ophiolite: High-Precision U–Pb Zircon Petrochronology Of The Metamorphic Sole, Matthew Rioux, Joshua M. Garber, Michael Searle, James L. Crowley, Sally Stevens, Mark Schmitz, Andrew Kylander-Clark, Kayla Leal, Tyler Ambrose, Andrew J. Smye
The Temporal Evolution Of Subduction Initiation In The Samail Ophiolite: High-Precision U–Pb Zircon Petrochronology Of The Metamorphic Sole, Matthew Rioux, Joshua M. Garber, Michael Searle, James L. Crowley, Sally Stevens, Mark Schmitz, Andrew Kylander-Clark, Kayla Leal, Tyler Ambrose, Andrew J. Smye
Geosciences Faculty Publications and Presentations
High-precision dating of the metamorphic sole of ophiolites can provide insight into the tectonic evolution of ophiolites and subduction zone processes. To understand subduction initiation beneath a young, well-preserved and well-characterized ophiolite, we performed coupled zircon laser-ablation inductively coupled mass spectrometry trace element analyses and high-precision isotope dilution-thermal ionization mass spectrometry U–Pb dating on 25 samples from the metamorphic sole of the Samail ophiolite (Oman-United Arab Emirates). Zircon grains from amphibolite- to granulite-facies (0.8–1.3 GPa, ~700–900°C), garnet- and clinopyroxene-bearing amphibolite samples (n = 18) show systematic trends of decreasing heavy rare earth element slope (HREE; Yb/Dy) with decreasing Yb …
Uav-Based Quantification Of Dynamic Lahar Channel Morphology At Volcán De Fuego, Guatemala, Jerry C. Mock, Jeffrey B. Johnson, Armando Pineda, Gustavo Bejar, Amilcar Roca
Uav-Based Quantification Of Dynamic Lahar Channel Morphology At Volcán De Fuego, Guatemala, Jerry C. Mock, Jeffrey B. Johnson, Armando Pineda, Gustavo Bejar, Amilcar Roca
Geosciences Faculty Publications and Presentations
This study quantified erosional and depositional processes for secondary lahars in Las Lajas drainage at Volcán de Fuego, Guatemala, during the rainy season from May to October 2021. Abundant pyroclastic material from ongoing eruptive activity is remobilized seasonally during heavy precipitation, which can impact infrastructure and populations living near Fuego. Our region of focus was in an agricultural zone 6 to 10 km from the summit, surveyed with an unoccupied aerial vehicle (UAV) quadcopter at monthly intervals. Imagery was processed into overlapping time-lapse structure from motion digital elevation models (DEMs). DEMs were differenced to find volumetric changes as a function …
The Ecological Effects Of Nitrogen Enrichment In Aridlands, Jennifer Holguin
The Ecological Effects Of Nitrogen Enrichment In Aridlands, Jennifer Holguin
Open Access Theses & Dissertations
Anthropogenic nitrogen (N) deposition is one of the most prominent factors driving global change. Across the globe, N deposition has driven major changes in terrestrial ecosystems, such as declines in plant biodiversity, enhanced exotic plant growth, and changes to biogeochemical processes involved in carbon and nutrient cycling. While noteworthy effort has been put forth to investigate the effects of N deposition on terrestrial ecosystems, a disproportionate number of N addition studies have been conducted in temperate mesic systems. Thus, we lack a holistic and mechanistic understanding of how N deposition impact aridland ecosystems. Additionally, our predictions of the effects of …
Growth Of Purple Sulfur Bacteria Allochromatium Vinosum On Solid Phase Metal Sulfides As Sulfur And Electron Sources, Hugo Alarcon
Growth Of Purple Sulfur Bacteria Allochromatium Vinosum On Solid Phase Metal Sulfides As Sulfur And Electron Sources, Hugo Alarcon
Open Access Theses & Dissertations
Purple sulfur bacteria (PSB) are photosynthetic microorganisms known for their vital roles in geochemical cycles, especially the sulfur cycle, within anoxic photic environments. PSB are also key contributors to the nitrogen, carbon, and oxygen cycles. This study focuses on the autotrophic growth of Allochromatium vinosum, a model strain of PSB, that utilize solid-phase metal sulfides (MS) as both sulfur and electron donors. Through characterizing the growth profiles of A. vinosum on pyrite (FeS2), nickel sulfide (NiS), and iron monosulfide (FeS) nanoparticles, respectively, and investigating the bacteria-MS interaction mechanisms, this work expands our current knowledge of the metabolic capabilities and flexibility …
Age And Paleontology Of The Turin Pit Locality, Monona County, Iowa, Samantha Wright
Age And Paleontology Of The Turin Pit Locality, Monona County, Iowa, Samantha Wright
Electronic Theses and Dissertations
The Turin Pit locality (Monona county, Iowa) has been known to paleontologists since 1908, yet the age of the fauna has been unclear. Early paleontologists considered Turin Pit to date to a pre-Illinoian interglacial (the “Aftonian).” Subsequent researchers suggested it dated to the last glaciation. This study provides a partial list of mammals in the Turin Pit fauna, and together with stratigraphic information, uses the known age ranges of taxa to estimate an age for the assemblage. The presence of Mammuthus, Aenocyon, and Castoroides combined with a magnetically-reversed till located stratigraphically above fossil-bearing deposits, suggest the Turin Pit …
High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman
High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman
All Dissertations
Atmospheric carbon dioxide (CO2) concentrations have been increasing at an accelerating rate for the past two centuries, profoundly impacting global climate change. Atmospheric CO2 concentrations are influenced by the global carbon cycle through physical and biogeochemical pathways. Tidal wetland environments play a vital role in the global carbon cycle by offsetting atmospheric CO2 concentrations through their natural physiochemical processes of high autotrophic productivity, allochthonous organic matter deposition, anoxic soils, and continuous accretion which promotes carbon sequestration with long-term storage at the land-ocean margin. The Intergovernmental Panel on Climate Change (IPCC) and United States Global Change Research …
Revisiting The Diffuse Layer Polarization Of A Spherical Grain In Electrolytes With Numerical Solutions Of Nernst-Planck-Poisson Equations, Qifei Niu
Geosciences Faculty Publications and Presentations
Induced polarization (IP) has been frequently used in solid earth geophysics, hydrology, and environmental sciences. A mechanistic understanding of the IP responses of geological materials is crucial for correctly interpreting field IP measurements. In this study, the fully-coupled, nonlinear Nernst-Planck-Poisson equations are numerically solved to analyze the electrochemical mechanism of diffuse layer polarization around a spherical grain immersed in electrolytes. The numerical results show diffuse layer polarization is formed by the charge separation between counterions in the diffuse layer and charges on the grain surface. Both tangential and normal movements of counterions in the diffuse layer are involved in the …
Whitewater Sound Dependence On Discharge And Wave Configuration At An Adjustable Wave Feature, Taylor A. Tatum, Jacob F. Anderson, Timothy J. Ronan
Whitewater Sound Dependence On Discharge And Wave Configuration At An Adjustable Wave Feature, Taylor A. Tatum, Jacob F. Anderson, Timothy J. Ronan
Geosciences Faculty Publications and Presentations
Stream acoustics has been proposed as a means of monitoring discharge and wave hazards from outside the stream channel. To better understand the dependence of sound on discharge and wave characteristics, this study analyzes discharge and infrasound data from an artificial wave feature which is adjusted to accommodate daily changes in recreational use and seasonal changes in irrigation demand. Monitorable sound is only observed when discharge exceeds ∼35 m3/s, and even above that threshold the sound-discharge relationship is non-linear and inconsistent. When sound is observed, it shows consistent dependence on wave type within a given year, but the …
High P-T Single Crystal Elasticity Of Zircon And Its Implications For Determining Metamorphic P-T Conditions In Nature, Arlacee Luu
Earth and Planetary Sciences ETDs
Understanding the natural petrologic and tectonic processes, such as slab subduction, requires accurate determination of the pressure (P) and temperature (T) conditions of these processes. Recent development of elastic thermobarometry based on the difference between the elastic evolution of mineral inclusions and their host minerals allows constraining the formation P-T conditions of the inclusion/host system without assuming thermodynamic equilibrium, which is typically needed for the widely used chemistry-based thermobarometry in metamorphic petrology. However, the reliability of elastic thermobarometry heavily depends on the accurate determination of the high P-T single-crystal elastic properties of relevant minerals. In this study, we performed the …
Weathering, Erosion, And Dust Accumulation At Stoneman Lake, Arizona, Usa: Timescales And Drivers Of Geomorphic Activity Across The Southwest, Spencer Staley, Peter J. Fawcett, R. Scott Anderson, Gonzalo Jiménez-Moreno, Vera Markgraf, Erik T. Brown, Matthew E. Kirby
Weathering, Erosion, And Dust Accumulation At Stoneman Lake, Arizona, Usa: Timescales And Drivers Of Geomorphic Activity Across The Southwest, Spencer Staley, Peter J. Fawcett, R. Scott Anderson, Gonzalo Jiménez-Moreno, Vera Markgraf, Erik T. Brown, Matthew E. Kirby
Earth and Planetary Sciences ETDs
Lengthy and well-dated terrestrial records of the Quaternary Period with the appropriate proxies show how the critical zone responds to environmental change. In southwestern North America, resolving the many effects of aridity through time provides crucial context for addressing contemporary climate issues. However, arid conditions are generally non-conducive to paleo-record preservation, causing knowledge gaps during relevant climatic episodes. An ~80 m-long sediment core (STL14) from Stoneman Lake contains a continuous archive of conditions from local to regional scale since the early Pleistocene (~1.3 Ma) and is, therefore, a unique and immensely valuable scientific resource. STL is situated in a montane …
Water Quality Land Cover Change And Water Quality In Wetlands At The City Of Gresham, Or, Evelyn Barajas, Michael Gonzalez
Water Quality Land Cover Change And Water Quality In Wetlands At The City Of Gresham, Or, Evelyn Barajas, Michael Gonzalez
altREU Projects
The City of Gresham, Oregon has implemented constructed wetlands around the area as an attempt to collect, filter, and purify water from different sources such as rain, agricultural waste, and domestic waste. We focused our research on three different facilities: Columbia Slough Water Quality Facility (CSWQF), Fairview Creek Water Quality Facility, and Brookside Water Quality Facility. For each of these, we conducted tests and looked at the concentration levels for nitrogen and phosphorus nutrients such as NH3-N (ammonium), NO3-N (nitrate), TKN (total Kjeldahl nitrogen), O-PO4 (phosphate), and Total P (total phosphorus), as well as heavy metals like Total Cu (total …
Understanding The Factors Affecting Nebraskan Farmers’ And Landowners' Decision To Adopt Precision Agricultural Technologies And Programs, Corrin C. Winter
Understanding The Factors Affecting Nebraskan Farmers’ And Landowners' Decision To Adopt Precision Agricultural Technologies And Programs, Corrin C. Winter
School of Natural Resources: Dissertations, Theses, and Student Research
Advisors: Andrew Little, Christopher Chizinski
To gain insights into the challenges faced by Nebraska farmers and landowners when adopting precision agriculture technologies, I analyzed data collected from a 2022 survey involving 7,503 participants, consisting of producers and farmland owners from across the state of Nebraska. The primary objective was to provide valuable insights for agencies seeking to improve their precision agriculture and conservation outreach efforts for the benefit of conservation and Nebraskan farmers and landowners. This study aimed to understand key factors influencing adoption behaviors by evaluating the constraints to precision agriculture adoption, assessing the impact of producer and landowner …
Influence Of Urbanization And Climate On Irrigation Diversions And Return Flows In The Lower Boise River Basin, Bridget Bittmann
Influence Of Urbanization And Climate On Irrigation Diversions And Return Flows In The Lower Boise River Basin, Bridget Bittmann
Boise State University Theses and Dissertations
The western US is facing both the rapid urbanization of agricultural lands and a changing climate, producing subsequent changes to irrigation water demand and availability. Adaptive water management requires knowledge regarding how and why water usage and availability is changing; however, managers often do not possess the tools or resources for the necessary analysis. These environmental changes are also place-based, meaning that water managers cannot directly use studies from other basins to actively manage theirs. Co-produced, actionable research can help fill this knowledge gap and provide the necessary information for adaptive management. The Lower Boise River Basin (LBRB) in southwestern …
Effects Of Discharge And Morphology On Fluvial Sound, Scott J. Gauvain
Effects Of Discharge And Morphology On Fluvial Sound, Scott J. Gauvain
Boise State University Theses and Dissertations
Rivers, streams, and tributaries play a critical role in the global water cycle and their dispersion of freshwater is essential for widespread human consumption, crop irrigation, waste management, and hydropower generation. Currently, there is a need for innovative, non-invasive, and low-cost methods of surface freshwater discharge gauging. With careful site selection, recording the acoustics produced by streamflow could be used reliably and inexpensively to infer changes in local discharge. An important knowledge gap currently preventing the use of acoustics for stream gauging is the unknown relationships by which stream sounds depend on discharge and stream morphology. To address this, I …
Picking Up Steam: A Year Long Infrasonic Record Of Steamboat Geyser. Minor And Major Paroxysms Of The Multi-Phase Eruptions At Steamboat Geyser, Yellowstone National Park, Margaret Holahan
Boise State University Theses and Dissertations
The renewed activity of the world’s tallest geyser, Steamboat Geyser (Yellowstone National Park) in 2018, offers the opportunity to utilize long-term continuous infrasound and low-frequency acoustic monitoring to quantify eruptive behaviors. Eruption parameters including onset timing, duration, phase transitions between steam and water, instantaneous sound intensity, eruptive power, energy content, and spectral character, may be used to characterize individual eruption styles and reveal eruption trends. I interpret the character of the acoustic radiation through corroboration of first-hand observations and time-lapse video. I find that infrasound (acoustic energy below 20 Hz) is a particularly effective tool for tracking the evolving eruption …
Characteristics Of Stream Source Water Contributions And Associated Geochemical Signatures Along A Climate And Vegetation Gradient In A Glacierized Landscape, Southcentral Alaska, Hannah K. Richardson
Characteristics Of Stream Source Water Contributions And Associated Geochemical Signatures Along A Climate And Vegetation Gradient In A Glacierized Landscape, Southcentral Alaska, Hannah K. Richardson
Boise State University Theses and Dissertations
Mountain-derived snow and ice melt are essential for global water resources, and over one-sixth of the population depends on melt for freshwater. Rising air temperatures are causing vegetation to replace snow- and ice-covered landscapes and precipitation regimes to change. Collectively, these changes will alter the hydrology of mountain environments, although the exact impacts to hydrologic regimes are poorly understood. The source waters of streamflow (i.e. the proportion of ice melt, snowmelt, rain, and groundwater) dictate the timing and magnitude and affect temperature, sediment, and nutrient fluxes. By examining differences in source waters across basins with varying land covers and precipitation …
Origin Of The Mega-Streamlined Morphology In Ne Africa And Arabia: Remote Sensing And Field-Based Investigations, Mohamed Samy Mohamed Elhebery
Origin Of The Mega-Streamlined Morphology In Ne Africa And Arabia: Remote Sensing And Field-Based Investigations, Mohamed Samy Mohamed Elhebery
Dissertations
Mega-streamlined landforms on Earth and Mars have been attributed to aeolian, glaciogenic, fluvial, and tectonic processes. Identifying the forces that shaped these landforms is paramount for understanding landscape evolution and constraining paleo-climate models and ice sheet reconstructions. Exhumed Late Ordovician glacial deposits and landscape of the North Gondwana are reported here for the first time from SE Egypt. Using field and remote sensing (Advanced Land Observing Satellite [ALOS], Phased Array L-band Synthetic Aperture Radar (PALSAR) radar, multispectral Landsat TM datasets, and digital elevation models (DEMs) I mapped the distribution of the Late Ordovician glacial features (i.e. deposits and landforms) in …
Phase Distribution Of Nickel, Chromium, And Cobalt In Seawater At Olivine-Enriched Beaches: Implications For Carbon Capture By Enhanced Silicate Weathering, Nathaniel J. Padrnos
Phase Distribution Of Nickel, Chromium, And Cobalt In Seawater At Olivine-Enriched Beaches: Implications For Carbon Capture By Enhanced Silicate Weathering, Nathaniel J. Padrnos
Master's Theses
The application of olivine to coastal areas is a proposed method of removing carbon dioxide from the atmosphere for climate change mitigation. Olivine is abundant and dissolves relatively fast, but it contains trace amounts of nickel (Ni), chromium (Cr), and cobalt (Co) which may be toxic to marine biota in cases of widespread coastal olivine spreading. Prior studies have suggested that Ni concentrations in marine sediments and/or the overlying water column due to olivine dissolution could be a limiting factor for its carbon capture potential. Therefore, it is critical to understand and model the processes affecting trace metal bioavailability after …
Late Jurassic Paleogeography Of The U.S. Cordillera From Detrital Zircon Age And Hafnium Analysis Of The Galice Formation, Klamath Mountains, Oregon And California, Usa, Kathleen D. Surpless, Ryan Wayne Alford, C. Barnes, A. Yoshinobu, Natalee E. Weis
Late Jurassic Paleogeography Of The U.S. Cordillera From Detrital Zircon Age And Hafnium Analysis Of The Galice Formation, Klamath Mountains, Oregon And California, Usa, Kathleen D. Surpless, Ryan Wayne Alford, C. Barnes, A. Yoshinobu, Natalee E. Weis
Earth and Environmental Geosciences Faculty Research
The Upper Jurassic Galice Formation, a metasedimentary unit in the Western Klamath Mountains, formed within an intra-arc basin prior to and during the Nevadan orogeny. New detrital zircon U-Pb age analyses (N = 11; n = 2792) yield maximum depositional ages (MDA) ranging from ca. 160 Ma to 151 Ma, which span Oxfordian to Kimmeridgian time and overlap Nevadan contractional deformation that began by ca. 157 Ma. Zircon ages indicate a significant North American continental provenance component that is consistent with tectonic models placing the Western Klamath terrane on the continental margin in Late Jurassic time. Hf isotopic analysis of …
Structural And Kinematic Investigation Of The Dadeville Complex-Brevard Zone Contact (Southern Appalachians): Polyphase Emplacement Of An Allochthonous Terrane On The Laurentian Margin, Andrew Williams
Master's Theses
The Dadeville Complex (DC) lies in the Inner Piedmont of eastern Alabama and western Georgia. The DC formed as a volcanic island arc during the Taconic orogeny (Ordovician Period) and was accreted onto Laurentia during the Acadian orogeny (Devonian-Mississippian Periods); however, the mechanism and role of accretion during the Acadian orogeny is not well constrained. Three proposed emplacement mechanisms for the DC include: (1) orogen-perpendicular translation; (2) orogen-parallel translation; (3) orogenic channel flow.
Today, the DC is a major (over 100 kilometers long) allochthonous terrane composed mostly of meta-igneous rocks. This study investigated structural fabrics and kinematic indicators in the …
New Species Of Dryolestoid From The Late Cretaceous Allen Formation And Implications For South American Faunal Diversity., Brigid Erin Connelly
New Species Of Dryolestoid From The Late Cretaceous Allen Formation And Implications For South American Faunal Diversity., Brigid Erin Connelly
Electronic Theses and Dissertations
Dryolestoids are extinct cladotherians mammals from the Jurassic and Cretaceous periods. I describe a collection of dryolestoid specimens from the Late Cretaceous localities of Cerro Tortuga (Allen Formation), Anfiteatro 1, and Shining (both La Colonia Formation) from Patagonia, Argentina. Using comparative morphology, I identify a new species of meridiolestidan dryolestoid based on eleven specimens across both formations. The new species’ recovery from La Colonia Formation represents the first dryolestoid connection between the two approximately contemporaneous formations. The species’ morphology may represent an ecological shift within Meridiolestida from insectivory to herbivory, showing a transition in characters between the plesiomorphic sharp-toothed meridiolestidans …
Effects Of Short-Term Exposure To A Pesticide Mixture On Free-Swimming Behavior In Goldfish, Carassius Auratus, Esmirna Cantu, Michelle Rivera, Brittney Lacy, Md. Saydur Rahman
Effects Of Short-Term Exposure To A Pesticide Mixture On Free-Swimming Behavior In Goldfish, Carassius Auratus, Esmirna Cantu, Michelle Rivera, Brittney Lacy, Md. Saydur Rahman
School of Earth, Environmental, & Marine Sciences Faculty Publications
Highlights
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We observed effects of pesticides exposure on free-swimming behaviors in goldfish.
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Pesticides profoundly impacting natural swimming patterns.
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Behavioral analysis showed a dose- and time-dependent, decrease in distance swam.
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Vertical/horizontal spatial behavioral use both affected under exposure conditions.
Abstract
The prevalence of pesticides in the aquatic environment continues to increase due to anthropogenic activities and poses a threat to aquatic organisms. Notably, the intensive use of pesticides can cause detrimental effects (i.e., chemical stressors) on animal behavior. The aim of this study was to determine the short-term exposure effects (5-day) of an environmentally relevant pesticide mixture (low- and high-dose: metolachlor …
Evaluating How Well Active Fault Mapping Predicts Earthquake Surface-Rupture Locations, Chelsea Scott, Ramon Arrowsmith, Rachel Adam, Christopher Madugo, Joseph Powell, John Ford, Brian Gray, Ashley Streig, Multiple Additional Authors
Evaluating How Well Active Fault Mapping Predicts Earthquake Surface-Rupture Locations, Chelsea Scott, Ramon Arrowsmith, Rachel Adam, Christopher Madugo, Joseph Powell, John Ford, Brian Gray, Ashley Streig, Multiple Additional Authors
Geology Faculty Publications and Presentations
Earthquake surface-fault rupture location uncertainty is a key factor in fault displacement hazard analysis and informs hazard and risk mitigation strategies. Geologists often predict future rupture locations from fault mapping based on the geomorphology interpreted from remote-sensing data sets. However, surface processes can obscure fault location, fault traces may be mapped in error, and a future rupture may not break every fault trace. We assessed how well geomorphology-based fault mapping predicted surface ruptures for seven earthquakes: 1983 M 6.9 Borah Peak, 2004 M 6.0 Parkfield, 2010 M 7.2 El Mayor–Cucapah, 2011 M 6.7 Fukushima-Hamadori, 2014 M 6.0 South Napa, 2016 …
Nitrogen Cycling In The Lower Chesapeake Bay And Mid- And South Atlantic Bight, Yifan Zhu
Nitrogen Cycling In The Lower Chesapeake Bay And Mid- And South Atlantic Bight, Yifan Zhu
OES Theses and Dissertations
Nitrogen (N) is central to marine primary production; its availability often limits the capacity and rates of primary productivity in most of the world’s oceans. Contrastingly, estuaries frequently receive anthropogenic N loading, oftentimes resulting in eutrophication, harmful algal blooms (HABs), and substantially degraded water quality. Nutrient variability in both estuaries and oceanic regimes results from meteorological forcing and physical processes, including wind-induced, tidal, and mesoscale mixing and upwelling. In this dissertation, a comprehensive investigation of N variability and cycling and its links to physical-biogeochemical processes was conducted using time-series monitoring approaches, flux estimations, satellite imaging, biogeochemical measurements, and molecular analyses. …