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Full-Text Articles in Physical Sciences and Mathematics

Active Tectonics Of Western Kosovo: Insights From Geomorphic And Structural Analyses, Alper Gürbüz, Astrit Shala, Shemsi Mustafa, Aytekin Erten May 2024

Active Tectonics Of Western Kosovo: Insights From Geomorphic And Structural Analyses, Alper Gürbüz, Astrit Shala, Shemsi Mustafa, Aytekin Erten

Bulletin of the Mineral Research and Exploration

Kosovo is located in a key position in the central-west part of the Balkans providing an opportunity to understand the far-field effects of distributed intracontinental deformation caused by the Aegean extension in the south and Adriatic compression in the west. It is also situated along the NE-SW trending Shkodër-Pejë transverse zone, where the Dinarides and Albanides-Hellenides orogenic belts are juxtaposed. While the instrumental seismicity of Kosovo indicates the activity of this fault zone and many others, the active faults in the country were not discussed in detail in the current literature. In this study, we analyzed both the geomorphic and …


Paleocene-Eocene Foraminifera From The Tuz Gölü Basin (Salt Lake Basin, Central Türkiye) And Their Paleoenvironmental Interpretations, Muhittin Görmüş, Mustafa Yildiz, Alper Bozkurt, Aynur Hakyemez May 2024

Paleocene-Eocene Foraminifera From The Tuz Gölü Basin (Salt Lake Basin, Central Türkiye) And Their Paleoenvironmental Interpretations, Muhittin Görmüş, Mustafa Yildiz, Alper Bozkurt, Aynur Hakyemez

Bulletin of the Mineral Research and Exploration

Paleocene-Eocene aged sediments from the east of Tuz Gölü Basin (Central Türkiye) provide significant data for foraminifera contents and their paleoenvironmental clues. They are important in revealing the stratigraphy of the region and the Paleocene-Eocene geological history of Türkiye. The sediments, composed mainly of carbonates, are known as Karapınaryaylası Formation. In this formation, benthic foraminifera representing SBZ2 to SBZ12 biozones corresponding to the Selandian-Late Cuisian time interval were identified in ten measured stratigraphical sections. The zonal interval from the E7 Zone (late Ypresian) to the E10 Zone (Lutetian) is characterized by the marker species of planktonic foraminifera defined in the …


Magnetic Inversion Modeling Of Subsurface Geologic Structures For Mineral Deposits Mapping In Southeastern Nigeria, Ema Abraham, Ayatu Usman, Kelvin Chima, George-Best Azuoko, Iheanyi Ikeazota May 2024

Magnetic Inversion Modeling Of Subsurface Geologic Structures For Mineral Deposits Mapping In Southeastern Nigeria, Ema Abraham, Ayatu Usman, Kelvin Chima, George-Best Azuoko, Iheanyi Ikeazota

Bulletin of the Mineral Research and Exploration

Magnetic inversion techniques have been implemented to infer the extension and geometry of magnetic structures and also evaluate its influence on mineralization within Abakaliki and its environs, southeastern Nigeria. The modeling approach considers the techniques of threedimensional (3D) magnetic data inversion, Euler deconvolution, analytic signal inversion, Enhanced Local Wavenumber (ELW) Technique and Particle Swarm Optimization (PSO) to estimate source parameters and compare results. Model solutions were interpreted to represent possible geologic units with varying trends, housing mineralization within the study region. Results from inversion computation over some active mine locations show subsurface bodies with magnetic susceptibilities >0.00188 SI. Model results …


Vitrinite Reflectances And Mineralogy Of Coal Clasts In The Late Carboniferous Sequences In The Two-Deep Research Wells From The Kozlu Coalfield (Zonguldak Basin, Nw Türkiye), Ali İhsan Karayi̇ği̇t, Rıza Görkem Oskay May 2024

Vitrinite Reflectances And Mineralogy Of Coal Clasts In The Late Carboniferous Sequences In The Two-Deep Research Wells From The Kozlu Coalfield (Zonguldak Basin, Nw Türkiye), Ali İhsan Karayi̇ği̇t, Rıza Görkem Oskay

Bulletin of the Mineral Research and Exploration

Fifty-four coal clast samples in the siliciclastic rocks (e.g., sandstone and conglomerate) were collected from cores of two-deep research wells (K20H and K20K) drilled at the Kozlu coalfield in Zonguldak Basin, and for the first time, they were evaluated using mineralogy by XRD and SEMEDX and random vitrinite reflectance (%Rr) measurements in order to find out their origin and timing. Petrographic observations on polish surfaces show that the coal clasts are either entirely xylitic/vitrinitic particles or coals including a broader range of macerals. The detected minerals in the samples are mostly derived from the parental coal seams and, to a …


Coal Quality, Mineralogy, Petrography, And Geochemistry Of The High-Strontium Bozburun Lignite (Malatya, Eastern Türkiye), Rıza Görkem Oskay, Ali İhsan Karayi̇ği̇t May 2024

Coal Quality, Mineralogy, Petrography, And Geochemistry Of The High-Strontium Bozburun Lignite (Malatya, Eastern Türkiye), Rıza Görkem Oskay, Ali İhsan Karayi̇ği̇t

Bulletin of the Mineral Research and Exploration

The Bozburun coalfield hosts a late Miocene 1.1 m thick coal seam. This study aims to determine coal quality, mineralogy, petrography and geochemistry, and controlling factors of elemental enrichments. The coals are generally black and greyish black in colour, and the low part of the seam commonly includes fossil shell remains. The ash yield displays a decreasing trend towards the upper part of the seam; in turn, gross calorific and total C values increase upwards. The total S content being generally higher than 5% (on dry basis), displays an increasing trend towards the upper part. In the entire seam, huminite …


Modelling And Computation Of Gravitational Attraction, Gradient Tensors, Rotational And Horizontal Invariants Of Asteroid Bennu (101955), Itokawa (25143) And Eros (433) Via 2d Non-Uniform Fft, İlkin Özsöz May 2024

Modelling And Computation Of Gravitational Attraction, Gradient Tensors, Rotational And Horizontal Invariants Of Asteroid Bennu (101955), Itokawa (25143) And Eros (433) Via 2d Non-Uniform Fft, İlkin Özsöz

Bulletin of the Mineral Research and Exploration

The internal structure and mass distribution of the terrestrial objects are yet unknown. The 2D gravity model with a constant density of the terrestrial objects can shed light on the surficial or textural heterogeneity due to topographic variations of the terrestrial objects. Three different steroids, which are Bennu (101955), Itokawa (25143) and Eros (433) are modelled in this study. During the modelling phase, a different number of edges, elements, nodes, and faces are used to describe the 3D models of Bennu, Itokawa, and Eros. These 3D models are used in 2D Non-Uniform Fast Fourier Transform (NU-FFT) applications to obtain gravitational …


Effects Of Urbanization On Eutrophication Parameters In Three Tidal Creeks, Ella Swantek May 2024

Effects Of Urbanization On Eutrophication Parameters In Three Tidal Creeks, Ella Swantek

Honors Theses

Marshes and swashes are vital environments as a controlling barrier between land affected by various pollutants and the ocean. Eutrophication and the effects of this process can be detrimental for the areas experiencing it. I am interested in ways areas that have little contact with human interactions compare to areas that are heavily urbanized, and whether either of these locations is at a higher risk for eutrophication. Using spectrophotometry and fluorometry, I analyzed samples collected from the relatively undeveloped and restricted-access locations of Waities Island Beach and Dunn Sound monthly for dissolved nutrients, and chlorophyll. At the time of sampling, …


Investigating The Drought Sensitivity Of Intermontane-Basin Groundwater Systems In Western Montana Using Standardized Drought Indices, Daniel Buckley May 2024

Investigating The Drought Sensitivity Of Intermontane-Basin Groundwater Systems In Western Montana Using Standardized Drought Indices, Daniel Buckley

Graduate Theses & Non-Theses

Drought is a worldwide phenomenon, and many metrics have been developed to help monitor and understand drought. In this study, the drought sensitivity of two different western Montana intermontane-basin groundwater systems were analyzed: the Bitterroot Valley and the Gallatin Valley. Different standardized meteorological drought indices, namely, the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), were compared against the Standardized Groundwater level Index (SGI) to better understand groundwater sensitivity to meteorological forcing. The SPI and SPEI were computed using precipitation and reference evapotranspiration data from the gridMET dataset. Groundwater level data from the Montana Bureau of Mines …


Characterizing The Engineering Properties Of Three Lithologies From Montana And Idaho Using Acoustic Emissions And Stress-Strain Measurements, Mary Humphreys May 2024

Characterizing The Engineering Properties Of Three Lithologies From Montana And Idaho Using Acoustic Emissions And Stress-Strain Measurements, Mary Humphreys

Graduate Theses & Non-Theses

In this study, stress and strain measurements from unconfined compression tests were used to determine the peak stress, yield stress, Young’s modulus, and Poisson’s ratio of 20 specimens representing three lithologies (sandstone, norite, and argillite-quartzite mix) from Idaho and Montana. Along with traditional strength and deformation parameters, crack initiation (CI) and crack damage (CD) values were also interpreted, corresponding to the stress levels associated with the formation and coalescence of microcracks as a specimen is exposed to increasing stress levels. Acoustic emissions (AE) data were collected along with traditional stress-strain data as this has become a popular method for interpreting …


Impacts Of Hurricane Idalia’S Surge On Coastal Sand Biogeochemistry, Wendy "Cor" Mchone May 2024

Impacts Of Hurricane Idalia’S Surge On Coastal Sand Biogeochemistry, Wendy "Cor" Mchone

Honors Theses

Beaches are heavily influenced by extreme events, such as hurricanes. Biological and chemical processes, such as primary production and diagenesis are often interrupted by these events. To examine the effects of hurricanes on coastal biogeochemistry, this study used sand and porewater samples from Waties Island, SC, which were collected before and after Hurricane Idalia. The samples were analyzed for macronutrient concentrations, organic content, and chlorophyll concentrations. Macronutrient pore water concentration changes were not uniform. The inventory of nitrite decreased significantly after the storm, which was reflected in slight increases in the inventories of nitrate and ammonium. Concentrations of nitrate, which …


Gis Analysis Application Of Flood Risk Map In Beijing, China, Yuxuan Liu May 2024

Gis Analysis Application Of Flood Risk Map In Beijing, China, Yuxuan Liu

Honors Capstones

From the end of July to the beginning of August 2023, Beijing, China, affected by Typhoon "Dusuri" experienced the most precipitation in the Beijing area in 140 years of instrument measurement records. This event led to the evacuation of more than 1.8 million people across the Beijing-Tianjin-Hebei region and the tragic loss of 62 lives. After experiencing such fierce heavy rainfall and flood disasters, how to predict and prepare for such catastrophic events and avoid losses in the future has become a crucial problem. Geographic information systems (GIS) can integrate different layers of geospatial information and provide us with powerful …


Sedimentary Conditions At A Tidal Creek That Exhibits Seasonal Pelagic-Benthic Variations, Jack B. Corbin May 2024

Sedimentary Conditions At A Tidal Creek That Exhibits Seasonal Pelagic-Benthic Variations, Jack B. Corbin

Honors Theses

Tidal creeks in the Grand Strand of South Carolina are small but numerous connectors between land and ocean. One of these creeks, White Point Swash, exhibits a seasonal switch between planktonic and benthic photosynthesizers. As plankton become less abundant in fall, benthic macroalgae bloom, aided by lower water levels due to fall-winter dredging of the main channel, until late Spring. This study builds on previous findings and examines sedimentary conditions at this site further. Sedimentary chlorophyll a (in microphytobenthos) and pore water nutrient concentrations are confirmed to be higher than water-column concentrations. Sedimentary nutrient fluxes to the sediment-water interface, calculated …


High Frequency And Seasonal Controls On Calcium Carbonate Saturation States In Two Maine Estuaries, Catherine Liberti May 2024

High Frequency And Seasonal Controls On Calcium Carbonate Saturation States In Two Maine Estuaries, Catherine Liberti

Electronic Theses and Dissertations

The Gulf of Maine is a highly productive shelf sea in the Northwest Atlantic Ocean that supports many important commercial shellfish. The Gulf of Maine has naturally low calcium carbonate saturation states (𝛀) due to its relatively cold and fresh waters. 𝛀 has been shown to be important predictors of larval and juvenile shellfish growth and mortality. Many of these shellfish species spend all or part of their life cycle within the estuaries that fringe the Gulf of Maine and shellfish aquaculture within the estuaries is increasing rapidly. The 𝛀 of these estuaries are poorly understood, particularly on high frequency …


Characterizing Potentially Harmful Environmental Legacy Issues Within A Declining Midwest City: A Street Sediment Study Of Northeastern Terre Haute, Indiana, Katelyn Adams '24, Ken Brown May 2024

Characterizing Potentially Harmful Environmental Legacy Issues Within A Declining Midwest City: A Street Sediment Study Of Northeastern Terre Haute, Indiana, Katelyn Adams '24, Ken Brown

Senior Research Symposium

Urban settings face unprecedented environmental challenges that include legacy issues as well as emerging pollution problems (e.g., micro-plastics) that continually impact the public health of its communities. Determining the baseline abundances of potentially harmful contaminants in soil, sediment, air, and water is essential to protecting residents. This study examines anthropogenic pollution in street sediments collected from three neighborhoods located in northeast Terre Haute, Indiana. Using stereomicroscopy, SEM/EDS, pXRF analyses, and geospatial analysis (GIS), the goal of this work is to characterize the types of pollutants present and place important constraints on their potential sources.

Stereomicroscopy on nine street sediment samples …


Dating The Ste. Genevieve Limestone In West-Central Indiana Using Sr-Isotope Stratigraphy, Claire Wolfe '24 May 2024

Dating The Ste. Genevieve Limestone In West-Central Indiana Using Sr-Isotope Stratigraphy, Claire Wolfe '24

Senior Research Symposium

A section of Mississippian limestone is exposed in quarry walls at the DePauw Nature Park in Greencastle, Indiana, but its precise age is not known. This research project aimed to date the exposed wall using 87Sr/86Sr isotopic ratios to determine the absolute age. Ten samples of brachiopods and ooids were collected at various levels along the stratigraphic column. Isotope ratios were measured in these samples at ALS Scandinavia using a Neptune Plus MC-ICP-MS. Those ratios were then placed on a LOESS seawater Sr-isotope curve (McArthur, 2020) to determine the absolute age range for each sample. Whereas several samples were contaminated …


A Laser Ultrasound System To Non-Invasively Measure Compression Waves In Granular Ice Mixes, J. Chris Mccaslin, T. Dylan Mikesell, Hans-Peter Marshall May 2024

A Laser Ultrasound System To Non-Invasively Measure Compression Waves In Granular Ice Mixes, J. Chris Mccaslin, T. Dylan Mikesell, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Accurate knowledge of snow mechanical properties, including Young's modulus, shear modulus, Poisson's ratio, and density, is critical to many areas of snow science and to snow-related engineering problems. To facilitate the assessment of these properties, an innovative non-contacting laser ultrasound system (LUS) has been developed. This system acquires ultrasound waveform data at frequencies ranging from tens to hundreds of kHz in a controlled cold-lab environment. Two different LUS devices were compared in this study to determine which recorded more robust ultrasound in granular ice mix samples. We validated the ultrasound observations with poro-elastic traveltime modeling based on physical and empirical …


Authigenic Minerals In Volcaniclastics From An Eastern African Paleolake: A Proxy For Paleoenvironment, Kaitlyn Truss May 2024

Authigenic Minerals In Volcaniclastics From An Eastern African Paleolake: A Proxy For Paleoenvironment, Kaitlyn Truss

Theses and Dissertations

Olduvai Gorge exposes the stratigraphy of Paleolake Olduvai, an often saline-alkaline rift lake that records volcanism from the Ngorongoro Volcanic Highlands. In 2014, cores retrieved from the study area revealed new stratigraphy, including the lacustrine Naibor Soit Formation (Fm) and the volcaniclastic Ngorongoro Fm. In the Ngorongoro Fm part of the cores, mineralogy and geochemistry are the best paleoenvironmental proxies, since under saline-alkaline conditions, volcanic glass alters into specific authigenic minerals (e.g., zeolite, feldspar). This study employs X-Ray Diffraction, X-Ray Fluorescence, and Scanning Electron Microscopy to analyze authigenic mineralogy and geochemistry. The lower Ngorongoro Fm experienced the most alteration, with …


Examination Of Chemical Variations In Fossil Resin With Two-Photon Excitation Fluorescence And Paleobotanical Inventory Reports On National Park Service Units, Katherine Mae Maxine Bober May 2024

Examination Of Chemical Variations In Fossil Resin With Two-Photon Excitation Fluorescence And Paleobotanical Inventory Reports On National Park Service Units, Katherine Mae Maxine Bober

Theses and Dissertations

Fossil resin can be difficult to chemically characterize due to its complex chemistry which can be complicated by a unique chemistry for each fossil resin sample. Using two-photon excitation fluorescence micro-spectroscopy, we measured the wavelengths at peak emission intensity: we compared these fluorescence results to FTIR spectra. There are variations in fluorescence which indicate differences in botanic origin. This method may be used in future research to better understand botanic origin when more traditional analyses fail.There has been a need for a comprehensive paleobotanical inventory report for NPS units. Four teams consisting of graduate students and mentors are completing the …


Rice Biomass Response To Various Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye May 2024

Rice Biomass Response To Various Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to rapidly decreasing rock phosphate reserves. Struvite can be generated via chemical and/or electrochemical precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice cultivar (Gemini 214, RiceTec) grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)] in a P-deficient silt …


Soil Carbon Sequestration Efforts In Arid And Semi-Arid Climates Under Conservation Agriculture And Reforestation, Samantha Lynn Colunga May 2024

Soil Carbon Sequestration Efforts In Arid And Semi-Arid Climates Under Conservation Agriculture And Reforestation, Samantha Lynn Colunga

Theses and Dissertations

Soil organic carbon (SOC) plays a vital role in the global carbon cycle and aids in climate change mitigation. However, deforestation and intensive agricultural practices threaten topsoil and carbon (C) pools through soil disturbances releasing vast amounts of carbon dioxide (CO2) by enhancing the decomposition of organic materials. Degraded soils typically lack stable aggregates, nutrient and water retention, and overall low fertility. In arid and semi-arid regions, soils are in an even more dire situation, as low precipitation and high temperatures slow down the accumulation of SOC. This thesis has two objectives: 1) to evaluate whether conservation tillage practices increase …


Geochemical Analysis Of Basement Rock As A Potential Metal Source In Mississippi Valley-Type Ores, Southern Midcontinent U.S.A., Mackenzie Margaret Moorhead May 2024

Geochemical Analysis Of Basement Rock As A Potential Metal Source In Mississippi Valley-Type Ores, Southern Midcontinent U.S.A., Mackenzie Margaret Moorhead

Graduate Theses and Dissertations

Mississippi Valley-Type (MVT) ores are epigenetic, sedimentary hydrothermal base metal deposits that exist worldwide with type localities in the midcontinent United States. These Permian-aged sulfide ores represent an extraordinary concentration of economic metals, Pb and Zn. Ore deposits occur in vast districts that have a rich mining history. The Pb and Zn from these deposits account for 24% of worldwide reserves. The geologic processes responsible for MVT ore genesis are not fully understood, especially the sourcing of ore constituents. In the midcontinent, the Ouachita Orogeny expelled saline hydrothermal brines in response to high rates of subsidence. These fluids migrated through …


Temporal Trends And Dental Metric Variation In The Macaca Sylvanus Lineage, Cristina Stan May 2024

Temporal Trends And Dental Metric Variation In The Macaca Sylvanus Lineage, Cristina Stan

Graduate Theses and Dissertations

The extensive collection of fossil macaques from Europe, spanning from the Late Miocene to the Late Pleistocene period, is believed to be of the species Macaca sylvanus. However, there has been a prolonged discussion regarding the classification of these specimens into a single taxonomic group as the existing dental sample exhibits a large amount of morphological and metric variation. Specifically, researchers have attempted to identify multiple subspecies based on chronological data of the paleontological locality and, secondly, based on dental metric variation. In this study, I assess temporal trends in the fossil record of Macaca sylvanus and compare overall variation …


Determining The Climatic Effects Of The Central Atlantic Magmatic Province Across The End Triassic Mass Extinction In The Elliot Formation, Southern Africa, Danielle Elizabeth Oberg May 2024

Determining The Climatic Effects Of The Central Atlantic Magmatic Province Across The End Triassic Mass Extinction In The Elliot Formation, Southern Africa, Danielle Elizabeth Oberg

Graduate Theses and Dissertations

Understanding the intricate relation between carbon-cycle perturbations, climate change, and biodiversity stability is crucial in the face of ongoing anthropogenic greenhouse-gas emissions. This thesis explores the impacts of rapid climate change induced by carbon-cycle perturbations and their potential repercussions on global climate. Large igneous provinces, particularly the Central Atlantic Magmatic Province, offer a lens through which to examine the nexus of volcanic activity, mass extinctions, and climate change. The emplacement of Central Atlantic Magmatic Province, covering vast regions across continents, emitted substantial amounts of carbon dioxide, profoundly impacting global climate and ecosystems. The end-Triassic Mass Extinction, attributed to Central Atlantic …


Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu May 2024

Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The uncertainty in model projections of future precipitation across the Sahel has persisted across many generations of Earth System Models (ESMs), with some models predicting drying and others moistening across this region. These discrepancies in future projections pose a challenge for stakeholders and decision makers. Many projections of Sahel precipitation found in the ESMs participating in the sixth phase of Coupled Model Intercomparison Project (CMIP6) show a zonal dipole in precipitation trend, with moistening across the Central and Eastern Sahel and drying projected for the Western Sahel. Previous studies have connected precipitation variability across the Sahel to changes in various …


Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson May 2024

Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Left-moving (LM) supercells, though rarer than right-moving (RM) supercells, may produce significant severe weather. However, there are very few existing studies on LM supercells, particularly polarimetric radar analyses. The upgrade of the nationwide Weather Surveillance Radar-1988 Doppler (WSR-88D) network to polarimetric capability and subsequent studies vastly improved understanding of RM supercells, but similar efforts have largely not been made for LM supercells. This study employs an automated polarimetric radar signature detection algorithm to examine a dataset of significant severe (hail ≥ 2.00”, wind ≥ 65 kts) LM supercells to quantify their polarimetric signatures. Comparisons are made with RM supercells to …


A Compilation, Analysis, And Categorization Of 403 Atmospheric And Climate Science Misconceptions, Haeli Leighty May 2024

A Compilation, Analysis, And Categorization Of 403 Atmospheric And Climate Science Misconceptions, Haeli Leighty

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The National Association of Geoscience Teachers (NAGT) has listed the inaccessibility of research related to misconceptions in atmospheric and climate science as a Geoscience Education Research Grand Challenge (Cervato et al. 2018). This project was a direct response to this call for research and consisted of three distinct steps: 1) data gathering, which included reviewing the literature for relevant misconception data, 2) a qualitative analysis, which included compiling, organizing, and categorizing the data collected, and 3) a quantitative analysis, which included determining the prevalence of each misconception across topic categories, demographic categories, and over time. A total of 403 misconceptions …


Effect Of Biomass Water Dynamics In Cosmic-Ray Neutron Sensor Observations: A Long-Term Analysis Of Maize-Soybean Rotation In Nebraska, Tanessa Morris May 2024

Effect Of Biomass Water Dynamics In Cosmic-Ray Neutron Sensor Observations: A Long-Term Analysis Of Maize-Soybean Rotation In Nebraska, Tanessa Morris

School of Natural Resources: Dissertations, Theses, and Student Research

The precise measurement of soil water content (SWC) is crucial for effective water resource management. This study utilizes the Cosmic Ray Neutron Sensor (CRNS) for area-averaged SWC measurements, emphasizing the need to consider all hydrogen sources, including the time-variable ones like plant biomass and water content. Chapter 1 presents a background on soil moisture estimation, CRNS technology, and an overview of the study. It discusses various soil moisture measurement techniques, highlights the gap in knowledge addressed by CRNS technology, explains CRNS functionality and advancements, and outlines the study's motivations and methods.

Chapter 2 reports a study conducted near Mead, Nebraska, …


Life On The Edge: The Cambrian Marine Realm And Oxygenation, Sara Pruss, Benjamin C. Gill May 2024

Life On The Edge: The Cambrian Marine Realm And Oxygenation, Sara Pruss, Benjamin C. Gill

Geosciences: Faculty Publications

The beginning of the Phanerozoic saw two biological events that set the stage for all life that was to come: (a) the Cambrian Explosion (the appearance of most marine invertebrate phyla) and (b) the Great Ordovician Biodiversification Event (GOBE), the subsequent substantial accumulation of marine biodiversity. Here, we examine the current state of understanding of marine environments and ecosystems from the late Ediacaran through the Early Ordovician, which spans this biologically important interval. Through a compilation and review of the existing geochemical, mineralogical, sedimentological, and fossil records, we argue that this interval was one of sustained low and variable marine …


Machine Learning And Geostatistical Approaches For Discovery Of Weather And Climate Events Related To El Niño Phenomena, Sachi Perera May 2024

Machine Learning And Geostatistical Approaches For Discovery Of Weather And Climate Events Related To El Niño Phenomena, Sachi Perera

Computational and Data Sciences (PhD) Dissertations

El Nino and La Nina are worldwide environmental phenomena brought about by repetitive changes in the water temperature of the Pacific Ocean. Even though the El-Nino impact focuses on a smaller area in the Pacific Ocean near the Equator, these developments have global repercussions, where temperature and precipitation are influenced across the globe, causing droughts and floods simultaneously. In this dissertation, we first derived a drought vulnerability index for the Nile basin, identifying regions with high and low drought risk under ENSO conditions. Next, we evaluated the coherence and periodicity of the ENSO signal to detect its implications on MENA …


Descriptions Of Interglacial Mastodons From Snowmass, Colorado, Connor White May 2024

Descriptions Of Interglacial Mastodons From Snowmass, Colorado, Connor White

Electronic Theses and Dissertations

The Ziegler Reservoir fossil site (ZRFS) in Colorado contains over 4000 mastodon bones that date from 140,000 to 100,000 years ago. At an elevation of ~2705 meters above sea level, ZRFS represents an alpine ecosystem dated to Marine Isotope Stage (MIS) 5. Formal descriptions of cheek teeth, mandibles, crania, and femora were completed. Statistical analyses of the upper and lower third molars, including a novel measurement of interloph(id) distances, indicate significant differences between ZRFS mastodons and Mammut pacificus, while falling within the ranges for Mammut americanum. This study agrees with the taxonomic assignment of ZRFS mastodons to Mammut …