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Detecting Prescribed Fire, Haying And Grazing Events Via Remote Sensing To Create Grassland Disturbance Landcovers For The Ring-Necked Pheasant (Phasianus Colchicus), Megan A. Baldissara

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

This dissertation developed disturbance detection models to fulfill the need for remote sensing landcover products describing grassland structure. The use of landcover products derived from remote sensing is increasing over time in pheasant (Phasianus colchicus) research. Such landcover, however, does not provide relevant pheasant structural habitat information (Chapter 1). Pheasants require tall, high-density grassland for nesting, tall grassland with medium density for brood rearing, and tall grassland for wintering. Time since disturbance can serve as a proxy for structure, as it shapes vegetation by removing biomass and resetting succession. Disturbance is easier to detect than structure with current …

Modeling The Greenland-Iceland-Faroe Ridge Using Integrated Geophysical Analysis, Zachary Clowdus

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

The Greenland-Iceland-Faroe Ridge (GIFR) is an area of significant geologic interest with anomalously thick crust related to enhanced melt generation from the interaction between the Mid-Atlantic Ridge and the Iceland hotspot. To the northeast of Iceland lies the Jan Mayen Microcontinent (JMMC), which is a continental fragment separated from Greenland during the opening of the Northern Atlantic. The overall extent of the JMMC, especially its southern boundary, remains poorly constrained. The crust beneath the GIFR is believed to be primarily of oceanic affinity. However, a recent discovery of felsic lavas in Iceland led to an alternative hypothesis that implies the …

The Urban Heat Island And Its Role In Shaping Convective Environments: An Observational Study, Benjamin W. Moll

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

The continued spread of urbanization and its well-documented effects on regional weather and climate necessitate further research. Urban environments are often warmer and drier than their rural surroundings. This trade-off between a warmer but drier environment could have a complex impact on deep convection and its initiation. Previous studies have noted significant changes in precipitation patterns around cities as well as changes to ongoing deep convection. Given the well-documented theory and past research, it is hypothesized here that urban areas have a significant impact on the PBL thermodynamics of convective environments. The urban heat island (UHI) component of the Micro …

Hydrological Responses To Rainfall Pulses In Desert Vadose Zones: A Multi-Scale Approach Integrating Geophysical, Isotopic, And Eddy-Covariance Measurements, Alfredo Dagda-Torres

Open Access Theses & Dissertations

Drylands are shaped by natural episodic precipitation, where short, intense rainfall pulses interrupt prolonged drought and drive most hydrological and ecological activity. Yet the mechanisms that determine how pulse water infiltrates, is redistributed, stored, evaporated, and ultimately used by desert vegetation remain under quantified in landscapes underlain by shallow petrocalcic horizons. This dissertation integrates three complementary approaches 1) three-dimensional electrical resistivity tomography, 2) eddy-covariance evapotranspiration partitioning, and 3) stable-isotope tracing to improve a mechanistic understanding of pulse-driven water movement and plant water use in a caliche-rich piedmont at the Jornada Experimental Range. The first component characterizes how infiltration pulses interact …

A Combined Multi-Isotope And Machine Learning Approach To Determine Groundwater Salinity And Solute Sources, Lower Valley Area, El Paso County, Texas, Gloria A. Ortiz Gamboa

Open Access Theses & Dissertations

Groundwater salinization is increasingly troublesome in aquifers in and around El Paso, Texas, where concern for available water resources has grown due to frequent droughts and increasing population. Both groundwater and surface water have experienced an increase in total dissolved solids (TDS), a trend that can pose future health and economic problems for residents who primarily rely on groundwater. To address this issue, this research focuses on the Hueco Bolson Aquifer and the Rio Grande Alluvial Aquifer within the Lower Valley area of El Paso, Texas, utilizing a multi-analysis approach to evaluate and determine solute sources and their possible end-members …

What Limits Dryland Ecosystems? Patterns Of Soil Fertility And Resource Limitation In The Chihuahuan Desert, Dylan Stover

Open Access Theses & Dissertations

Human activities are substantially altering global resource cycles with widespread implications for biogeochemistry and ecosystem functioning globally. Drylands, regions where precipitation is outweighed by water losses, are especially sensitive to these large shifts in resource cycles due to their inherently low and variable resource availability. In these regions, resource availability and biological activity are often concentrated around plants – or fertile islands – and predominantly driven by pulses of water. However, our knowledge of the processes influencing biological productivity in drylands – patterns of soil fertility and resource limitation – remains lacking, and their unique biogeochemical and biological processes create …

Metal Zonation And Evolution Of The Bronson Slope Porphyry Cu-Au-Mo Deposit In The Iskut Region Of British Columbia, Canada, Luis Jacobo Yagual

Open Access Theses & Dissertations

Bronson Slope is a Cu-Au-Mo porphyry deposit located within the Stikine Terrane in the Golden Triangle District of northwestern British Columbia, Canada. This deposit represents a complex, multistage magmatic-hydrothermal system emplaced into sedimentary and volcanoclastic rocks of the Triassic Stuhini Group. Bronson has an inferred resource of 517.3 Mt at 0.33 g/t Au, and 0.09% Cu. This study integrates detailed and quick logging from 20 drill holes, totaling 20,296m, SWIR spectral analysis, ICP-MS geochemistry, XRF analysis, magnetic susceptibility measurements, geochronology, and 3D models developed in Leapfrog Geo which define the stratigraphy, intrusive geometry, extension, alteration footprint assemblage, metal zonation, and …

A Kinematic, Data-Parameterized Approach To Constrain Subducted Seafloor During The Emplacement Of Shatsky Rise, Alexzandrya Katrina Shotorban

OES Theses and Dissertations

This study investigates ridge spreading rates and plate boundary geometry in interactions between large igneous provinces and mid ocean ridges, and their role in the kinematics of Shatsky Rise, an undersea volcanic plateau in the western Pacific Ocean that is roughly the size of the state of California. Shatsky Rise formed at a ridge-ridge-ridge (RRR) triple junction (TJ) (Hilde et al., 1976; Sager et al., 1988), at the intersection of the Pacific-Izanagi, Pacific-Farallon, and Izanagi-Farallon ridges, beginning at approximately 147 Ma. Investigations into Shatsky Rise’s formation are limited by the fact that two-thirds of the seafloor data has subducted with …

An Investigation Of Paleoclimate Through A Sedimentological Lens In The Gulf Of Mexico And Western North Pacific, Sarah Monica

Dissertations

This dissertation explores the use of sediment cores as proxy data for the reconstruction of paleoclimatic and environmental conditions. Human-caused climate change is leading to dramatic shifts in the global climate. As the instrumental record of climate is relatively short compared to the amount of time Earth has experienced weather, this work aims to extend our knowledge of climate beyond the instrumental record, thereby improving our holistic understanding of the climate system. In Chapter one, sediment cores from the central Texas inner shelf are used to produce a record of intense tropical cyclone (TC) activity over a ~4500-year period. X-Ray …

Evidence Of Backwater Morphodynamics In Stratigraphy On Earth And Mars: Implications For Ancient Mars, Cory Mitchell Hughes

Graduate Theses and Dissertations

Geologic evidence indicates that liquid water once flowed in abundance across the martian surface. For this reason, in the search for evidence of extraterrestrial life, Mars represents a prime target for scientific inquiry. River systems encode climatic and environmental signals in their deposits on Earth and Mars, often in fan-shaped landforms (e.g., alluvial fans, river deltas, etc.). Distal fan-shaped deposits (i.e., river deltas), in particular, act as a relatively high-fidelity record of dynamic geologic processes. As such, NASA frequently sends rovers to locations on Mars’ surface with hypothesized river deltas (e.g., Perseverance and Jezero crater). Problematically, there are many different …

East Antarctic Ice Sheet History At The Outback Nunataks Using Geographic Information Systems And Cosmogenic Dating, Jacob P. Baker

Electronic Theses, Projects, and Dissertations

This study investigates the history of ice sheet surface elevation at the Outback Nunataks in East Antarctica using exposure age dating and geomorphic mapping. We identified glacial landforms at Roberts Butte, Miller Butte, and Frontier Mountain, in the Outback Nunatak range, using 2023 Landsat Image Mosaic of Antarctica (LIMA) and 2022 Reference Elevation Model of Antarctica (REMA). We collected bedrock and glacial erratic samples for cosmogenic nuclide analysis from Roberts Butte and Miller Butte during the 2023-24 United States Antarctic Program field season. Analysis of glacial erratics reflect inherited cosmogenic nuclide concentrations, resulting in apparent exposure ages between 359 and …

Groundwater Arsenic Contamination In The Oro Grande Wash, Dalila Boice

Electronic Theses, Projects, and Dissertations

This study investigates the distribution of naturally occurring arsenic in groundwater within the Oro Grande Wash in San Bernardino County, California. Depth-discrete groundwater quality data were collected over multiple years using nested and Westbay monitoring wells. Water quality results showed higher levels of arsenic in the deeper aquifers, ranging between 600 feet and 1,000 feet below ground surface. Arsenic levels in these regions reached as high as 66 µg/L. At roughly 800 feet and below, water quality data from the wells reveal that arsenic concentrations exceeded the 10 µg/L maximum contaminant level (MCL) in 87% of cases. These data provide …

Using Luminescence Of Quartz Temper From Archaeological Pottery To Infer Wildfire Intensity In The Southwestern Us, Brooklyn D. Dib

All Graduate Theses and Dissertations, Fall 2023 to Present

The size and frequency of wildfires have increased recently, impacting ecosystems, communities, and human health. This research uses the heat-sensitive luminescence signals of quartz sand temper within archaeological pottery to record past wildfire conditions. Pottery sherds, which are fragments of archaeological pottery, from the forest floor in sites in New Mexico and Arizona were collected from different fire contexts (no fire exposure, historical fires, prescribed burns, and modern wildfires). These forests are primarily Ponderosa Pine with a grassy understory. The interior sand grains of each sherd sample were analyzed using optically stimulated luminescence, which dates when the mineral grains were …

Direct And Satellite-Based Quantification Of Greenhouse Gas Fluxes In Small Ponds., Mark Christopher Tierney

Electronic Theses and Dissertations

As evidenced by their historic losses due to anthropogenic activities, wetlands are undervalued ecosystems that provide numerous ecosystem services, from recreational opportunities to carbon (C) storage. However, these wetlands are also the largest natural source of atmospheric methane (CH₄). Additionally, small water bodies (< 10,000 m²) are disproportionately large emitters relative to larger lakes and reservoirs. As construction and restoration efforts proceed, it is crucial to identify wetlands that need restoration and to understand the factors driving both greenhouse gas (GHG) fluxes and the C balance of these systems. This dissertation investigates the drivers of greenhouse gas fluxes …

Engineering Risk And Indigenous Resilience Toward Intelligent Decision Support For Mining In Ancestral Lands, Izech Brian O. Edwin, King Harold A. Recto

Electronics, Computer, and Communications Engineering Faculty Publications

Mining within ancestral territories reveals an ongoing conflict between technical viability and Indigenous consent. This collaborative study, conducted by an engineering scholar and a policy researcher of Indigenous heritage in Benguet among the Ibaloi and Kankanaey peoples, investigates how risk transparency and policy alignment can bridge existing divides, while formulating principles applicable to other Indigenous mining contexts. The study provides an initial evaluation of the feasibility of a proposed large-scale mining operation within a risk-informed, data-driven governance framework. Three elements of engineering risk were assessed utilizing literature-derived and proxy parameters: (1) Land degradation is indicated by a Soil Productivity Index …

Long-Term Sedimentation Rates And Patterns Of Alluvial Ridge Basins (Esteros) Of The Rio Grande Delta (Tx, United States Of America), Kynan Joseph Rutan

Theses and Dissertations

Little is known about the century-scale sedimentation rates and patterns of Alluvial Ridge basins within river deltas, especially in the Rio Grande Delta (RGD). To better constrain this, 22 cores were collected in the Bahia Grande Complex (BGC) and analyzed for grain size, organic content, age dates, and elemental composition.

Results show that grain size and sedimentation rates decrease from an artificial inlet to the basin interior, with elevated sedimentation in the south. Also, human activities, such as the construction of the Brownsville shipping channel in the 1930s, altered sedimentation dynamics in the basin by blocking natural inlets and leading …

Updating The Surface Geological Maps In The Boston Mountains Region Of Arkansas Using Subsurface Well Log Correlation And Lidar Mapping, Olivia Smith

Graduate Theses and Dissertations

The Pennsylvanian Atoka Formation are the primary surface outcrops of the Boston Mountains in northwest Arkansas. Where fully preserved in the Arkoma Basin to the south, the Atoka Formation exceeds 18,000 feet of sandstone and shale. It is mapped as a single “undifferentiated” unit on the surface geological map of Arkansas. This project correlates ten subsurface subdivisions of the Atoka Formation plus the Desmoinesian to the surface outcrops of the southern Boston Mountains. This produced a higher resolution surface map beyond the current Atoka Undifferentiated scheme. Recognition of the Atoka Formation subdivisions in surface outcrops using standard lithostratigraphic and biostratigraphic …

Agricultural Practices’ Impact On Soil Health Indicators In Mid-South U.S. Crop Production Systems, Katherine Suzanne French

Graduate Theses and Dissertations

Soil health and regenerative agriculture are concepts gaining popularity across global agriculture systems. The effect of sustainable farming practices such as nutrient management, cover crops, adoption of no-tillage, and residue retention on crop yield, as well as environmental resilience, is increasingly being studied. This research aimed to evaluate the impacts of (i) cover cropping and nutrient management, and of (ii) soil sampling depth and timing on indicators of soil health in various mid-southern irrigated row crop systems. Soil health indicators like soil organic matter (SOM), carbon dioxide respiration (CDR), beta-glucosidase enzyme activity (BG), permanganate oxidizable carbon (POXC), and the soil …

The Effects Of Green Orientation And Technological Agility On Sustainable Competitive Advantage Under Environmental Uncertainty: Organizational Agility As A Pathway, Sahilali Saiyed, Vimal Kumar, Abdul Waaje, Adi Prasetyo Tedjakusuma

Michigan Tech Publications

Despite the strengthened efforts on sustainability and technological activities by firms, the existing literature lacks a clear picture regarding how green orientation (GO) and technological agility (TAG) can be transformed into sustainable competitive advantage (SCA) and at what time the conversion process may be most efficient. This paper conceptualizes organizational agility (OGA) based on the resource-based view (RBV) and dynamic capabilities theory (DCT) and hypothesizes that GO and TAG indirectly affect SCA with the mediating impact of environmental uncertainty (ELU). A moderated-mediation model was tested based on a sample of 200 managers (HR, marketing, accounting/finance, quality control, R&D) of auto-parts …

Modern Water And Sediment Transport Patterns In Alluvial Ridge Basins Of The Rio Grande Delta, South Texas, Usa, Waqid Nabi

Theses and Dissertations

Alluvial ridge (AR) basins are shallow, marine-influenced depressions within river deltas, yet their flow and sediment dynamics remain poorly understood. This study examines hydrodynamics and sediment transport patterns in the Bahia Grande Complex, which are AR basins of the Rio Grande Delta, using tilt current meters, water-level and turbidity loggers, and suspended and bed-sediment sampling. The AR basins function as wind-dominated, microtidal environments, where pre-existing basin geometry and hydrodynamic forcings control water flow and sediment distribution patterns. Seasonal wind patterns and storms modulate water levels and flow connectivity. Substrate patterns reflect frequent resuspension in the shallow northern basin, maintaining coarse …

Advancements In Sinkhole Remediation: Field Data-Driven Sinkhole Grout Volume Prediction Model Via Machine Learning-Based Regression Analysis, Bubryur Kim, Yuvaraj Natarajan, K. R. Sri Preethaa, V. Danushkumar, Ryan Shamet, Jiannan Chen, Rui Xie, Timothy Copeland, Boo Hyun Nam, Jinwoo An

Civil Engineering Faculty Publications

Sinkhole formation poses a significant geohazard in karst regions, where unpredictable subsurface erosion often necessitates costly grouting for stabilization. Accurate estimation of grout volume remains a persistent challenge due to spatial variability, site-specific conditions, and the limitations of traditional empirical methods. This study introduces a novel machine learning-based regression model for grout volume prediction that integrates cone penetration test (CPT)-derived Sinkhole Resistance Ratio (SRR) values, spatial correlations between CPT and grouting points (GPs), and field-recorded grout volumes from six sinkhole sites in Florida. Three data transformation methods, the Proximal Allocation Method (PAM), the Equitable Distribution Method (EDM), and the Threshold-based …

Understanding Outer Solar System Ice Composition Through Impact Processes: Simulations And Hydrates, Jill Rebecca Mcdonald

Graduate Theses and Dissertations

This work concerns solar system ices, particularly water ice and clathrate hydrates. Water ice is abundant as a mineral in the outer parts of the solar system, providing source material for the formation of clathrates. We explored constituents through a combination of numerical modeling and laboratory experiments. Understanding the differences and similarities between these materials can shed light on planetary habitability, composition, and evolution. Chapter one contains relevant background information. This chapter introduces the ices that will be studied and gives insight into the locations of interest within our solar system. It also explains the mechanics of impact cratering processes …

Terrestrial And Lacustrine Organic Matter Biomolecular Transformations Via Thermal Maturation And Oxidative Degradation, Louis Connor Bondurant

Chemistry & Biochemistry Theses & Dissertations

The most abundant source of fossil fuel-forming kerogen on Earth is classified as Type II kerogen, believed to originate from marine biomass. However, a significant amount of lacustrine and terrigenous carbon is transported to the ocean through fluvial discharge. Less than half of the exported organic carbon is observed in coastal regions and the open ocean. There is a great need for an explanation of what is happening to this organic carbon during transport and deposition. Traditionally, the marine organic matter in coastal regions accumulates to eventually be buried and transformed into petroleum over millions of years due to its …

An Integrated Lithospheric Geotherm Model From Seismic Data And Plate Ages, Amanda R. Leaman

All Graduate Theses and Dissertations, Fall 2023 to Present

This research aims to develop advanced methods to accurately depict temperature profiles within the lithosphere, the Earth’s rigid outer layer. These temperature profiles extend from Earth’s surface to the asthenosphere, the ductile layer below the lithosphere. Constraining the poorly-known temperature distribution within the upper Earth is important for modeling the deformation of Earth’s crust over varying timescales and is essential for advancing realistic simulations of Earth dynamics. Here, I utilize enhanced global seismic data, coupled with recent advances in our understanding of mineral systems, to create several global lithospheric models in which I estimate temperature profiles from seismically observable features …

Interactions Between Black, Brown, Blue And Green Carbon From Terrestrial To Marine Ecosystems: A Critical Review, Allison White, Richard Kline, Md. Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Black and brown carbon are byproducts of the incomplete combustion of biomass or fossil fuels. These light-absorbing aerosols influence climate by altering the radiative balance through the absorption and scattering of sunlight, exacerbating global climate change. Their subsequent deposition on terrestrial and marine environments affects surface albedo, snow and ice melt, and biogeochemical processes, leading to further environmental consequences. In contrast, green and blue carbon refer to carbon stored in terrestrial vegetation and marine ecosystems, respectively. These ecosystems play a crucial role in mitigating climate change by sequestering atmospheric carbon; however, they are increasingly threatened by climatic disturbances, anthropogenic activities, …

Leptinotarsa Texana Schaeffer And Gargaphia Arizonica Drake & Carvalho As Potential Biocontrol Agents For The Noxious Weed Solanum Elaeagnifolium Cav, Samikshya Subedi, Stephanie L. Kasper, Alexis Racelis, Greg Lefoe, Rupesh R. Kariyat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Silverleaf nightshade (Solanum elaeagnifolium Cav.; SLN) is a perennial forb native to the southern United States, Mexico and South America that has become a serious agricultural weed across the world. Biological control has emerged as a significant alternative for the management of (SLN) due to the challenges and high costs associated with chemical and mechanical controls. In this study, we used a combination of field and laboratory studies to (1) explore the fundamental and realized host ranges of two North American insects, Leptinotarsa texana Schaeffer and Gargaphia arizonica Drake & Carvalho and (2) assess their suitability as potential biological …

Climate Change Has Increased Global Evaporative Demand Except In South Asia, Saeed Karimzadeh, Arman Ahmadi, Dennis Baldocchi, Joshua B. Fisher

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Climate change alters how strongly the atmosphere draws water from the land, yet a consistent global assessment of this evaporative demand has been lacking. Here, we analyze 45 years of climate data and global models to quantify trends in the key drivers—air temperature, humidity, radiation, wind speed, and cloud cover—that determine the atmosphere’s drying power. We find that evaporative demand has increased worldwide, indicating a stronger atmospheric thirst, except in South Asia, where it has declined. There, widespread irrigation has increased soil and air moisture, enhanced cloud formation, and reduced sunlight reaching the surface, counteracting the global signal. These contrasting …

High Variability In Flood Discharge And Stage Accelerates River Mobility, Chenliang Wu, Wonsuck Kim, Shuo Yang, Frank Tsai, Jeffrey A. Nittrouer, Tian Y. Dong, Duhwan Keum, Kyle M. Straub

School of Earth, Environmental, & Marine Sciences Faculty Publications

Lateral channel migration is a fundamental process in natural alluvial rivers; however, the factors that control the rate of migration remain unclear. Despite its importance in shaping river morphology, the impact of water discharge on river mobility is still largely unexplored. Here, we leverage a dataset of 64 rivers across the globe to show that higher variability in river discharge and stage promotes higher rates of river migration. To reveal the physical processes behind this relationship, we focused analyses on the lowermost 500 kilometers of the Mississippi River, where a pronounced gradient in water stage variability and migration rate exists. …

Phase Equilibria Modeling Constraints On Channel Flow Of Metasedimentary Crust Beneath The Southeastern Tibetan Plateau, Govind Joshi, Gregory Dumond

Geosciences Faculty Publications and Presentations

Lower crust of the southeastern Tibetan Plateau includes 100 s of km2-scale zones of low resistivity at 20-40 km-depths indicating the presence of melt +/- fluid +/- graphite. These zones coincide with interconnected zones of low shear wave velocity. Data from central and southeastern Tibet support the occurrence of meta-sedimentary felsic granulites in the lower crust along a backarc-like geothermal gradient. Phase equilibria modeling of average metasedimentary pelite and greywacke bulk compositions constrained by these geophysical data explored the impact of partial melting on shear wave velocity for a range of fluid content. Low shear wave velocities beneath southeastern Tibet …

An Objective Method To Locate Shear Lines During The Northeast Monsoon Season In The Philippines, Lyndon Mark P. Olaguera, John A. Manalo, Jun Matsumoto, Faye Abigail T. Cruz, Jose Ramon T. Villarin

SOSE Affiliate: Manila Observatory

The shear line is a narrow zone of maximum horizontal wind shear, typically identified as a confluence zone of low-level wind streams. Previous studies showed that this system can trigger heavy to extreme rainfall events in the Philippines during the northeast monsoon season. However, a research gap remains in objectively identifying and locating this system. Thus, this study develops a detection method that may be used for monitoring and forecasting the location of shear lines. Results show that the gradient of meridional winds in the y-direction (∂V925hPa/∂y), the boundary layer moisture flux convergence, and the 925 hPa relative vorticity may …