Digital Commons Network^™

Do Cover Crops Influence Beneficial And Herbivorous Arthropod Communities Across Growing Seasons?, Adegboyega Fajemisin, Satinderpal Kaur, Alejandro Vasquez, Alexis Racelis, Rupesh R. Kariyat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Cover crops provide multiple ecosystem services in agriculture, yet their influence on arthropod communities remains poorly understood, especially in commercial farming. Despite their potential benefits, it remains unexplored how cover crops affect arthropod community dynamics across multiple growing seasons. We conducted a two-year study across three commercial farms in the Lower Rio Grande Valley, Texas, to examine how cover crops influence arthropod community composition and abundance, whether beneficial arthropods (natural enemies and pollinators) persist into cash-crop phases, and how cover crops affect natural enemy–herbivore relationships. We compared arthropod communities between cover-crop treatments and control plots and tracked responses through subsequent …

Formation Mechanism Of High-Quality Reservoirs In The Shanxi Formation Of The Qingyang Gas Field In A Meandering River Delta Setting, Xingming Duan, Shu Liu, Meng Wang, Yecan Fan, Xiyu Wang, Xinan Yu, Zubing Li

Turkish Journal of Earth Sciences

As global energy demand rises, unconventional gas resources, particularly tight gas reservoirs, have become increasingly important for future energy supply. Located in the southwestern Ordos Basin, the Qingyang gas field is a newly discovered deep tightgas field with proven geological reserves exceeding 31.8 × 109 m3 and has become a strategic focus for deep-gas exploration in China. Despite rapid appraisal that delineated several stable gas-bearing zones, a comprehensive understanding of the sedimentary architecture, diagenetic transformation, and enrichment mechanisms of high-quality reservoirs in the Permian Shanxi Formation remains incomplete. Focusing on the Shan 1 Member (hereafter referred to as Shan 1), …

Hyperspectral Image Classification Using Novel 1-D And 2-D Deep Neural Networks, Özlem Polat, Zümray Dokur, Tamer Ölmez

Turkish Journal of Earth Sciences

Hyperspectral image (HSI) classification is of critical importance in many fields including agriculture, geology, environmental monitoring, and urban planning. In recent years, many researchers have utilized deep neural networks (DNNs), known for their high performance in the classification of HSIs. When 2-D/3-D convolutional neural networks are used in HSI classification, filters are applied using input patches typically larger than 11 × 11. This allows spectral and spatial features to be evaluated together. However, this combination creates several problems. Because HSIs have low spatial resolution, they often do not contain strong texture details. Furthermore, features with little relevance to classification make …

Applicability Of Machine Learning For Shear-Wave Velocity Prediction From Conventional Well Logs: The Lsboost Approach, Rahmat Catur Wibowo, Fadsyah Muhammad Arby, Bagus Sapto Mulyatno, Ordas Dewanto, Isti Nur Kumalasari, Muh Sarkowi

Turkish Journal of Earth Sciences

Shear-wave velocity (Vs) is one of the most critical parameters for determining geomechanical properties and basin overpressure. However, assessing Vs via techniques like core analysis requires considerable effort and expense. This study predicts Vs using several approaches and compares the accuracy levels of all models. For this objective, the multiple linear regression, multiple linear stepwise regression, support vector machine, and least-squares boost (LSBoost) methodologies were selected. The six well-logging data inputs of density (RHOB), gamma-ray (GR), deep resistivity (ILD), acoustic wave velocity (Vp), shale volume (VCL), and water saturation (SW) were selected as effective variables, whereas Vs was regarded as …

A Shallow Landslide Hazard Assessment Using A Probabilistic Approach: An Example From Northeastern Türkiye (Beşikdüzü, Trabzon), Kübra Tezel, Aykut Akgün

Turkish Journal of Earth Sciences

The objective of this study was to identify and assess shallow landslide hazard in both spatial and temporal terms within the boundaries of Beşikdüzü District in northeastern Türkiye. The workflow was initiated with the development of a detailed multitemporal mass‑movement inventory map derived from satellite imagery provided on the Google Earth platform,1 covering the period between 2000 and 2018. Inventory mapping was complemented by extensive field verification campaigns to identify discrepancies, confirm spatial accuracy, and document additional morphological details that could not be detected from imagery alone. A 10-m spatial resolution digital elevation model (DEM) was generated from 1:25,000-scale digital …

Spectral Classification Of Diverse Lithologies Using Multi- And Hyperspectral Satellite Data: A Comparative Study, Önder Gürsoy, Emre Özelkan, Rutkay Atun, Ayşe Betül Çalişkan, Ahmet Efe

Turkish Journal of Earth Sciences

Accurate lithological mapping requires selecting the appropriate remote sensing data and classification methods. This study evaluates the performance of four satellite datasets—Landsat 8 OLI, Sentinel-2A, ASTER, and Hyperion EO-1—using three spectral classification techniques: Matched Filtering (MF), Spectral Angle Mapper (SAM), and Spectral Information Divergence (SID). The study area is located between the Zara and Koyulhisar districts in eastern Türkiye and comprises diverse lithological units. A total of 49 rock samples collected in the field were used for validation. The results indicate that MF consistently outperformed the other methods, achieving the highest accuracy with Landsat 8 (Kappa = 94.2%). ASTER data …

Geoelectrical Signatures Of The Giant Karaburun Pelitic-Mafic-Type Volcanogenic Massive Sulfide Mineralization In The Central Pontides (Türkiye), Kurtuluş Günay, Türker Yas, Buğra Çavdar, Ertan Pekşen

Turkish Journal of Earth Sciences

The Karaburun deposit, hosted in greenschist facies metamorphic rocks, is a newly discovered giant volcanogenic massive sulfide (VMS) deposit in Anatolia and provides an exceptional natural laboratory for geophysical monitoring. The main ore body is less affected by metamorphism than the surrounding wall-rocks, where metamorphic and metasomatic processes formed pyritemagnetite- sericite-quartz assemblages that significantly influence geoelectrical properties. In this study, the geometry and extent of mineralization within geologically defined target zones were investigated using direct current resistivity and two-dimensional timedomain induced polarization (2D-TDIP) methods and the results were compared with the geology. A pole–dipole electrode array was employed in the …

Quantifying Co2 And Ch4 Fluxes In A Semi-Arid Floodplain: Assessing Spatial And Temporal Drivers, Miles E. Kelsey

Earth and Planetary Sciences ETDs

Rivers transport sediment and carbon across Earth’s surface, and their floodplains can store carbon over decades to millennia, making them important to terrestrial carbon management. While soil carbon can persist long term, it may be released as greenhouse gases through processes like methanogenesis and heterotrophic respiration. Environmental controls on these fluxes remain poorly constrained across floodplains in different climate and geomorphic setting, but especially in semi-arid systems where measurements are limited. To address this gap, we quantified CO₂ and CH₄ fluxes along the Middle Rio Grande (New Mexico, USA) using 227 chamber measurements collected May to November 2025 at three …

Marine Geophysical Studies Of Coupled Tectonic And Sedimentary Processes At Active Plate Boundaries, Sarah R. Rysanek

Earth and Planetary Sciences ETDs

Deep-sea and convergent margin sedimentary systems preserve critical records of tectonic and climatic processes that shape Earth’s surface. This dissertation investigates source-to-sink sediment routing and forearc deformation to better constrain the interplay between sedimentary and tectonic processes, through investigations of a deep-sea fan system, and the forearc geomorphology offshore Nicaragua. In the Gulf of Alaska, we integrate ultra-long-offset and regional multi-channel seismic reflection data, multi-resolution bathymetry, and plate reconstructions to remap the Baranof Fan system. Results show that the fan is larger than previously recognized and constructed by two primary depocenters linked to distinct glacial sediment pathways, with accommodation space …

Constraining Magmatic Processes In The Central American Arc Using Melt Inclusion Vapor Bubble Analysis And Triple Oxygen Isotope Modeling And Exploration Of Volatile Contributions To The Production Of Continual Radio Frequency (Crf) Lightning Events, John M. Hamilton

Earth and Planetary Sciences ETDs

Magmatic volatiles are key to determining the processes happening in the subsurface that we cannot directly sample. Advances in measuring volatile and isotope contents from erupted volcanic samples have given us the ability to understand magmatic processes, mixing components that produce the bulk magma composition and potentially precursors to eruptive hazards, such as lightning.

Through analysis of melt inclusions that sample the melt at depth and triple oxygen isotope quantification of olivine crystals from multiple volcanic edifices, the three following studies display how I have utilized these analytical techniques to help unravel processes happening in the subsurface that lead volcanic …

Evaluating The Spatial Relationship Between Geomorphology And Subsurface Structures On The Us Atlantic Margin With Applications To Other Terrestrial Planets, Andrea Caitlyn Stiles

Theses and Dissertations

High-resolution digital elevation models (DEMs) are widely available for terrestrial planetary bodies, but subsurface structural data remain limited. This research evaluated whether surface geomorphology could predict subsurface features, specifically faults and methane seeps, along the US Atlantic continental margin as an analog site. Faults were mapped with seismic interpretation and compared with quantitative geomorphic classifications derived from 100-m bathymetry including slope, aspect, rugosity, bathymetric position index, and geomorphon classes. Maximum-entropy modelling was used to predict fault occurrences from surface data. Results indicated that specific geomorphic landforms and slopes had the strongest control on fault presence, reflected in topographic expression of …

Using Seafloor Geomorphology, Classification Schema, And Spatial Analysis To Predict Geologic Structures, With Applications For Mars, Emma Morgan

Theses and Dissertations

This study evaluated whether seafloor geomorphology can be used to predict subsurface fault locations along the Cascadia continental margin and explored whether such relationships can be transferred to Mars. Geomorphological classification schemas such as geomorphons, bathymetric position index (BPI), slope, rugosity, aspect, and curvature were derived from seafloor bathymetry data and used as predictor variables in maximum entropy (MaxEnt) models developed separately for Pre-Pleistocene, Pleistocene, Quaternary, and active fault datasets. Model performance ranged from AUC = 0.62 to 0.67, showing moderate predictive skill, with younger fault systems exhibiting stronger geomorphic associations. A secondary analysis showed a weaker but detectable relationship …

2d And 3d Insights Into The Formation And Emplacement Of Martian Meteorites, Sierra Rhaye Ramsey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Martian meteorites are the only samples currently available from Mars, making their study critical for understanding martian igneous processes. Despite extensive study over the last five decades, the formation (e.g., mantle sources, crystallization pressures), emplacement (e.g., intrusive versus extrusive), and shock histories of these rocks remain uncertain due to their innate lack of geologic context and limited petrologic tools calibrated for martian conditions. This dissertation analyzes a large suite of 22 igneous martian meteorites using complementary 2D and 3D analytical methods to better constrain the magmatic, emplacement, and shock processes responsible for their formation and ejection from Mars.

Chapters 2 …

Transboundary Groundwater Flow Between Niger And Nigeria In The Iullemeden Aquifer System, Gare Ambrose-Igho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater is important in regions where water resources are not abundantly distributed such as arid and semi-arid regions. In many countries in Africa, groundwater serves as the most reliable source of water supply and supports over 50% of the African population. Groundwater is stored in underground water-bearing permeable rocks, rock fractures, or unconsolidated materials known as aquifers. Groundwater can be transboundary, meaning it crosses international political boundaries between two or more sovereign states. Transboundary aquifers are prone to overexploitation that depletes the groundwater resource and can cause a lowering of the water table and possible ground subsidence. Overexploitation in transboundary …

Preservation Of Sedimentary Rubidium Isotopic Signatures In Subduction Zones: Insights From The Schistes Lustrés Hp-Uhp Metasediments, Western Alps, Mary Clarich

UNLV Theses, Dissertations, Professional Papers, and Capstones

When oceanic plates bend and sink into the mantle at subduction zones, they carry sediments from the surface down into the mantle. The recycled sediments contain elements, that are depleted in the mantle, thereby influencing the composition of the mantle wedge and the formation of arc magmas, which are the building blocks of juvenile continental crust. However, it remains poorly constrained how much these elements, particularly fluid-mobile elements such as rubidium (Rb), are lost into fluids during metamorphic dehydration, and how much is transported to sub-arc depths where arc magmas are generated. Rubidium in subducting sediments is mainly hosted in …

Harnessing Backcasting To Identify Drivers Of Critical Warming At Hoover Dam Using Hydrodynamic And Machine Learning Models, Eunice Ledres

UNLV Theses, Dissertations, Professional Papers, and Capstones

Elevated water temperatures can pose a significant threat to dam infrastructure, potentially damaging turbines, overheating internal components, and forcing generator shutdowns. This study uses a backcasting framework to evaluate how future scenarios may result in elevated water temperatures. Backcasting defines undesirable outcomes and works backward to identify the conditions that lead to them. The developed backcasting framework integrates 3D physics-based simulations with a Long-Short Term Memory (LSTM)surrogate model and SHapely Additive exPlanations (SHAP) interpretation. The combination captures temporal water temperature dynamics and quantifies the contributions of different drivers to elevated water temperature releases. As proof of concept, these methods are …

Assessing The Relationship Between Subsurface Geology And Surficial Geomorphology: Remotely Predicting Geologic Features And Geohazards Using An Elevation-Trained Machine Learning Algorithm In The Northern Gulf Of Mexico, Allison L. Wing

Theses and Dissertations

This thesis evaluates the capacity to predict subsurface geologic features and submarine landslide susceptibility using surficial geomorphology derived from bathymetric elevation data in the Northern Gulf of Mexico. Quantitative geomorphic variables including slope, curvature, aspect, rugosity, geomorphons, and Bathymetric Position Index were generated from 30-meter digital elevation models and used as explanatory variables in presence-only Maximum Entropy models. Known locations of faults, pockmarks, mud volcanoes, hydrocarbon seeps, and landslides (particularly intact scarps) were used to train and validate predictive models through k-fold cross validation. Model performance was assessed using omission rates and AUC values. Results demonstrate that specific geomorphic signatures, …

Digging Deep Into Curation: A Guide To Creating A Local Fossil Museum, Syd Joheim, René Shroat-Lewis

Research and Creative Works Expo

In Arkansas, the dissemination of educational content related to evolution and natural history is often constrained by prevailing cultural dynamics. This has resulted in a significant gap in the exposure of primary and secondary school students to foundational concepts in natural history and physical sciences. Even the state’s most popular science and history museums often intentionally exclude exhibits that risk upsetting a large portion of their visitors, further exacerbating the issue. As a consequence, many children do not receive proper education on natural history and physical sciences.  To address this educational deficiency, researchers identified and cataloged specimens from a collection …

A Gis Analysis Of The Relationship Between Ndvi Value, Slope, And Aspect Of The Terrain Of The Prairie Restoration Project, Basil Lund

2026 Symposium

The Prairie Restoration Project (PRP) encompasses 115 acres of land on the west side of the EWU campus. The goal of the PRP is to restore what was once a section of wheat farm back to its original Palouse prairie state. Here, I am using publicly available satellite data to examine some potential variables affecting the health of wheat plants planted in the years 2009 to 2017. I have used 4-band aerial imagery to create a map of NDVI values within the bounds of the PRP, which visualizes the near-infrared wavelengths that are reflected by healthy, chlorophyll-rich plants. I have …

Urban Conflagrations: Structural Ash And Soil Metal(Loid) Contamination After California’S Eaton And Palisades Fires, S. Anselme Dossou, Leon Kelly, P. Louis Lu, Robin Jones, Oliver O'Donnell, Justin St. P. Walsh, Daniel D. Richter

Art Faculty Articles and Research

In the weeks after California’s Eaton-Palisades wildfires, structural ash of burned homes and soils from yards and curbsides were sampled for analysis of Pb, As, and eight metals from 32 burned residences. About six months after fires and after US Army Corps of Engineers’ Phase 2 cleanups removed 15 cm from structural ash footprints, 17 properties were resampled within about a meter of original sampling sites. Concentrations of metal(oid)s in structural ash and residential soils varied between and within properties with significant spatial and temporal patterns. Lead concentrations were highest in structural ash and soil of yards of select pre-1970s …

A Geotechnical Analysis Of Mid-Slope Soil Sample Pp-15 From The Palouse Prairie Restoration Project In Cheney, Wa, Basil Lund, Robin Roose, Chloe Jensen

2026 Symposium

The Palouse is an Inland Northwestern ecoregion with loess hills created by aeolian processes related to Pleistocene glacial events. Eastern Washington University’s Prairie Restoration Project aims to restore a 120-acre site located in Cheney, Washington. EWU is gradually seeding bunchgrasses and perennial forbs to increase biodiversity of the site, which will be used for educational and recreational purposes. The objective of this project was to determine to what extent the engineering properties of soil on the site varies along a slope. To determine if location on the slope affects soil properties on the site, we sampled and performed a geotechnical …

Analyzing Surface Water And Groundwater Interactions From Pfas Contamination In The West Plains Region Of Spokane County, Jerusha R. Hampson

2026 Symposium

The West Plains region of Spokane County has been significantly impacted by PFAS contamination due to the decades-long use of aqueous film-forming foam (AFFF) for firefighting training at both Fairchild Air Force Base (FAFB) and the Spokane International Airport (SIA). Groundwater contamination is significant, but surface waters are impacted by the contamination as well. Groundwater flows to the north and east, meaning surface water bodies that make up the northern and eastern boundaries (Deep Creek, Hangman Creek, and the Spokane River) can be impacted by PFAS contamination. The West Plains aquifer system is complex but combining data about aquifer flow …

Preliminary Geologic Assessment And Pfas Occurrence In Western Cheney, Washington, Sydney Frandsen

2026 Symposium

In 2021 Cheney Water Well #5 was closed due to toxic per- and polyfluoroalkyl substances (PFAS) levels above the current State Action Limits and the National Drinking Water Protection Act (https://www.cityofcheney.org/207/Water), which is a concern since PFAS has been associated to types of cancer, birth defects, and other negative human and environmental health concerns (https://doh.wa.gov/communityand-environment/contaminants/pfas). The City of Cheney also tested two downgradient deep-groundwater-wells (Cheney wells #6 and 7) and halted investigation due to the wells being below state and federal drinking water standards. However, a local resident’s shallow groundwater well tested to be above federal and state levels of …

Evapotranspiration Everywhere, All The Time: Towards A Unified View From Earth Observation, Joshua B. Fisher, Martha C. Anderson, Diego G. Miralles, Kanishka Mallick, Paul C. Stoy, Youngryel Ryu, Wim G. M. Bastiaanssen

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Scientists want to know everything, everywhere, and all the time. This is particularly true in Earth science, where we seek to understand processes that span from the molecular to the planetary scale in how the world works, how it affects us, and how we impact it—especially the water cycle. Evapotranspiration (ET) was the last component to be measured in closing the water cycle: for decades, closing the water budget meant adding up all the measurable components, then inferring ET as the residual. Early measurements relied on water loss from pans and weighing lysimeters, followed by sensors inserted into plants to …

A Study Of The Links Between Denudation, Lithology, And Tectonics In The Tropical Andes, Helbert Garcia-Delgado

Dissertations - ALL

Landscape evolution in the tropical Northern Andes is governed by complex interactions between tectonic deformation, climatic shifts, and bedrock lithology. Standard geomorphic models often struggle to capture the full spectrum of these processes, particularly in active orogens where topographic steady state is frequently challenged by variable sediment dynamics and deep weathering. Understanding how these factors dictate landscape responses over different timescales is critical for interpreting the relationship between landscape evolution and surface processes of tropical mountain belts. This dissertation utilizes a combination of cosmogenic nuclide dating, numerical modeling, and subsurface borehole analysis to examine the structural, climatic, and lithological controls …

Impacts Of Organic Matter On Laser Particle-Size Analysis Of Marsh Sediments, Alexander Powell

Honors Theses

Grain size analysis (GSA) is widely used in sedimentology and paleoenvironmental reconstruction; however, its utility can be constrained by the presence of organic matter. This study assesses the impact of organic matter through the analysis and comparison of untreated and hydrogen peroxide-treated samples. Organic-rich samples from the Thousand Acre marsh in Georgetown, SC, were subjected to three treatments: untreated, standard, and enhanced. Grain size distribution was measured for each of these treatments using a CILAS 1190 laser diffraction particle analyzer, and organic matter was quantified by loss-on-ignition (LOI). Results show that untreated samples are significantly coarser than treated samples, demonstrating …

The Role Of Peat Matrix Structure In The Accumulation, Storage, And Release Of Biogenic Gases From A Variety Of Peat Soils Across A Latitudinal Gradient, Md Rajeun Islam

Electronic Theses and Dissertations

Peatlands store about a third of the global soil carbon pool and are among the most important natural sources of biogenic greenhouse gases, including methane (CH₄) and carbon dioxide (CO₂). While biogenic gas production in peatlands has been studied extensively over the last few decades, the physical controls that regulate how these gases accumulate within the soil matrix and their influence on gas dynamics as they get released to the atmosphere still remain uncertain. Most studies investigating biogenic gas dynamics in peatlands have inferred in-situ gas distribution either exclusively from measurements of gas flux releases, or …

Badlands And Bison, Andrew Ressler

The Cicadian

“Badlands and Bison” is a fragmentary travel-fiction hybrid set in the mythic badlands of North Dakota. It merges reportage with invention, parody with elegy: a narrator half pilgrim, half comedian drifts from piano keys to prairie herds, searching for sincerity in a landscape that resists it. The form bends between essay and story, using humor, lyric observation, and shifting registers to question how we mythologize place.

Riki&Dolphin: Real Time Data Transmission From The Bottom Of A Cave To A Website, Luca Tringali, Giacomo Canciani Dr., Tecla Tripari, Alexander Debenjak, Caterina Bearzotti

International Journal of Speleology

Coming from over 10 years of experience in cave monitoring in northeast Italy, Gruppo Speleologico Talpe del Carso, has designed Riki and Dolphin: customizable, low cost, and easy to assemble tools for getting real time data transmission from the bottom of a cave, even underwater, to a webserver. Their use has been tested to monitor air temperature inside the Abisso Bonetti Cave (Classical Karst, Italy), proving for the first time that a cave in Gorizian Karst can systematically be colder than the outdoor temperature even in winter, recording an internal temperature even lower than 0°C. The Dolphin device can be …

A Remote Sensing Approach To Identifying Zones Of Instability In Mine Tailings Impoundments Using Multi-Sensor Satellite Data, Arden K. Pierce

Honors Theses

Mine tailings impoundments are structures built to contain the chemical and sedimentary byproducts generated by ore extraction activities. In this common method of mining waste storage, the tailings can be pumped into containment ponds and held behind earthen embankments to prevent the release of hazardous substances into the surrounding environment. Monitoring environmental factors that influence the structural integrity of these impoundments is essential for identifying areas vulnerable to instability and failure. Soil moisture is a factor that can affect the stability of mine tailings impoundment structures. This study evaluates the relationship between satellite-derived soil moisture and surface deformation at mine …