Earth Sciences Commons^™

Critical Mineral Exploration In The Superior Province Of Northwestern Minnesota - A Geophysical Data Analysis, Michell L. Waterman

Graduate Theses/Dissertations

The Archean basement geology of northwest Minnesota, a region covered by glacial deposits and historically underexplored for minerals, was analyzed using gravity, magnetic, radiometric, and geochemical data. These datasets were integrated to aid in identifying subsurface structures and evaluating the area's potential for economic mineralization within the Wabigoon, Quetico, and Wawa Subprovinces of the Superior Province. Gravity and magnetic datasets, analyzed through upward continuation, derivative maps, and two-dimensional modeling, revealed distinct northeast-to-southwest-trending maxima corresponding to fault-bounded, high-density, and magnetically susceptible bodies. These features were interpreted as mafic to ultramafic intrusions and dikes, several of which align with known Proterozoic fault …

Integrated Valuation Of The Ecological, Social And Economic Benefits Provided By A Multifunctional Nature-Based Solution, Laura Costadone, Shan Zhang

ODU Articles

Nature-based Solutions (NbS) offer multifunctional approaches to address climate change and environmental challenges, providing a sustainable alternative to traditional gray infrastructure. Despite their promise, widespread adoption remains limited, in part due to an incomplete understanding of their full costs and benefits relative to conventional infrastructure. Traditional benefit–cost analyses often overlook non-monetized benefits and the interconnected ecosystem services provided by NbS. This study introduces a methodological approach to quantify both the physical and monetary value of ecosystem services and co-benefits delivered by an NbS project. We applied an integrated valuation framework to a case study in Virginia Beach, VA, USA, where …

Teaching Agroecology Through Play: A Board Game On Companion Planting Using Agroecological Principles, Ashmita Das, Julie Capito-Hernandez, Estelí Jiménez-Soto

School of Geosciences Faculty and Staff Publications

Board games themed around environmental topics are promising tools for promoting awareness of complex sustainability issues, as the materiality, sociality, and multidimensionality of gameplay can help overcome some of the inherent limitations of more traditional learning formats. To explore the potential relevance of board games for communicating about agrifood system topics in particular, we designed and tested a game called Companion: An Agroecological Adventure, in which players take on the role of community gardeners who must apply both social and ecological principles of agroecology to cultivate a thriving garden plot. In this paper, we present the results of a study …

Food Sovereignty Among Migrant Farmworkers: The Role Of Agrobiodiversity For Autonomy And Resistance In A Mexican Coffee Plantation, Estelí Jiménez-Soto, Sanya Cowal, April Lopez

School of Geosciences Faculty and Staff Publications

Coffee agroecosystems represent the economic base for thousands of small growers and agricultural workers, as well as a significant proportion of many regional economies in Latin America. Every year, the production of coffee in this region attracts a great number of laborers and their families, particularly during the harvest season. Despite being essential workers in the food system, agricultural workers continue to be one of the most marginalized actors in the coffee production chain. Even with an environment of precarity, agricultural workers exercise their autonomy and food sovereignty—the process by which agricultural workers, in this case, define their food system …

Stream Response To A Dam Removal: Mill Creek, Davenport, Ca, Jessica J. Williamson

Master's Theses

Dams have many effects on stream morphology and ecology, including a loss of sediment supply downstream, reduced access to the entire stream for aquatic fauna, and a flooded area upstream of the dam. Dams are a hurdle for migrating organisms such as anadromous fish, which is a group of concern. An over 100-year-old dam on Mill Creek, a stream draining a coastal watershed in central California, was removed in the fall of 2021. The site is in the Santa Cruz Mountains, where endangered salmonids such as steelhead, Oncorhynchus mykiss, have historically lived. To study the change in the stream from …

Agu's Scientific Legacy, Eileen E. Hofmann, Tissa Illangasekare, Francis A. Macdonald, Michael J. Mcphaden, Anne Meltzer, Imke De Pater, Susan J. Roberts, Anne M. Thompson

OES Faculty Publications

The AGU community is a resource for insights into how past research has influenced today's science and will continue to inform the Earth and Space sciences of the future. To capture the voices and opinions from this community, three interviews were held at the 2024 AGU Meeting and broadcast on AGUTV. The interviews with Richard Alley, Susan Lozier and Rana Fine aligned with the daily themes for the 2024 AGU Meeting. The interviewees shared insights from their experiences about the importance of science and how science has shaped their careers and society.

Impact Of Submarine Groundwater Discharge On Microbial Communities In A Highly Anthropized Coastal Lagoon (Mar Menor, Se Spain), Daniel Romano-Gude, Júlia Dordal-Soriano, Júlia Rodriguez-Puig, Andrea G. Bravo, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Marc Diego-Feliu, Cristina Romera-Castillo, Rebeca Mallenco-Fornies, Javier Gilabert, Jordi Garcia-Orellana, Valentí Rodellas, Clara Ruiz-González

OES Faculty Publications

Submarine groundwater discharge (SGD) supplies large quantities of nutrients and other terrestrial elements to coastal ecosystems, impacting marine biota and ecosystem functioning. Despite the relevance of prokaryotes for marine biogeochemistry, little is known about their responses to groundwater inputs. Here we explored the impact of SGD on the spatiotemporal patterns of prokaryotic communities from the Mar Menor (Murcia, Spain), a highly anthropized hypersaline coastal lagoon that receives large amounts of nutrient-polluted SGD. Using 16S rRNA amplicon sequencing, activity assays, and flow cytometry, we investigated the dynamics of prokaryotic communities across the lagoon and its connected environments (freshwater streams, groundwater, soils, …

A Paleobiological And Paleoecological Analysis Of Mississippian Trilobites With Segmentation Abnormalities, April Catherine Cerami

Graduate Theses, Dissertations, and Problem Reports (ETD)

Trilobites are a well-preserved group of arthropods, with a fossil record extending from the Cambrian to the end of the Permian. Abnormalities, such as injuries or teratological defects, have been observed and described in multiple individuals, although investigating how these abnormalities occur in populations has been largely overlooked.

One possible cause of abnormalities in marine arthropods is heavy metal pollution. Such metals can leave individuals more susceptible to teratological deformities and injuries, interfering with the molting and healing process. Here, methods for analyzing elemental composition and preservation of the trilobite cuticle were refined, finding that 30 μm thin sections are …

Revealing Rainfall Partitioning Characteristics Of Shrubs In Semi-Arid Sandy Land: Based On In-Situ Measurement Data, Hu Liu, Limin Duan, Yongzhi Bao, Xin Tong, Huimin Lei, Zhiming Han, Wenrui Zhang, Xixi Wang, V. P. Singh, Tingxi Liu

Civil & Environmental Engineering Faculty Publications

Rainfall is partitioned by the vegetation canopy into three components: throughfall, stemflow, and canopy interception, which profoundly influence key hydrological processes, including vegetation growth, groundwater recharge, water cycling, and regional water balance. However, research comparing the applicability of throughfall measurement methods in semi-arid shrub communities remains scarce, and quantitative analyses of rainfall partitioning processes based on in-situ observations are still inadequate. This study focuses on the sand-fixing pioneer vegetation of semi-arid sandy land, Caragana microphylla, and conducts simultaneous throughfall measurements using the rain gauge method and the trough method to compare the differences between the two approaches. Based on …

Permafrost And Structural Controls On Holocene Bedrock Landslide Occurrence Around Eyjafjörður, North‐Central Iceland, Adam Booth, Halldór G. Pétursson

Geology Faculty Publications and Presentations

Rapid, transient, landscape‐scale changes associated with deglaciation can condition slopes for failure and trigger bedrock landslides. However, the mechanisms leading to paleo rock slope failures following the last glacial period are challenging to infer because observations of how both landsliding and potential driving factors were distributed in space and time are limited. Here, we map and analyze the spatiotemporal pattern of 676 post‐glacial bedrock landslides around Eyjafjörður in north‐central Iceland using 2‐m resolution digital elevation data generated from optical stereo satellite imagery. Frequency‐ratio analysis demonstrates that after controlling for slope, landslides are most overrepresented within 2.6 km horizontal distances from …

The Petrology Of The Ozerki Meteorite Constrained By Electron Backscatter Diffraction And X-Ray Computed Tomography, Alice Macente, Luke Daly, Sammy Griffin, Maria Gritsevich, Jarmo Moilanen, Josh Franz Einsle, Patrick Trimby, Chris Mulcahy, Jonathan Moffat, Alexander M. Ruzicka

Geology Faculty Publications and Presentations

Combining electron backscatter diffraction (EBSD) with X-ray computed tomography (XCT) offers a comprehensive approach to investigate shock deformation and rock texture in meteorites, yet such integration remains uncommon. In this study, we demonstrate the synergistic potential of XCT and EBSD in revealing deformation metrics, thereby enhancing our understanding of petrofabric strength and shock-induced deformation. Our analysis focuses on the Ozerki (L6, S4/5, W0) meteorite fall, which was instrumentally observed on June 21, 2018, and subsequently recovered by the Ural's branch of the Russian Fireball Network (UrFU) recovery expedition a few days later. The trajectory analysis conducted by the Finnish Fireball …

Global Patterns Of Coseismic Landslide Runout Mobility Differ From Aseismic Landslide Trends, Alex R. R. Grant, Natalie K. Culhane

Geology Faculty Publications and Presentations

Coseismic landslides significantly contribute to human and economic losses during and immediately following earthquakes, yet very little data on the runout of such landslides exist. While well-established behavior of aseismic (e.g., hydrologically triggered) landslide runout mobility suggests strong correlation between landslide size and mobility, limited studies of coseismic landslide runout find conflicting mobility trends. We present a global dataset of runout lengths produced from a new automated method for estimating landslide runout, developed and validated using 1726 manually mapped landslides from five unique earthquakes. We then apply the automated runout tool to 23 global earthquake-induced landslide inventories, producing a compiled …

The Geography Of Rock Glaciers In The American West, Allison Reese Trcka, Andrew G. Fountain, Bryce Allen Glenn

Geology Faculty Publications and Presentations

Rock glaciers are relatively common in conterminous United States west of the 100° meridian, yet their distribution and number are not well known. Using aerial and satellite imagery, we inventoried the population of rock glaciers, yielding 2,257 rock glaciers totaling 234.28 km² with an area of uncertainty of 7 percent. Of these, 1,561 (155.44 km²) are considered intact (moving) and 696 (76.84 km²) relict. Based on published estimates of ice content, total water-equivalent volume is roughly 2.52 km³. Rock glacier elevations increase from the northwest (Washington) to the southeast (Colorado), following a spatial …

Cold Atmospheric Plasma Induced Degradation Of Organophosphate Pesticides On Kevlar Swatches, Ta Chun Lin, Victor Somtochukwu Mbanugo, Boluwatife Stephen Ojo, Yue-Wern Huang, Marek Locmelis, Frank Daoru Han

Biological Sciences Faculty Research & Creative Works

Cold atmospheric plasma (CAP) was evaluated for degrading organophosphate pesticide (OP) residues (acephate, malathion, and dimethoate) from Kevlar fabrics. Fourier transform-Infrared (FTIR) spectroscopy, scanning electron microscope (SEM) imaging and tensile strength testing confirmed that CAP treatment preserved Kevlar's structural integrity and mechanical properties. Results show degradation efficiency increased with higher power, shorter discharge gaps, and longer exposure duration. Hyperspectral imaging supported the detection of plasma-induced spectral changes, reinforcing the presence of reactive species. The strong oxidative potential of CAP facilitated the rapid breakdown of OPs into nontoxic byproducts. These findings demonstrate the potential of CAP as a portable, energy-efficient solution …

Controls On Longitudinal Stream Profile Evolution In Guadalupe Mountains National Park, Samuel Schoenmann, Lisa Tranel, Eric W. Peterson, Jonathan Boyd Thayn

Faculty Publications - Geography, Geology, and the Environment

Canyons in Guadalupe Mountains National Park are excellent locations to study the discrete boundary conditions that influence longitudinal channel profile evolution including climate, tectonics, hydrology, and lithology. The Guadalupe Mountain landscape records deep earth mantle processes in combination with surficial channel erosion and incision. Knickpoints and convex segments in longitudinal river profiles document impacts of climate change, tectonics, or surface processes. This study combines field observations with an analysis of longitudinal profile slopes and residual errors to evaluate how bedrock strength can be distinguished from features created by climate change, faulting, or subsidence in Pine Springs and McKittrick Canyons within …

A Unionid Mussel Biodiversity Hotspot Experiencing Unexplained Declines: Evaluating The Influence Of Chemical Stressors Using Caged Juveniles, W. Aaron Wilson, Christine Bergeron, Jennifer Archambault, Jason M. Unrine, Jess Jones, Braven Beaty, Damian Shea, Peter R. Lazaro, Jody L. Callihan, Jennifer J. Rogers

Plant and Soil Sciences Faculty Publications

Unionid mussel populations in a section of the Clinch River in Virginia, USA, has declined substantially, but the causes of the decline remain unknown. To investigate this zone of decline (ZOD), we deployed juvenile freshwater mussels (Villosa iris in 2012 and Lampsilis fasciola in 2013) in both cages and silos at sites within the Clinch River System. We analyzed mussel tissues for trace element and organic contaminant concentrations, shells for trace elements, and environmental media (total water, dissolved water, particulate sediment, and bedload sediment) for both inorganic and organic contaminants. We found a few differences between mussels deployed in cages …

Characterizing The Earth's Magnetosheath With In Situ Measurements, Hector A. Salinas

Physics Dissertations - Archive

Earth’s magnetosheath is a region of shocked plasma that mediates energy and momentum transfer from the solar wind to the magnetosphere. The dynamics and thus the plasma structures of this region are highly dependent on upstream solar wind conditions. As such, the region is often characterized as a turbulent environment, with the most intense periods of turbulence occurring often under quasi-parallel bow shock conditions. This magnetosheath turbulence displays as variable and large-scale fluctuations with in-situ measurements. Given that turbulence is a characteristic feature of the magnetosheath, this dissertation asks two questions: (1) How are plasma structures inside the sheath affected …

Quantifying So₂ Emissions From Explosive Events Of The 2021 La Soufrière Eruption Using Dscovr/Epic, Yuxi Jin

Dissertations, Master's Theses and Master's Reports

Volcanic eruptions release large quantities of gases, including sulfur dioxide (SO₂), aerosol precursors, and ash into the atmosphere. Quantifying the emission fluxes and temporal variability of SO₂ is crucial for understanding volcanic processes and assessing their impacts on air quality, climate, and aviation safety. Episodic vulcanian to sub-Plinian explosive eruptions are a common feature of many arc volcanoes, but the underlying causes of such episodic behavior remain poorly understood. The 2021 La Soufrière eruption (St. Vincent) featured up to 40 discrete eruptive events between April 9 and April 22, presenting a rare opportunity to analyze time-resolved volcanic SO₂ emissions during …

Growth, Survival, And Herbivore Browsing Preferences Of Seedlings Planted In Black Ash Stands Of Northern Michigan And Wisconsin, Seth W. Davenport

Dissertations, Master's Theses and Master's Reports

To mitigate the cascading ecosystem impacts of widespread black ash (Fraxinus nigra) mortality due to the invasive emerald ash borer (Agrilus planipennis), forested wetlands can be underplanted with seedlings of alternative species that later repopulate the vacated canopy. This study examined the survival and growth, factors influencing performance, and herbivore browsing preferences of seven non-ash species planted in northern Michigan and Wisconsin. The best performing species were river birch (Betula nigra), silver maple (Acer saccharinum), and swamp white oak (Quercus bicolor). The worst performing species was black spruce (Picea …

Comprehensive Analysis Of Krauklis Waves And Long Period Seismic Events In Fluid-Filled Fractures Via Integrated Physical And Numerical Modeling, Sananda Ray

Dissertations, Master's Theses and Master's Reports

Long-period (LP) seismic events, commonly recorded in volcanic and hydrothermal environments, are widely attributed to the resonance of fluid-filled fractures and the excitation of Krauklis waves along the solid-fluid interface. These low-velocity, dispersive waves are sensitive to both fluid dynamics and fracture geometry, offering critical insights into subsurface fluid transport, fracture evolution, and seismic source processes. Despite robust theoretical treatments, experimental validation under realistic geological conditions has remained limited. To address this, I aimed to develop a series of laboratory-based experimental models that systematically investigate the key physical mechanisms driving LP signal generation. In the first set of experiments, I …

Sulfate Sources In Groundwater From An Agricultural Area Central Illinois, Christabel I. Obi

Theses and Dissertations

Increasing sulfate (SO₄^2-) concentrations in the water environment, corresponding with increases in urbanization and industrialization, are a rising global concern. Over 250 mg/L, sulfate threatens human health and ecosystems. Elevated concentrations influence carbonate rock weathering, contributing to the evolution of the global carbon cycle. Knowledge of sulfate sources, whether natural or anthropogenic, is essential for understanding sulfate transport and fate in groundwater. This study investigates SO₄^2- origin and transport in groundwater in an area dominated by agricultural land use in Mclean County, Illinois. Specifically, we explored these questions: 1) Do sulfate concentrations change with groundwater …

Investigating Heterogeneity Of Hydraulic Conductivity And Its Influence On Groundwater Flow Dynamics Within A Saturated Riparian Buffer In Central Illinois, Joseph L. Awuku

Theses and Dissertations

The use of Saturated Riparian Buffers (SRBs) in agricultural settings as a means of reducing contamination of surface water and groundwater resources has gained popularity due to their trapping ability and solute removal (nutrient recycling) capacity. In light of SRB’s nutrient-trapping and removal ability, numerous studies have been conducted to characterize the effectiveness of SRBs. However, most studies on SRBs have paid minimal attention to heterogeneity of hydraulic conductivity (K) and groundwater flow dynamics within SRBs. This study investigated the heterogeneity in horizontal K and estimated the vertical groundwater-specific discharge (q_v) between the upper weathered and its …

The Serendipity Of Discovery: Life Of A Geochemist, Willard S. Moore

Faculty Publications

My strategy for writing this autobiography is to use examples of how working on seemingly different projects can often lead to outcomes more important than originally envisioned. Serendipity is a "happy accident"; specifically, the accident of discovering something useful without directly looking for it. This often occurs when two research projects converge unexpectedly. The main text contains examples of how serendipity has led me to important discoveries including: (a) finding surprisingly high ²²⁸Ra activities in the ocean, (b) developing a means of rapidly and quantitatively extracting radium from seawater, (c) devising a rapid, sensitive method of measuring ²²⁴Ra …

The Tyrant King Of The Auction House: The Disastrous “Fine Artification” Of The Dinosaur, Amelia C. Kolstad

Anthós

This article examines how fine art auctioneers market dinosaur fossils as art pieces to wealthy collectors, depriving the paleontological field of specimens for scientific research. Drawing from recent examples of fossils sold at fine art auctions, this article notes how rising auction prices for specimens as ‘art’ prevent museums and research institutions from acquiring specimens for research and restoration. Kolstad concludes that the art auction houses’ marketing of fossils as art is detrimental to paleontological research. To protect fossils and their scientific value, Kolstad proposes alternatives, such as selling replicas to collectors and highlighting the importance of original specimens for …

Cover Crops Can Reduce Greenhouse Gas Emissions From No-Till Maize In Southern Brazil: Insights From A Long-Term Field Experiment, Guilherme Rosa Da Silva, Adam J. Liska, Cimélio Bayer

Adam Liska Papers

Brazil is one of the countries that has the most agricultural area under no-till (NT) management. This research study aims to evaluate life-cycle greenhouse gas (GHG) emissions from maize (M) grain production in agroecosystems that used different cover crops under NT management in southern Brazil. The data for this study were from a long-term 41-year field experiment in southern Brazil. The long-term experiment evaluated the effects of fallow (F) and cover crops (oat (O), vetch (V), cowpea (B), pigeon pea (P), and lablab (L)) on nitrous oxide and methane emissions and soil carbon (C) sequestration in maize agroecosystems. Five cropping …

Investigating The Thermal Stratification Patterns Of A Shallow Polymictic Boreal Shield Lake And The Effectiveness Of Models In Predicting Shallow Lake Thermal Profiles, Matthew Roberts

Theses and Dissertations (Comprehensive)

Thermal stratification is a core process of lakes which plays a critical role in shaping the ecological dynamics of lakes, influencing major processes like nutrient cycling and oxygen availability. For shallow polymictic lakes, thermal stratification patterns present some unique differences due to the complex and variable nature of these lakes. In this thesis, I examined thermal stratification in a shallow polymictic lake in northwestern Ontario during the ice-free season of 2019 to investigate the frequency, duration, and driving factors of thermal stratification. The lake underwent 146 separate stratification events, with a median duration of 2 hours per event, with a …

Controls Of Wetland Hydrology In The Zone Of Discontinuous Permafrost, Northwest Territories, Canada, Iain Thomson

Theses and Dissertations (Comprehensive)

Mean annual air temperatures are increasing rapidly in northwestern Canada, which is among the most rapidly warming regions on Earth (Box et al., 2019). Consequently, permafrost thaw within northwestern Canada is proceeding at a rate not found in the historical record (Pelletier et al., 2017), with areal thaw rates especially high in the peatland-dominated southern margin of discontinuous permafrost (Quinton et al., 2019). Permafrost thaw has caused vast land cover changes and transformed the permafrost underlain forest into permafrost free wetlands over much of Taiga Plains (Carpino et al., 2018; Jorgenson & Osterkamp, 2005). This land cover change has …

Efficacy Of Stress Acclimation Techniques In Coastal Wetland Plants (Spartina Alterniflora And S. Patens): Implications For Restoration And Nursery Production, Taylor M. Sloey, Kylie D. Gieser, Kaitlyn Pounders, Sofía E. Báez, Jennifer L. Whytlaw

Biological Sciences Faculty Publications

The implementation of coastal nature-based features, created wetlands, and wetland restoration has increased globally over recent years. Many of these projects have been successful in meeting their goals, however, when projects fail, it is often attributed to mortality of transplanted vegetation. Transplant mortality may be due to inappropriate timing, poor site selection, or abiotic stressors associated with transplant shock. Science-backed guidelines have been well established in many coastal regions regarding site specifications and species selection, but nursery practices for reducing transplant shock remain inconsistent. In this study, we tested a combination of four salinity acclimation treatments and two inundation acclimation …

Carbon Dynamics Across The Mangrove-Tidal Flat Ecotone In A Tropical Seascape, E. S. Yando, I. J.B. Alemu, L. Kiah Eng, T. M. Sloey, M. Van Breugel, Bhatia N. Friess

Biological Sciences Faculty Publications

Mangroves and other blue carbon ecosystems are important for climate through the storage and sequestration of carbon. Most research estimates carbon dynamics by subsampling central portions of the ecosystem and are then upscales using habitat maps to patch, landscape, or regional levels. However, heterogeneity is rarely accounted for - particularly at edges. Further, adjacent tidal flat ecosystems have only recently been considered for carbon storage, but may be undervalued if areas where they transition with vegetated systems are not accounted for. To address the lack of information at coastal ecotones, we examined both soil carbon storage and carbon dioxide flux …

Advancing Root Trait Measurements For A Deeper Understanding Of Soil Biogeochemistry, Brian Rinehart

Theses and Dissertations--Plant and Soil Sciences

Climate change is disrupting (agro)ecosystems, with the potential for significant losses in crop productivity and ecosystem resilience due to changes in water and biogeochemical cycling. These disruptions can also release more carbon dioxide into the atmosphere through the degradation of soil organic matter. Plant roots have emerged as a potential tool for mitigating these effects, given their roles in plant function and in driving soil biogeochemistry. While this interest is growing, our ability to implement root trait selection is limited due to constraints on characterizing roots and limited clarity on the effects of traits on plant and ecosystem function. My …