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A New Method To Invert For Interseismic Deep Slip Along Closely Spaced Faults Using Surface Velocities And Subsurface Stressing-Rate Tensors, Hanna Elston, Michele Cooke, John Loveless, Scott Marshall Jan 2024

A New Method To Invert For Interseismic Deep Slip Along Closely Spaced Faults Using Surface Velocities And Subsurface Stressing-Rate Tensors, Hanna Elston, Michele Cooke, John Loveless, Scott Marshall

Geosciences: Faculty Publications

Inversions of interseismic geodetic surface velocities often cannot uniquely resolve the three-dimensional slip-rate distribution along closely spaced faults. Microseismic focal mechanisms reveal stress information at depth and may provide additional constraints for inversions that estimate slip rates. Here, we present a new inverse approach that utilizes both surface velocities and subsurface stressing-rate tensors to constrain interseismic slip rates and activity of closely spaced faults. We assess the ability of the inverse approach to recover slip rate distributions from stressing-rate tensors and surface velocities generated by two forward models: (a) a single strike-slip fault model and (b) a complex southern San …


Various Surfactant Soil Conditioner Effect On Plant Nutrient Concentration, Soil Nutrient Depletion, Soil Volumetric Water Content, Plant Biomass And Yield In Corn, Timothy Veldkamp Jan 2024

Various Surfactant Soil Conditioner Effect On Plant Nutrient Concentration, Soil Nutrient Depletion, Soil Volumetric Water Content, Plant Biomass And Yield In Corn, Timothy Veldkamp

Electronic Theses and Dissertations

Soil conditioners help improve soil structure by increasing aeration, water infiltration and water holding capacity leading to nutrient availability and reduced irrigation needs. The goal of this study was to evaluate the impact of multiple soil conditioners (SC1, SC2, SC3, SC4, and SC5) on corn (Zea mays L.) and their ability to reduce irrigation by 30%. This was evaluated in the field in 2022 and 2023 by Aurora, SD using a Randomized Complete Block Design with six replications. Conditioners were applied as broadcast pre-emergence treatments with 70% irrigation. Control treatments of 70% and 100% irrigation, respectively were included. SC1 application …


Interconnectivity Of Melt During Partial Melting And Deformation Of A Peridotite, Jordan Collins Jan 2024

Interconnectivity Of Melt During Partial Melting And Deformation Of A Peridotite, Jordan Collins

Williams Honors College, Honors Research Projects

The mechanisms that allow basaltic magma to be transported to the surface are well understood, but not much is known about how the transport channels form as the basalt melt forms at the source. I performed experiments to determine these mechanisms during general shear deformation of a natural olivine aggregate (dunite) from Anita Bay, New Zealand as it partially melts using a high pressure/temperature rock deformation apparatus. Samples were analyzed using the scanning electron microscope and I observed that melt pockets started to form at the grain scale (1-2 vol% melt) prior to becoming interconnected at the sample scale (3 …


Hydrogeomorphic Response To Flooding In Northern Yellowstone National Park, Zachary P. Deluca Jan 2024

Hydrogeomorphic Response To Flooding In Northern Yellowstone National Park, Zachary P. Deluca

Graduate Student Theses, Dissertations, & Professional Papers

Understanding and predicting flood-induced geomorphic change, and the relative influences of fluvial forces and valley-bottom geometry on system response, are persistent quandaries in geomorphic process studies. We combine field surveys, remote sensing, and hydraulic modeling to assess the hydrogeomorphic effects of historic flooding in northern Yellowstone National Park (YNP) in a variety of channel configurations. We compare impulse, a metric that incorporates a flow duration threshold based on threshold channel theory, grain size, channel-bed slope, and flood depth and stream power estimates with hydrogeomorphic response. Measurements of pre- and post-flood active-channel width change in aerial photos captured geomorphic response associated …


Revegetation Of Two Drained Reservoirs On The Elwha River Ten Years After Dam Removal, Michael Trier Jan 2024

Revegetation Of Two Drained Reservoirs On The Elwha River Ten Years After Dam Removal, Michael Trier

EWU Masters Thesis Collection

The Elwha and Glines Canyon dams on the Elwha River, Washington, USA were removed between 2011 and 2014 after being in place for a century, and at the time were the largest dams ever removed. The resulting dewatering of Lake Aldwell, the reservoir of the Elwha dam, and Lake Mills, the reservoir of the Glines Canyon dam exposed over 270 hectares of land that had been submerged. While several studies have examined the revegetation of these drained reservoirs, none have gone beyond 5 years since dam removal. These studies found that sediment grain size and reservoir landform (valley walls, terraces …


Mangroves Of The Warm Temperate Northwest Atlantic, Daniel A. Friess, Ena L. Suárez, Anna R. Armitage, Cheryl Doughty, Laura C. Feher, Ilka C. Feller, Alejandro Fierro, Kara R. Radabaugh, Lorae T. Simpson, William C. V Vervaeke, Carlos Zamora-Tovar Jan 2024

Mangroves Of The Warm Temperate Northwest Atlantic, Daniel A. Friess, Ena L. Suárez, Anna R. Armitage, Cheryl Doughty, Laura C. Feher, Ilka C. Feller, Alejandro Fierro, Kara R. Radabaugh, Lorae T. Simpson, William C. V Vervaeke, Carlos Zamora-Tovar

School of Earth, Environmental, & Marine Sciences Faculty Publications

The ‘Mangroves of the Warm Temperate Northwest Atlantic’ province is a regional ecosystem subgroup (level 4 unit of the IUCN Global Ecosystem Typology). It includes the marine ecoregions of Carolinian and Northern Gulf of Mexico. The biota is characterized by 3 species of mangroves: Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle, and 1 mangrove associate Conocarpus erectus, though not all species are equally distributed throughout the province. Mangroves in this province cross the USA and Mexico and are quite unique, as they exist at the latitudinal range limit of the mangrove ecosystem. The majority of mangroves in this province are …


Assessing Tax Revenue Implications Of Environmental Policy: A Case Study Of China’S Channel City Policy, Yongwen Yang, Juhee Lee Jan 2024

Assessing Tax Revenue Implications Of Environmental Policy: A Case Study Of China’S Channel City Policy, Yongwen Yang, Juhee Lee

School of Earth, Environmental, & Marine Sciences Faculty Publications

Recent studies suggest that while environmental policies yield positive environmental effects, they also incur costs for various entities. However, there is a gap in research regarding these policies’ financial impact from the government's perspective. To investigate the extent to which government tax revenue is affected by environmental policies, we employ the Difference-inDifferences (DID) method to estimate the impact of a regional air pollution control policy in China known as the Channel City Policy on the tax revenue of city governments. Our findings indicate that the Channel City Policy (CCP) enhances air quality by reducing PM2.5, SO2, and NOx concentrations by …


Investigating Drought Response And Paleoclimate Potential Of A New Network Of White Oak Chronologies In Western Kentucky, Usa, Audrey J. Heichelbech, Maegen L. Rochner, Megan Gibson Jan 2024

Investigating Drought Response And Paleoclimate Potential Of A New Network Of White Oak Chronologies In Western Kentucky, Usa, Audrey J. Heichelbech, Maegen L. Rochner, Megan Gibson

Undergraduate Research Events

In Kentucky, historic and paleo-climate data are limited, and current understanding of long-term climate change in the state relies on instrumental data spanning only 1895-present. Proxy data are necessary to extend the temporal and spatial span of climate information. One potential proxy source for Kentucky is tree ring data, but currently, only four such datasets are publicly available on the International Tree Ring Data Bank (ITRDB). Archaeological and archival timber sources may help to fill in this gap. In the 1940s, Florence Hawley-Ellis, the first woman dendrochronologist, collected samples of white oak (Quercus alba L.) from four counties in western …


Petrologic And Geochemical Constraints On The Pre-Eruptive Storage Conditions Of Magmas Erupted During The ~12.5 Ka Flare Up Of Medicine Lake Volcano, Ca, Regina M. Khoury Jan 2024

Petrologic And Geochemical Constraints On The Pre-Eruptive Storage Conditions Of Magmas Erupted During The ~12.5 Ka Flare Up Of Medicine Lake Volcano, Ca, Regina M. Khoury

Cal Poly Humboldt theses and projects

The Medicine Lake Volcano (MLV) system in the California Cascades is composed of a large shield volcano with numerous basaltic to rhyolitic vents on and around the flanks, many of which are aligned with N-S trending normal faults. A significant portion of the post-glacial volcanic activity at MLV is comprised of the ~12.5 ka “flare up” eruptions of basalt and basaltic andesite magmas from seven discrete flank vents. Prior work documented surface areas (0.02-198 km2), volumes (0.0001-4.35 km3), and eruption styles (Hawaiian to Strombolian; Donnelly-Nolan, 2010) of the ~12.5 ka deposits. This study uses new geologic …


Supporting Dataset For The Influence Of Tile-Water On Groundwater Nitrate Concentrations Within A Saturated Riparian Buffer Zone, Aminat Tosin Abdulsalam, Eric Wade Peterson Jan 2024

Supporting Dataset For The Influence Of Tile-Water On Groundwater Nitrate Concentrations Within A Saturated Riparian Buffer Zone, Aminat Tosin Abdulsalam, Eric Wade Peterson

Faculty Publications - Geography, Geology, and the Environment

In the U.S. Midwest, where fertile soils with high water retention are prevalent, the installation of tile drainage networks have become a common practice to drain excess soil water, which enhances plant growth and increases crop productivity. However, tile drainage networks coupled with the use of inorganic fertilizers have significant implications on water quality, contributing to eutrophication, leading to harmful algal blooms, and resulting in hypoxic conditions in surface water bodies. To mitigate excess nutrient exports to surface water bodies, edge-of-field practices have been introduced. One such practice is the saturated riparian buffer (SRB), which utilizes a diversion system to …


Petrologic Relationship Between Lamprophyres, Carbonatites, And Heavy Rare-Earth Element Enriched Breccias At Hicks Dome, Jarek Trela, Jared T. Freiburg, Esteban Gazel, Laurence Nuelle, Anton H. Maria, David H. Malone, John M. Molinarolo Jan 2024

Petrologic Relationship Between Lamprophyres, Carbonatites, And Heavy Rare-Earth Element Enriched Breccias At Hicks Dome, Jarek Trela, Jared T. Freiburg, Esteban Gazel, Laurence Nuelle, Anton H. Maria, David H. Malone, John M. Molinarolo

Faculty Publications - Geography, Geology, and the Environment

New petrological, geochemical, and P–T modelling results from igneous samples clarify how carbonatite-lamprophyre magmatism, fluorite and rare earth element (REE) enrichment are petrogenetically related in southern Illinois. P–T modelling reveals that igneous rocks derive from a deep mantle carbonated source, that is consistent with trace element signatures for a fluorine-rich transition zone origin. Major element systematics suggests liquid-immiscibility with lamprophyric melts as the origin for Ca-carbonatites. Heavy REE (HREE) enrichments in Hicks Dome breccias likely formed through preferential partitioning and transport of HREE by brine-melts, exsolved from a deep carbonatite body. Brine-melts redistributed HREEs throughout the …


Transport And Fate Of Nitrate In A Saturated Buffer Zone As Assessed With A Chloride Tracer Test, Alhassan Sahad, Eric W. Peterson Jan 2024

Transport And Fate Of Nitrate In A Saturated Buffer Zone As Assessed With A Chloride Tracer Test, Alhassan Sahad, Eric W. Peterson

Faculty Publications - Geography, Geology, and the Environment

The Upper Mississippi Basin, which includes Illinois, has highly fertile soils and experiences intensive agricultural practices. Although fertile, the soils do not drain well, resulting in the installation of tile-drainage systems. The practices of tile systems coupled with the application of nitrogen-rich fertilizers have led to the excessive export of nitrate from the agricultural fields into surface waters, contributing to eutrophication and the development of hypoxic zones in aquatic environments. Saturated riparian buffer zones (SRBs) have been proposed as a means to reduce the amount of nitrate discharged from tile-drained waters into streams. Previous works show a reduction in the …


A Cytosine Analogue 5-Azacitidine Improves The Accumulation Of Licochalcone A In Licorice Glycyrrhiza Inflata., Xiaoling Ma, Ningxin Jiang, Jingxian Fu, Yuping Li, Lijun Zhou, Ling Yuan, Ying Wang, Yongqing Li Jan 2024

A Cytosine Analogue 5-Azacitidine Improves The Accumulation Of Licochalcone A In Licorice Glycyrrhiza Inflata., Xiaoling Ma, Ningxin Jiang, Jingxian Fu, Yuping Li, Lijun Zhou, Ling Yuan, Ying Wang, Yongqing Li

Plant and Soil Sciences Faculty Publications

Licochalcone A (LCA) is a characteristic compound of Glycyrrhiza inflata with anti-inflammatory, antioxidant and antitumor activities. However, G. inflata produces LCA in low quantities that does not meet the market demand. In this study, we found that DNA methylation inhibitor 5-azacitidine (5-azaC) successfully improved the LCA contents in G. inflata seedlings. Transcriptome analysis revealed a series of differentially expressed genes (DEGs), including transcription factors such as MYB, ERF, WRKY, and some structural genes related to flavonoid biosynthesis. However, whole genome bisulfite sequencing (BS-seq) results showed little effect of the 5-azaC treatment on the alteration of DNA methylation on these genes, …


The Mechanism Of Sperm (Pro)Nuclear Migration In Plants And Animals, Yilin Zhang, Tomokazu Kawashima Jan 2024

The Mechanism Of Sperm (Pro)Nuclear Migration In Plants And Animals, Yilin Zhang, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

Gamete nuclear migration is a critical process during fertilization in flowering plants, yet its molecular mechanisms remain poorly understood. Recent studies have highlighted the essential role of cytoskeletal elements, particularly F-actin, in directing sperm nuclear migration, contrasting with the microtubule-driven migration in animals. We summarize the process of sperm nuclear migration in plants and the involvement of Class XI myosin XI-G in Arabidopsis, along with the ROP8-SCAR2 pathway’s ARP2/3-independent mechanism for F-actin nucleation. We also provide a comparative overview of examples from sea urchins, C. elegans, mice and yeast contrasting these mechanisms with those in plants. Finally, we …


Seismic Refraction Mapping Of The Pre-Glacial Teays River Valley In West Central Ohio Using A Seismic Reflection Dataset, Matthew L. Klempp Ii Jan 2024

Seismic Refraction Mapping Of The Pre-Glacial Teays River Valley In West Central Ohio Using A Seismic Reflection Dataset, Matthew L. Klempp Ii

Browse all Theses and Dissertations

The Teays River Valley is an ancient river valley system that existed before the Pleistocene Ice Age and spanned present-day Illinois, Indiana, Ohio, West Virginia, and Virginia. During the Pleistocene Ice Age, the Teays River Valley was buried by advancing continental glaciers and meltwater throughout most of its length. Due to the Teays’ average width of roughly 2 miles and burial depth of approximately 200 meters (656 feet), the Ohio Geological Survey has been pursuing geophysical methods to map the location and depth of the Teays River Valley in Ohio. The present study is a refraction analysis using the first …


Distribution And Fate Of Selected Non-Point Source Pollutants In The Dayton Streams And Tributaries: Effect Of Land Use In An Urban Watershed, Smriti Bastakoti Jan 2024

Distribution And Fate Of Selected Non-Point Source Pollutants In The Dayton Streams And Tributaries: Effect Of Land Use In An Urban Watershed, Smriti Bastakoti

Browse all Theses and Dissertations

This study investigates the distribution of water pollutants in the urban and suburban watershed (Beavercreek Sub-watershed (BCS) and Little Beavercreek Sub-watershed (LBS)) of Dayton, Ohio USA focusing on the relationship between water quality and land use types based on 2021 land use maps obtained from MRLC. These watersheds are home for aquatic life and regulate the flow of surface water and recharge groundwater so, it is crucial to maintain good water quality by balancing urbanization and farmland within these two watersheds. We analyzed chloride, nitrate, and sulfate using ion chromatography (IC) and orthophosphate using UV/Vis Spectrophotometry. Additionally, three pesticides (Atrazine, …


Hydrologic Pathways Of A Northern Hardwood Catchment In The Great Lakes Basin Using End Member Mixing Analysis, Cory C. Burkwald Jan 2024

Hydrologic Pathways Of A Northern Hardwood Catchment In The Great Lakes Basin Using End Member Mixing Analysis, Cory C. Burkwald

Dissertations, Master's Theses and Master's Reports

This study investigated the seasonality of hydrologic pathways, the role of wetlands in streamflow generation, and how hydrologic pathways affect the export of nutrients by streamflow in the Sturgeon River using endmember mixing analysis. The results indicated that streamflow consists of three main components: shallow subsurface water from wetland soils, shallow groundwater, and surface runoff from precipitation. Snowmelt plays a dominating role in regulating stream water chemistry (~80% volume at peak) during the snowmelt season and likely also after that. Wetland soils store snowmelt, together with rainwater though the fraction is unknown, and then gradually release through summer in the …


Novel Analytical Approaches For The Study Of Energy And Nutrient Flow In Streams, Michelle Catherine Kelly Jan 2024

Novel Analytical Approaches For The Study Of Energy And Nutrient Flow In Streams, Michelle Catherine Kelly

Dissertations, Master's Theses and Master's Reports

This dissertation applied novel modeling, experimental and statistical approaches to overcome the challenges of measuring and analyzing energy and nutrient cycling in streams through 3 studies: (1) determining the predictors of respiration and denitrification in streams across the United States, (2) simultaneous estimation of denitrification and nitrogen (N) fixation rates, and (3) the impact of C lability metrics on the interpretation of C degradation in DOM incubation experiments. In the first study, I used predictive modeling approaches to show that respiration and denitrification were positively correlated across the landscape but were predicted by factors at different spatial scales. Denitrification rates …


A Gis Tool For Optimal Forage Species Selection, David B. Hannaway, Christopher Daly, Michael D. Halbleib, Linda Brewer, Sophie Baur, Chelsea Clark, Emilie Krecklow, Scott Bassett Jan 2024

A Gis Tool For Optimal Forage Species Selection, David B. Hannaway, Christopher Daly, Michael D. Halbleib, Linda Brewer, Sophie Baur, Chelsea Clark, Emilie Krecklow, Scott Bassett

IGC Proceedings (1977-2023)

To determine appropriate forage species for US ecoregions, geographic information technologies (GIS) are being used to create climatic and soil factor maps. Excel spreadsheets and RStudio are used to create response functions of forage species to minimum and maximum temperature, annual precipitation, soil pH, soil salinity, and salinity. National forage data and expert opinion will evaluate quantitative tolerances, seasonal yield profiles, and pollinator suitability. These maps and agronomic and livestock use information will be shared with forage specialists and farmers to provide alternatives for improved perenniality, increased diversity, and system circularity. Future work will include development and evaluation of climate …


Petrography Study Of The Recent Sediments In Hareer’S Region At Basrah Governorate - Southern Iraq, K J. Al-Sudani, B N. Albadran, A S Y Al-Hadadi, M H. Al-Jaberi, Jennifer R. Pournelle Jan 2024

Petrography Study Of The Recent Sediments In Hareer’S Region At Basrah Governorate - Southern Iraq, K J. Al-Sudani, B N. Albadran, A S Y Al-Hadadi, M H. Al-Jaberi, Jennifer R. Pournelle

Faculty Publications

Two sites of Hareer’s region is located in the southern part of Iraq, specifically in the northern Basrah Governorate. The sites are at a depth of 5 meters. The results of heavy mineral analysis showed that there are fifteen types include; Opaque grain (Iron Oxide), Chlorite, Muscovite mica, Biotite, Orthopyroxene, Clinopyroxene, Amphibole (Hornblende and Actinolite), Epidote, Garnet, Kyanite, Staurolite, Zircon, and Tourmaline. On the other hand the light minerals and the results of the mineral analyses revealed that they were primarily composed of rock fragments, with a variety of quartz minerals, feldspar minerals, evaporate minerals, clay-coated grains, and trace amounts …


Multiscale Characterization Of Splays Produced By A Historic, Rain-On-Snow Flood On A Large Braided Stream (Platte River, Central Usa), J. T. Korus, R. M. Joeckel, A. R. Mittelstet, N. Shrestha Jan 2024

Multiscale Characterization Of Splays Produced By A Historic, Rain-On-Snow Flood On A Large Braided Stream (Platte River, Central Usa), J. T. Korus, R. M. Joeckel, A. R. Mittelstet, N. Shrestha

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Locating And Assessing Oregon Trail Ruts With Aerial Stereophotographs, Satellite Imagery And Lidar, P.R. Hanson, Robert Matthew Joeckel, L. M. Howard Jan 2024

Locating And Assessing Oregon Trail Ruts With Aerial Stereophotographs, Satellite Imagery And Lidar, P.R. Hanson, Robert Matthew Joeckel, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Landscape And Paleoenvironmental Change In Stream Valleys Of The Central Great Plains, North America During Marine Isotope Stage 3 (Ca. 59-27 Ka)., T. Layzell, K. Andrzejewski, R. D. Mandel, P.R. Hanson Jan 2024

Landscape And Paleoenvironmental Change In Stream Valleys Of The Central Great Plains, North America During Marine Isotope Stage 3 (Ca. 59-27 Ka)., T. Layzell, K. Andrzejewski, R. D. Mandel, P.R. Hanson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains, J. J. Smith, Robert Matthew Joeckel, H. L. Field, G. A. Ludvigson, A. Moller, A. Layzell, S. T. Tucker Jan 2024

Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains, J. J. Smith, Robert Matthew Joeckel, H. L. Field, G. A. Ludvigson, A. Moller, A. Layzell, S. T. Tucker

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Wetlands In The Nebraska Sandhills, Nawaraj Shrestha Jan 2024

Wetlands In The Nebraska Sandhills, Nawaraj Shrestha

Conservation and Survey Division: Faculty and Staff Publications

Infographic titled “Status of Wetlands in the Nebraska Sandhills” showing multiple maps and charts. The top left features a color-coded wetland persistence map where blue indicates more consistent wetlands and red indicates intermittent wetlands. Additional inset maps show a regional zoom and a U.S. location map highlighting Nebraska. A large scatter plot displays wetland occurrence percentages over time using MODIS (green points) and Sentinel (blue points) satellite data from 2000 to 2024. Text explains how wetlands vary seasonally and annually and how satellite imagery tracks these changes. A smaller bottom chart shows long-term wetland trends, noting increasing occurrence since 1984. …


Stage And Discharge Prediction From Documentary Time-Lapse Imagery, Kenneth W. Chapman, Troy E. Gilmore, Mehrube Mehrubeoglu, Christian D. Chapman, Aaron R. Mittelstet, John E. Stranzl Jr. Jan 2024

Stage And Discharge Prediction From Documentary Time-Lapse Imagery, Kenneth W. Chapman, Troy E. Gilmore, Mehrube Mehrubeoglu, Christian D. Chapman, Aaron R. Mittelstet, John E. Stranzl Jr.

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Imagery from fixed, ground-based cameras is rich in qualitative and quantitative information that can improve stream discharge monitoring. For instance, time-lapse imagery may be valuable for filling data gaps when sensors fail and/or during lapses in funding for monitoring programs. In this study, we used a large image archive (> 40,000 images from 2012 to 2019) from a fixed, ground-based camera that is part of a documentary watershed imaging project (https://plattebasintimelapse.com/). Scalar image features were extracted from daylight images taken at one-hour intervals. The image features were fused with United States Geological Survey stage and discharge data as …


Rates And Patterns Of Permafrost Thaw Induced Landcover Change At Scotty Creek, Canada, Mason Dominico Jan 2024

Rates And Patterns Of Permafrost Thaw Induced Landcover Change At Scotty Creek, Canada, Mason Dominico

Theses and Dissertations (Comprehensive)

In the peatland-dominated regions of discontinuous permafrost in northwestern Canada, permafrost thaw is altering landscapes at rates without precedent in the historical record. The present study uses a combination of remote sensing and ground based methods to examine the rates and patterns of permafrost thaw and how such thaw is changing the form and function of the landscape. The area within a 4 km2 area of interest underlain by permafrost decreased from 51% in 1977 to 43% in 2010, and to 40% in 2018, indicating an increase in the permafrost thaw rate from 0.24% yr-1 between 1977 and 2010, and …


Evaluating The Risk Posed By Gadolinium In The Grand River Watershed, Johann Memmel Jan 2024

Evaluating The Risk Posed By Gadolinium In The Grand River Watershed, Johann Memmel

Theses and Dissertations (Comprehensive)

Gadolinium (Gd) is a rare earth element (REE), primarily used in contrast agents for magnetic resonance imaging (MRI), with additional applications in metallurgy, phosphors, neutron shielding, and other niche applications. Both Gd and Gd-based contrast agents (GBCAs, the form used for MRIs) have been detected downstream of wastewater effluent discharges and there is currently little research into the risk this poses to aquatic ecosystems. This study investigated the potential environmental risks of Gd and GBCAs using the Grand River watershed (GRW) in southwestern Ontario as a model ecosystem due to it containing a variety of land uses (urban, industrial, agricultural) …


Fold-Related Faults Track Progressive Fold Development From Layer-Parallel Shortening To Subsequent Orthogonal Extension Within An Appalachian Buckle Fold System: Bear Valley Mine, Shamokin, Pa Usa, Arlo B. Weil, Mary Beth Gray, Kylie G. Cush, Mattathias D. Needle, Juliet G. Crider Jan 2024

Fold-Related Faults Track Progressive Fold Development From Layer-Parallel Shortening To Subsequent Orthogonal Extension Within An Appalachian Buckle Fold System: Bear Valley Mine, Shamokin, Pa Usa, Arlo B. Weil, Mary Beth Gray, Kylie G. Cush, Mattathias D. Needle, Juliet G. Crider

Faculty Journal Articles

Outstanding three-dimensional exposures of adjacent folds in an abandoned coal mine within the Appalachian Valley-and-Ridge tectonic province permit a detailed analysis of macroscopic strain accommodation by minor faulting in the lead up to and during buckle folding. A kinematic analysis of more than 900 outcrop-scale faults coupled with clearly established relative age relationships allows delineation of distinctive fault sets and their roles in accommodating strain within a quartz-dominated sandstone and an overlying silty shale. Conjugate contractional faults are interpreted as evidence of layer-parallel shortening (LPS) prior to and during fold initiation, based on geometric relationships to primary bedding. A clearly …


Keynote Address And Meeting Program, Academy Editors Jan 2024

Keynote Address And Meeting Program, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.