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Full-Text Articles in Physical Sciences and Mathematics

Uncovering The Mysteries Of Retention Ponds: Comparing The Abundance And Type Of Microplastics In Storm Water Ponds In London Ontario, Natalie Rose Minda Aug 2022

Uncovering The Mysteries Of Retention Ponds: Comparing The Abundance And Type Of Microplastics In Storm Water Ponds In London Ontario, Natalie Rose Minda

Undergraduate Student Research Internships Conference

Microplastics are plastics <5 mm (Liu, 2019; Arthur et al., 2009). They are created in two ways: Intentionally or from the fragmentation of larger pieces of plastic (National Ocean Service, 2021). They can negatively impact human, wildlife and ecosystem health in many ways depending on the exposure, type, size, and shape of the microplastic (Campanale, 2020). Retention ponds are often created in neighborhoods to collect water in order to prevent flooding. They also often serve as habitat for wildlife. Sediment samples were collected in two ponds in London Ontario both dredged in 2016. Samples were processed in the lab and further analyzed under the microscope to isolate the microplastics. Results have not been determined yet, but the abundance and type of microplastic varies in both ponds. Plastic pollution in retention ponds should be considered more, as it poses a threat to human and ecosystem health.


A Pressure And Stress Study Of Reidite, Gillian G. Noonan Aug 2022

A Pressure And Stress Study Of Reidite, Gillian G. Noonan

Undergraduate Student Research Internships Conference

Zircon is a mineral that can commonly be found in many rocks in the Earth’s crust and other planetary bodies. Meteorite impact sites have also been shown to contain zircon and its high-pressure polymorph, Reidite.


Thoughts And Suggestions On Development Of Earth Sciences In China, Lihua Zhou, Xin Wang, Chengxiong Zhou, Quanyou Liu, Jianhua Si, Wang Zhang, Zhijun Jin Mar 2022

Thoughts And Suggestions On Development Of Earth Sciences In China, Lihua Zhou, Xin Wang, Chengxiong Zhou, Quanyou Liu, Jianhua Si, Wang Zhang, Zhijun Jin

Bulletin of Chinese Academy of Sciences (Chinese Version)

Earth Sciences is a multi-disciplinary science, which takes the interaction of Earth's various spheres and their resources and environmental effects as the research object. As a comprehensive and systematic science that not only expands the frontier of human knowledge but also serves the social and economic development of human beings, Earth Sciences not only studies the past and reveals the evolution history of the Earth, but also faces the future and provides solutions for the sustainable development of human beings. Based on the analysis of the international development trends of Earth Sciences and the summary of the development status and …


Taxonomic And Nutrient Controls On Phytoplankton Iron Quotas In The Ocean, Benjamin S. Twining, Olga Antipova, P. Dreux Chappell, Natalie R. Cohen, Jeremy E. Jacquot, Elizabeth L. Mann, Adrian Marchetti, Daniel C. Ohnemus, Sara Rauschenberg, Alessandro Tagliabue Jan 2021

Taxonomic And Nutrient Controls On Phytoplankton Iron Quotas In The Ocean, Benjamin S. Twining, Olga Antipova, P. Dreux Chappell, Natalie R. Cohen, Jeremy E. Jacquot, Elizabeth L. Mann, Adrian Marchetti, Daniel C. Ohnemus, Sara Rauschenberg, Alessandro Tagliabue

OES Faculty Publications

Phytoplankton iron contents (i.e., quotas) directly link biogeochemical cycles of iron and carbon and drive patterns of nutrient limitation, recycling, and export. Ocean biogeochemical models typically assume that iron quotas are either static or controlled by dissolved iron availability. We measured iron quotas in phytoplankton communities across nutrient gradients in the Pacific Ocean and found that quotas diverged significantly in taxon‐specific ways from laboratory‐derived predictions. Iron quotas varied 40‐fold across nutrient gradients, and nitrogen‐limitation allowed diatoms to accumulate fivefold more iron than co‐occurring flagellates even under low iron availability. Modeling indicates such “luxury” uptake is common in large regions of …


Comparative, Lithology-Based Biogeography Of Phreatophytic And Non-Phreatophytic Matrices Along A North-South Gradient Of The South Texas Sand Sheet, Christopher Joaquin Munoz May 2019

Comparative, Lithology-Based Biogeography Of Phreatophytic And Non-Phreatophytic Matrices Along A North-South Gradient Of The South Texas Sand Sheet, Christopher Joaquin Munoz

Theses and Dissertations

A 70km-long, N-S stratigraphic cross-section spanning the entirety of the South Texas Sand Sheet (STSS) has been rendered along Texas Interstate 69C. The cross-section indicates localized zones of substantial STSS thickness (>4m) as well as zones where the underlying Goliad Formation is either exposed or just below the surface (<0.5m). Spatial patterns of both phreatophytic and non-phreatophytic vegetation assemblages were analyzed by means of remote sensing and in situ herbaceous species evaluations. Biogeographic patterns were comprised of three vegetation matrices: P. glandulosa-dominated, Q. virginiana-dominated and a matrix of herbaceous plants. The geographic distribution of vegetation assemblages corresponded to specific lithological parameters and features. Namely, Q. virginiana concentration exhibited a positive linear relationship with the lithological parameter of STSS thickness (P =2.122x10-11) (α = 0.05). P. glandulosa/V. farnesiana …


Effects Of Global Warming On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In The American Oyster, Sarah B. Nash May 2019

Effects Of Global Warming On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In The American Oyster, Sarah B. Nash

Theses and Dissertations

Global warming due to climate change is predicted to intensify the heat stress in marine and coastal organisms, affecting their development, growth and reproductive functions. In this study. I analyzed gonadal development, heat shock protein 70 (HSP70), nitrotyrosine protein (NTP), dinitrophenyl (DNP) expressions, cellular apoptosis, and coelomic fluid (CF) conditions in American oyster. Oysters were placed in six aquariums and exposed to control (24°C), medium (28°C), and high (32°C) temperatures for one week. Higher temperature significantly decreased the number of eggs and sperm. CF protein concentrations also declined compared to control. In contrast, CF pH and HSP70 expression in gonad …


Impacts Of Basin-Scale Climate Modes On Coastal Sea Level: A Review, Weiqing Han, Detlef Stammer, Philip Thompson, Tal Ezer, Hindu Palanisamy, Xuebin Zhang, Catia M. Domingues, Lei Zhang, Dongliang Yuan Jan 2019

Impacts Of Basin-Scale Climate Modes On Coastal Sea Level: A Review, Weiqing Han, Detlef Stammer, Philip Thompson, Tal Ezer, Hindu Palanisamy, Xuebin Zhang, Catia M. Domingues, Lei Zhang, Dongliang Yuan

CCPO Publications

Global sea level rise (SLR) associated with a warming climate exerts significant stress on coastal societies and low-lying island regions. The rates of coastal SLR observed in the past few decades, however, have large spatial and temporal differences from the global mean, which to a large part have been attributed to basin-scale climate modes. In this paper, we review our current state of knowledge about climate modes’ impacts on coastal sea level variability from interannual-to-multidecadal timescales. Relevant climate modes, their impacts and associated driving mechanisms through both remote and local processes are elaborated separately for the Pacific, Indian and Atlantic …


Longitudinal And Temporal Comparison Of Beach Sand On The Rio Grande Delta System, Samantha B. Moore Dec 2018

Longitudinal And Temporal Comparison Of Beach Sand On The Rio Grande Delta System, Samantha B. Moore

Theses and Dissertations

The Rio Grande is the 5th longest river in North America and defines a significant extent of the United States-Mexico border. It extends for 2830 km from its headwaters in the Rocky Mountains of Colorado to the Gulf of Mexico. The Rio Grande is fed by streams from the Sangre de Cristo Mountains, the Rio Conchos, the Pecos River, runoff from the Sacramento Mountains area, Devils River, the Rio Salado, and the Rio San Juan. This study addresses how the composition of sand forming the Rio Grande river delta into the Gulf of Mexico at Boca Chica Beach is changed …


Seismic Structure Near The Mariana Trench And Deep Earthquake Triggering In The Tonga Flat Slab, Chen Cai Aug 2018

Seismic Structure Near The Mariana Trench And Deep Earthquake Triggering In The Tonga Flat Slab, Chen Cai

Arts & Sciences Electronic Theses and Dissertations

This dissertation utilizes multiple techniques of earthquake location and seismic tomography to investigate deep seismicity in the Tonga flat slab region and the upper mantle structure of the Mariana subduction zone. I study the rupture property and aftershock distributions of the largest earthquake ever recorded in the Tonga flat slab region, defined by scattered seismicity and velocity anomalies. These, along with background seismicity, regional 3-D seismic velocity model and tectonic reconstructions of relict Vitiaz subduction zone, suggest the earthquakes are occurring in the final portion of the slab subducted at the now inactive Vitiaz trench. The associated Coulomb stress change …


Quantifying Factors That Influence Road Deicer Retention And Export In A Multi-Landuse Upstate New York Watershed, David Joseph Saba May 2018

Quantifying Factors That Influence Road Deicer Retention And Export In A Multi-Landuse Upstate New York Watershed, David Joseph Saba

Graduate Dissertations and Theses

Chloride contamination of streams and groundwater has become a prevalent issue throughout urbanizing areas in the last half century, particularly in northern latitudes where deicing salts are applied to roadways. This study determined how deicer impacted runoff disperses through sub-urban and urban areas on seasonal and multi-year scales. Chloride concentration changes were then modelled under varying pollutant loading scenarios through an integrated catchment model (INCA-Cl).

Six in-stream conductivity/stage/temperature sondes, recording at 15-minute intervals, were installed within the small (~9.6 km2) Fuler Hollow Creek multi-landuse watershed in Broome County NY and monitored over a 1-year period. Weekly grab samples were taken …


Development Of Lower Rio Grande River Water Quality Transportation Numerical Model For Bi-National River Management, Jose O. Gonzalez Aug 2017

Development Of Lower Rio Grande River Water Quality Transportation Numerical Model For Bi-National River Management, Jose O. Gonzalez

Theses and Dissertations

Traditionally, water quality modelling has focused on modelling individual water bodies. However, water quality management problems must be analyzed at the larger scale to include influences from various water bodies that are interconnected. This paper provides a study on the hydrologic and quality transportation calculation by developing a hydrodynamic (unsteady state) channel routing model using a water-balanced approach. A one dimension Lagrangian river model was developed and applied to the 210 plus miles for the lower Rio Grande River Basin from the Falcon Dam to the head water of Brownsville that pours onto the Gulf of Mexico. This model can …


Development Of A Multiband Remote Sensing System For Determination Of Unsaturated Soil Properties, Cyrus D. Garner May 2017

Development Of A Multiband Remote Sensing System For Determination Of Unsaturated Soil Properties, Cyrus D. Garner

Graduate Theses and Dissertations

A multiband system including active microwave sensing and visible-near infrared reflectance spectroscopy was developed to measure unsaturated soil properties in both field and laboratory environments. Remote measurements of soil volumetric water content (θv), soil water matric potential (ψ), and soil index properties (liquid limit [LL], plastic limit [PL], and clay fraction [CF]) were conducted. Field-based measurement of θv was conducted using a ground-based radar system and field measurements within 10 percentage points of measurements acquired with traditional sampling techniques were obtained. Laboratory-based, visible and near infrared spectroscopy was found to be capable of obtaining empirical, soil specific regression functions (partial …


Lost Names In The Paleozoic Lithostratigraphy Of Arkansas, Noah Morris May 2017

Lost Names In The Paleozoic Lithostratigraphy Of Arkansas, Noah Morris

Graduate Theses and Dissertations

The geology of Arkansas has been studied for nearly 160 years, and our understanding of it is continually evolving. Part of this ever-changing study is the nomenclature of the stratigraphy. From the early reports to today, several lithostratigraphic names have been proposed and abandoned to improve the accuracy and clarity of the understanding of Arkansas’ geology. Over these 160 years of study, 214 names have been proposed for the Paleozoic beds of Arkansas, with nearly 80 of them currently in use today. These names are a testimony and legacy of the history of Arkansas’ natural resource development and Arkansas’ geologists. …


Comparison Of Flow Dynamics And Bifurcation Angles In Tributary And Distributary Channel Networks, Thomas Coffey May 2017

Comparison Of Flow Dynamics And Bifurcation Angles In Tributary And Distributary Channel Networks, Thomas Coffey

Graduate Theses and Dissertations

The dynamics of channel mouth bifurcations on river deltas can be understood using theory developed in tributary channel networks. Bifurcations in groundwater-fed tributary networks have been shown to evolve dependent on diffusive ground water flow patterns

directly adjacent to the channel network, producing a critical angle of 72°. We test the hypothesis that bifurcation angles in distributary channel networks are likewise dictated by a diffusive external flow field, in this case the shallow surface water surrounding the subaqueous portion of distributary channels in a deltaic setting. We measured 25 unique distributary bifurcations in an experimental delta and 197 bifurcations in …


Lake Magadi And The Soda Lake Cycle: A Study Of The Modern Sodium Carbonates And Of Late Pleistocene And Holocene Lacustrine Core Sediments, Emma Mcnulty Jan 2017

Lake Magadi And The Soda Lake Cycle: A Study Of The Modern Sodium Carbonates And Of Late Pleistocene And Holocene Lacustrine Core Sediments, Emma Mcnulty

Graduate Dissertations and Theses

The Magadi Basin, Kenya, within the East African Rift Valley, contains two closed-basin alkaline lakes, Lake Magadi and Nasikie Engida that now precipitate trona (Na2CO3.NaHCO3.2H2O) and nahcolite (NaHCO3). Observations of the conditions of modern trona and nahcolite deposition in the Magadi Basin form the basis of the “soda lake cycle”. This study aims to use the sedimentary structures of the modern sodium carbonates of Lake Magadi as an analogue for similar ancient deposits around the world, including the vast trona and nahcolite deposits of the Eocene Green River Formation. Lake Magadi has been evolving since 1.08 Ma within a well-known …


Exploring The Potential Impacts Of Climate Change On North America's Laurentian Great Lakes Tourism Sector, Natalie Chin Dec 2016

Exploring The Potential Impacts Of Climate Change On North America's Laurentian Great Lakes Tourism Sector, Natalie Chin

Open Access Dissertations

Climate change is one of the major challenges facing the global hospitality and tourism sector in the coming century and, given the important role that weather and climate play in all aspects of the tourism experience, tourism businesses owners need to start thinking about and enacting climate change adaptation strategies now. This work has utilized a combination of social science and physical science methods to (1) understand how the Great Lakes tourism sector could be impacted by climate change and (2) provide some insights into how researchers can help business owners prepare for these potential impacts. Overall, the results of …


Hydrocode Modeling Of Oblique Impacts Into Terrestrial Planets, Jordan D. Kendall Dec 2016

Hydrocode Modeling Of Oblique Impacts Into Terrestrial Planets, Jordan D. Kendall

Open Access Dissertations

The abundance of moderately siderophile elements (“iron-loving”; e.g., Co, Ni) in the Earth’s mantle is 10 to 100 times larger than predicted by chemical equilibrium between silicate melt and iron at low pressure, but it does match expectation for equilibrium at high pressure and temperature. Recent studies of differentiated planetesimal impacts assume that planetesimal cores survive the impact intact as concentrated masses that passively settle from a zero initial velocity and undergo turbulent entrainment in a global magma ocean; under these conditions, cores greater than 10 km in diameter do not fully mix without a sufficiently deep magma ocean. I …


Miocene-Pliocene Strike-Slip Basin Development Along The Denali Fault System In The Eastern Alaska Range: Chronostratigraphy And Provenance Of The Mccallum Formation And Implications For Displacement, Wai Kehadeezbah Allen Dec 2016

Miocene-Pliocene Strike-Slip Basin Development Along The Denali Fault System In The Eastern Alaska Range: Chronostratigraphy And Provenance Of The Mccallum Formation And Implications For Displacement, Wai Kehadeezbah Allen

Open Access Theses

The Denali fault system represents one of the major strike-slip faults in North America but very little is known about the amount and timing of displacement on this 2000-km-long structure. The 7.9 M 2002 Denali Earthquake emphasized the importance of this fault system for understanding the deformational record of the upper plate of the southern Alaska convergent margin. Our analysis of the Miocene-Pliocene McCallum Formation located along the east-central part of the Denali fault provides one of the few records for Neogene displacement as well as changes in surface and basin processes related to tectonic transport. We have established a …


Modeling The Impact Of Land Surface Feedbacks On Post Landfall Tropical Cyclones, Subashini Subramanian Dec 2016

Modeling The Impact Of Land Surface Feedbacks On Post Landfall Tropical Cyclones, Subashini Subramanian

Open Access Dissertations

The land surface is an important component of numerical models. The land surface models are modules that control energy partitioning, compute surface exchange coefficients and form the only physical boundary in a regional scale numerical model. Thus, an accurate representation of land surface is critical to compute surface fluxes, represent the boundary layer evolution and affect changes in weather systems. Land surface can affect landfalling tropical cyclones in two ways: (i) when the cyclone is offshore and land can influence cyclones by introducing dry (or moist) air that can weaken (or strengthen) the organized convective structure of cyclones, and (ii) …


Unraveling The Fingerprints Of Nox Using Stable Isotopes: Implications For Nox Source Partitioning And Oxidation Chemistry, Wendell William Walters Dec 2016

Unraveling The Fingerprints Of Nox Using Stable Isotopes: Implications For Nox Source Partitioning And Oxidation Chemistry, Wendell William Walters

Open Access Dissertations

The nitrogen (N) and oxygen (O) stable isotope composition (δ15N & δ18O) of nitrogen oxides (NOx )may be a useful tool for constraining NOx emission sources as well as for understanding the atmospheric oxidation pathways responsible for its removal if various NOx sources and sink processes exhibit characteristic isotopic compositions (“fingerprints”). However, this requires (1) an accurate and complete inventory of δ15N(NOx) values from major emission sources, (2) an assessment of the kinetic and equilibrium isotope effects that can impact δ15N and δ18O values of NOx, (3) and test these assumptions by conducting accurate in situ δ15N and δ18O measurements …


An Examination Of Geographic Patterns Of Soil Climate And Its Classification In The U.S. System Of Soil Taxonomy, Hans Edwin Winzeler Dec 2016

An Examination Of Geographic Patterns Of Soil Climate And Its Classification In The U.S. System Of Soil Taxonomy, Hans Edwin Winzeler

Open Access Dissertations

Soil climate, the record of temporal patterns of soil moisture and temperature, is an important component of the structure of U.S. Soil Taxonomy. The U.S. Soil Survey has used the Newhall Simulation Model (NSM) for estimating soil climate from atmospheric climate records at weather stations since the 1970s. The current soil climate map of the U.S. was published in 1994 by using NSM runs from selected weather stations along with knowledge-based hand-drawn mapping procedures. We developed a revised soil climate mapping methodology using the NSM and digital soil mapping techniques.

The new methodology is called Grid Element Newhall Simulation Model …


Investigation Of Ambient Seismic Noise Using Seismic Interferometry In The Midwestern United States, Joshua Dakota Boschelli Dec 2016

Investigation Of Ambient Seismic Noise Using Seismic Interferometry In The Midwestern United States, Joshua Dakota Boschelli

Open Access Theses

The portion of the North American craton occupied by the Midwestern United States is a cratonic platform, where a veneer of Phanerozoic sedimentary strata buries the Precambrian basement up to 7 km. Due to the sediment cover and low topographic relief, the at depth structure of the region remains poorly understood. This region is of particular interest because over the past half-billion years tectonic forces have resulted in the formation of epeirogenic provinces in a stable cratonic interior. Using the OIINK flexible seismic array and the Earthscope Transportable Array, Ambient Seismic Noise Tomography was applied to investigate the crustal structure …


A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly Dec 2016

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …


Examining Denitrification In Agricultural Ditch Sediments Vegetated With Rice Cutgrass (Leersia Oryzoides): Modeling Seasonal Variation Across Increasing Levels Of Nitrate Loading And Model Application To Pre-Existing Datasets, Shannon Lee Speir Dec 2016

Examining Denitrification In Agricultural Ditch Sediments Vegetated With Rice Cutgrass (Leersia Oryzoides): Modeling Seasonal Variation Across Increasing Levels Of Nitrate Loading And Model Application To Pre-Existing Datasets, Shannon Lee Speir

Graduate Theses and Dissertations

Nitrogen (N) derived from fertilizer application in agricultural systems may contribute to significant environmental impacts, including eutrophication of fresh and coastal waters. Rice cutgrass (Leersia oryzoides) can significantly enhance denitrification potential in agricultural ditch sediments, but relationships with known drivers are not well understood. To address this, I examined effects of nitrate (NO3-) availability on dinitrogen gas (N2) and NO3- fluxes seasonally in Chapter 2. Denitrification rates were measured as N2 flux from intact vegetated sediment cores using Membrane Inlet Mass Spectrometry (MIMS). Michaelis-Menten models were developed from observations to mathematically describe N2 fluxes across the spring, summer, and fall …


Stratigraphy And Depositional Environment Of The Middle Atoka Formation, Central Arkoma Basin, Western Arkansas, Yueyang Wang Dec 2016

Stratigraphy And Depositional Environment Of The Middle Atoka Formation, Central Arkoma Basin, Western Arkansas, Yueyang Wang

Graduate Theses and Dissertations

Wire line logs are widely used in analysis of the subsurface stratigraphy of the middle Atoka Formation, Central Arkoma Basin, Western Arkansas. SP log, Gamma ray log, resistivity log and conductivity log provide valuable information to construct cross sections.

The middle Atoka formation is composed of a succession of shale and sandstone alternations with thickness reaching approximately 3000 feet in the study area. It contains several sandstone units which include Morris, Tackett, Areci, Bynum, Casey and Dunn”A” separated by shale intervals. The purpose of this study is to identify these units and predict sequence stratigraphy and depositional environment by constructing …


Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb Dec 2016

Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb

Graduate Theses and Dissertations

Dissolved concentrations of CO2 in a karst aquifer are a major control on calcite dissolutional processes, as CO2 combines chemically with water to form carbonic acid. As increasing amounts of CO2 are added to the system, greater resultant water aggressivity generates greater rates of dissolution. Spatial and temporal variations in carbon flux through the system may occur over a range of time scales, and high-resolution data collection is needed to truly understand and characterize such variability. Continuous CO2 monitoring in War Eagle Cavern, Arkansas, will suggest a number of influential parameters with varying degrees of importance throughout an annual cycle. …


Sedimentary Petrology Of The Hartshorne Formation, Southeastern Arkoma Basin, Arkansas, Ruizhe Yin Dec 2016

Sedimentary Petrology Of The Hartshorne Formation, Southeastern Arkoma Basin, Arkansas, Ruizhe Yin

Graduate Theses and Dissertations

The Pennsylvanian Hartshorne Sandstone crops out in an east trending belt across central Arkansas immediately north of the Ouachita orogenic belt and south of the Boston Mountains. The unit, composed of massive to cross bedded sandstone ranging to 150m in thickness, was deposited by a west-flowing river system that extended from central Arkansas to southeastern Oklahoma. The source of the sediment has been extensively discussed but not completely established. The object of this thesis is to constrain the source area and terrain based on thin section mineralogy and texture. Thin sections were prepared from outcrops in the Arkoma Basin and …


The Role Of The Picuris Orogeny In The Tectonic Evolution Of Proterozoic North America, Ruth Frances Aronoff Aug 2016

The Role Of The Picuris Orogeny In The Tectonic Evolution Of Proterozoic North America, Ruth Frances Aronoff

Open Access Dissertations

North America is a continent that has grown over time by horizontal attachment of material onto its margins. Studying the process of continental growth in the geologic past gives insight into fundamental components of plate tectonics, and sheds light onto processes at work at modern plate boundaries, in which mid- and lower-crustal rocks are generally hidden from view.

This study focuses on the growth of North America during the Proterozoic. Researchers have debated the role of three orogenies in shaping the southwestern margin of North America: the ∼1.80-1.60 Ga Yavapai and Mazatzal orogenies, and the newly recognized ∼1.40 Ga Picuris …


Simulation Of Flow And Water Quality From Tile Drains At The Watershed And Field Scale, Colleen Moloney Aug 2016

Simulation Of Flow And Water Quality From Tile Drains At The Watershed And Field Scale, Colleen Moloney

Open Access Theses

Simulation models such as the Soil and Water Assessment Tool (SWAT) have become widely used in determining the water quality impacts of various management practices. Ensuring that the algorithms accurately represent the processes simulated has become an important goal. Tile drainage is a standard practice in the Midwest, US in order to reduce risk of yield loss due to excess water. Multiple tile drainage and water table algorithms have been available in the SWAT model between the initial SWAT release and revision 638 used in this study. Testing of those algorithms is often limited. Furthermore, algorithms in the current version …


Role Of River Bathymetry In Hydraulic Modeling Of River Channels, Sayan Dey Aug 2016

Role Of River Bathymetry In Hydraulic Modeling Of River Channels, Sayan Dey

Open Access Theses

Accurate geometric representation of the river channel is required for accurate hydraulic modeling of rivers. These are generally obtained through remote sensing techniques such as Light Detection and Ranging (LIDAR). However, these techniques lack the ability to model the submerged channel bed effectively and need to be complemented with surveyed bathymetric data for complete representation of the channel bathymetry, which can be time and cost prohibitive. An alternative to address this issue is to develop conceptual models that can estimate bathymetry.

This study aims to evaluate the potential of a conceptual model, the River Channel Morphology Model (RCMM) which estimates …