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Neodymium Isotope Ratios And A Positive Δ13c Excursion: Connecting Oceanographic And Climate Changes Near The M4-M5 Sequence Boundary Of The Late Ordovician, Zachary Wright

LSU Master's Theses

A significant positive carbon isotope excursion first described from the Guttenberg Member of the Decorah Formation in Iowa called the GICE is a defining feature of Late Ordovician chemostratigraphy. It occurs near the M4-M5 sequence boundary of the Late Ordovician and has been correlated across the globe using prominent K-bentonite ash beds and conodont biomarkers. The cause of the GICE has been debated, with some arguing that it represents the initiation of a glacial period in a greenhouse climate 10 Ma before the end Ordovician glaciation and extinction. A variety of cooling signals have been identified across the M4-M5 sequence …

The Extraordinary Voyage Of Kamome; A Tsunami Boat Comes Home, Lori Dengler, Amya Miller, Amy Uyeki

Trade & Scholarly Monographs

This sweet story, intended for lower elementary grades, is intended to provide a window for discussing earthquakes, tsunamis, marine debris, preparedness and cultural awareness in the classroom and within families.

On April 7, 2013, a little over two years after the magnitude 9 Tohoku-oki Japan earthquake triggered a massive tsunami off the coast of northeastern Japan, a lone boat washed up on the shores of Crescent City, California. The confirmation of the boat as belonging to a high school in Rikuzentakata was first step in an amazing story that has linked two tsunami-vulnerable communities on opposite sides of the Pacific …

The Relative Importance Of Methanogenesis In The Decomposition Of Organic Matter In Northern Peatlands, J. Elizabeth Corbett, Malak M. Tfaily, David J. Burdige, Paul H. Glaser, Jeffrey P. Chanton

OES Faculty Publications

Using an isotope-mass balance approach and assuming the equimolar production of CO₂ and CH₄ from methanogenesis (e.g., anaerobic decomposition of cellulose), we calculate that the proportion of total CO₂ production from methanogenesis varies from 37 to 83% across a variety of northern peatlands. In a relative sense, methanogenesis was a more important pathway for decomposition in bogs (80 ± 13% of CO₂ production) than in fens (64 ± 5.7% of CO₂ production), but because fens contain more labile substrates they may support higher CH4 production overall. The concentration of CO₂ produced from methanogenesis (CO …

Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken

OES Faculty Publications

The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and …

Octocoral Mitochondrial Genomes Provide Insights Into The Phylogenetic History Of Gene Order Rearrangements, Order Reversals, And Cnidarian Phylogenetics, Diego F. Figueroa, Amy R. Baco

School of Earth, Environmental, & Marine Sciences Faculty Publications

We use full mitochondrial genomes to test the robustness of the phylogeny of the Octocorallia, to determine the evolutionary pathway for the five known mitochondrial gene rearrangements in octocorals, and to test the suitability of using mitochondrial genomes for higher taxonomic-level phylogenetic reconstructions. Our phylogeny supports three major divisions within the Octocorallia and show that Paragorgiidae is paraphyletic, with Sibogagorgia forming a sister branch to the Coralliidae. Furthermore, Sibogagorgia cauliflora has what is presumed to be the ancestral gene order in octocorals, but the presence of a pair of inverted repeat sequences suggest that this gene order was not conserved …

Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan

Doctoral Dissertations

"Holocene sedimentary deposits in Al Qahmah coast, southern Red Sea, in Saudi Arabia have been accumulated on an arid siliciclastic coast in a rift tectonic setting. This study provides a detail interpretation and analysis of sedimentary facies, stratigraphy, depositional environment, and major geological processes. Two studies have been undertaken. First, petrological study of composition and texture of modern sediments and facies mapping delineate facies distribution and mechanisms of sediment transport and deposition. A unique suite of complex riverine, wave, tidal, wind, and chemical and biological processes affect the composition, texture, and distribution of the facies. Second, the depositional environments of …

Spatio-Temporal Patterns Of Water Table And Vegetation Status Of A Deserted Area, Limin Duan, Tingxi Liu, Xixi Wang, Yanyun Luo

Civil & Environmental Engineering Faculty Publications

Understanding groundwater-vegetation interactions is crucial for sustaining fragile environments of desert areas such as the Horqin Sandy Land (HSL) in northern China. This study examined spatio-temporal variations in the water table and the associated vegetation status of a 9.71 km² area that contains meadowland, sandy dunes, and intermediate transitional zones. The depth of the water table and hydrometeorologic parameters were monitored and Landsat Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) data were utilized to assess the vegetation cover. Spatio-temporal variations over the six-year study period were examined and descriptive groundwater-vegetation associations developed by overlaying a water table …

Vapor Flow Resistance Of Dry Soil Layer To Soil Water Evaporation In Arid Environment: An Overview, Xixi Wang

Civil & Environmental Engineering Faculty Publications

Evaporation from bare sandy soils is the core component of the hydrologic cycle in arid environments, where vertical water movement dominates. Although extensive measurement and modeling studies have been conducted and reported in existing literature, the physics of dry soil and its function in evaporation is still a challenging topic with significant remaining issues. Thus, an overview of the previous findings will be very beneficial for identifying further research needs that aim to advance our understanding of the vapor flow resistance (VFR) effect on soil water evaporation as influenced by characteristics of the dry soil layer (DSL) and evaporation zone …

Heterotrophic And Autotrophic Contribution To Dinitrogen Fixation In The Gulf Of Aqaba, Eyal Rahav, Barak Herut, Margaret R. Mulholland, Natalia Belkin, Hila Elifantz, Ilana Berman-Frank

OES Faculty Publications

We evaluated the seasonal contribution of heterotrophic and autotrophic diazotrophy to the total dinitrogen (N₂) fixation in the photic zone of a pelagic station in the northern Gulf of Aqaba, Red Sea. N₂ fixation rates were highest during a Trichodesmium bloom in winter (0.7 nmol N l^-1 d^-1), decreased 7-fold 1 wk later throughout the upper 200 m (~0.1 nmol N l^-1) d^-1), and were significantly coupled with both primary and bacterial productivity. N₂ fixation rates were generally higher in the upper 200 m (~0.4 nmol N l^{-1 …}

Predicting Irrigation Efficiency In The Rio Grande Project, Gerardo Melendez

Open Access Theses & Dissertations

Surface water losses in the Bureau of Reclamation’s (USBR) Rio Grande Project have become more prevalent within the past few years of the drought of the 2000’s. Simple regressions were performed in order to find correlations and determine factors that may affect the flows within the Rio Grande Project. Correlations were found in the difference between Rio Grande below Caballo flows and Rio Grande at El Paso flows, and between the diversion ratio and groundwater levels. Caballo Reservoir release amounts were found to be fairly well correlated with the difference between the Rio Grande below Caballo and the Rio Grande …

Ontogenetic Scaling Patterns And Functional Anatomy Of The Pelvic Limb Musculature In Emus (Dromaius Novaehollandiae), Luis P. Lamas, Russell P. Main, John R. Hutchinson

Department of Basic Medical Sciences Faculty Publications

Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive, as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow emus to cope with their rapid growth and locomotion, which can be partly addressed via scaling (allometric) analysis of morphology. In this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area …

Registration Of ‘Newell’ Smooth Bromegrass, K P. Vogel, R B. Mitchell, B L. Waldron, M R. Haferkamp, J D. Berdahl, D D. Baltensperger, Galen Erickson, T J. Klopfenstein

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Soil Carbon And Nitrogen Mineralization And Crop Parameters In Typical Maize-Bean Intercropping In Western Kenya, Judith A. Odhiambo, Urszula Norton, Emmanuel C. Omondi, Dennis Ashilenje, Jay B. Norton

Agricultural and Environmental Sciences Faculty Research

Smallholder farmers in western Kenya who plant maize (Zea mays L.) intercropped with beans (Phaseolus vulgaris L.) face many challenges associated with nutrient-poor soils and weather-related crop failures. In regions where temperatures are favorable, crops are grown twice per year during long and short rainy seasons and in other regions, once per year during one long growing season. Growing crops two times per year necessitates frequent land preparation using inversion-type tillage. Little is known about the impact of current tillage-intensive crop management on annual soil organic matter (SOM) recovery. The aim of this study was to assess changes to soil …

Modeling Mussel Mortality: Investigating The Importance Of Swash And The Potential Implications Of Changing Wave Environments, Shadow Leigh Gulledge

Theses and Dissertations

Rising sea level and increases in temperature are causing biogeographic shifts in intertidal zones and can also lead to shifts in the local vertical zonation of organisms due to changes in body temperature during aerial exposure during low tide. Swash is an important determinant of aerial body temperatures, and vulnerability of intertidal zones to changes in climate could potentially depend on how much and how often animals are cooled by waves. While wave heights (and thus swash) are generally expected to increase with climate change, anthropogenic physical structures, such as breakwaters and wave energy converters, can decrease wave height and …

Zinc And Copper Isotopic Fractionation During Planetary Differentiation, Heng Chen

Arts & Sciences Graduate Student Theses and Dissertations

Zinc and copper are two important transition metal elements that are widely involved in every stage of planetary formation and differentiation. Their isotopic ratios are robust tracers used to understand the origin of the Solar System, planetary formation and differentiation processes. In this thesis, I focus on their isotopic behaviors during magmatic processes. I report the Zn isotopic compositions of representative igneous rocks to determine potential isotopic fractionations associated with magmatic processes, and to estimate the bulk silicate Earth value. I report isotopic compositions of various groups of iron meteorites (samples of which represent the core of asteroids) and discuss …

Temporal Constraints On Holocene Initiation And Termination Of Mound Development At An Episodic Gas Hydrate And Cold Seep System, Woolsey Mound, Northern Gulf Of Mexico, Nathan Robinson

Theses and Dissertations

Woolsey Mound is a thermogenic gas hydrate and cold seep system in the deepwater (900m) Gulf of Mexico. A set of sub-bottom seismic profiles acquired at MC-118 Woolsey Mound provide decimeter-scale vertical resolution of the upper ~50m of the subsurface throughout the lease block. Integration of these data with radiocarbon, lithostratigraphic, and biostratigraphic data from shallow gravity cores provides the basis for detailed interpretation of the mound evolution within the last 12,000 years. Uniform sedimentation during the Last Glacial Maximum and following changes in sediment distribution over MC-118 suggests modern mound activity did not begin until at least ~12ka. Development …

Climate-Induced Changes In The Germination Phenology Of Boechera Stricta, Samuel Johnson

Theses and Dissertations

Climate change is having demonstrable, worldwide impacts on ecological systems in ways that have modified aspects of organism behavior. Plant phenologies have responded to warmer temperatures in a variety of ways that may have implications for long-term species survival. How germination phenology changes in response to warmer climate is a largely unexplored question yet the ability of a plant to advance or delay germination in unfavorable conditions is critical for survival. Knowing the relative success and timing of germination under different climate regimes is important in understanding whether species can keep pace with the rate of climate change via migration …

The Late Ordovician Biogeochemical Carbon Cycle, John Garrecht Metzger

Arts & Sciences Graduate Student Theses and Dissertations

The isotopic composition of the carbonate carbon (δ13Ccarb) is one of the best tools for understanding the biogeochemical carbon cycle through Earth history. δ13Ccarb is also used to chemostratigraphically correlate coeval strata. This dissertation has three main foci that all utilize δ13Ccarb as the common data type. The geologic interval investigated was the Late Ordovician (458-444 Ma) with emphasis on the Guttenberg δ13C excursion, a globally correlated, positive ~3 / event that is ~400 kyr in duration. In the first topic we evaluate post-depositional alteration (i.e., diagenesis) of δ13Ccarb signals. In the second topic, we make reconstructions of sea level …

Structural And Hydrological Controls On The Development Of A River Cave In Marble (Tapagem Cave - Se Brazil), William Sallun Filho, Bruna Medeiros Cordeiro, Ivo Karmann

International Journal of Speleology

Tapagem Cave (or Devil’s Cave) is a river cave developed in the dolomite marble karst of the Serra do André Lopes (State of São Paulo, southeastern Brazil). Although this region is a plateau with significant variation in elevation and a humid subtropical climate, the cave is an anomalous feature in the André Lopes karst because there are few other caves. The marble, which is in a synclinal structure with subjacent phyllites, is a karst aquifer perched above the regional base level (Ribeira River) and has little allogenic recharge. The cave developed on a secondary anticline on the northwest flank of …

Soil Respiration Patterns And Controls In Limestone Cedar Glades, Jennifer Cartwright, Dafeng Hui

Biology Faculty Research

Aims

Drivers of soil respiration (R s ) in rock outcrop ecosystems remain poorly understood. We investigated these drivers in limestone cedar glades, known for their concentrations of endemic plant species and for seasonal hydrologic extremes (xeric and saturated conditions), and compared our findings to those in temperate grasslands and semi-arid ecosystems.

Methods

We measured R s , soil temperature (T s ), volumetric soil water content (SWC), soil organic matter (SOM), soil depth, and vegetation cover monthly over 16 mo and analyzed effects of these variables on R s .

Results

Seasonally, R s primarily tracked T …

Urban Garden Survival, Phoebe Ferguson, Rachel Martin

Biology Presentations

Urban gardens are community led plots designated for agricultural purposes in residential and urban areas. Greenville County has seen a recent growth in urban gardens with the assistance of non-profit groups like Gardening for Good. The current total in Greenville County stands at 79 with new gardens added every year. While the growth is encouraging, some gardens have failed. This study uses GIS to explore the social and ecological factors that correlate with urban garden survival in an effort to provide garden managers with information that will help them develop gardens that thrive and persist.

Optical Characterization And Distribution Of Chromophoric Dissolved Organic Matter (Cdom) In Soil Porewater From A Salt Marsh Ecosystem, Catherine D. Clark, Paige Aiona, Jason K. Keller, Warren J. De Bruyn

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To characterize chromophoric dissolved organic matter (CDOM) in marsh porewaters and its contribution as a carbon source, optical properties (absorbance, fluorescence indices, 3-dimensional excitation-emission matrices [EEMs]) of soil porewater and surface water were measured in a southern Californian salt marsh. Absorption coefficients and fluorescence intensities were higher in porewater than in overlying surface waters, consistent with higher CDOM concentration at depth. Humic-type peaks A and C were observed in EEMs in all samples, and peak M was observed in surface waters and shallow porewater to -5 cm depth. Fluorescence:absorbance (flu:abs) ratios and spectral slopes (S) decreased across the surface interface, …

Determination Of Seasonal Crop Coefficients For The Cal Poly Campus Vineyard Using The “Paso Panel”, Daniel L. Vyenielo

Wine and Viticulture

Seasonal Crop Coefficients were determined using the "Paso Panel" during the summer of 2014 at the Cal Poly Trestle Vineyard in the Pinot and Syrah blocks.

Ecosystem Regime Change Inferred From The Distribution Of Trace Metals In Lake Erie Sediments, Fasong Yuan, Richard Depew, Cheryl Soltis-Muth

Biological, Geological, and Environmental Faculty Publications

Many freshwater and coastal marine ecosystems across the world may have undergone an ecosystem regime change due to a combination of rising anthropogenic disturbances and regional climate change. Such a change in aquatic ecosystems is commonly seen as shifts in algal species. But considerably less detail is known about the eutrophication history in terms of changes in algal productivity, particularly for a large lake with a great deal of spatial variability. Here we present an analysis of trace metals (Cu, Ni, Cd, and Pb) on a sediment core recovered from Lake Erie, off the Vermilion coast of northern Ohio, USA, …

Trophic Dynamic Interactions In A Temperate Karst River, Elizabeth Malloy

Masters Theses & Specialist Projects

Surface streams in karst landscapes are often characterized by high nutrient levels due to incomplete filtration through series of innumerable, below-ground conduits. Seasonal growth of the filamentous alga, Cladophora, is typically associated with nutrient-rich waters. This research compared macroinvertebrate food web structure between riverine reaches with contrasting underlying karst topography, nutrient levels, and Cladophora cover during summer 2012 and autumn 2013. Recent work in these reaches found a high correlation between Cladophora cover and nutrient content, particularly nitrate. Four questions were addressed during this study: 1. Do longitudinal trends in algal and consumer δ13C values relate to decreased DIC availability …

Development Of A Hydrologic Model For An Urban Headwater Stream: The Influence Of Pervious Surface Properties On Runoff Dynamics, Dawn A. Farver

Graduate Theses and Dissertations

A hydrologic model was developed for the Mullins Creek (MC) catchment located on the University of Arkansas campus in Fayetteville, Arkansas. The MC catchment is a small, dynamic urban stream system with a range of land use/land cover (LULC), an extensive and well-developed stormwater drainage network, and extensive urbanization (over 90% developed, and almost 50% impervious surface area (ISA)). Selected datasets provided information on the stormwater drainage network, the physical attributes of the catchment and receiving waterway (i.e. drainage area, slope, etc.), infiltration potential of soil map units, LULC, and percent ISA. These datasets were analyzed to provide input parameters …

Structure, Aboveground Biomass, And Soil Characterization Of Avicennia Marina In Eastern Mangrove Lagoon National Park, Abu Dhabi, Tareefa Alsumaiti

Graduate Theses and Dissertations

Mangrove forests are national treasures of the United Arab Emirates (UAE) and other arid countries with limited forested areas. Mangroves form a crucial part of the coastal ecosystem and provide numerous benefits to society, economy, and especially the environment. Mangrove trees, specifically Avicennia marina, are studied in their native habitat in order to characterize their population structure, aboveground biomass, and soil properties. This study focused on Eastern Mangrove Lagoon National Park in Abu Dhabi, which was the first mangrove protected area to be designated in UAE. In situ measurements were collected to estimate Avicennia marina status, mortality rate (%), …

Core Handling And Processing For The Wais Divide Ice-Core Project, Joseph Souney Jr, Mark S. Twickler, Geoffrey M. Hargreaves, Brian M. Bencivengo, Matthew J. Kippenhan, Jay A. Johnson, Eric D. Cravens, Peter D. Neff, Richard M. Nunn, Anais J. Orsi, Trevor J. Popp, John F. Rhoades, Bruce H. Vaughn, Donald E. Voigt, Gifford J. Wong, Kendrick C. Taylor

All Materials

On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are …

A Remote Sensing Based Early Warning System For Algal Blooms In Kuwait Bay And Coastal Waters, Cameron Manche

Masters Theses

The Kuwait Bay and its coastal waters are being threatened by a perpetual hazard, the proliferation of harmful algal blooms (HABS). The frequency of HAB occurrences is a growing problem that is only reported subsequent to the onset of a HAB event. Little effort has been invested in investigating the spatial and temporal distribution of these events in Kuwait Bay and even less is known about their controlling factors. All previous studies within the Kuwait Bay have focused either on measuring nutrient availability and the biodiversity of algal species.

The overall study objective is four-fold: (1) to monitor the spatial …

Geochemical Tracers Of Holocene Environmental Change Along The East Antarctic Margin, Natalie Romanoff

Theses, Dissertations and Culminating Projects

Marine sediment geochemistry targeting both organic and inorganic compounds can be used for the reconstruction of paleoenvironmental conditions. Part 1 of this study was a qualitative organic geochemical analysis implemented on sediment cores from the Antarctic Peninsula (AP) and East Antarctic Margin (EAM). Intervals of organic or diatomaceous rich sediment were analyzed by Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS) with the goal of identifying soft-bodied algae responsible for elevated wt% carbon levels in horizons where diatoms are absent, and identifying the presence of methanogens in basins where cold seeps are likely to be present. The identification of biomarkers in Antarctic sediment was …