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Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson

LSU Master's Theses

Rivers and wetlands are a major source of terrestrial derived carbon for coastal ocean margins. Unfortunately, Louisiana’s wetlands are threatened by ongoing high rates of erosion, deterioration, and unprecedented rates of river water discharge that changes seasonally, leading to a net loss of terrestrial carbon into the northern Gulf of Mexico (nGOM). There exists a current lack of understanding about the distribution of dissolved inorganic carbon (DIC) and total alkalinity (TAlk) within the shallowest regions of the Louisiana shelf. Even less is known about how the transport of DIC alters seasonally with changes in river outflow and shelf currents. Quantifying …

Vegetation Prior To And During Onset Of East Antarctic Glaciation: High Resolution Palynological Insights From Sabrina Coast, East Antarctica, Meghan L. Duffy

LSU Master's Theses

The Aurora Subglacial Basin (ASB) contains an estimated 3.5 m of global sea-level equivalent ice volume and is primarily drained by the Totten Glacier system, which terminates at the Sabrina Coast, East Antarctica. Thinning and retreating of the Totten Glacier indicate that this region is highly susceptible to oceanographic and atmospheric warming. The paleoclimate reconstruction of these changes, conducted in the context of this MS thesis, will improve understanding of East Antarctic Ice Sheet (EAIS) dynamics in this sensitive system. A recent study used seismic and sediment core data to document a dynamic early evolution of the EAIS in the …

Constraining Prograde Metamorphic Paths In Archean High-Grade Garnet-Bearing Lithologies From The Eastern Beartooth Mountains, Montana, Usa, Larry Fisher Cliff-Tuttle Jr

LSU Master's Theses

Prograde metamorphic pressures and temperatures of Archean high-grade garnet-bearing lithologies from the eastern Beartooth Mountains of Montana provide an important constraint on the tectonometamorphic history of this terrane and the early Earth in general. A particularly useful means to approximate prograde metamorphic conditions is examining entrapment conditions of garnet mineral inclusions during garnet growth. Lithologies of the eastern Beartooth Mountains are well-suited to this approach because of the presence of abundant mineral inclusions within garnet porphyroblasts. Consequently, prograde metamorphic pressures and temperatures in the Beartooth Mountains, conditions that have only been broadly constrained previously, can be more accurately determined and …

Hydrodynamics And Sediment Dynamics In A Receiving Basin For Sediment Diversion: A Case Study In Barataria Bay, Louisiana, Usa, Guandong Li

LSU Master's Theses

Barataria Bay is a receiving basin of Mid-Barataria Sediment Diversion in Louisiana, USA. In this region the data of sediment transport and hydrodynamics are scarce but important for the design and planning of sediment diversion to be implemented in near future. Four-months bottom boundary layer observation was conducted to study winter and spring hydrodynamics and sediment dynamics in the bay. Hourly waves, tides, currents and bottom suspended sediment concentration were measured using multiple optical and acoustic sensors attached to two tripod platforms. High-temporal resolution data indicated that during winter, salinity at northern bay was mainly controlled by northerly wind during …

Effect Of Channelized And Unchannelized Lateral Outflow On Three-Dimensional Flow Structure And Sediment Transport Mechanisms In A River Delta, Mohammad Kifayath Chowdhury

LSU Master's Theses

Spatial and temporal patterns in three-dimensional flow structure have been linked to channel morphology and processes in many environments, including river meander bends, confluences-diffluences, and bedrock canyons. However, there is not yet an understanding of how channelized and gradual, distributed lateral outflows that are often prevalent in deltaic distributary systems influence three-dimensional flow structure and sediment transport mechanisms. This thesis presents an analysis of 3D flow structure data collected from Wax Lake Delta, a naturally developing river-dominated delta in the northern Gulf of Mexico. Three hydrographic surveys were conducted using boat-mounted acoustic Doppler current profiler (ADCP) at two sites: an …

Mass Spectrometric Calibration For Real -Time Hydrocarbon Detection, Makuachukwu Mbaegbu

LSU Master's Theses

Determining gas compositions from live well fluids on a drilling rig is critical for real time formation evaluation. However, development and utilization of a reliable mass spectrometric method to accurately characterize these live well fluids is always a challenging issue because of lack of a robust, quick and effectively selective instrument and method. The primary goal of this research is to understand reasons of such discrepancies in results between “good” spectra, and “poor” ones. The objectives are thus to identify the detection issues, calibrate and QA/QC the instruments, and analyze the results in lab settings. In this study, we used …

Reinterpreting The Tectonic Model Of The Southern Part Of The Taconic Orogeny Through A Provenance Study Of Late Ordovician Sandstones, Juan Carlos Guerrero

LSU Master's Theses

A provenance study of quartz arenites that stratigraphically are closely associated with major Ordovician K-bentonites has been conducted in order to further our understanding of the tectonic setting of eastern Laurentia during the Late Ordovician. Using laser ablation ICP-MS, detrital zircons separated from Ordovician sandstone samples in the southeastern Appalachian Mountains (Virginia to Alabama) were dated using U-Pb geochronology. Analytical results show three dominate age ranges for the zircons from these sandstones: ~440-490 Ma, ~900-1300 Ma, and ~1300-1500 Ma. In addition, some zircon ages grouped into older ranges of ~1600-1800 Ma, ~1800-1900 Ma, and ~2600-2800 Ma. Zircon ages from ~900-2800 …

Sandy Dredge Pit Sedimentation – Characteristics And Processes In Caminada Borrow Area, Ship Shoal, Louisiana Shelf, Usa, Zehao Xue

LSU Master's Theses

Mississippi River Deltaic Plain’s barrier islands are undergoing rapid disintegration due to high rates of subsidence and a deficit in coastal sediment supply. To mitigate for barrier island land loss, Louisiana has implemented a restoration program that supplements coastal sediment deficits by introducing sand from outside of the active coastal system. Ship Shoal is an inner-shelf submarine shoal with large amounts of restoration quality sand that was dredged in 2013-2016 for the Caminada Headland Restoration Project in central Louisiana, USA.

Vibracore samples (1.5 - 3.5 m deep) collected in 2017 and 2018 in Caminada Borrow Area revealed new silts and …

Multicomponent Model Of Crustal Stress At Cajon Pass, Southern California With Implications For Stress Field Heterogeneity, Elliott Conley Helgans

LSU Master's Theses

Earthquake processes in plate boundary settings are chiefly controlled by the in situ crustal stress field. Knowledge of the relative importance of various active processes acting on a fault system is necessary to understand the mechanics of faulting. This is of extreme importance to the Cajon Pass region of southern California, which may function as an earthquake gate, imposing control on large multifault ruptures. We model the in situ stress field at seismogenic depth in Cajon Pass by balancing the orientation of the modern stress field inferred from earthquake focal mechanisms against the superposition of the far field tectonic driving …

Sources And Chemical Stability Of Soil Organic Carbon Along A Salinity Gradient And A Chronosequence Of Created Brackish Marshes In Coastal Louisiana, Megan L. Kelsall

LSU Master's Theses

Tidal marshes have been recognized for providing a number of important ecological services including soil carbon sequestration. However, the loss of tidal marsh habitat due to climate change and anthropogenic stressors exposes previously stored soil organic carbon (SOC) to oxidation. The vulnerability of SOC to oxidation depends on its chemical stability and environmental conditions limiting decomposition. Labile organic carbon (LC), decomposes quickly unless abiotic conditions limit decomposition. Recalcitrant organic carbon (RC) decomposes slower and is stored for longer time periods. Predicting long-term storage of SOC is complicated by the potential for multiple SOC sources, differences in chemical stability, and variation …

Cogongrass (Imperata Cylindrica (L.) Beauv.) In Louisiana: Cause And Consequence, Lorissa A. Radunzel-Davis

LSU Master's Theses

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive species from East Asia, is found worldwide and is problematic in several countries. In the United States, it grows primarily in the Southeast, reducing biodiversity by growing in dense patches and potentially causing mortality and reducing value of native and planted pinelands due to a high burning temperature. Using Lee Memorial Forest, a Louisiana State University AgCenter property in Washington Parish as a study site, this thesis explores cogongrass in Louisiana with emphasis on soil microbes and soil legacy effects on native plant species. Cogongrass populations at Lee Memorial Forest were more …

Matrix Recharge In A Shrink-Swell Floodplain Forest Soil, Savannah R. Morales

LSU Master's Theses

Despite the global distribution of fine-grained Vertisols, the hydrology of these floodplain soils is still not well understood. Vertisols shrink and swell depending on soil moisture leading to a range of soil pore sizes, from large macropore cracks to smaller micropores, and consequently a range of hydraulic conductivities. Despite the plethora of research indicating the importance of both flooding and soil moisture in floodplain ecosystems, the specific role that flooding plays in soil moisture recharge has been less widely studied and remains of interest. Blue food dye and deuterated water were used as tracers to determine the role of the …

Rare Earth Geochemistry Of Apatitic Fossils From The Middle-Upper Ordovician Southern Margin Of Laurentia, Rafael Adrian Villanueva

LSU Master's Theses

Widespread deposition of phosphate and a transition from tropical to cool water carbonates is seen throughout Middle-Upper Ordovician Nashville Dome area spanning the M4/M5 sequence boundary. Hypotheses explaining the onset of these lithologic changes have included the onset of glaciation, drawdown of CO₂ related to the Guttenburg Isotope Carbon Excursion (GICE), and siliciclastic weathering, yet none of these studies have provided definitive evidence that shows any of these are the sole factor driving paleoenvironmental changes across the M4/M5 boundary. In order to test whether rapid subsidence along the southeastern margin of Laurentia may have caused an influx of phosphate …

Spatiotemporal Variation Of Benthic Silica Fluxes In The Ngom Shelf, Byron Ebner

LSU Master's Theses

Dissolved silica (DSi), plays an important role in regulating primary productivity of silicifying organisms, such as diatoms which precipitate hard parts composed of biogenic silica (bSi) in coastal and shelf ecosystems fed by major rivers. In the Northern Gulf of Mexico (NGOM), loading of nitrogen and phosphorous have increased compared to a decline in DSi in the Mississippi River. Continued decreasing in DSi loading could lead to limited diatom growth and production or shifts in community composition, therefore, it is important understand the role of benthic fluxes in providing silica to the overlying water column as there are few regional …

Structure Beneath The Northern Los Angeles Basins From Teleseismic Receiver Functions, Guibao Liu

LSU Master's Theses

This thesis presents part of the work published in Liu et al. (2018).

The Los Angeles area is at high risk of seismic amplification due to its location on top of sedimentary basins. It is very important to obtain accurate information on the crustal structure, in particular, the basin structure of the northern basins, in order to estimate the resulting ground motion and earthquake hazards due to a large San Andreas fault earthquake. In the Liu et al. (2018) study, we image the crustal structure beneath the northern basins using a densely spaced, autonomous 3-component seismometer array in the urban …

Sediment Transport And Channel Morphology Of A Natural And A Leveed Alluvial River, Bo Wang

LSU Master's Theses

Alluvial rivers are shaped by interactions of flow and sediment transport. Their lower reaches to the world’s oceans are highly dynamic, often presenting engineering and management challenges. This thesis research aimed to investigate channel dynamics and sediment transport in a natural river and a highly engineered river in South Louisiana, in order to gain much-needed science information for helping develop sustainable practices in river engineering, sediment management, and coastal restoration and protection. Especially, the thesis research examined (1) riverbed deformation from bank to bank in the final 500-km reach of the Mississippi River, (2) bed material transport at the Mississippi-Atchafalaya …

Suspended Sediment Transport Revealed By Patterns In Turbidity And Electrical Conductivity Curves In Three Cave Systems In Missouri, Usa., Caroline M. Mierzejewski

LSU Master's Theses

In cave streams, the movement of sediment as suspended and bed loads are linked to the occurrence of precipitation events on the surface. During precipitation events, the discharge of the streams in the basin increases. As those surface streams flow into cave streams via sinkholes or fissures, the discharge in cave streams increase. In addition to changes in discharge, the response of the surface and cave streams to precipitation include changes in turbidity and electrical conductivity of the stream water.

Changes in turbidity (Tu), electrical conductivity (EC), and discharge (Q) of water in the cave stream can be used to …

Exploring Geochemical Proxies For Identifying Cryptic Sequence Boundaries In The Geologic Past Using Modern Bahamian Analogues, Evan B. Magette

LSU Master's Theses

Previous studies of carbonate diagenesis have suggested that bulk Sr concentrations and inorganic δ¹³C values may be a useful proxy for identifying cryptic sequence boundaries in meteorically altered limestones due to geochemical processes associated with carbonate mineral stabilization in cement precipitation in the meteoric diagenetic environment. However, it is possible that natural geochemical variation in sediments may produce geochemical shift which could be misinterpreted as a cryptic sequence boundary. To test this, the Two Pines roadcut containing a previously identified protosol on Eleuthera, Bahamas, which has been affected by vadose meteoric diagenesis was sampled for bulk geochemical analysis. …

Reflector Dip Trends In Seismic Sh-Wave Imaging Of A Modern Lower Mississippi River Point Bar, Adam Gostic

LSU Master's Theses

Various studies of ancient point bars have noted that a relationship can be observed between the dip angle and grain size of point bar lateral accretion deposits, with the most mud-rich deposits tending to exhibit the greatest dip. No analysis and only cursory explanations for this relationship have been provided. Additionally, buried mid-channel bars are absent from typical models of point bar architecture.

We successfully image the architecture of late-stage point bar deposits with a near surface 2D seismic SH-wave reflection survey and generate an SH-wave velocity model of the subsurface in the study area in order to interpret the …

An Evaluation Of Modified Bed Load Sediment Transport Equations For Enhanced Sediment Transport Quantification In Steep Mountain Streams – Case Study Little Fountain Creek, Colorado Springs, Co., James Emerson Smith Iv

LSU Master's Theses

In mountainous regions, extreme floods occur every year, placing societies and infrastructures at risk. Communities rely on local, state, and federal agencies to emplace flood structures, perform flood risk assessments, and simulate catastrophic events. While, our ability to quantify and predict the movement of sediment in streams with low gradients is well developed (Bathurst, 1987), our ability to quantify and predict the movement of sediment along steep mountain streams (SMS) has not been developed to a similar degree (Yager, 2012; Schneider, 2016). To most effectively manage mountainous watersheds and understand the risk associated with flood events, scientists must better understand …

Analysis Of Fluvial Scroll Bar Development With Surface Wave Inversion: False River, Louisiana, Blake Odom

LSU Master's Theses

The development of ridge-and-swale scroll bar topography of meandering river point bars is not well understood. We hypothesize that scroll bars formed during lateral accretion by the landward migration of transverse bars. To explore this, we relate the scroll bar topography to the internal sedimentary structure. We acquire, invert, and interpolate three pseudo-2D shear wave velocity profiles in two regions of the False River point bar, a Mississippi river oxbow lake in Pointe Coupee Parish Louisiana. Prior studies provide electrical conductivity well logs and cores as well as SH seismic reflection images along the same seismic surveys. LiDAR elevation data …

New Borehole Breakout Derived Stress Constraints And Their Implications For Stress Heterogeneity Near High Risk Fault Systems In The Santa Barbara Channel, Southern California, Edward Harris Pritchard

LSU Master's Theses

The Santa Barbara Channel represents the offshore portion of the Ventura Basin in Southern California. Ongoing transpression related to a regional left step in the San Andreas Fault has led to the formation of E-W trending en-echelon fault systems, with both north and south dips, which accommodate varying rates of localized shortening across the basin. Recent studies have suggested that faults within the northern region of the channel could be capable of a multisegment rupture and producing a M_w 7.7–8.1 tsunamigenic earthquake. However, dynamic rupture models producing these results have not accounted for stress heterogeneity, which is …

A Regional Survey Of River-Plume Sedimentation On The Mississippi River Delta Front, Andrew J. Courtois

LSU Master's Theses

Many studies of the Mississippi River Delta (MRD) have shown historic declines in sediment load over the last few decades. Recent studies also reported that ~50% of the suspended load during floods is sequestered within the delta. While the impact of declining sediment load on wetland loss is relatively well documented, submarine sedimentary processes on the delta front during this recent period of are understudied. To better understand modern sediment dispersal and deposition across the Mississippi River Delta Front, 31 multicores were collected in June 2017 from locations extending offshore from the main river outlets in water depths of 25-280 …

The Sedimentology And Origins Of A Giant Mass Transport Complex: The Nataraja Slide, Arabian Sea, Sarah Dailey

LSU Master's Theses

A giant mass transport complex (MTC) was recently discovered in the eastern Arabian Sea exceeding in volume all but one other known complex on passive margins worldwide. The complex, named the Nataraja Slide, was drilled by IODP Expedition 355 in two locations where it is ~300 m (Site U1456) and ~200 m thick (Site U1457). The top is defined by the presence of both reworked microfossil assemblages and deformation structures, such as folding and faulting. The deposit consists of two main phases of mass wasting, each which consists of smaller pulses, with generally fining upward cycles, all emplaced just prior …

Effects Of Natural And Anthropogenic Forcing On Marsh Channel Evolution, Jeremiah Robinson

LSU Master's Theses

Wetlands have many ecological and physical properties that are essential for coastal communities. These ecosystems sustain local economies, provide essential habitats, are a source of numerous ecological and biological services, and protect coastal populations from storms. Of the many wetland types, salt marshes are among the most vulnerable to environmental changes. Salt marshes quickly respond to natural and human-driven perturbations and their high rate of loss in the last century is cause for concern.

In this project the rate of marsh loss driven by channel widening was measured through a comparative analysis of modern high resolution images and historic aerial …

Groundwater And Thermal Legacy Of A Large Paleolake In Taylor Valley, East Antarctica As Evidenced By Airborne Electromagnetic And Sedimentological Techniques, Krista Falcon Myers

LSU Master's Theses

During the Last Glacial Maximum, grounded ice in the Ross Sea extended into the otherwise ice-free McMurdo Dry Valleys, creating a series of large ice dammed paleolakes. Grounded ice within the mouth of Taylor Valley allowed for lake levels to reach elevations not possible at modern day and formed what is known as Glacial Lake Washburn (GLW). GLW extended from the eastern portion of Taylor Valley roughly 20 km west to a level ~300 m higher than modern day Lake Fryxell. The formation and existence of GLW has been debated, though previous studies correlate the timing of GLW with early …

Predicting River Stage Using Recurrent Neural Networks, Eric Rohli

LSU Master's Theses

River stage prediction is an important problem in the water transportation industry. Accurate river stage predictions provide crucial information to barge and tow boat operators, port terminal captains, and lock management officials. Shallow river levels caused by prolonged drought impact the loading capacity of barges and tow boats. High river levels caused by excessive rainfall or snowmelt allow for greater tow capacities but make downstream transportation and lock management risky. Current academic river height prediction systems utilize either time series statistical analysis or machine learning algorithms to forecast future river heights, but systems that combine these two areas often limit …

Spatial Trends And Variability Of Marsh Accretion Rates In Barataria Basin, Louisiana, Usa Using 210pb And 137cs Radiochemistry, Samuel Bryant Shrull

LSU Master's Theses

Coastal Louisiana is presently experiencing large amounts of coastal land loss with estimated rates exceeding 50 km² lost per year. In an attempt to mitigate or reverse land loss, billions of dollars are earmarked for restoration projects that promote land reclamation, habitat stabilization, and defending against saline intrusion. This study was performed in an effort to better understand spatial trends of accretion rates in Barataria Basin in coastal Louisiana. Data for this project came from twenty-five shallow cores extracted over a broad span of the entire basin, from freshwater to saline environments. Cores were processed for ¹³⁷Cs and …

Glyphosate In Soils: Retention, Transport, And Effect Of Phosphate, Joshua Padilla

LSU Master's Theses

Glyphosate [N-(phosphonomethyl) glycine)] (GPS) is currently the most commonly used herbicide worldwide, and is generally considered as immobile in soils. However, numerous reports of the environmental occurrence of the herbicide coupled with recent evidence of human toxicity require further investigation as to the behavior of GPS in the soil environment. The objectives of this study were to quantify GPS sorption and mobility in two Louisiana agricultural soils with varying physiochemical properties; Commerce silt loam and Sharkey clay. Results of batch sorption studies indicated a high affinity of both soils for solvated GPS, with 24-hour Freundlich partitioning coefficients of 158 and …

Joint Geodetic And Seismic Analysis Of Englacial And Subglacial Hydraulic Effects On Surface Crevassing Near A Seasonal, Glacier-Dammed Lake On Gornergletscher, Switzerland, Louis Stephen Garcia

LSU Master's Theses

Glacial outburst floods are difficult to predict and threaten human life. These events are characterized by rapid draining of glacier-dammed lakes via the sub/englacial hydraulic network to the proglacial stream. The glacier-dammed lake on Gornergletscher in Switzerland, which fills and drains each summer, provides an opportunity to study this hazard. For three drainages (2004, 2006, and 2007), icequakes (IQ) are tracked as well as on-ice GPS movement. The seasonal seismic networks had 8 – 24 three-component stations and apertures of about 300 – 400 m on the glacier surface. The seasonal GPS arrays contained 4 – 8 GPS antennae on …