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Oceanography and Atmospheric Sciences and Meteorology

Louisiana State University

2017

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Dinoflagellate Cysts Track Eutrophication In The Northern Gulf Of Mexico, Andrea M. Price, Melissa M. Baustian, R. Eugene Turner, Nancy N. Rabalais, Gail L. Chmura Dec 2017

Dinoflagellate Cysts Track Eutrophication In The Northern Gulf Of Mexico, Andrea M. Price, Melissa M. Baustian, R. Eugene Turner, Nancy N. Rabalais, Gail L. Chmura

Faculty Publications

We examined organic-walled dinoflagellate cysts from one 210Pb-dated sediment core and 39 surface sediment samples from the northern Gulf of Mexico to determine the relationship between nutrient enrichment and cyst assemblages in this region characterized by oxygen deficiency. The core spans from 1962 to 1997 and its sampling location is directly influenced by the Mississippi River plume. Surface sediments were collected in 2006, 2007, 2008, and 2014 and represent approximately 1 to 4 years of accumulation. A total of 57 cyst taxa were recorded, and four heterotrophic taxa in particular were found to increase in the top section (1986–1997) of …

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How Dredge Pits Evolve Over Time: A Look At Their Geomorphologic Evolution And Infilling Processes, Patrick Robichaux Nov 2017

How Dredge Pits Evolve Over Time: A Look At Their Geomorphologic Evolution And Infilling Processes, Patrick Robichaux

LSU Master's Theses

As coastal environments become more susceptible to land loss through accelerating sea level rise and subsidence, new restoration methods harnessing borrowed sediment are more valuable than ever. Mud-capped dredge pits (MCDPs) are a relatively new source of restoration-quality sediment that has only recently been utilized for beach and barrier island restorations in Louisiana. Because MCDPs have been in use for less than two decades in only a handful sites, little is understood about their evolution over decadal timescales. To improve our understanding of MCDPs after they are dredged, we have conducted a suite of geophysical surveys including bathymetry, sidescan sonar, …

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Effects Of Increased Sedimentation On Carbon Accumulation Of Salt Marsh Benthic Biofilms, Abbey Hotard Apr 2017

Effects Of Increased Sedimentation On Carbon Accumulation Of Salt Marsh Benthic Biofilms, Abbey Hotard

Honors Theses

No abstract provided.

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Influence Of Nutrient Availability And Sediment Supply On Productivity Of Spartina Patens, Shannon Matzke Apr 2017

Influence Of Nutrient Availability And Sediment Supply On Productivity Of Spartina Patens, Shannon Matzke

Honors Theses

No abstract provided.

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Sediment Transport And Slope Stability In The Northern Gulf Of Mexico, Jeffrey Blake Obelcz Jan 2017

Sediment Transport And Slope Stability In The Northern Gulf Of Mexico, Jeffrey Blake Obelcz

LSU Doctoral Dissertations

Sediment transport and slope stability are fundamental organizing agents of the geological record. These processes have been extensively studied along the northern margin of the Gulf of Mexico basin for both basic and applied purposes, but our knowledge of them is limited by the spatial and temporal sampling capabilities of traditional geologic oceanographic surveying tools such as coring, single-beam echosounders, and sidescan sonar. This dissertation seeks to update the state of knowledge regarding northern Gulf of Mexico sediment transport and slope stability from annual to millennial timescales, primarily using relatively high-resolution acoustic geophysical tools such as swath bathymetric echosounders and …

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Development And Application Of A Modis Inorganic Sediment Model During The 2016 Mississippi River Diversion In Lake Pontchartrain, Louisiana, Robert Lee Iles Iv Jan 2017

Development And Application Of A Modis Inorganic Sediment Model During The 2016 Mississippi River Diversion In Lake Pontchartrain, Louisiana, Robert Lee Iles Iv

LSU Master's Theses

The Bonnet Carré Spillway (BCS) is a Mississippi River diversion located on the southwestern coastline of Lake Pontchartrain in Louisiana. The discharge of potentially high amounts of Mississippi River nutrients and sediments during BCS diversion events has a noted ecological impact on the Lake Pontchartrain estuary. Projected river flooding prompted the opening of the Spillway from 10 January to 1 February 2016. MODIS satellite images were aerosol-corrected and then compared to in-situ measurements of inorganic sediment concentration (ISC) to derive a predictive algorithm for estimating ISC (in mg L^-1) in Lake Pontchartrain for satellite images in January and February. The …

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Differential Responses Of Soil Greenhouse Gas Production And Denitrification To Salinity Alterations Along A Wetland Salinity Gradient, Natalie Ceresnak Jan 2017

Differential Responses Of Soil Greenhouse Gas Production And Denitrification To Salinity Alterations Along A Wetland Salinity Gradient, Natalie Ceresnak

LSU Master's Theses

Coastal wetlands provide several valuable services, such as carbon (C) storage and nitrogen (N) removal. Although wetlands serve as net C sinks, wetland soils release greenhouse gases (GHGs) including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Wetlands can buffer the influx of nitrate (NO3-) by transforming it into gaseous N (N2O, N2) through denitrification microbial pathway. Salinity is a regulator of soil biogeochemistry and long- (e.g. saltwater intrusion) and short-term (e.g. storm surges, river diversions) exposures may affect soil GHG production and denitrification. In this study, soil GHG production and denitrification enzyme activity (DEA) rates were examined over …

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Modeling The Influence Of Energy And Climate Megatrends On Future Costs And Benefits Of Marsh Creation In The Mississippi Delta, Adrian R. H. Wiegman Jan 2017

Modeling The Influence Of Energy And Climate Megatrends On Future Costs And Benefits Of Marsh Creation In The Mississippi Delta, Adrian R. H. Wiegman

LSU Master's Theses

Over 25% of Mississippi delta (MRDP) wetlands were lost over the past century. There is currently a major effort to restore the MRDP focused on a 50-year time horizon, a period during which the energy system and climate will change dramatically. I modeled hydraulic dredging to sustain marsh from 2016-2066 and 2016-2100 under a range of scenarios for sea level rise, energy price, and management regimes. A marsh elevation model was calibrated to data from MRDP marshes. I developed a model to simulate dredging costs based on the price of crude oil and a project efficiency factor. Crude oil prices …

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