Evaluation of Possible Inputs of Oil From the Deepwater Horizon Spill to the Loop Current and Associated Eddies in the Gulf of Mexico

Author(s):  
Terry L. Wade ◽  
Stephen T. Sweet ◽  
John N. Walpert ◽  
José L. Sericano ◽  
James J. Singer ◽  
...  
Shore & Beach ◽  
2020 ◽  
pp. 65-71
Author(s):  
Whitney Thompson ◽  
Christopher Paul ◽  
John Darnall

Coastal Louisiana received significant funds tied to BP penalties as a result of the Deepwater Horizon incident. As it is widely considered that the State of Louisiana sustained most of the damage due to this incident, there has been a firm push to waste no time in implementing habitat restoration projects. Sustaining the land on the coast of Louisiana is vital to our nation’s economy, as several of the nation’s largest ports are located on the Gulf coast in Louisiana. In addition, the ecosystems making up the Louisiana coast are important to sustain some of the largest and most valuable fisheries in the nation. Funded by BP Phase 3 Early Restoration, the goals of the Natural Resource Damage Assessment (NRDA) Outer Coast Restoration Project are to restore beach, dune, and marsh habitats to help compensate spill-related injuries to habitats and species, specifically brown pelicans, terns, skimmers, and gulls. Four island components in Louisiana were funded under this project; Shell Island Barrier Restoration, Chenier Ronquille Barrier Island Restoration, Caillou Lake Headlands Barrier Island Restoration, and North Breton Island Restoration (https://www. gulfspillrestoration.noaa.gov/louisiana-outer-coast-restoration, NOAA 2018). Shell Island and Chenier Ronquille are critical pieces of barrier shoreline within the Barataria Basin in Plaquemines Parish, Louisiana. These large-scale restoration projects were completed in the years following the Deepwater Horizon incident, creating new habitat and reinforcing Louisiana’s Gulf of Mexico shoreline. The Louisiana Coastal Protection and Restoration Authority (CPRA) finished construction of the Shell Island NRDA Restoration Project in 2017, which restored two barrier islands in Plaquemines Parish utilizing sand hydraulically dredged from the Mississippi River and pumped via pipeline over 20 miles over levees and through towns, marinas, and marshes to the coastline. The National Marine Fisheries Service (NMFS) also completed the Plaquemines Parish barrier island restoration at Chenier Ronquille in 2017 utilizing nearshore Gulf of Mexico sediment, restoring wetland, coastal, and nearshore habitat in the Barataria Basin. A design and construction overview is provided herein.


2010 ◽  
Vol 60 (5) ◽  
pp. 1075-1084 ◽  
Author(s):  
Yuehua Lin ◽  
Richard J. Greatbatch ◽  
Jinyu Sheng

2012 ◽  
Vol 109 (50) ◽  
pp. 20303-20308 ◽  
Author(s):  
H. K. White ◽  
P.-Y. Hsing ◽  
W. Cho ◽  
T. M. Shank ◽  
E. E. Cordes ◽  
...  

Author(s):  
T. Kokkinis ◽  
R. E. Sandstro¨m ◽  
H. T. Jones ◽  
H. M. Thompson ◽  
W. L. Greiner

A number of spars are being installed in deepwater areas in the Gulf of Mexico (GoM), which are subject to loop / eddy current conditions and must be designed for Vortex-Induced Motion (VIM). This paper shows how recent advances in VIM prediction enabled an efficient and effective mooring design solution for the existing Genesis classic spar, which is installed in Green Canyon Block 205 in the GOM. The solution may also be applicable to new spar designs. During the Gulf of Mexico Millennium Eddy Current event in April 2001, the Genesis spar platform underwent vortex induced motions (VIM) which were greater than anticipated during the design of the mooring & riser systems. Analysis showed that if such large motions were to occur in higher currents in the range of the 100-year event, they could cause significant fatigue damage, and could lead to peak tensions in excess of design allowables. After a comprehensive evaluation of potential solutions, Stepped Line Tensioning (SLT) was determined to be the best approach for restoring the platform’s original mooring capacity on technical, cost and schedule grounds. SLT did not require extensive redesign of the existing mooring system of the spar. Furthermore, SLT provided a means to improve mooring integrity on an interim basis, while completing details for permanent implementation. Under SLT, the pretensions of the mooring lines are adjusted based on forecast currents in order to keep the platform below the VIM lock-in threshold at all times and for all eddy/loop current conditions up to and including the 100-year condition. High Reynolds number model tests conducted with a new test methodology were used to get a reliable prediction of the spar’s VIM response for this evaluation.


2013 ◽  
Vol 20 (1) ◽  
pp. 85-96 ◽  
Author(s):  
F. Andrade-Canto ◽  
J. Sheinbaum ◽  
L. Zavala Sansón

Abstract. Determining when and how a Loop Current eddy (LCE) in the Gulf of Mexico will finally separate is a difficult task, since several detachment re-attachment processes can occur during one of these events. Separation is usually defined based on snapshots of Eulerian fields such as sea surface height (SSH) but here we suggest that a Lagrangian view of the LCE separation process is more appropriate and objective. The basic idea is very simple: separation should be defined whenever water particles from the cyclonic side of the Loop Current move swiftly from the Yucatan Peninsula to the Florida Straits instead of penetrating into the NE Gulf of Mexico. The properties of backward-time finite time Lyapunov exponents (FTLE) computed from a numerical model of the Gulf of Mexico and Caribbean Sea are used to estimate the "skeleton" of flow and the structures involved in LCE detachment events. An Eulerian metric is defined, based on the slope of the strain direction of the instantaneous hyperbolic point of the Loop Current anticyclone that provides useful information to forecast final LCE detachments. We highlight cases in which an LCE separation metric based on SSH contours (Leben, 2005) suggests there is a separated LCE that later reattaches, whereas the slope method and FTLE structure indicate the eddy remains dynamically connected to the Loop Current during the process.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Elliott L. Hazen ◽  
Aaron B. Carlisle ◽  
Steven G. Wilson ◽  
James E. Ganong ◽  
Michael R. Castleton ◽  
...  

Ocean Science ◽  
2014 ◽  
Vol 10 (6) ◽  
pp. 947-965 ◽  
Author(s):  
Y. S. Androulidakis ◽  
V. H. Kourafalou ◽  
M. Le Hénaff

Abstract. The anticyclonic Loop Current Eddy (LCE) shedding events are strongly associated with the evolution of Loop Current Frontal Eddies (LCFEs) over the eastern Gulf of Mexico (GoM). A numerical simulation, in tandem with in situ measurements and satellite data, was used to investigate the Loop Current (LC) evolution and the surrounding LCFE formation, structure, growth and migration during the Eddy Ekman and Eddy Franklin shedding events in the summers of 2009 and 2010, respectively. During both events, northern GoM LCFEs appeared vertically coherent to at least 1500 m in temperature observations. They propagated towards the base of the LC, where, together with the migration of Campeche Bank (southwest GoM shelf) eddies from south of the LC, contributed to its "necking-down". Growth of Campeche Bank LCFEs involved in Eddy Franklin was partially attributed to Campeche Bank waters following upwelling events. Slope processes associated with such upwelling included offshore exports of high positive potential vorticity that may trigger cyclone formation and growth. The advection and growth of LCFEs, originating from the northern and southern GoM, and their interaction with the LC over the LCE detachment area favor shedding conditions and may contribute to the final separation of the LCE.


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