When Hurricane Ivan took intention on the Alabama coast in 2004, the highly effective storm triggered an underwater mudslide that collapsed a Taylor Vitality oil platform, setting off the longest-running oil spill in U.S. historical past.
Now, a crew of LSU researchers is learning how hurricanes and different occasions result in mudslides within the Gulf of Mexico, in a bid to raised perceive the results of mudslides on offshore vitality manufacturing of every kind.
To gauge the place and when mudslides happen, the LSU crew will map the seabed round Louisiana’s “hen’s foot,” or the a part of the Mississippi River delta that splits into Southwest Go, South Go and Go a Loutre. Their work quantities to the primary complete map of the delta entrance in additional than 40 years, officers stated.
Taylor Vitality’s MC-20 Saratoga oil platform standing within the Gulf of Mexico earlier than Hurricane Ivan destroyed it in 2004.
Bankrolling the $3.8 million effort is the federal Bureau of Ocean Vitality Administration, or BOEM, which points leases of offshore house for typical and renewable vitality manufacturing. Different organizations concerned are the Water Institute of the Gulf, the Naval Analysis Laboratory, or the NRL, and the Nationwide Oceanic and Atmospheric Administration, to call just a few.
“The final main examine like this was within the Nineteen Seventies, and was additionally led by LSU,” stated Sam Bentley, the marine geologist who’s main the crew, in an announcement. “A lot has modified since then, from the seabed circumstances to the instruments used to map the seabed and the wants for offshore vitality infrastructure. The data gaps and doable liabilities are enormous.”
Bentley added in an interview that BOEM requested his crew to start laying the groundwork for such a examine roughly a decade in the past.
Underwater mudslides happen when unfastened sediment on an incline begins to slip down the incline suddenly resulting from waves or different shifts. When there are bigger waves, like from a storm or hurricane, bigger mudslides can type.
“Think about a kitchen board with pancake batter,” Bentley stated. “In order for you it to circulation down slope, down a low angle… you may jiggle [the kitchen board]. When the Mississippi River dumps sediment out of the mouth, mud piles up proper offshore. Generally, it piles up so steeply that it slides down of its personal accord.”
There are over 100 oil rigs sitting within the hen’s foot, Bentley stated, and all of them use pipelines that run by the seabed. When the mud flows down the seabed, even slowly, it will possibly depart oil piping uncovered that was meant to be embedded in sediment. And when a mudslide occurs, pipelines will be moved miles away from their supposed areas.
In 2004, a 100-foot-thick slab of mud was the reason for the Taylor vitality oil spill. It broke by a pipeline security valve the oil firm relied on to stop spills. Cleansing up the Taylor Vitality spill has value $353 million thus far to plug the leaking wells, with Taylor investing an extra $432.5 million in a belief in case the continuing clean-up proves costlier. This does not embrace one other $43 million the corporate should pay in civil penalties and different federal-led clean-up endeavors.
A U.S. Coast Guard boat floats close to an oily sheen over the toppled Taylor Vitality platform website within the Gulf of Mexico.
Bentley hopes his crew’s analysis may also help vitality corporations construct offshore tasks in a safer means. Researchers plan to outfit their gear with monitoring capabilities in order that slower, smaller adjustments within the seabed’s geology can even be proven, adjustments previous surveys of the hen’s foot have missed.
“Previously, many surveys have been achieved both earlier than or after landslides, however not throughout landslides, which regularly occur when there are hurricanes and river floods,” stated Kehui Xu, the LSU Coastal Research Institute director and a professor in LSU’s Division of Oceanography & Coastal Science. “Whereas common sensors deployed earlier than such occasions will be displaced, buried or broken, we will likely be working with the NRL to check and deploy some rugged and new sensors that may ‘journey with’ landslides.”
Researchers can even depend on a shipwreck to trace when and the way mud has slid within the hen’s foot over time. The SS Virginia is an oil tanker from World Conflict II that was sunk by a German U-boat in 1942, an occasion that killed 27 crew members. The shipwreck is among the solely massive landmarks within the hen’s foot that may present the seabed’s historical past of motion, researchers stated.
“Shipwrecks, such because the SS Virginia, and what they’ll inform us concerning the frequency and trajectory of those mudflow occasions present essential info for BOEM’s decision-making because it pertains to oil and fuel growth on the Mississippi River Delta Entrance,” stated Melanie Damour, a marine archaeologist with BOEM.