For a ship that sank 80 yrs in the past, the SS Virginia has traveled a good length: the oil tanker has moved far more than 10 kilometers due to the fact it was torpedoed by a German U-boat in 1942.
The shipwreck, situated off the coastline of Louisiana, is riding lobes of mud transferring above the seafloor. These mudflows arise simply because the Mississippi River is constantly dumping wide portions of sediments—more than 550 million metric tons each and every year—into the Gulf of Mexico, and earthquakes and storms often set some of that content going en masse. Mudflows sculpt the underwater landscape and supply nutrients to ecosystems, but they can also be damaging: in 2004 a mudflow triggered by potent waves from Hurricane Ivan toppled an oil and gasoline system. “It in essence destroyed the platform and buried it,” states Melanie Damour, a maritime archaeologist at the Bureau of Ocean Power Management’s Gulf of Mexico Area business office. Oil has been leaking from the crippled structure ever given that, and ongoing cleanup initiatives have value hundreds of millions of dollars. The Gulf of Mexico hosts hundreds of oil and gas constructions, and Damour suggests that the threat of an function like this going on again is really real.
There is appropriately a have to have to improved recognize the actions of mudflows in the Gulf. But geophysical surveys that address large swathes of the seafloor are unusual, Damour notes. “The very last complete mapping exertion that seemed at the whole Mississippi River Delta Entrance took area in 1979,” she states.
This is exactly where the Virginia comes in. From onboard a study vessel, researchers can bounce sound waves off the shipwreck about 85 meters below the area to pinpoint its area. The more than 150-meter-extensive metallic hull stands out in stark contrast to the rest of the seafloor. “It’s crystal very clear what it is,” Damour says.
She and her colleagues identified the wreck has moved noticeably over time, according to success they presented in December at the American Geophysical Union’s Fall Meeting. A study other scientists carried out in 2006 and 2007—not lengthy immediately after hurricanes Katrina and Ivan—revealed that the shipwreck had moved southeast by roughly 400 meters given that it had previous been surveyed in 2004. A much more the latest survey, done in 2017, confirmed it had switched tack and headed southwest, albeit at a slower tempo. Total it has traveled much more than 10 kilometers from exactly where it originally sank, the group estimates. That quantity of movement is “surprising in the context of how significantly force is needed to shift a 500-foot-extended [more than 150-meter-long] metal-hulled shipwreck embedded in the seafloor—not just after or two times but potentially dozens of times,” Damour states.
This is the very first time a shipwreck has been utilized to trace mudflows, states Leila Hamdan, a marine ecologist at the College of Southern Mississippi, who was not concerned in the research. “I don’t feel that any person has place individuals two factors alongside one another prior to this get the job done,” she adds. “But it tends to make so significantly sense.”
By monitoring the route of the Virginia, scientists are getting a far better knowing of the advanced nature of mudflows. “We now know that a mudflow can swap route,” Damour claims. That expertise assists improved assess the threats posed by mudflows and their likely impacts on at-sea infrastructure, she provides.
The researchers prepare to study the Virginia once again this fall. They assume to find the wreck has sailed throughout the base nevertheless yet again, Damour says—particularly specified the modern passage of quite a few tropical storms and Hurricane Ida.