BP Oil Spill Left Rhode Island-Sized ‘Bathtub Ring’ on Ocean Floor

Study finds 10 million gallons of oil settled and coagulated on the floor of the Gulf near the Deepwater Horizon rig

By Anastasia Pantsios

The aftereffects of the April 20, 2010 explosion of the Deepwater Horizon in the Gulf of Mexico and the subsequent massive oil spill that gushed for three months go on and on and on—in the lives of Gulf-area residents and businesses, the legal offices of BP and its contractors, and in the courts.

A new study reveals that the disaster, which BP claims has been cleaned up and its impacts exaggerated, left a deposit of oil the size of Rhode Island on the ocean floor.

Deepwater Horizon Oil Spill Sitephoto by Green Fire Productions, on FlickrDay 30 of Deepwater Horizon oil spill in the Gulf of Mexico, 2010

Researchers from the University of California, Santa Barbara, University of California, Irvine, and Woods Hole (Massachusetts) Oceanographic Institution, led by geochemistry professor Dave Valentine from UCI, have published a study Fallout Plume of Submerged Oil from Deepwater Horizon. Analyzing sea sediment, they discovered what they referred to as a “bathtub ring,” saying it “formed from an oil-rich layer of water impinging laterally upon the continental slope (at a depth of 900 - 1,300 m) and a higher-flux ‘fallout plume’ where suspended oil particles sank to underlying sediment.”

“Following the sinking of the Deepwater Horizon in the Gulf of Mexico, an unprecedented quantity of oil irrupted into the ocean at a depth of 1.5 km,” the study said. “The novelty of this event makes the oil’s subsequent fate in the deep ocean difficult to predict. This work identifies a fallout plume of hydrocarbons from the Macondo Well contaminating the ocean floor over an area of 3,200 km. Our analysis suggests the oil initially was suspended in deep waters and then settled to the underlying sea floor. The spatial distribution of contamination implicates accelerated settling as an important fate for suspended oil, supports a patchwork mosaic model of oil deposition and frames ongoing attempts to determine the event’s impact on deep-ocean ecology.”

The official government estimates said that about 5 million barrels of oil were released into the ocean in what the study refers to as an “uncontrolled emission.”

“Among the pressing uncertainties surrounding this event is the fate of 2 million barrels of submerged oil thought to have been trapped in deep-ocean intrusion layers at depths of 1,000 - 1,300 m,” says the study.

In September, a federal court in Louisiana found that BP’s “willful misconduct” and “gross negligence” caused the spill. That finding could expose BP to fines of up to $18 billion, well beyond the 2012 $9.2 billion settlement it reached with mostly non-governmental plaintiffs.

BP issued a statement saying the study was overblown. “The authors failed to identify the source of the oil, leading them to grossly overstate the amount of residual Macondo oil on the sea floor and the geographic area in which it is found,” a BP spokesman told AP.

But Valentine and his team suggested the impact could be even more far-reaching. “We also suggest that a significant quantity of oil was deposited on the ocean floor outside this area but so far has evaded detection because of its heterogeneous spatial distribution,” the study said

You Make Our Work Possible

You Make Our Work Possible

We are standing at a pivotal moment in history, one in which education and advocacy around the climate emergency, public health, racial injustice, and economic inequity is imperative. At Earth Island Journal, we have doubled down on our commitment to uplifting stories that often go unheard, to centering the voices of frontline communities, and to always speak truth to power. We are nonprofit publication. We don’t have a paywall because our mission is to inform, educate and inspire action. Which is why we rely on readers like you for support. If you believe in the work we do, please consider making a tax-deductible year-end donation to our Green Journalism Fund.

Donate
Get the Journal in your inbox.
Sign up for our monthly newsletter.

The Latest

Turning the Tide on Large-Scale Hydropower

In Colombia, activists and scientists are boosting mega-dam resistance by showing the cumulative impacts of these destructive projects.

Daniel Henryk Rasolt

Interstate Water Wars are Heating Up Along with the Climate

States should put at least as much effort into reducing water use as they do into litigation, because there are no guaranteed winners in water lawsuits.

Robert Glennon

Sailing the Seas on Reused Plastic

A Swahili dhow known as the FlipFlopi shows that environmental innovation can coexist with tradition.

Tasha Goldberg

A Plea to Recognize the Legal Rights of the Maas River

I am advocating for a new legal status for the Maas in the hope that it becomes the first river in Europe with rights.

Jessica den Outer

Nearly 60 Million Americans Don’t Drink Their Tap Water, Research Suggests

Distrust and disuse of tap water is a public health problem.

Asher Rosinger

Uruguay’s Remarkable Shift to Renewables Offers a Blueprint for Energy Progress

However, the country’s ground-breaking energy initiatives now face a new challenge — a new governing party with more conservative views.

Andy McDonough