Remember the Deepwater Horizon BP Oil Disaster? Remember the underwater cameras that showed that never-ending plume of oil pouring into the Gulf of Mexico for week after week, month after month? BP and the rest of the oil industry would like you to forget that. Alas, they left a permanent calling card:
New research shows that the BP oil spill left an oily “bathtub ring” on the sea floor that’s about the size of Rhode Island. The study by UC Santa Barbara’s David Valentine, the chief scientist on the federal damage assessment research ships, estimates that about 10 million gallons of oil coagulated on the floor of the Gulf of Mexico around the damaged Deepwater Horizons oil rig. Valentine said the spill left other splotches containing even more oil. The rig blew on April 20, 2010, and spewed 172 million gallons of oil into the Gulf through the summer.
As most of us recall, a great deal of the oil washed ashore on Florida, Texas and Louisiana beaches. David Valentine has
spearheaded the effort to find out where all of the rest of the oil went:
He and his team explored hundreds of kilometers of the Gulf, finding “patterns in all those areas that pointed us right back to the Deepwater Horizon source.”
“At a small scale, it’s like a splatter: It landed in small drops, bigger drops, and there may even be some giant drops out there,” Valentine says. “It splattered on the seafloor in such a way that if you took five samples within a few feet of each other, you might see a hundredfold difference in the amount of oil between each other.”
The oil droplets, he and his team found, sank about a centimeter or two into the seabed. On deep sea coral in particular, they settled in “a very large area of very high concentration.”
The
location of approximately 2 million barrels of oil thought to be trapped in the deep ocean has been a mystery. The
study confirms that between 4-30 percent of that oil (or between 2 and 16% of the total amount of oil discharged due to the disaster) is found
within a 1250 square mile patch of sea floor, surrounding the Deepwater Horizon rig.
The fallout of oil created thin deposits that are most extensive to the southwest of the Macondo Well. The oil is concentrated in the top half-inch of the sea floor and is patchily distributed.
The investigation focused primarily on hopane, a nonreactive hydrocarbon that served as a proxy for the discharged oil.
The researchers analyzed the distribution of hopane in the northern Gulf of Mexico and found that it was concentrated in a thin layer at the sea floor within 25 miles of the ruptured well, clearly implicating Deepwater Horizon as the source.
The study's author David Valentine describes its findings as ”a smokingly clear signal, like a bulls-eye” that circles the well, its obvious source.
“The evidence is becoming clear that oily particles were raining down around these deep sea corals,” Valentine added, lending support to findings, hotly contested by BP, that they were damaged by the spill.
One unresolved question is why the oil sank to the ocean floor in the first place, and what caused its dispersal. Oil is generally not disposed to "sink." After the disaster we were treated to a panoply of fascinating theories suggesting that microbes in the water "ate" the oil, causing it to magically disappear. BP cited that theory in the very recent op-ed posted in
Politico, linked above. And indeed, microbes have developed the ability to consume oil coming from natural seepage from the Gulf floor. It is possible that microbes could have "weighed down" the oil, causing it to sink to the ocean floor where it is now.
However, that wouldn't necessarily account for the wide dispersal of the oil. But the two million gallons of toxic dispersants BP poured into the spill might. A possibility, suggested study by co-author Sarah Bagby, is that:
BP’s highly controversial use of dispersants to break up the oil in the spill’s immediate aftermath may have contributed to the problem. Critics see the cleanup method, which BP defends as standard, as part of the company’s attempt to make things look less bad than they are; some suggested, back in 2010, that such attempts would only serve to worsen the spill’s impact in the long-term.
If the dispersant made the oil drops smaller, Bagby explained in an email to Salon, it could account for the wide range of oil they discovered. But “the thing is, there’s no control condition,” she wrote. “We know how big the contamination footprint we observed is, and we know about how much oil has been found there. But is that the result of successful dispersant application (that is, the drops were smaller than they would have been otherwise, and that allowed them to spread this far), or of a failed dispersant application (that is, there wasn’t a substantial or lasting change to the drop size, so the drops settled out where they would have in any case)? That’s not something we’ve been able to address yet.”
BP's response to the study was--I kid you not--to assert that they
couldn't prove it was their oil:
"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," the company said in a statement to NBC News. "Instead of using rigorous chemical fingerprinting to identify the oil, the authors used a single compound that is also found in every natural oil seep in the Gulf of Mexico, causing them to find false positives all over the sea floor."
The crass level a corporation will go to defend its
gross negligence apparently knows no bounds.
