http://green.blogs.nytimes.com/2010/06/02/evidence-of-undersea-oil-plumes/?src=mv&ref=scienceJune 2, 2010, 8:19 am
Evidence of Undersea Oil Plumes
By JUSTIN GILLIS AND JOHN COLLINS RUDOLF
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At least three groups of researchers have now reported evidence for these undersea plumes of oil droplets. And the government, with little fanfare, posted a map this week showing the location of one plume, based on sampling done by a research ship operating under contract to BP. This would seem to be the most detailed confirmation yet by a federal agency that the undersea plumes are real.
The first group to report the subsea plumes was led by Samantha Joye of the University of Georgia and Vernon Asper of the University of Southern Mississippi, who found several apparent plumes at various ocean depths, generally stretching west or southwest from the gushing oil well.
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Their report was followed last week by an announcement from researchers at the University of South Florida who found a similar plume stretching northeast of the leaking well, toward Mobile Bay. And a group at Louisiana State University has also reported finding similar indications of oil hovering below the surface.
All of this work is preliminary, and neither the government nor university researchers have released definitive chemical analyses that would show what is in the deep water. Lately researchers have begun pulling up samples from within the plumes that display a visible sheen and the smell of hydrocarbons. But the main evidence still consists of unusual readings taken with instruments that are lowered by cable from ships to the ocean floor.
Passing through a suspected plume, these instruments show huge spikes in a reading known to oceanographers as C.D.O.M., for colored dissolved organic matter. Dissolved oil can produce such spikes. It is not the only substance capable of doing so, but the others are rarely found in quantity in the deep ocean.
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