Estimates run to 80,000 barrels a day
After the Deepwater Horizon offshore oil rig sunk in the Gulf of Mexico on 21 April 2010, estimates about the oil spill have altered as to the extent of the oil spilling from a fractured pipe a mile below the surface.
First estimates by BP, the oil company responsible for the rig were 1000 barrels of crude oil a day, or around 35000 gallons, but these figures were quickly superseded by the US Coast Guard who estimated the volume of oil escaping into the Gulf of Mexico was closer to 5000 barrels a day, or 210,000 gallons.
Photo courtesy of BP
However, from new footage of the leaking oil from remote cameras, marine scientists have been able to calculate how much oil is likely billowing out, and the calculations make unsettling reading; around 70000 barrels a day, or 2,450,000 gallons. To put that in context, that is the equivalent of an Exxon Valdez spill every four days.
Oil spill latest - velocimetry calculates spill
The scientist in charge of calculating the spill from underwater footage was Steve Werely, an associate professor at Purdue University, using a technique called particle image velocimetry, which puts the range of the oil spill from 56,000 to 84,000 barrels a day.
"You can see in the video lots of swirls and vortices pumping out of the end of the pipe, and I used a computer code to track those swirls and come up with the speed at which the oil is shooting out of the pipe [...] From there it is a very simple calculation to figure out what is the volume flow," Werely told the Guardian.
Photo courtesy of BP
Another scientist, Eugene Chiang, an associate professor at the University of California Berkeley, who teaches a class on measurement, estimated the flow of oil from the burst pipe to be around 20,000 to 100,000 barrels a day.
"This is a huge disaster exceeding the magnitude of the Exxon Valdez spill by quite a large margin," Chiang has said. "The calculation is uncertain, but I am confident enough to say that this is one of the big ones. It is not 5000 barrels a day. That much I can say."
Despite the new estimates, British oil giant BP is keeping to its original estimate of 5000 barrels a day.
Oil spill latest: The cost of clumsiness | Gulf oil spill latest: Containing the spill | US oil rig sinks and causes oil spill off US coast | Oil spill latest: Senators knuckle wrap oil execs | Gulf of Mexico oil spill: dome sent to contain leak
Like this article? Get the RSS feed: