One analysis suggests gusher is 70,000 barrels daily, or an Exxon Valdez every four days, and 12 times more powerful than estimates by Coast Guard or BP
Marine scientists were carefully viewing footage of oil and gas billowing out of a ruptured well on the ocean floor today, to try to deliver the first reliable estimates of the crude gushing into the Gulf of Mexico – it could be as much as 70,000 barrels a day.
The video could help resolve the increasingly contentious debate about the scale of the disaster, and the oil companies' willingness to give access to any information.
BP has claimed repeatedly there is no way of measuring the scale of the leak. The US Coast Guard, meanwhile, has stuck to an early estimate of 5,000 barrels a day.
Independent marine researchers have suggested the spill could be much larger.
National Public Radio in the United States last night reported that the well is spewing up to 70,000 barrels of oil a day – the equivalent of an Exxon Valdez disaster every four days. Nearly 11 million gallons of oil were spilled in Alaska's Prince William Sound in 1989 when the Exxon Valdez tanker ran aground, oiling beaches and poisoning marine life for generations. NPR said scientific analysis of newly released video footage from the ocean floor suggested the gusher was 12 times more powerful than estimates offered so far by the Coast Guard or BP.
Its analysis was conducted by Steve Werely, an associate professor at Purdue University, using a technique called particle image velocimetry, a method was accurate to 20%. That puts the range of the oil spill from 56,000 to 84,000 barrels a day.
Werely told The Guardian he based his estimate on techniques which track the speed of objects travelling in the flow stream.
"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 oils is shooting out of the pipe," he said. "From there it is a very simple calculation to figure out what is the volume flow."
He said he had use the method for 15 years, and elsewhere it had been in use for 25 years.
Scientists had spent the day scouring the video footage of the gushing pipe on the ocean floor to try to arrive at estimates.
Eugene Chiang, an associate professor at the University of California Berkeley who teaches a course on measurement, said he had been copied on an email which set it as a science challenge for academics.
"It was just like estimating the number of jelly beans in a can, it had that kind of a feeling – but of course with much more serious consequences," he told the Guardian.
Chiang said he used relatively "back of the envelope" calculations to put an estimated rate for the spill at 20,000 to 100,000 barrels a day.
