By Frank James and Allison Richards
May 13, 2010, 7:02 pm
NPR has learned that much more oil, 70,000 barrels a day or more than ten times the official estimate, is gushing into the Gulf of Mexico from the Deepwater Horizon pipe, based on scientific analysis of the video released Wednesday.
That's the equivalent of one Exxon Valdez tanker full every four days.
The U.S. Coast Guard has estimated that oil was gushing into the ocean at the rate of 5,000 barrels a day. But, again, NPR has been told that estimate is very low.
We'll link in a bit to a segment on All Things Considered that explains more.
By Richard Harris
May 13, 2010
The volume of oil pouring into the Gulf of Mexico from the Deepwater Horizon oil rig may be at least 10 times higher than previously estimated, NPR has learned.
The U.S. Coast Guard has estimated that oil was gushing from a broken pipe on the Gulf floor at the rate of 5,000 barrels a day.
But sophisticated scientific analysis of sea floor video made available Wednesday by the oil company BP shows that the true figure is closer to 70,000 barrels a day, NPR's Richard Harris reports.
That means the oil spilling into the Gulf has already far exceeded the equivalent of the 1989 Exxon Valdez tanker accident in Alaska, which spilled at least 250,000 barrels of oil.
The analysis was conducted by Steve Werely, an associate professor at Purdue University, using a technique called particle image velocimetry. Harris tells Michele Norris that the method is accurate to about 20 percent. That means the flow could range between 56,000 barrels a day and 84,000 barrels a day.
Another analysis by Eugene Chiang, a professor of astrophysics at the University of California Berkeley, calculated the rate of flow to be between 20,000 barrels a day and 100,000 barrels a day — both higher than the Coast Guard's estimate.
But the pipe is spewing both oil and gas and the BP does not make it clear how much is oil and how much gas.
"BP has always said there is no way to measure the amount spilling from the pipe," Harris said.
But, he said, the uncertainty could be reduced if BP would share more information with the scientists.