Follow up to postings on the Gulf Coast oil spill: “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 seafloor 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 Wereley, an associate professor at Purdue University, using a technique called particle image velocimetry. Harris tells Michele Norris that the method is accurate to a degree of plus or minus 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. Even the most conservative of those estimates is much higher than what the Coast Guard has so far said. But the pipe is spewing both oil and gas and it’s not clear in the BP video how much is oil and how much is gas. BP disputes these results, and maintains there is no reliable way to calculate the flow of oil from a broken pipe.”