At NPR’s request, experts examined video that BP released Wednesday. Their findings suggest the BP spill is already far larger than the 1989 Exxon Valdez accident in Alaska, which spilled at least 250,000 barrels of oil.
Steven Wereley, an associate professor of mechanical engineering at Purdue University, analyzed videotape of the seafloor gusher using a technique called particle image velocimetry.
A computer program simply tracks particles and calculates how fast they are moving. Wereley put the BP video of the gusher into his computer. He made a few simple calculations and came up with an astonishing value for the rate of the oil spill: 70,000 barrels a day — much higher than the official estimate of 5,000 barrels a day.
The method is accurate to a degree of plus or minus 20 percent.
Given that uncertainty, the amount of material spewing from the pipe could range from 56,000 barrels to 84,000 barrels a day. It is important to note that it’s not all oil. The short video BP released starts out with a shot of methane, but at the end it seems to be mostly oil.
“There’s potentially some fluctuation back and forth between methane and oil,” Wereley said.
But assuming that the lion’s share of the material coming out of the pipe is oil, Wereley’s calculations show that the official estimates are too low.
“We’re talking more than a factor-of-10 difference between what I calculate and the number that’s being thrown around,” he said.
Here’s the BP video: