BP oil company is preparing to deploy its latest effort to cap an undersea well that is leaking oil in the Gulf of Mexico. New underwater video of the leak is raising questions about the extent of the problem.
BP engineers say the current effort involves placing a tube inside a broken oil pipe that has been leaking oil for the past four weeks. Engineers hope the tube, which is fitted with a rubber cap, will enable them to pump most of the oil to a surface ship.
Coast Guard Commander Thad Allen said the tube is one of several techniques that BP is developing to stop the leak.
"I would caution everyone that this is a leak mitigation effort," said Admiral Allen. "It is not intended to completely capture all the oil that is leaking from there. But it should substantially reduce it, if it is successful."
BP representatives say a permanent fix for the leak is to drill a new well, which could take three months.
Earlier this week, BP released video from a remote controlled submarine, which showed oil spewing from a gash in the undersea pipe. Some scientists and oil experts say the video shows that far more oil is leaking than official estimates of 5,000 barrels a day. BP representatives say that number is hard to determine, because the leak is 1.5 kilometers below the surface.
Commander Allen says the debate over leak estimates has not affected the response from the U.S. Coast Guard.
"Whether it was one, five, 10 or 15 [thousand barrels of oil], our mobilization of resources has been for something far beyond that, because we are always prepared for a catastrophic event," he said.
Since the leak began last month, researchers at the University of Miami have been using satellite images images to track the oil spill on the surface. Imaging expert Hans Graber says initial data suggested there was at least 5,000 barrels leaking a day, and probably more.
He says bad weather has made it hard to estimate the leak rate, but the latest imagery shows the slick now covers 9,000 square kilometers.
"There is clearly a lot coming out," he said. "What we don't know is how much is evaporating or even staying below the surface."
Scientists say it is important to understand the size of the leak to prepare measures to combat it. BP oil company has been spraying chemicals to disperse the oil in the water, where they say microorganisms will break it down over time.
Researchers say the warm waters of the Gulf of Mexico may speed that process. But oceanographer Jennifer Cherrier of Florida A&M University says it may not be that simple. In her research, she has found that some parts of the Florida coastline have microorganisms that break down oil, while others do not.
Cherrier says it is unclear how the oil will affect the diverse regions of the gulf, and the growth of oil-eating microorganisms.
"Would they grow in, if they were continually exposed [to oil]? Probably," said Jennifer Cherrier. "Would they eat the oil at the rate that we want to see it eaten? Probably not."
So far, BP oil company says it has spent $450 million to fight the oil spill. The final cost of clean-up work and compensation payments is expected to be several billion dollars.
A map of some of the world's worst oil spills
