U.S. officials say new analysis shows the oil leak in the Gulf of Mexico is leaking at least twice as much oil as first thought. VOA reports the new estimates suggest between 12,000 and 19,000 barrels of oil were leaking for several weeks.
US officials say the new estimates are the product of a team of scientists working for days to understand the oil leak from a broken undersea well in the Gulf of Mexico.
U.S. Geological survey Director Marcia McNutt said the team used two different methods to study the leak. One team studied aerial images of the Gulf of Mexico, and found between 130,000 barrels and 270,000 barrels of oil on the surface last week.
"The initial estimates from the mass balance team is that the rate of release from the well was between 12,000 to 19,000 barrels of oil a day," McNutt said.
Shortly after the leak was detected last month, U.S. scientists used surface data to estimate at least 5,000 barrels of oil a day were escaping from the well. But they warned the numbers were difficult to confirm because it was unclear how much oil had surfaced, and how much oil remained under water.
In recent weeks, independent researchers have disputed those estimates, saying underwater video shows much more oil is escaping the broken well.
Marcia McNutt said a separate team studied underwater video and concluded some of the material escaping was natural gas, and not oil. Experts say gas dissipates quickly and does not pose a long-term risk to marine life, as oil does. McNutt said the video team estimated the leak was between 12,000 and 25,000 barrels of oil a day.
She said comparing the results from both teams helps them to rule out the natural gas release and provide more accurate estimates. "It really was mostly the surface that was telling us more about the release rate, and that is why we are now getting better estimates because now we can correct for the gas phase," she said.
McNutt says the data on surface oil is especially useful to cleanup crews working to skim or burn pools of oil on the water's surface. BP representatives and U.S. officials have said the goal is to fight the oil spill at sea, before it hits delicate marshland and beaches. The oil has coated about 160 kilometers of coastline and 12 hectares of marshland.
The new estimates may help environmental experts understand the impact of the oil spill in the Gulf of Mexico. The worst oil spill in U.S. history occurred in 1989, when a tanker spilled 250,000 barrels of oil on the Alaska coastline.