Research published in Science shows that the BP oil leak pumped out approximately of 4.4 million barrels of oil before being completely capped. That's around 185 million gallons, or 700 million liters. Scientists from Columbia University's Lamont-Doherty Earth Observatory studied high resolution footage of the plume, and used a technique known as optical plume velocimetry to gauge the volume. From this, they state that between 22 April and 3 June the output was 56,000 barrels per day, ±21%, after which it increased to 68,000 barrels per day, ±19%, until it was capped on the 15th of July. This is a rate substantially higher than those originally put forth by the Government or BP, which originally started at just 1,000 barrels per day, but in line with current estimates.