In the first independent and peer-reviewed analysis of the Gulf of Mexico oil spill, scientists from Columbia University have determined that 4.4 million barrels of petroleum leaked into the water following the sinking of the Deepwater Horizon rig in late April. The study, which was the work of Columbia researchers Timothy J. Crone and Maya Tolstoy, was published online in the September 23 edition of the journal Science. As part of their work, Crone and Tolstoy analyzed underwater video footage of the busted Macondo 252 well, and found that it leaked at least 56,000 and 68,000 barrels daily between April 22 and July 15. This is a video used by the researchers to analyze the oil flow. Credit: Courtesy US Senate Committee on Environment and Public Works