Late on the night of April 20, 2010, methane gas blew out from a wellhead a mile below the Gulf of Mexico. At a pressure 150 times greater than air at the Earth's surface, the gas shot up through a drilling riser to the Deepwater Horizon oil platform and exploded, killing 11 workers. As the burning rig sank two days later, the worst offshore oil spill in history was already gushing. For 87 days, more than 200 million gallons of crude spread in a four-dimensional disaster that reached from the Gulf's floor to its surface, its seashore and across time. For years, a consortium of universities and researchers called C-IMAGE, led by marine scientists at the University of South Florida, has been studying the effects of the BP spill — and what we can learn. With the five-year anniversary of the spill upon us, two of the USF scientists — Steven Murawski and David Hollander — agreed to share some key findings. Here is their summary of what we now know, illustrated by three Times news artists. — Jim Verhulst, Perspective editor
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What happened to the oil?
Emergency crews skimmed up some, burned some and also applied chemical dispersants to break up some of it so that it would either dissipate or be small enough for microbes to eat. But even five years later, up to 10 percent remains in marshes and anywhere from 3 to 30 percent — though 10 percent is probably a good estimate — is on the ocean floor. Add it all up, and that means that at least 40 million gallons — enough to fill 60 Olympic pools — is likely still out there. The spill spread oil across more than 68,000 square miles on the surface — an area larger than Florida. And not all of the oil ever reached the surface.
One of the emergency responses to the spill was literally to open the floodgates, to let Mississippi fresh water flood through the wetlands in hopes of pushing the oil out to sea. This had unintended consequences, as we'll see in a minute.
CAM COTTRILL, STEVE MADDEN AND DON MORRIS | Times