This weekend will mark the four-year anniversary of the Deepwater Horizon disaster, a Gulf of Mexico rig explosion that killed 11 workers and led to the worst offshore oil spill in U.S. history. Oil gushed from the sea floor for 87 days before the well was capped; by some estimates, nearly five million barrels of oil spilled into the Gulf, inflicting untold environmental damage.
The event highlighted how little we know about containing deep-water oil spills or about how the oil spreads. Oil washed up hundreds of miles away on coastlines in Louisiana, Alabama, Mississippi, and Florida, but scientists struggled to determine where all of the oil had gone. Had some of it evaporated, or was it hiding below the surface? Had it been carried by currents to the Gulf's deep waters, or perhaps even further, to the Atlantic Ocean and beyond? No one could say for sure.
David Murphy, a postdoctoral fellow in the Department of Mechanical Engineering at Johns Hopkins, hopes to change that. He is studying oil spills in a lab environment, focusing on the behavior and fate of oil released from the ocean bottom as a high-flow-rate jet. In particular, he is investigating the combined effects of ocean currents and chemical treatment on dispersing oil.
Learning about the physics of the process will help predict where spilled oil goes and how much dispersant to apply in future oil well blowouts. Data gathered in the lab tests will be used to develop computer models to help predict how oil will spread when future spills occur.
"We study what happens when oil is released into a natural environment, and we look at how that oil spreads out," says Murphy, who grew up in Alabama, near the coastal area affected by the Deepwater Horizon spill. "On a small scale, we replicate a blowout that happens on the bottom of the ocean and use high-speed video to look at plume behavior—how quickly it rises. The more small droplets we have, the easier it is for microorganisms to attack and break down the oil."