A cap over the leaking oil well in the Gulf of Mexico is BP's latest attempt to stem the flow. Over the last six weeks tens of millions of gallons of oil have spread through the Gulf. But nobody knows where it will all go? Michel Boufadel, chair of Civil and Environmental Engineering at Temple, has been studying oil spills for years. He says that one of the challenges of the current spill is that it came out from the deep sea. "It is really spreading and dispersing in the whole water column. So it is really difficult to track the movement of the subsurface plume," he said.