As bad as the oil spill looks on the surface, it may be only half the problem, said University of California Berkeley engineering professor Robert Bea, who serves on a National Academy of Engineering panel on oil pipeline safety.
"There's an equal amount that could be subsurface too," said Bea. And that oil below the surface "is damn near impossible to track."
Obama has halted any new offshore drilling projects unless rigs have new safeguards to prevent another disaster



