Another scientist, Nils Asp, an oceanographer from the Federal University of Pará in Brazil, told me that one of the biggest challenges for drillers was simply piercing their way through thousands more feet of thick and unstable silt than was typically found elsewhere. The plume was a marauding threat, the scientists explained. It could swallow a driller’s ROV in a matter of minutes. And the front edge of the sea shelf, where most of the oil was thought to reside, routinely experienced massive underwater landslides that could topple rigs.
