Not everyone agrees that the surface features Kolawole is identifying can say much about forces tens of kilometers below the surface. “I don’t think he has enough evidence,” says Cynthia Ebinger, a seismologist at Tulane University who has spent her whole career studying African rifts. The region’s plates are so thick that it’s hard to see how surface weaknesses matter much, she says. “It’s the whole plate,” she says. “Not just the upper crust.”