The fault line where tectonic plates meet under the Olympic Peninsula in the Pacific Northwest is deeper than previously thought, according to a new study. That suggests the region will be hit hard the next time there is a megathrust earthquake. Andrew Calvert, a professor of Earth Sciences at Simon Fraser University, led the study, which was carried out by a team of scientists from Canada and the U.S. Calvert told the Globe and Mail that the fault line is seven kilometres deeper than previously thought, although it’s unclear what that means. He did, however, predict that a massive earthquake—magnitude 9, probably—in the area is imminent. Calvert says a megathrust earthquake happens in the Pacific Northwest every 500 to 600 years. The last one was in 1700.