"This is the last thing you need to worry about," Fan told The Associated Press.
Storms trigger giant waves in the sea, which cause another type of wave. These secondary waves then interact with the seafloor — but only in certain places — and that causes the shaking, Fan said. It only happens in places where there's a large continental shelf and shallow flat land.
Fan's team found 14,077 stormquakes between September 2006 and February 2015 in the Gulf of Mexico and off Florida, New England, Nova Scotia, Newfoundland, Labrador and British Columbia. A special type of military sensor is needed to spot them, Fan said.