"Frost quakes" rattled Ohio, Indiana

Here’s one I’d never heard of: The Dayton Daily News reported last week that seismic shakes felt by residents of southwest Ohio and southeast Indiana on Feb. 10 were actually “frost quakes.” Known to scientists as “cryoseisms,” they can occur when temperatures plummet to below zero. Moisture in the soil or rock freezes and expands, setting off sudden and violent cracking. The Ohio shakes reportedly persisted for eight hours. No damage was reported. Similar cryoseisms have occurred in Wisconsin, Michigan, Maine and upstate New York.