Mysterious Booms Heard, Felt Again in Central Oklahoma

A series of unexplained booms in the Norman area has returned.

Oklahoma Geological Survey research seismologist Austin Holland said the second series of booms started at 11:19 a.m. Friday, after numerous booms were reported starting about the same time on Thursday.

Both Holland and National Weather Service meteorologist Matthew Day say they have no explanation for the booms that have rattled houses and frightened livestock.

Holland said there have been no earthquakes near enough the area to be the cause of the booms and Day says the cause is not likely a phenomenon known as cryoseisms – which occurs when water freezes quickly in soil or rock, then expands and cracks.