The Polar Vortex Might Be Causing 'Frost Quakes' in Chicago | WHAT REALLY HAPPENED

The Polar Vortex Might Be Causing 'Frost Quakes' in Chicago

It might be cold enough in Chicago right now to make the ground shake.

Local news station WGN reported today (Jan. 30) that its viewers had heard "frost quakes" in the city overnight. And though the reports in Chicago are still unconfirmed, frost quakes are indeed a real thing.

Frost quakes, or "cryoseisms," occur when water trapped underground freezes suddenly as the temperature drops, causing it to expand. (Water expands as it freezes.) All that rapidly expanding water underground can split rocks and put stress on the soil, causing loud booms. Frost quakes are fairly rare events and difficult to positively identify. A huge blast that shook northwest Calgary, Canada, in 2014 was widely attributed to a loud cryoseism, but researchers never confirmed that as the cause. [9 Tips for Exercising in Winter Weather]

Charles Mott, a meteorologist at the National Weather Service (NWS) office serving Chicago, told Live Science he hasn't personally heard any frost quakes in recent days, but added "that has to do with being inside all day."

But Mott said that there's been some chatter about the possibility of them around the office, and that he has no reason to doubt WGN's report.