What are 'frost quakes'? Here's a brief explainer

SALT LAKE CITY — Frost quakes may be shaking up Chicago this week.

Chicago residents were awakened Wednesday morning by a series of large quakes, according to WGN-TV.

These are actually related to cryoseism, which is nicknamed "frost quake."

Area you hearing loud bangs? Some of those could be Cryoseisms! AKA Frost Quakes! @WGNMorningNews @WGNNews pic.twitter.com/I3cRIS4hdC

— Morgan Kolkmeyer (@MorganKolkmeyer) January 30, 2019

"It happens when water underground freezes and expands, causing soil and rock to crack," CNN reports.

The event begins when there is an extreme drop in temperature. As USA Today reports, the quick drop in temperature will lead to a quick freeze. The soil bursts rather than expand.

• "I thought I was crazy! I was up all night because I kept hearing it," said viewer Chastity Clark Baker on Facebook. "I was scared and thought it was the furnace. I kept walking through the house. I had everyone's jackets on the table in case we had to run out of here."

As we reported yesterday, Chicago suffered a drop to record-breaking temperatures, reaching close to 27 below.

However: Frost quakes are so small that it's hard for geologists to prove, according to USA Today.

• "It's more of a noise phenomenon, like a balloon popping, than a physical danger," said Dave Call, a meteorologist at Ball State University.

from Deseret News http://bit.ly/2TsBHvk