The Polar Vortex Is Causing Startling ‘Frost Quakes.’ Here’s the Science Behind Them

Weather that feels like it’s -50° F outside is unnerving enough on its own. But for some midwesterners trapped in an icy polar vortex this week, those bone-chillingly cold temperatures have been accompanied by an unsettling phenomenon: loud and seemingly inexplicable banging sounds.
“A huge noise woke me around 2:30 am,” said one Twitter user. “Scared the living daylights out of me. Didn’t know what it was. A few minutes later, it happened again.”

In case you missed this yesterday…
A huge noise woke me around 2:30 am. Scared the living daylights out of me. Didn’t know what it was. A few minutes later, it happened again. Needless to say, I didn’t go back… https://t.co/daR5CGuzKI
— paula ks gardner (@paulaksgardner) January 31, 2019

“I heard loud knocks all night and couldn’t figure out what they were,” said another.

Oh goodness I heard loud knocks all night and I couldn't figure out what they were. Not sure if I'm relieved or more worried they were caused by "ice quakes". https://t.co/13ysXGQRc4
— Nancy Shepard (@njshepard) January 30, 2019

What’s causing these strange sounds? They’re most likely due to an extreme cold weather phenomenon called a “frost quake.” Also called ice quakes or cryoseisms, the cracking or booming sounds occur when moisture below ground starts to freeze and expand. As it does, it can move rocks and soil, occa...

Source: TIME: Science - January 31, 2019 Category: Science Authors: Alejandro de la Garza Tags: Uncategorized onetime weather Source Type: news