What's An 'Ice Quake?' Perhaps The Answer To The Noises You're Hearing At Night

RICHFIELD, Minn. (WCCO) – Whether it's a bang, crash or a snap – perhaps you've been woken up to a loud noise coming from outside your home this week.

"I hear it just about every year when it gets cold," said Bob Daggett, who lives in Richfield.

The noises, most often coming from the foundation or roof of your home, have a simple explanation.

"The official scientific term is cryoseisism," said Jacob Beitlich of the National Weather Service Twin Cities Office. "It's where you have water that seeps into the ground, then when you get temperatures to drop very quickly, that water freezes, expands and it doesn't have anywhere to go so it sends a crack through the ground."

That crack, Beitlich says, can sound like a "boom" to many.

"It's like a bomb went off in your house sometimes," Daggett said. "Unless you've experienced it, it's just like, what the heck? It's like, what's going on? You're looking outside, you don't see anything. You look up there, it's like, there's nothing wrong, it's like, why is this occurring?"

Beitlich says the winter phenomena, oftentimes referred to as "ice quakes," tends to happen at night when temperatures dip. Despite the noise, they're relatively harmless to your home's structure, he says.

"It's just a big bang boom," Daggett said. "It's almost like you get in a car accident, like your roof is getting in a car accident- it's getting hit or something. It's just making this big popping noise. You go outside and look and it's like, the roof is still there."

"They're part of that winter season that we know and love," Beitlich said.