Did you hear a loud 'pop' Saturday? Frost quake unlikely


Chad Canfield was watching a movie in his basement Saturday morning when he heard a “quick, heavy pop.”

Canfield didn’t jump at the sound, which he immediately thought was a cryoseism — better known as a frost quake.

“It was just unsettling. I’ve never heard anything like it before,” said Canfield, of Cedar Rapids, describing the sound as “deep in the ground.” It was different from the routine sounds of his house settling, snowplows or construction work.

The sound probably wasn’t a cryoseism, however, said National Weather Service meteorologist David Sheets.

More likely, water freezing on houses Saturday caused the loud popping sounds, he said.

“As far as frost quakes, that happens really infrequently in temperatures negative 10 degrees and below,” Sheets said. “It causes water in the ground to freeze, and sometimes you can get seismic activity. I don’t think we’ve been cold enough for that.”

Sheets said that while he is not aware of frost quakes damaging houses or trees, he can’t rule it out.

If a frost quake did occur, the ground would shake slightly like a minor earthquake, and it would sound like a lower-frequency thud as opposed to a pop, Sheets said.

It possibly would be powerful enough to wake someone from their sleep.


Walford resident Tim Fees was startled by popping sounds he heard Saturday, which he at first thought was ice cracking on the deck of his house. Then, he thought it was coming from the attic.

“I heard a loud thud, like something heavy dropped on the floor,” Fees said.

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