CONCORDIA (KSNT) – A couple in Kansas said they recently witnessed a winter weather phenomenon known by several names: cryoseisms, frost quakes or ice quakes.

Melody Gillan, who recently moved to Concordia with her husband, explained what she discovered.

“I was outside one day and kept hearing these ‘pops’ that sounded like firecrackers going off underground, right by where I was standing,” Gillan said. “My husband thought I was crazy. He said it was someone shooting a gun off in the distance.”

Gillan filmed the popping noises as they happened again Tuesday.

“A few days later I was outside and he finally decided I wasn’t crazy, there was something popping in the yard under the ground,” Gillan said. “My husband was born here in Concordia and lived here 37 years, and we have friends here and none have ever heard of frost quakes.” 

KSNT’s StormTrack Weather Team created this graphic to help explain the process that causes frost quakes. When temperatures fall rapidly, it causes underground water to quickly freeze. This newly frozen ice expands and puts extra pressure on the soil and bedrock around it.

Once the pressure builds enough, it can make the soil and even bedrock lower underground crack. As a result, the cracking can cause loud booms and sometimes even shaking.

The Encyclopedia Brittanica reports frost quakes can sometimes be mistaken for true earthquakes because of how intense the seismic vibrations can get, and they’re more common in polar and mountainous regions where glaciers move. However, because Gillan and her husband did not report any shaking, the StormTrack Weather Team believes the frost quakes they experienced were caused by pressure cracks in the soil, not the bedrock lower underground.

Visit KSNT’s Share It section to submit videos of frost quakes around Northeast Kansas, or go to the StormTrack Weather page for the latest forecasts and interactive radar.