‘Frost quakes’ were felt around Chicago this week. Here’s what scientists do and don’t know about the seismic phenomenon

A cold weather phenomenon known as a frost tremor, which produces a loud rumbling or popping sound and small earthquake-like tremors, was felt around Chicago during sub-zero temperatures this week. 'Frost tremors' were felt around Chicago this week. Here's what scientists do and don't know about earthquakes Measuring an inch wide and at least eight to ten inches deep, his rural driveway in Waupun, Wis., recently experienced a weather phenomenon known as an ice quake. This results in the accumulation and expansion of water in the soil and bedding. (AP Photo/The Reporter, Eileen Andrews) No sale A man measures a crack in his driveway in Waupun, Wisconsin, after a cold weather event known as a frost tremor hit the region in January 2014. Eileen Andrews/AP Explore the universe with news on fascinating discoveries, scientific advances and more. A cold weather phenomenon known as a frost quake, which makes a loud rumbling or popping sound and causes small earthquake-like tremors, was felt around Chicago this week during sub-zero temperatures. Illinois State Climatologist Trent Ford said there is no formal reporting system for snow quakes. , which happens after the ground suddenly freezes, but he saw and heard about the incident on social media. He has also experienced some frost tremors in the past, formally known as cryoseisms. “It sounds like someone is either ripping a very large branch off a tree or maybe popping very large bubble wrap. It's not quite a gunshot, but it's like that, and it can be so loud," Ford said. "Shaking is less common," he added. "They can be like small earthquakes, not to the extent where pictures fall off the wall." Snow tremors can be unsettling, especially if people aren't aware of them, but they don't pose any real danger, Ford added. In extreme cases, they can damage roads or building foundations, but that's rare.