Frost quakes are when water seeps into the ground, making the soil beneath the ground become wet with moisture.
This, according to Barys, is where residents heard a loud boom, and this natural phenomenon will not be picked up on a seismograph which is why an quake is ruled out.
Extremely cold air like we have this week can cause lots of creaking and snapping sounds, but on rare occasions, it can cause a boom or bang.
Brent Hewett, a meteorologist at the NWS office in the Twin Cities region of Minnesota, said that there had been no reports of cryoseisms in that area, probably because there's snow on the ground.
When that expansion happens, it causes loud booms to occur. "When liquid water freezes, becoming ice, it expands", CBS News climate and weather contributor Jeff Berardelli said.
The ground is heavily saturated from recent heavy rains.
Paul Barys said, "Ice quakes that we have around here are very localized, you don't hear them from far away, it's nothing like an natural disaster, it's just a little bit of movement of the ice under the ground once the ground is saturated". According to Maine's Department of Agriculture, Conservation and Forestry, "there is not much scientific data about cryoseisms" since they normally only have "minor effects" and occur only under certain conditions that are hard to predict.
The outlet says that after posting about the possible quakes on social media, it received "tons" of responses from people who had heard unusual booming noises during the night.
Central Illinois is not typically a place known for earthquakes, but what about frost quakes? If that stress gets strong enough, it may only be able to relieve that stress in a sudden, explosive way as a frost quake. Per CNN, meteorologists suspect the sounds were caused by underground water freezing and expanding-a weather phenomenon known as cryoseism, aka a "frost quake". These are heard most often at night.