Extreme cold snap in the US is accompanied by a rare phenomenon called "frost quakes."
Cryoseisms occur when moisture-saturated soil is suddenly exposed to extremely low temperatures. The water inside quickly turns to ice and expands, creating extreme pressure on the surrounding rock. This causes the ground to crack, accompanied by explosion-like sounds and noticeable vibrations that often frighten residents at night.
Residents of Kentucky and surrounding regions have reported loud explosions and slight tremors caused by extreme cold. Meteorologists have identified these phenomena as cryoseisms, or "frost earthquakes," caused by the rapid freezing of moisture in the ground.
The National Meteorological Service emphasizes that, despite the frightening acoustic effects, cryoseisms are mostly harmless to infrastructure and people. The main danger now is not the sound anomalies, but the extremely low temperatures and winds, which pose a risk of frostbite.