MADISON, Wis. (WMTV) Reports of loud pops and booms have been reported across southern Wisconsin Thursday night. This is likely the result of frost quakes. A frost quake is a natural phenomenon that occurs when extremely cold temperatures lead to sudden deep freezing of the ground, after it has been saturated with water. When this occurs, the sudden freeze will cause underground ice to expand, causing soil and rock to crack, which will produce these booms, and in more extreme cases, shakes.
You may also be hearing these strange sounds in your home in which a similar situation is occurring. The materials making up your home also expand and contrast with temperature and environmental changes. The rapid change in temperature can also cause cracking and popping sounds in buildings.
While the sounds can be eerie and cause alarm, there isn't really a huge concern. Frost quakes are not commonly reported with damage or injuries. What is of more concern with the flash freeze is the potential ice on roadways. Anything that was wet or slushy earlier today is likely solid and icy at this point. Use caution when traveling through early Friday.