A wave of cold in the United States has caused a surge in 'frost quakes' or cryoseisms. This phenomenon occurs when the ground freezes and contracts suddenly, creating small cracks and loud, explosive noises. According to a meteorologist from the National Weather Service in Kentucky, where most of these events have been reported, this happens when the ground becomes saturated with rain or sleet, and then a rapid temperature drop causes the moisture to freeze and expand very quickly. These loud 'booms' are not paranormal; they are cryoseisms. The extreme cold is caused by a displacement of the polar vortex, which has brought Arctic air to unusual latitudes, with Florida expecting its lowest temperatures in 15 years.
