Posted Wednesday, February 17, 2021
A look around social media this morning brought a number of reports of loud booms heard last night and early this morning. I read reports on my Facebook page this morning from Dover down to Bakersfield. Many folks thought one of the kids fell out of bed or something fell off a shelf. It woke several folks up from sleep.
These were likely something called frost quakes. Frost quakes can often occur when the ground becomes saturated after a rain or snow event – as we had on Monday. Ground temperatures then need to get really cold quickly – just as they did last night and early this morning.
The sudden drop in temperatures causes pockets of moisture deep underground to freeze and expand. As it expands, pressure around the frozen moisture increases because there is no where for the ice to go. When the pressure of expanding moisture exceeds the strength of the soil it releases rapidly resulting in a load boom or frost quake.
Frost quakes can be very loud. They can even shake a house or cause cracks in hard surfaces like roads and sidewalks. Technically, they are a seismic event and can even register on a seismograph if one is within range.
Frost quakes are also known as ice quakes. The scientific name for them is cryoseism.