bats at halloween

Did you hear any loud booms during the most recent polar vortex? Some people in other areas reported these noises that turned out to be frost quakes. They may sound dangerous, but they are not like “real” earthquakes which have to do with the earth’s tectonic plates. Frost quakes – technically called cryoseism – are triggered by a combination of weather related events.

Usually we have a pretty decent layer of frost in the ground by this time of year. This year is different. We had soggy soils insulated by a heavy coating of snow that kept it from freezing. The sudden drop in temperature to below zero helped bring about the frost quake. So what is needed for a frost quake to occur? Here are the four keys to determining the likelihood of a frost quake.

The first pre-requisite is that you live in an area that usually gets frost in the winter. That would be us. The second is that the soil needs to be saturated with water. Without water, there is nothing to freeze and cause frost. The more water you have, the harder the ground can crack. We can check that one as well. A third necessary component is a little bit of snow, but not too much snow. Too much would be over six inches because then it insulates the ground under it. This is one that would prevent frost quakes this year for us. The final necessity would be a rapid temperature drop from near freezing to zero or below (Fahrenheit).  Sudden means within 48 hours or less. This causes the groundwater to solidify and expand. The force of this can cause a crack and a boom loud enough to wake people up.

You never know what Mother Nature will throw at you, but it will provide another learning opportunity. Enjoy the snow while it lasts.