What are frost quakes?
As Atlantic Canadians prepared for the bitter cold last weekend, there was concern about power outages, burst pipes and dead car batteries.
One thing likely not on the minds of many, myself included, was a phenomenon known as frost quakes.
I first received a message from a reader near Stewiacke, N.S., last Friday evening that frost quakes had been occurring.
There were reports from around the region and outside of Atlantic Canada of loud booms and light shaking.
A frost quake is much different than an actual earthquake, but how does one happen?
A frost quake, also known as a cryoseism, can occur when temperatures drop rapidly below freezing, which most often occurs behind cold fronts ushering arctic airmasses into the region.
The sudden drop in temperature causes the water in the ground to freeze.
The frozen water then expands and puts extra pressure on the soil and bedrock in the ground. The stress from this pressure continues to build until the bedrock or soil cracks which can result in a loud boom noise and, in some cases, shaking.
Despite the earthquake-like features of booms and shaking, frostquakes are caused solely by weather. In contrast, the movement and stress of tectonic plates below the Earth's surface lead to sometimes deadly and destructive earthquakes.
A frost quake can be startling, and some have caused minor damage.
It's also tough to identify frost quakes because they often aren't picked up by seismometers. The noise and vibrations are very localized and can be compared to things like nearby construction.
However, if temperatures have plummeted and loud bangs or light shaking occurs, it's more than likely a frost quake.
Allister Aalders is the weather specialist for the SaltWire Network, providing forecasts and analysis for Atlantic Canada. #AskAllister