Frost quakes, also known as cryoseisms, occur during sudden, drastic drops in temperature—in recent weeks, by the way, temperatures have dipped below -20 degrees Celsius.
At such low temperatures, deep groundwater starts to freeze and expand, causing the ground to crack.
“And it seems like the cracking occurs very explosively, very suddenly. And when it does so, it can actually cause the ground to vibrate (and) cause a loud boom,” says John Ebel, a professor of geophysics at Boston College.
Because temperatures are coldest at night, the loudest cracks have occurred in the early hours of the morning. Some have even compared the sound to that of an “explosion” or a “distant bombing.”
While cryoseisms can cause thunderous sounds, they are local weather events that are far weaker than traditional earthquakes, according the Maine Geological Survey. “In some cases, people in houses a few hundred yards away do not notice anything.”
Consequently, the instruments at Earthquake Canada are not sensitive enough to detect frost quakes. So, it can only assume that’s what people are hearing based on reports from the public.
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