Hot Trends: 'My house was shaking': 'Frost quakes' blamed after Toronto residents wake to ...

The extreme cold is leaving Toronto with a bang rather than a whimper as residents around the GTA report loud booming sounds in the night that may be caused by "frost quakes."

People reported noises loud enough to wake them up as temperatures dipped below -20.

The booms occur when moisture in the ground freezes and expands, putting pressure on rock. This pressure is ultimately released with a loud boom and the rock cracks.

According to the Maine Geological Survey, the phenomenon is also known as cryoseisms. The agency calls it "a literal 'cold snap'" and describes the sounds variously as a "deep rumbling" that sent windows shaking, a "shudder" and a cracking sound.



"Last night, I think I heard four of them," said one Markham resident. "It's like a loud boom and almost sounds like something exploded or landed on the roof."

"I think the house shakes a little... but it's more the sound than the vibration," he said.

The sounds have striking in the night, usually between midnight and around 5 a.m.

What they are is cracking of ice or two blocks of ice moving one against each other. It happens because ice expands when it gets cold

Allison Bent, a seismologist with Earthquakes Canada, explained how the "frost quakes" felt similar to earthquakes but were caused by ice.

"What they are is cracking of ice or two blocks of ice moving one against each other. It happens because ice expands when it gets cold," said Bent.

"So it often happens when it's extremely cold, like minus 20 or colder and particularly if there's been a sudden drop in temperature, and especially near lakes and rivers."

It feels a lot like an earthquake to someone close to it, but Earthquake Canada's instruments don't pick up the shaking since these ice quakes are very localized, according to Bent.



"So we suspect that's what's people have been feeling," she said.

As for potential for damage, Bent said she's "never heard of there being any. Usually the effects are very, very localized."

"You can feel the shaking, but as far as I'm aware there's never been any damage from a frost quake," she said, comparing it to a very weak earthquake.