Heard a bang? Maybe it was a 'frost quake'

CTV Kitchener: Many hear ‘frost quakes’ Loud noises that sound like gunshots or intruders are likely just a rare natural phenomenon called a ‘frost quake’. Carina Sledz explains.

Across Ontario, residents have been hearing loud bangs this week.

They can sound like gunshots, but experts say they’re most likely ‘frost quakes’ -- or ‘cryoseisms’, as they’re known scientifically.

Frost quakes most commonly happen when there has been a rapid decline in temperature, causing moisture trapped in cracks in the ground to quickly freeze and expand.

The expansion puts pressure on the surfaces it is caught between, and as that pressure is released, it can cause fissures, cracks and loud sounds.

December’s ice storm created the conditions for frost quakes to occur – and that’s just what appears to be happening this week across the province.

In Guelph, police say they received four calls about loud noises Thursday alone, all of which are believed to have been caused by cracking ice – either frost quakes or construction elements reacting to contraction.

“When police went out to check these residences, we found that there was nothing out of the ordinary,” says Const. Mike Gatto.

Some people called police thinking the noise meant their house was being broken into or otherwise damage.

“You don’t need to be worried,” says Gatto.

“Any wintertime, ice can cause damage to your home … but just because you’ve heard the noise doesn’t mean that your home is in any jeopardy.”

Their home being in jeopardy is exactly what Ryan and Kelly Gerritsen, who live in Guelph, thought they were hearing around 4 a.m. Friday.

“It sounded like either someone was breaking into the house or one of the kids had fallen out of bed,” Kelly says.

Ryan, who was awake and getting ready for work, quickly checked through the house and found nothing amiss.

He says it’s the third time since Christmas Eve his family has heard the sounds.

“It sounds like a car is actually hitting the concrete of your garage. It’s very fast,” he says.

On Twitter, local residents likewise report hearing unexplained loud noises – potential frost quakes – in recent days.

“A loud bang woke me up last night. I thought the house was falling,” Puslinch Township resident Charlene Johnson tweeted.

“Heard 3 in Baden last night between 3am and 4am,” added Doug Ribey.

Environment Canada meteorologist Geoff Coulson says he began hearing reports of frost quakes in the Toronto area Christmas Eve.

“We had more reports in southern Ontario this past Monday morning, more reports … last night,” he says.

Earthquakes Canada says they do not record frost quakes, which takes place much closer to the surface than the seismic activity they monitor.