Who, What, Why: What Are Frostquakes?

[Turk]

6 January 2014 Last updated at 14:14 GMT

Loud explosions heard in parts of Canada are being blamed on a phenomenon called frostquakes. What are they?

Ontario is no stranger to temperatures approaching -20C (-4F) but in recent days the winter freeze has been accompanied by unusual sound effects - bangs waking people up during the night.

@sydney_grieve was one of many to tweet: "Heard a loud bang outside of my room at 2am. My whole family was searching the house thinking someone broke in. #frostquake"

Emergency services in the Greater Toronto Area received reports of loud noises, prowlers and bangs on the roof. Few of those calling in expected to be told it was probably the weather.

Known to experts as cryoseisms, frostquakes happen when moisture that has seeped into the ground freezes very quickly. It expands and builds up pressure, causing the frozen soil or rock near the surface to crack, emitting a sound that people have likened to a sonic boom.

The answer
The loud cracking of frozen soil caused by expanding ice beneath the surface
It is uncommon and requires a plunge in temperatures following wet weather

Frostquakes are not very common because they require such a rapid change in temperature. In southern Ontario, a drop from about 5C (41F) to about -20C (-4F) was preceded by an ice storm, which ensured there was a lot of moisture in the ground waiting to become ice.

That doesn't happen every year, says Geoff Coulson of Environment Canada, who says the term "frostquake" is new to him. It's like a very weak earthquake and the house might shake but there is hardly ever significant damage, he says, and it will only be felt or heard within a kilometre (0.6 miles) at most.

One peculiarity is that it rarely sounds like it is coming from below, due to the way the soundwave travels - one couple he knows thought a truck had hit their house, while others feared a tree had fallen on the roof.

"The peak time is between 3am and 8am, and that's related the depth of cold at that time," he says. But sometimes the ice slowly builds and the explosion may happen days after the temperature drops.

Frostquakes have been reported before - northern US states such as Ohio had a similar experience in 2011. But the phenomenon was not widely reported until this winter, says Coulson, largely because people who would previously have shared their experiences with friends are now putting them on social media, where they travel far and wide.
http://www.bbc.co.uk/news/blogs-magazine-monitor-25620598

[Ambrocious]

I live in Colorado and a few nights ago when the temp got down to -2 I heard loud bangs outside as well but when I asked some other people if they too had heard it, they didn't. I know this has happened in Canada but this isn't the first time loud booms have been heard from the sky. Checking back a few years, multiple towns in the United States have reportedly heard loud booms coming from the sky with no good explaination. My suspician is that it's HAARP or something else like it.

[dMog]

really... read the freaking article...PROVEN to be frost and in the ground...again not everything is what YOU wish it to be or suspect it to be...remember thoughts and thinking driven by paranoia are never the actual reality

edit ...@turk google haarp and tell us if you think that is what it actually is...or as stated as in the article

Edited January 8, 2014 by dMog

[Turk]

Well, Ambrocious is the only "Cold Veteran" conspiracy author of Nsane Forum. I like his comments, even if most of time I do not agree with his conspiracies, as in this HAARP Case: http://www.cracked.com/funny-3304-haarp-conspiracy-theory

I feared off that he would leave the forum forever when Mod has moved his post recently. :) BTW, I respect all Hot/Cold Veterans. :)

Edit: I am sure you know it, but anyway here official HAARP website:

http://www.haarp.alaska.edu

Edited January 8, 2014 by Turk

[smallhagrid]

When we get an overnight temp here below -20F on the thermometer we hear loud things like that too.

Quite often the ones that sound like gunshots out in the yard are actually from the trees; when it is that deep cold they start 'popping'.

It can be quite loud and of course you cannot see where it is coming from either.

I like to go out & listen when it is happening because it is a very unique & different thing.

[dMog]

not wanting to start another war with you know who but i am very surprised he has not been here with proof that the "polar vortex" is a weaponized weather event from HAARP

Edited January 8, 2014 by dMog