Seismologist warns B.C.’s calm earthquake period adding to tectonic pressures toward Big One

VANCOUVER (NEWS 1130) — While things have been “unstable” above ground through this past year, analysis shows the earth beneath our feet through 2020 has been relatively stable here in Canada — but this doesn’t necessarily bode well for 2021.

A review of the stats by Natural Resources Canada shows that across Canada, there were over 3,300 earthquakes recorded through 2020.

3,329 earthquakes were located in/near #Canada during 2020 (so far).
57 were felt, the largest was M5.3 and most earthquakes occurred along the west coast.
M5-5.9: 5
M4-4.9: 77
M3-3.9: 494
M<3: 2753
Search for earthquakes in your neighbourhood:https://t.co/YAlYdmpNb3 pic.twitter.com/j5Ap1odU7a

— John Cassidy (@earthquakeguy) December 31, 2020

While that number is within the normal range, what we didn’t experience this past year was a major shaker, with the largest quake recorded in Canada measuring 5.3, making 2020 the least active — in terms of large earthquakes — since 1981.

And while this may seem like a good thing, Seismologist John Cassidy cautions that this just means more pressure being built up.

“It’s the larger earthquakes of magnitude sixes or sevens or eights that release most of the energy. So these small magnitude ones or twos are such a tiny drop in the bucket — they really don’t release any energy associated with movement of tectonic plates,” he explains.

“The pressure is, of course, building up it’s because these tectonic plates are moving. They’re trying to move at least they move typically at about the same speed that your fingernails grow, so five or six centimetres a year. But they also tend to lock together, where these tectonic plates meet, like off the west coast of Haida Gwaii, off the west coast of Vancouver Island. So these plates are locked stuck together, and storing energy.”

Earthquakes of 2020: Southwest #BritishColumbia
779 earthquakes (largest M5.2) – only a few were felt.
This is one of Canada's most seismically active regions, where plates collide, move apart and slide past one another.
M>4: 17
M3-3.9: 193
M<3: 569https://t.co/wlgp9sbQbN pic.twitter.com/2Fe61Nr5v2

— John Cassidy (@earthquakeguy) January 2, 2021

In seismic terms, the west coast is due for a major earthquake at magnitude eight or higher — but seismologists still can’t say whether that’s coming tomorrow or in the next 100 years.