Ryan Thoms – “The 1946 Vancouver Island Earthquake”

Ryan Thoms – “The 1946 Vancouver Island Earthquake”
by Andrew Bryant, 21 Oct 2021.

After many years with the BC Wildfire Service, Ryan Thoms now lives in Powell River and is manager of the qathet Regional District’s Regional Emergency Preparedness Service.

His topic was apt, for not many remember the Vancouver Island earthquake of 1946.  Fortunately the local damage was not severe.  Some chimneys were toppled, and the school was damaged.  But residents were fortunate.  The fact that it happened at 10:13 AM on a Sunday in June meant that most people were home.  Had it occurred on a weekday in January things might have been quite different.

Beginning with historical images and newspaper accounts, Ryan took our understanding of the event to a new level with application of modern geophysical methods.  There were a few surprises.  I was unaware, for example, that there was a freshwater tsunami on Powell Lake, and a substantial “debris flow avalanche” just off Grief Point.

History is indeed surprising…and please take warning…often repeats itself!




Alison Bird – “Earthquakes of Coastal BC”

Alison Bird – “Earthquakes of Coastal BC”
by Andrew Bryant, 14 Sept 2017.

Alison Bird works as Earthquake Seismologist for Natural Resources Canada, and is based in Saanich.  Our club, in partnership with the Powell River Regional Emergency Program (PRREP), invited her to come talk to us about her area of expertise – earthquakes – and she graciously obliged.

Beginning with the amazing story of how researchers were able to date, to the day, a massive earthquake that hit waaaay back in 1700, Alison took us through the basics.  What are fault-lines, subduction zones, and plate tectonics?   How big is big?  An excellent one-page primer can be found here.

Using images from around the world, Alison stressed that while the forces unleased in an earthquake truly baffle the imagination, the damage suffered largely depends on more mundane things.  Location is important (obviously) but soil types, vertical topography, and ocean basin topography are all of great importance – as are building codes, enforcement, retrofitting, and keeping an emergency kit.

Will the “big one” happen?  Most assuredly.  Can we predict when it happen?  No.  Can we mininize risks, through attention to detail?  Yes.

A talk not to be missed.

The Cascadia Mega-Tsunami (given time-zones, this occurred at around 9:00 PM local time, 26 January 1700)