The advertising was great – Thank You! – T. Greenwood
Despite the earlier start and different venue, it was a fair turn-out – A. Bryant
This map shows two weeks worth of small earthquakes (yellow circles) and five years worth of large (pink circles, magnitude >4). – Natural Resources Canada
This was a big one (magnitude 8.9). A huge wave rolls over the tsunami barrier at Miyako City, Japan, on March 11, 2011. – M. Shimbun (REUTERS)
Another big one (magnitude 6.3). Damage to the Christchurch Catholic Cathedral, New Zealand, February 22, 2011 – D. Wethey (NZPA)
This is magnitude 5.1 Workers survey the damage in Gracefield, Quebec, 2010. – A. Wyld (CANADIAN PRESS)
Earthquakes happen for a variety of reasons. The Juan de Fuca oceanic plate is trying to move under the North American plate. As a result, the South Coast of B.C. can get both megathrust earthquakes off the coast as well as shallow earthquakes just below some of the major cities. – Natural Resources Canada
Earthquakes in southwestern BC are spread across broad bands, rather than laying tightly along fault-lines as seen in California. The earthquakes on this map are occurring within both the North American Plate, and the Juan de Fuca plate. – Natural Resources Canada
Most of these would go un-noticed. Here’s Alison with a seismograph (i.e., a machine designed to notice the unnoticeable!) – Victoria Times-Colonist
Why the “Big One” is going to come….sometime – U.S. Geological Survey
The biggest earthquake to hit Japan since records began 140 years ago struck in 2011, triggering a 10-metre tsunami that swept away everything in its path, including houses, ships, cars and farm buildings – and left this ferry perched on a roof! – Anonymous (AP)
This man, a local reporter, miraculously escaped – Kamaishi Port Office (REUTERS)
Japan suffered a “perfect storm” of earthquake, tsunamii, fire, and the Fukeshima nuclear event after a massive 8.9 magnitude quake hit northeast Japan in 2011 – A. Kyodo (REUTERS)
Unbelievable power. – I. Inouye (AP)
If you felt an earthquake, don’t wait – get to high ground – the fellow seen on the roof at top-left had the right idea – Anonymous (REUTERS)
If you FEEL an earthquake, do this! Alison demonstrating the classic “duck and cover” approach to surviving an earthquake – A. Bird (TWITTER)
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)