Saturday, September 10, 2011

Did You Feel It? Earthquakes in BC & the American Northwest

Perhaps I should be grateful that I have felt few, if any, earthquakes during my lifetime. But I'm always a bit annoyed when other people have felt shaking and I haven't!

There was a fairly sizeable earthquake yesterday afternoon, its epicentre far from Vancouver, though apparently a friend of a friend's UBC lab was quivering noticeably.

From Earthquakes Canada (NRCAN):

If you've never been to the Pacific Geoscience Centre or Natural Resources Canada's earthquake sites, you're missing out! Here's the report on EarthquakesCanada for yesterday's 6.3 coastal quake.

It's an amazing website - you can watch seismographs in real time (the squiggly lines machines that tells you an earthquake is occurring) from the comfort of your own PC; you can see where the most recent earthquakes have happened and their magnitudes (they're much more prevalent than you might think!); but most importantly of all, you can read about Megathrust Earthquakes, such as the imminent "Big One" destined to shake the living daylights out of Vancouver, Victoria, Seattle, Portland and everywhere in between, and which will invariably send an enormous tsunami at Japan (as the last one did, dated January 26, 1700 according to meticulous Japanese record keeping, and corresponding perfectly with oral histories of BC's aboriginal population, as well as sediment and tree-ring data studied today).

Thankfully, some of the biggest waves I've ever seen come from the wake of ferries. I'm rather glad I don't have a photo of a tsunami to post here!

Here's a scary quote (from Natural Resources Canada (NRCAN) at, with my emphasis put in:
Points on the outer coast of the North American Margin, which overlay the locked portion of the Cascadia Subduction Zone, move at rates of over 10 mm/yr in a north-easterly direction. The fact that inland sites move at half that rate, or less, indicates that the outer margin is slowly being compressed like a giant spring. At the time of the next great earthquake it is expected that the accumulated compression will be totally released and that the outer coast of southern Vancouver Island will move up to 5 metres to the south-west.
What bothers me most of all are politician's short stints in office, and how instead of wanting to leave a lasting legacy long after they've retired (like seismically stable hospitals and schools), they appear to focus on short-term goals and gains that will keep them in good stead for the coming election n months from today.

Another risk to Vancouver is the resulting fire from downed, above-ground electrical lines. There won't be any water pressure left in the hydrants to put it out, since those water lines will also likely rupture.

St Paul's hospital, for example, is going to crumble to nothing at all. Parts of it, still used, were built before 1900. Most of it was built in the 1930's. It's composed of brick (unreinforced masonry) and is estimated to be destroyed by an earthquake of even 7.0 on the Richter scale. And that includes the newest Providence Building. Yikes.

This is the corner I'll be cowering in during an earthquake (provided I'm, mercifully, at home when it strikes); it's potentially the most structurally rigid part of the apartment, away from appliances, windows and large/tall furniture.

Interestingly, "The Big One" is not the worst-case scenario for seismic events in Vancouver. Many experts point to the 1995 Kobe, Japan earthquake - Kobe had wonderful building codes to weather a subduction zone earthquake like our impending "Big One" (NRCAN reference here), but it didn't focus on shallow, 'crustal' earthquakes which shake differently (and whose epicentres are closer to the city and its buildings). Unfortunately, the large crustal earthquake experienced by Kobe pretty well wiped it out completely, killing countless people and destroying livelihoods, homes, and public infrastructure.

"The Big One" is likely going to affect Vancouver the way the 1964 Alaskan earthquake did (reference here at NRCAN), as the subduction zone is about 150km from our city. (Photos of the Alaskan Subduction Zone Quake can be seen here, on the US Geological Survey's website on the subject. My personal favourite is found here, though this one and this one are also amazing to behold). This is bad enough, if you ask me! Check out those photos - wow wow wow!

A large crustal earthquake, however, could occur directly below Vancouver. This is our biggest threat.

Quote again from NRCAN, on a FAQ page (source here):

If a magnitude 6.9 earthquake can devastate Kobe, Japan, what would a magnitude 9 megathrust earthquake do to Vancouver?
The Kobe earthquake was right beneath the city and the megathrust earthquake will be about 150 kilometres from Vancouver. The damage pattern would be very different. We can get a good example of the kinds of damage Vancouver can expect to experience if we look at what happened to Anchorage, Alaska, during the 1964 magnitude 9.2 megathrust earthquake. Anchorage is about the same distance from the Alaska subduction fault. Small buildings generally had little or no damage, unless they were affected by landsliding. Almost all the damage involved large buildings or large structures such as bridges.
Are megathrust earthquakes our biggest earthquake hazard?
No. Inland earthquakes, which are not as big but can be much closer to our urban areas and occur much more frequently, are our biggest earthquake hazard. 

Hopefully I've managed to get your attention to the great risk of earthquakes here (yes, you should opt into earthquake insurance, absolutely!). I hope it didn't scare you too much, 'cause it scares me like crazy. I have found, however, that I worry significantly less now that I've prepared for an earthquake (as much as you ever can, of course!). Read my past blog post on how you can make yourself an earthquake kit on the cheap.

Purchased Earthquakes Preparedness kits are costly. Find the Green, Broke & Living in Kits alternative DIY kit suggestions via the link above.

To me, earthquakes are like tornadoes and great white sharks: they are really scary things, best avoided, and yet I can't seem to get enough of Shark Week* on TV and I think I've seen 99% of all broadcast video footage of American tornadoes. Morbid curiosity forbids me from changing the channel/not watching the next queued online clip.
*Mike - I still want in on your gruesome but hilarious Shark Week drinking game. It's terrible. And it's ingenious!  

Earthquakes are absolutely amazing, and they have lovely benefits in the long run (i.e. Whistler and Blackcomb; Mt Rainier, Mt Baker, Mt Shasta, and the late Mt St Helen's, which was also an amazing cataclysm in recent history).

Okay, these are in the Rockies and not a direct result of the Cascadia subduction zone. But they are lovely, lovely results of plate tectonics and past seismic upheavals!

But it really does behoove us all to not completely bury our heads in the proverbial sand and let important issues become "Somebody Else's Problem*" because, let's face it - if the inevitable happens, it's going to instantly become 100% YOUR PROBLEM and there won't be a lot you can do about it after the fact!
 *(We miss you, Douglas Adams!)

Let's not get in that regrettable and tragic position and try to have some foresight. I personally view science and engineering to be divine gifts that should be used for the betterment of all people - and that certainly includes building structurally sound hospitals, schools, homes and infrastructure that won't easily collapse and unnecessarily take lives. Especially in the case of hospitals - it's an irony I can't even laugh at.

We may not be able to predict earthquakes, but that doesn't mean we haven't been blessed with the technology and scientific research that shows invariably that we need to prepare now, and prepare well, for them! Let's demand better for our cities and put new hospitals, schools and bridges before completely frivolous things like casinos and even better stadiums (not that I have anything against sports - I really don't!).

Our building was built in the 1960's and is made of wood. It's already shifting on its foundations. One part of our apartment is about 4" lower than the other, and this difference occurs over just 2 feet!

First off though, let's house and feed the poor. (Now there's something that could be considered a seismic upheaval - sacrificing our personal wealth for the good of others! What a radical idea! Oh wait, it's been around for 1000's of years....). We can use the bricks that constitute the current walls of St Paul's to make lovely brick-work paths and patios in the fruit and vegetable producing gardens of the beautiful and seismically smart social housing projects we're going to build. I will personally build (and plant!) raised planting beds from the bricks of St Paul's hospital, given the opportunity!*
*Now there's a good use for them - if The Big One hits when you're gardening, you'll bruise your foot. Much better than a horrifying fall from the 7th floor as the Burrard Building caves in on itself, entombing you and everyone else in it.

Being broke and having to live in Vancouver (or Seattle/Victoria/Portland or areas nearby) doesn't mean you're screwed! See my post on DIY earthquake preparedness kits (conveniently doubling as camping gear!) and start hoarding jugs of sterile drinking water around the house. And try to keep the heavy things off the top shelves!

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