Experts determine likely future earthquake source in BC

[Ingrid Brunkhorst Hurrell 990]

Experts determine likely future earthquake source in BC

http://globalnews.ca/news/1923225/experts-determine-likely-future-earthquake-source/

Earthquake-preparedness is part & parcel of life in BC.

This is just an updated report on some of the latest scientific findings after the Haida earthquake in 2012.

[Raquel 1,305]

"The scientists’ findings were revealed shortly after the provincial government released a consultation report that found B.C. is falling behind on earthquake preparedness."

That doesn't make me feel warm and fuzzy inside!

Interesting article though - thanks Ingrid...

[Ingrid Brunkhorst Hurrell 990]

"The scientists’ findings were revealed shortly after the provincial government released a consultation report that found B.C. is falling behind on earthquake preparedness."

That doesn't make me feel warm and fuzzy inside!

Interesting article though - thanks Ingrid...

Raquel, the thing is: earthquakes happen all the time in the Pacific Rim of Fire, and a bunch of countries are affected by it, including the west coast of Canada/USA. Kids learn from an early age at school what to do in the event of an earthquake. Building standars have changed/are changing to withstand stronger earthquakes. Other areas have tornadoes or hurricanes or other natural disasters. One learns to live with it and prepare as best as you can. The 1964 Great Alaska earthquake (9.2, triggered a tsunami) - was the most powerful/recorded earthquake in N.American history, caused a lot of damage - even down to Oregon as in houses that got swept away etc. A friend of mine was a little girl when it happened and remembers how their family had to move away from the beach area in Seaside, Oregon on to higher ground. Good thing too as a tsunami wave swept away some bridges. houses etc. Not to downplay the severity of this quake but I think a lot was learnt as a result.

The emergency response teams are well-trained, the tsunami warning systems in place, (in Cannon Beach, OR. we had to evacuate 3 times in 6 years and the whole process went extremely well, which shows how good the warning systems are) If one develops an awareness of what can be done to prepare, in doing so become more proactive, (not fearful, but alert), then that is really all one can do, besides prayer. Now Cannon Beach is a small coastal town and compared to Vancouver, BC. we are talking apples and oranges as a city the size of Vancouver has its own set of challenges, eg the Sky trains, George Massey tunnel, etc.

Every town, city, country has its own set of challenges and potential disaster areas, and we cannot allow ourselves to live in fear of "what could happen." If you haven't been to BC yet, I guarantee you, you wil love it.

[Raquel 1,305]

Ingrid - thank you for that information - and you are indeed correct that each country has its challenges.

It all depends which ones you are willing to put up with that assists you in deciding where to settle!

It sounds like they are well prepared in comparison to South African standards - and I guess this is not something we have to deal with down here, but as stated previously, sadly we have challenges of our own!

I have not been to BC - however intend to settle there... if the CIC could just invite me already!!!

It is so lovely to still have someone who has long left RSA still being so active on this wonderful forum, guiding and preparing us, for whom this exciting journey has just begun, each step of the way! Thank you!!!!

[Helanie 462]

:DThanks Ingrid for the information - your contributions are always welcomed and topics always interesting!

:offtopic:I couldn't agree more with Raquel!! Thank you Ingrid and everyone for helping and assisting and guiding us through this unsure period in our lives! Sharing is CARING!

[Jules 1,390]

Undortunately BC is long overdue for a large earthquake. And the longer the wait for the big one the more likely the big one will be very big. In layman terms it is pressure building up, so several smaller quakes are actually good because it relieves pressure. When I say smaller quakes I'm not talking about the minor tremors of under 2.0. I mean having several newsworthy smaller quakes - like something around 5.0

Part of my job involves involves catastrophic reinsurance. It's interesting dealing with the experts who do predictability modeling on quake and hurricane risk (where I work we some reinsurance risk exposure in the Caribbean and Latin America)

[Tracey22 839]

Ottawa valley is also due for an earthquake....

[Raquel 1,305]

Wow Jules! Must be an extremely interesting line of work in terms of expert opinions of when they are due and how extreme they may be!

[Ingrid Brunkhorst Hurrell 990]

Undortunately BC is long overdue for a large earthquake. And the longer the wait for the big one the more likely the big one will be very big. In layman terms it is pressure building up, so several smaller quakes are actually good because it relieves pressure. When I say smaller quakes I'm not talking about the minor tremors of under 2.0. I mean having several newsworthy smaller quakes - like something around 5.0

Part of my job involves involves catastrophic reinsurance. It's interesting dealing with the experts who do predictability modeling on quake and hurricane risk (where I work we some reinsurance risk exposure in the Caribbean and Latin America)

I find any type of natural disasters - the why's and the when's etc - fascinating information Jules. Your job must be extremely interesting.

Racquel, this website has a list of the biggest quakes BC has had: http://www.cbc.ca/news/canada/british-columbia/5-biggest-earthquakes-to-hit-b-c-that-we-know-of-1.2504277

In the 1900's, it is estimated that a quake of at least a 9.0 magnitude hit the coast. First Nations' folklore confirms it.

We lived in Tornado Alley down in the States for a while. That's a different animal. At least damage is more constricted geographically but as we all know, they can be pretty nasty too.

[Raquel 1,305]

Interesting article Ingrid - thank you...

I have got to admin that I am somewhat fearful of moving to earthquake country, but I do think it has a lot to do with the fact that I have absolutely no idea what the do's and don'ts are when an earthquake hits!

I guess that old saying that "knowledge is power" reigns true here - will just need to inform ourselves and we will be just fine!

I remember how fearful I felt last year when we had an earthquake here in JHB: http://www.enca.com/tremor-rocks-gauteng

I was located in JHB CBD (rather far from the epicenter) and felt a slight tremor - what did I do, grab my bag and ran out the building! lol

What the hell was I thinking grabbing my bag first????

[Jules 1,390]

Being prepared helps a lot but the outcome is largely driven by the size of the quake. I've had a number of discussions with our catastrophic reinsurers on the west coast fault lines and they have said that they are concerned because of the absence of smaller quakes over the last couple of decades. Last decent quakes on the west coast were in California and that was around 30 years ago. BC hasnt had enough large pressure relieving quakes.

Having said that, the damage (even from a mega quake) depends on the depth and epicenter location. A shallow 6.0 is worse than a deep 8.0

And a 6.0 centered right under downtown does more damage than 8.0 centered in a less dense population area and 100km away from the city.

So BC could have the big one (>8.0) but it could be deep and be centered away from downtown and do little damage. BC has enough open and rural land to actually stack the odds in favour of the big one to likely be centered away from Vancouver. That is good. Now if it's centered off the coast then the island does face a legitimate tsunami risk.

[Raquel 1,305]

Interesting Info Jules - makes perfect sense.

[MaryJane 2,815]

Having experienced a cataclysmic 7.8 magnitude earthquake in my schooldays in the Philippines (complete with a volcano eruption and raining ashes everywhere), I can definitely say that it is no fun. Truly indescribable feeling. You know what you're supposed to do and you know what needs to get done, but somehow, in the midst of the earth moving and buildings shaking, and your feet trying to claw some sort of stability on the ground, it just doesn't all come together.

A major city ill-prepared for a big earthquake will suffer tragic damages, no doubt about it. More than those few seconds of tremors that I survived (and the shocks that came after), what terrified me the most was the aftermath of that event - mourning the lives lost, searching for the missing under rubbles, destruction of major infrastructure (hotels, schools), etc.

Maybe I was young then...but those images are still with me to this day.

[Raquel 1,305]

Not cool MaryJane! Sorry you ever had to experience that!

[Eva 58]

Ingrid, I remember discussing this briefly when we met. I must admit that living below sea level and on silty ground here in Ladner makes me a bit nervous, even though we have the dikes and I would imagine that the Island should protect us from a tsunami. It may be something for those wanting to move to the BC coastal region to consider. Would it be safer to live in Maple Ridge for example, where the ground is much more stable and far from the coast?

There is so much to consider when deciding where to move to. I can't belive that a year ago we were still in SA trying to make up our minds about where to settle. In the end, the better weather of the lower mainland won and thanks to our incredibly supportive friends, Hans and Chantėl, whom we met via this forum, we are very happily settled in Ladner.

MaryJane, that must have been a very traumatic experience!

[Jules 1,390]

While I would never discourage anyone from moving to BC because every region has its risks and challenges, I would not recommend anyone to live in a region below sea level close to the ocean that is on a fault line. Personally I wouldn't live in Ladner but I'm a little risk averse.

[Ingrid Brunkhorst Hurrell 990]

Having experienced a cataclysmic 7.8 magnitude earthquake in my schooldays in the Philippines (complete with a volcano eruption and raining ashes everywhere), I can definitely say that it is no fun. Truly indescribable feeling. You know what you're supposed to do and you know what needs to get done, but somehow, in the midst of the earth moving and buildings shaking, and your feet trying to claw some sort of stability on the ground, it just doesn't all come together.

A major city ill-prepared for a big earthquake will suffer tragic damages, no doubt about it. More than those few seconds of tremors that I survived (and the shocks that came after), what terrified me the most was the aftermath of that event - mourning the lives lost, searching for the missing under rubbles, destruction of major infrastructure (hotels, schools), etc.

Maybe I was young then...but those images are still with me to this day.

Amazing (and very traumatic) experience, MaryJane.

Very thankful you escaped unscathed (physically) but I can imagine this is a very raw topic for you, and that it brings back a lot of bad memories.

[Ingrid Brunkhorst Hurrell 990]

Ingrid, I remember discussing this briefly when we met. I must admit that living below sea level and on silty ground here in Ladner makes me a bit nervous, even though we have the dikes and I would imagine that the Island should protect us from a tsunami. It may be something for those wanting to move to the BC coastal region to consider. Would it be safer to live in Maple Ridge for example, where the ground is much more stable and far from the coast?

There is so much to consider when deciding where to move to. I can't belive that a year ago we were still in SA trying to make up our minds about where to settle. In the end, the better weather of the lower mainland won and thanks to our incredibly supportive friends, Hans and Chantėl, whom we met via this forum, we are very happily settled in Ladner.

It's one of those "iffy" things...experts say it is coming, for sure, but no one can predict when.

Re. as to where to live...well, I compiled a few things here for you-not to create fear, but to give information as to what could happen.

I think BC needs to be more pro-active with re. to putting up signs indicating a tsunami-safe route that takes people to higher ground.

Again, no one is sure when, but always good to be informed:

Tsunami Hazard to North and West Vancouver, British Columbia

http://www.nsemo.org/sites/default/files/files/NSEMO%20report.pdf

Earthquake BC and the Fraser ValleyWhat factors might be involved in the Fraser Valley? Should we take some comfort that Vancouver Island is between us and the Juan de Fuca plate? I would suggest getting prepared and if nothing happens - count that is being a good day.

I wrote recently that the Fraser Valley is unique in that it falls between the intersection of two mountain ranges, the Cascades to the south and the Coast Mountains to the north. Tremendous plate activity has already occurred the evidence is visual just have a look around. What I didn't know until I started to research this piece was that two fault lines run through the Fraser Valley known as the Vedder Mountain and Sumas faults. Perhaps this is the reason that an earthquake monitoring station is maintained by Natural Resources Canada on Vedder Mountain. If you are wanting to have a look at the seismogram monitors in Canada go to the NRC seismogram site. It would appear that there is a greater vulnerability than I first thought. Not to panic of course with a 400-500 years event horizon.

What can you do?

• Purchase earthquake house insurance
• Earthquake proof your home
• Develop an disaster plan and survival kit sufficient for 72 hours.
• Contact and become involved with your local government as they will lead the initial response to a disaster in the community.
• Volunteer.

Here are some good sites to prepare for an earthquake:

• Emergency Management BC Prepare for an Earthquake in British Columbia
• Emergency Management BC Earthquake Preparedness
• Government of Canada Earthquakes - What to Do?

http://www.frasercheam.com/2014/04/earthquake-bc-and-fraser-valley.html

Earthquake risk in B.C.

British Columbia has the highest earthquake risk in Canada. In fact, several thousand small earthquakes are recorded in B.C. every year. A much smaller number are big enough to be felt and over the last 10 years there has been an average of one larger earthquake of at least magnitude 6 per year.

Although earthquake risk exists throughout the Province, it is southwestern B.C. and Haida Gwaii which are at highest risk. This encompasses all of the Lower Mainland, the Fraser Valley and beyond, coastal areas and Vancouver Island.

http://www.bcaa.com/campaigns/earthquake/overview/risk-impact

Recent Significant Earthquake Reports

Nice map of the locations of recent earthquakes here: http://www.earthquakescanada.nrcan.gc.ca/index-eng.php

BC Fault Line, Tsunami Risks

CLOCK IS TICKING TO 'BIG ONE'

While British Columbians have long been warned of “The Big One,” two studies released last month are pegging a megathrust earthquake as arriving sooner and causing more devastation than ever predicted.

The fault line closest to Kitimat is the Queen Charlotte Fault Zone, which has been called "Canada's San Andreas fault" and triggered an 8.1 magnitude quake in 1949. But the area with the most potential for a devastating quake is the Cascadia Fault which stretches from northern California to southern Vancouver Island.

http://www.huffingtonpost.ca/2012/09/21/bc-fault-line-tsunami-earthquake-northern-gateway-pipeline-kitimat_n_1902422.html

2005 Richmond-Delta Study

Fig. 8

Professors John Clague (Department of Earth Sciences, Simon Fraser University) and Ian Hutchinson (Department of Geography, SFU) completed a study of near-surface sediments beneath the plain of the Fraser delta in the summer of 2005. Their objective was to determine whether or not any prehistoric tsunamis had crossed what are now Richmond and Delta. A total of 33 cores were retrieved from sites (Fig. 8) where the likelihood of tsunami deposit preservation

Fig. 9

was highest. The cores likely preserve sediments dating as far back as 4000 years ago. The investigation revealed no evidence of tsunami deposits in the Fraser River delta. Drs. Clague and Hutchinson could not completely rule out the possibility that tsunamis have inundated portions of the Fraser River delta in the past, but but that the tsunami threat to Richmond and Delta is very small (Fig. 9).

http://www.richmond.ca/safety/prepare/city/hazards/tsunamis/tsunamistudy.htm?PageMode=HTML

‘Catastrophic’ earthquake and tsunami brewing off B.C. coast

DECEMBER 29, 2014

Small quakes regularly rattle the west coast, but megathrust quakes are a different beast. Cascadia’s subduction quakes are huge – magnitude 9 or more. The last one stuck Jan. 26, 1700, creating a tsunami that destroyed First Nations villages and swept across the Pacific causing damage in Japan.

There is no predicting when the next on will strike. But experts say there is a 12% probability a Cascadia megathrust earthquake will hit in the next 50 years.

http://www.vancouversun.com/technology/Catastrophic+earthquake+tsunami+brewing+coast/10682930/story.html

Earthquakes While earthquakes are common in British Columbia and adjacent coastal waters, most are minor in energy release or are sufficiently remote to have little effect on populated areas. Nevertheless, earthquakes with a magnitude of up to 7.3 have occurred within 150 kilometres of the Lower Mainland.

Based on geological evidence, however, stronger earthquakes appear to have occurred at approximately 600-year intervals. Therefore there is a probability that there will be a major earthquake in the region within the next 200 years.^[14]

In April 2008, the United States Geological Survey released information concerning a newly found fault line south of downtown Abbotsford, called the Boulder Creek Fault. Scientists now believe this fault line is active and capable of producing earthquakes in the 6.8 magnitude range.^[15]

http://en.wikipedia.org/wiki/Lower_Mainland

Tsunami, Flooding, Storm Surge Would Wipe Out Richmond, Parts Of Metro Vancouver

11/04/2012

Vancouver would survive a tsunami, but Richmond might have a hard time coping if it was flooded with the same force as Hurricane Sandy this week, according to a graphic created by a B.C. student.

The striking image circulating the interwebs shows what would happen if the sea level were to rise by four metres. The graphic shows Vancouver surviving just fine, but the suburbs of Richmond, Delta and Ladner are completely submerged underwater.

Yan learned from the website that Steveston, Richmond's touristy fishing village, would be wiped out, and much of Delta and Ladner's agricultural land would be completely flooded. Surrey and Langley would also see flooding in certain areas. http://www.huffingtonpost.ca/2012/11/04/tsunami-flooding-storm-surge-vancouver-richmond-earthquake_n_2066649.html?

[Eva 58]

Some great resources here to look at. Thanks Ingrid!

[Old Van 264]

Please allow the Geologist to chime in here if that's ok.

I like to deal with facts and not the fear mongering BS that get's splattered in the sensationalistic and (bad) news hungry media.

Lets' start with "The big one". I actually find it extremely irritating when people talk about "the big one" and how Vancouver is due, HOGWASH! What would any sane person or someone reasonably intelligent consider to be 'the big one"? As Jules correctly stated, a 6 can do much more damage than an 8 depending on the location and depth of the epicentre. I would regard anything above 7 to a pretty "big one". Now if that is the case we've had "the big one" FOUR TIMES in the last 60 years, one as recently as 2012!!! So, I would argue that statistically, we are actually far from due!

Another "fact" that the media loves to report is how the zone has gone "quiet". Really??? We've had in excess of 340 seismic events in the last THIRTY DAYS! Some close to 5 magnitude.

Here are some facts:

• The most active fault plane is the Queen Charlotte fault that runs up the western side of Haida Gwaii. So that area is more prone to damage and injury in the event of a quake.
• Yes we are in an area where the Juan de Fuca plate is subducting under the North American plate, BUT the geometry is very unfavourable to cause a megathrust earthquake with an epicentre right below Vancouver. See here:
  http://www.earthquakescanada.nrcan.gc.ca/zones/cascadia/images/cas1.jpg
• The big quakes are more prevalent in shear or strike-slip scenarios like the San Andreas fault. (Which is not the fault geometry around Vancouver).
• A nasty Tsunami following a seismic event in the region is indeed a very real possibility. That's why I'm located 100m above sea level in Maple RIdge!
• The Richmond-Delta-Ladner area is definitely precariously located in an area kept dry by a dike system. Should a serious breach occur (Tsunami or no Tsunami) I would rather be a little higher up!
• One only needs to look at Google flood maps to realize what even a 1m change in sea level can do in the future.

I can go on and on about the Geology and plate tectonics, but it gets rather boring, SO the bottom line is, your chances of getting injured by the garburator in your kitchen sink is about 1000 times better than getting injured in an earthquake. And the Lord alone knows what can happen to you, should you decide to stay in South Africa to avoid "The Big One!"

And yes, I have nothing against being prepared for any natural disaster.

Edited April 13, 2015 by Old Van

[Ingrid Brunkhorst Hurrell 990]

Please allow the Geologist to chime in here if that's ok.

I like to deal with facts and not the fear mongering BS that get's splattered in the sensationalistic and (bad) news hungry media.

Lets' start with "The big one". I actually find it extremely irritating when people talk about "the big one" and how Vancouver is due, HOGWASH! What would any sane person or someone reasonably intelligent consider to be 'the big one"? As Jules correctly stated, a 6 can do much more damage than an 8 depending on the location and depth of the epicentre. I would regard anything above 7 to a pretty "big one". Now if that is the case we've had "the big one" FOUR TIMES in the last 60 years, one as recently as 2012!!! So, I would argue that statistically, we are actually far from due!

Another "fact" that the media loves to report is how the zone has gone "quiet". Really??? We've had in excess of 340 seismic events in the last THIRTY DAYS! Some close to 5 magnitude.

Here are some facts:

• The most active fault plane is the Queen Charlotte fault that runs up the western side of Haida Gwaii. So that area is more prone to damage and injury in the event of a quake.
• Yes we are in an area where the Juan de Fuca plate is subducting under the North American plate, BUT the geometry is very unfavourable to cause a megathrust earthquake with an epicentre right below Vancouver. See here:

  http://www.earthquakescanada.nrcan.gc.ca/zones/cascadia/images/cas1.jpg

• The big quakes are more prevalent in shear or strike-slip scenarios like the San Andreas fault. (Which is not the fault geometry around Vancouver).
• A nasty Tsunami following a seismic event in the region is a very real possibility. That's why I'm located 100m above sea level in Maple RIdge!
• The Richmond-Delta-Ladner area is definitely precariously located in an area kept dry by a dike system. Should a serious breach occur (Tsunami or no Tsunami) I would rather be a little higher up!
• One only needs to look at Google flood maps to realize what even a 1m change in sea level can do in the future.

I can go on and on about the Geology and plate tectonics, but it gets rather boring, SO the bottom line is, your chances of getting injured by the garburator in your kitchen sink is about 1000 times better than getting injured in an earthquake. And the Lord alone knows what can happen to you, should you decide to stay in South Africa to avoid "The Big One!"

I like this!

You should have spoken up longgg ago!

Love learning more about earthquakes/severe weather etc, so please keep talking.

Were you around when Seattle had the 6.8 quake in 2001? seattle earthquakes 2001

We were living down in Cannon Beach, Oregon at that stage and everything shook: computers, the hedge outside, etc. Had to evacuate the town for potential tsunami. Learnt a lot though that experience. Have a healthy respect for what Mother Nature can do.

[Old Van 264]

Ingrid, I was on the 14th floor in my office in Georgia Street in downtown Vancouver when "the big one" from 2012 hit. It was mild swaying at best. The best part was seeing Paula, my PA diving under her desk in a mini skirt.

Edited April 13, 2015 by Old Van

[Ingrid Brunkhorst Hurrell 990]

Ingrid, I was on the 14th floor in my office in Georgia Street in downtown Vancouver when "the big one" from 2012 hit. It was mild swaying at best.

2012? That was the Haida Gwaii 7.8-quake, right? I don't recall feeling it but hubby may have as he also worked downtown Vancouver.

The 1989 San Francisco quake impacted me quite a bit - not that I was there, but we were visiting friends on a ranch in Oregon and of course, the media stopped reporting on anything but The Quake. Lots of sad stories and also miracles with that one.

[Raquel 1,305]

I can go on and on about the Geology and plate tectonics, but it gets rather boring, SO the bottom line is, your chances of getting injured by the garburator in your kitchen sink is about 1000 times better than getting injured in an earthquake. And the Lord alone knows what can happen to you, should you decide to stay in South Africa to avoid "The Big One!"

This post makes me feel much better... And I agree that I would rather take my chances on waiting for "The Big One"

[Raquel 1,305]

Ingrid, I was on the 14th floor in my office in Georgia Street in downtown Vancouver when "the big one" from 2012 hit. It was mild swaying at best. The best part was seeing Paula, my PA diving under her desk in a mini skirt.

lol