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The chances of an earthquake in the Vancouver BC area
On September 9th 2011 there was a 6.4 magnitude earthquake under the Pacific Ocean off the coast of Vancouver Island.
The effects of this shift were felt all over the Lower Mainland of British Columbia Canada. Although the tremors were very minor, this event has caused many people in the area to start planning for the next "Big One" and to wonder when this might be.
What is probably lesser known is that there was also an earthquake in a similar area on August 11 2011, which was a magnitude of 3.3. In fact there are around a couple of thousand small earthquakes happening across Canada every year.
The video below shows a map of where earthquakes have been occurring across the world recently, most of which have been too small to have a noticeable effect. However, the video suggests that there may be more activity in these areas during the two weeks following September 9.
Unfortunately, even now, it's not easy to predict when a severe earthquake may happen in a specific area; it could happen tomorrow or possibly in a couple of hundred years.
Evidence that large earthquakes have occurred here before
In 1988 the CBC broadcast a documentary about the likelihood of earthquakes in the Vancouver area of BC. At that time it was reported that the Vancouver area had experienced eight significant earthquakes in the last century.
So where's the evidence that a really big earthquake may happen in this area?
Earthquake scientists have examined the coastline of Western BC to see of there have been any changes. It appears that there are areas of ancient forest on the West Coast of Vancouver Island that have sunk down under the waterline suggesting that there have been very large earthquakes occurring there in the past.
A large earthquake big enough to drag down the coast of Vancouver Island into the ocean would result in a huge shock wave affecting Victoria, Vancouver, Seattle and even as far away as Portland Oregon.
Why is the Vancouver area susceptible to earthquakes?
The Vancouver BC area sits on the so called Pacific "ring of fire". This a narrow region that encircles the Pacific ocean that contains a number of active volcanoes (see link) in fact 75% of the total number of the world's volcanoes. The area is known for it's frequent earthquakes and includes the areas in Japan and New Zealand where earthquakes have occurred in 2011.
This "ring of fire" is so active because it is the region where the pacific tectonic plate meets other tectonic plates of the globe. Tectonic plates are vast pieces of the earth's surface that move around and collide with each other resulting in the creation of so much energy that rock is melted causing volcanic eruptions and the ground tremors we know as earthquakes.
The threat of a Tsunami
Any large earthquake in or near the ocean can result in a Tsunami, as we saw in Japan earlier in 2011. The West Coast of North America is no exception.
In fact Port Alberni on Vancouver Island experienced a 14ft Tsunami in 1964, following the huge earthquake in Alaska. Trees were ripped up, cars were strewn everywhere, and houses were knocked off their foundations.
Recently the city of Port Alberni has begun a Tsunami awareness campaign following the recent events in Japan.
What can be done to make the area safer
Because of the unpredictable nature of earthquake activity, it's not usually going to be possible to evacuate the area prior to the event. Consequently, measures have been taken by the BC government, and utility and construction companies, to reduce the amount of damage that could be incurred and mitigate the associated injury to the population.
One scheme that has been under-way for some time is the seismic upgrading of BC schools. Since 2001 over $580 million has been spent on this project, however there is still some concern as to whether there will be enough cashto complete this.
A number of the numerous bridges in the lower mainland of BC have also been retroactively given seismic upgrades over the years.
The electricity company BC Hydro plans to spend $6 billion over the next three years carrying out seismic upgrades on some of it's facilities.
With the increasing cost of all this quake-proofing, and no real evidence that the "big one" will hit some are wondering if all this spending on old buildings is really cost-effective.
All new buildings in BC are required to conform to a code of regulations that require earthquake safety measures are incorporated. The most recent regulations are from 2005 (click here for a summary). This report from the CBC compares BC codes with those from Christchurch in New Zealand which was hit by a 6.3 magnitude aftershock in Feb 2011.
Certainly there is no harm in being prepared and practising what you will do in the event of an earthquake.
General advice is to "drop, cover, and hold" when the shaking begins. (Note that the "triangle of life" approach has been disproved for the types of buildings we have in the West). If you're inside tuck yourself down under a sturdy table facing away from any windows (to avoid flying glass). The greatest danger at this point is from objects flying around the room and pieces of ceiling falling on you. Do NOT go outside until the shaking has stopped, because you're very likely to be hit by debris falling from buildings. If you are already outside try to find an open place where it is least likely that something will fall on you. If you are in a car, stop and wait until the shaking finishes. Usually the earthquake will only last a few moments or even seconds, but there may be several aftershocks for hours or days afterwards.
Purchasing an earthquake kit or making up your own emergency supply box will also make you feel a little more organised. This kind of kit can be used in the event of any natural disaster and even come in useful if you have a significant power outage at your home.
There is a great deal of information on the Internet about what to do in the event of an earthquake, especially from countries that are frequently affected, like New Zealand and Australia - the information is applicable regardless of which it comes from - but be sure to look for reputable sources.
British Columbia Provincial Emergency Program
- Earthquake Preparedness - Provincial Emergency Program
Information about earthquake preparedness in British Columbia. Includes further links and pdf documents.
- Prepare Now for an Earthquake in British Columbia
A guide for BC families and individuals
- Be earthquake prepared : Know what to do before, during and after
Concise tips on what to do during and after an earthquake,from New Zeeland
- Earthquake Survival: Surviving an Earthquake
Some personal information on how to survive earthquakes
- Lessons from Japan: Earthquake Survival 101 - Carry On | Travel + Leisure
Precautions that can be taken when travelling to earthquake prone areas...
Real-time earthquake information
U.S. Geological Survey Earthquake Hazards Program
For real-time information about all earthquakes around the world of a magnitude 2.5 and above, together with maps click here.
An excellent kit with all the items you are likely to require during any disaster.