British Columbia Earthquake And Tsunami Safety Is Uncertain

British Columbia Earthquake And Tsunami Safety Is Uncertain
Map of the Gulf Islands - Image by: Qyd (GIS data) (Public domain), via Wikimedia Commons

British Columbia earthquake and tsunami safety is uncertain.  Since the Japan disaster, tsunami fears have risen to new levels and Canadians are wondering if the same disaster could occur in their home regions.  This should be considered a wakeup call for the residents of Vancouver Island, the gulf islands, and the lower mainland.

A good number of British Columbians on the eastern side of Vancouver Island, the gulf islands, and the neighbouring mainland are under the misconception that should the worst happen, they are protected by Vancouver Island.

It should be noted that in 2007, warning signs for tsunamis were put in place in the low-lying areas of Nanaimo.  The average person in this region and the gulf islands as well, would be wise to pay head to these signs and consider it a wakeup call.  These areas are in fact exposed to the same type of devastation that can be incurred by these natural disasters, similar to those in the northern reaches of Japan.

It is commonly acknowledged by scientists that an earthquake of a similar magnitude to the Japan quake will hit the Queen Charlotte Fault off the west coast of British Columbia at some point in time.

However, the estimate is that a resulting tsunami would not reach the Nanaimo area for approximately three hours after a large quake hit the west coast, and the tsunami waves would have expended a significant amount of energy and decreased to a smaller size by then.

So by virtue of location on the protected part of Vancouver Island, Nanaimo should receive sufficient warning before an incoming tsunami reached the city and surrounding areas.  The exposed west coast areas of Tofino, Uclulelet, and Port Alberni would not be so lucky.

There is a factor that people are not aware of, so they should not assume that because they have shelter from the open Pacific Ocean, that they are not in harm’s way.

A B.C. Hydro study prepared a few years past concluded that a possibility exists for an earthquake, in the magnitude of 7.5 or higher, to occur which has the potential to activate a gigantic undersea landslide of the built-up and unstable sediments at the entrance to the Fraser River.

Approximately ten thousand cubic metres of sedimentary materials are flushed down the Fraser River to its mouth each second accumulating over seventeen million tonnes every year.

A high magnitude earthquake could trigger a massive landslide of this sedimentary material and create huge tsunami waves marching across the Strait of Georgia directly to the Gulf Islands and the east coast of Vancouver Island.  The timeline for this occurrence would be mere minutes.

The study performed simulations which indicated that should a sufficient amount of the sediment, maybe as small an amount as seven hundred and fifty thousand cubic metres, eighteen metre high tsunamis could be created and suddenly flow towards Galiano and other Gulf Islands.

The waves would reduce down to about five metres high by the time they reached Nanaimo, inundating the low-lying areas.

In such an occurrence, no systems for early warning would provide sufficient time to warn people in these areas to go to higher elevations because estimations are that the time between the actual underwater slide and the tsunamis hitting these areas would only be ten minutes.