Other Countries Benefitting from Canada’s Earthquake Research
At 2:46 p.m. on March 11, 2011, Japan's northeast coast was shaken by a magnitude 9.0 earthquake, the largest ever recorded in the country's history. Twenty-six minutes later, towering tsunami waves rolled in. As of June 2011, more than 14,000 people are thought to have died, although the true tally may never be known. The World Bank ranks it as the world's costliest natural disaster, with economic damage estimated at $235 billion.
The Indian Ocean tsunami, on the morning of December 26, 2004, was triggered by an even larger magnitude earthquake (9.2). It was much deadlier, claiming the lives of more than 250,000 people in 14 countries bordering the Indian Ocean. The economic cost of $14 billion, however, was far less than in Japan, “partly because of low property and land values in the affected areas,” according to The Economist.
These cases illustrate the reality of natural disasters in the 21st century, says Dr. John Clague, Canada Research Chair in Natural Hazards and Director of the Centre for Natural Hazards at Simon Fraser University. “In poor countries, deaths from natural disasters are increasing, while in wealthy countries, economic damage from natural disasters is increasing.”
In Canada, happily, there have been no major earthquakes to date that have led to large-scale property destruction and personal injury or death. Many of the country’s major urban centers, however, are vulnerable to earthquakes to some degree.
The west coast is Canada's most seismically active area: of the approximately 4,000 earthquakes recorded annually in Canada, half occur in or offshore British Columbia. This puts Vancouver and Victoria at the top of the list of urban centers at risk. But Montreal, Ottawa, Toronto, and Quebec City are all at risk of an earthquake as well.
The Canadian Risk and Hazards Network has concluded that a significant earthquake is Canada's greatest potential natural disaster, seeing as much of our urban infrastructure predates the seismic-based building codes introduced in the 1970s. The magnitude 6.7 Northridge, California, earthquake in 1994 illustrates the level of damage that could occur on Canada's West coast under similar circumstances. It left 60 people dead, 7,000 injured and more than 40,000 buildings damaged in Los Angeles and surrounding counties.
Although it's not yet possible to predict exactly when and where an earthquake will occur, Canadian scientists are carrying out a range of geophysical studies, both on land and offshore, to develop reliable prediction methods.
At Natural Resources Canada, one project with strong potential benefits uses global positioning satellite technology to measure clusters of miniscule tremors along faults that form where the Juan de Fuca tectonic plate is being forced under (or subducted beneath) the North American Plate. This is Canada's most earthquake-prone region, and great earthquakes of magnitude 9.0 or higher occur here on average every 500 to 600 years, the last one being in 1700.
These clusters of miniscule tremors, known as “episodic tremor and slip” events, were first identified by seismologists at the Geological Survey of Canada in 2003. They occur like clockwork every 12 to 16 months and last for several weeks.
While more research is required to fully understand these events, seismologists are certain that they are a key to improving forecasts of when and where the next great earthquake will occur in the region. Other countries, such as Japan and Chile, with similar geological environments, are adapting this Canadian discovery to their own research.
Another project is taking advantage of NEPTUNE, one of Canada's most exciting big science projects. NEPTUNE has wired a 497-mile loop on the seafloor of the Juan de Fuca Plate and sprinkled it with instruments that allow scientists of all disciplines to conduct experiments via the Internet.
Using NEPTUNE, researchers at Natural Resources Canada have set up a deep-water seismograph network that records real-time seismic activity on the Juan de Fuca Plate. This data is fed into the land-based Canadian National Seismograph Network, which is used to determine the size and location of earthquakes as they happen.
Dr. Clague suggests there could be another interesting theoretical application. Should a big earthquake occur at the plate interface, it would be picked up by the NEPTUNE seismometers in real time and transmitted to shore stations, arriving as much as a minute before the earthquake hit Victoria or Vancouver.
Granted a minute is not much time, but Japan had that much advance warning from their monitoring systems at the start of the March 2011 earthquake. This gave them enough time to shut down their railways, preventing the possible derailment of high-speed trains due to the shaking and averting another level of human tragedy.
The Earth is in constant motion, full of tremors and twitches, as its plates push into and under each other. Dr. Clague points out that earthquakes, devastating as they can be, are just part of the natural order. "Science and engineering can help us to understand earthquakes and live more safely with them,” he says. “But at the individual level, we have to know the basics of emergency preparedness, so if an earthquake strikes we will have a better chance of getting ourselves and our loved ones through it."
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