Applied Science prof Carlos Ventura on the risk of earthquake in B.C.
As the province gets ready to ShakeOut on Oct. 17, Carlos Ventura, director of the Earthquake Engineering Research Facility, discusses what his team is doing to reduce the risk of earthquakes in B.C.
Why is B.C. a particularly high-risk earthquake zone?
B.C. is on the edge of the Cascadia subduction zone. From mid-Vancouver Island to northern California, the Juan de Fuca Plate is moving beneath the mantle of the North American Plate. The two plates are continually moving towards one another and sometimes they become stuck. Eventually the build-up of strain exceeds the friction between the two plates and a huge megathrust earthquake occurs.
But the “Big One” from Cascadia is not the only type of earthquake that should concern us. If the epicentre was located somewhere in the Strait of Georgia, a significant crustal-type quake could result in severe damage and losses to the region. The same could be said about a subcrustal earthquake between Vancouver and Seattle.
How soon do you expect the Big One to occur?
It’s a question of probabilities. In the Cascadia subduction zone, 13 megathrust events have occurred in the last 6,000 years, averaging one every 500 to 600 years. Some have been as close together as 200 years and some have been as far apart as 800 years. The last one was 300 years ago.
What are you doing to prepare for earthquakes?
The team at UBC’s Earthquake Engineering Research Facility works with the provincial government to optimize infrastructure, reduce seismic risk and minimize potential losses from earthquakes—both in terms of human lives and physical damage.
As part of the Ministry of Transportation’s Gateway Program, through the BC Smart Infrastructure Monitoring System (BCSIMS), we have installed sensors to assess the health of structures like bridges and public schools before, during and after earthquakes. Similar to a check-up with your doctor, the sensors assess the vital signs of the bridge and tell us how much stress is on a bridge and what may be beyond its capacity. The BCSIMS makes use of state-of-the-art technology to monitor these structures on a continuous basis, 24/7.
After an earthquake, we can analyze the data in a fast and efficient manner to develop post-earthquake prioritization and emergency response for British Columbia. The data also allow us to monitor the effects on the structure and plan maintenance schedules.