Ottawa’s heritage buildings weren’t built with modern techniques, making them vulnerable to earthquakes. Among these are the Laurentian Leadership Centre on Metcalfe.
Older buildings in Centretown are at risk of damage if a major earthquake hits the Ottawa area, an active seismic zone, experts say.
Buildings constructed before 1990 “may be at risk” because they were not designed to be earthquake-resistant, says Murat Saatcioglu, a civil engineering professor at the University of Ottawa and president of the Canadian Association for Earthquake Engineering.
These include older brick buildings such as McAuliffe House and Knox Presbyterian Church on Lisgar Street.
Buildings constructed since the 1980s can better withstand the impact of an earthquake.
“We currently design buildings for them to behave in a ductile manner, which means if the capacity is exceeded during a strong earthquake, they would deflect the form and bounce back to their original position rather than collapsing,” Saatcioglu says.
“Ductile materials like steel and well-designed reinforced concrete can do that.”
Older buildings built with stone and brick masonry do not have this ability to flex and move.
The National Building Code of Canada sets out provisions for the design and construction of new buildings to make them capable of handling up to a 7.0 magnitude earthquake. A magnitude of 6.0 and above is considered strong and can cause severe damage.
When the magnitude of an earthquake increases by one, the energy released by that quake is 10 times higher.
But older buildings such as those in Centretown are not up to these provisions and must be updated, says Mohammad Rayhani, a professor specializing in earthquake engineering at Carleton University.
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“If we experience strong earthquakes with a magnitude like 6.0 or 7.0, older buildings that we have are going to experience damage over there,” he says.
Rayhani adds that damage to the buildings could range from cracking to a complete collapse.
“The buildings can be strengthened with stronger beams and columns, and flexible materials that allow slightly more rocking,” he says.
Built in 1909, Trinity Western University’s Laurentian Leadership Centre (also known as Booth House) has not been retrofitted for earthquake readiness, says Janet Epp-Buckingham, director of the centre.
Designated a national historic site, the brick-and-stone building on Metcalfe Street was commissioned by lumber baron John R. Booth.
It remained in the Booth family until 1947 when it was sold to the Laurentian Club of Ottawa. Trinity Western bought the building in 2001 and opened the centre in 2002.
“Clearly the building has stood the test of time in surviving over 100 years. As far as I am aware, it has not been retrofitted in terms of earthquake readiness,” says Epp-Buckingham. “However, we have been undergoing restoration work on the building envelope over the last few years. Everest Restoration, which has completed the work thus far, has told me that the building is very well-built and structurally sound.”
Located in the western Quebec seismic zone, the Ottawa area is one of the most active earthquake zones in Canada. But these earthquakes tend not to be strong.
“(Western Quebec gets) about 100 to 150 earthquakes that are recorded every year. Most of those are at magnitude 2.0 to magnitude 3.0. Of those 100, 150 events, about 10 are felt every year,” says Stephen Halchuk, a seismologist with Natural Resources Canada.
He adds that there is no damage to buildings at such a low magnitude.
“Usually, (earthquakes) have to get up to a magnitude 5.0 before you start seeing significant damage.”
Historically, major earthquakes in the western Quebec seismic zone have not surpassed a 7.0 magnitude.
Halchuk adds that massive earthquakes such as the recent 9.0 magnitude quake in the Tohuku region of Japan cannot happen in the Ottawa area.
“The mechanics aren’t in place for a similar-sized event. In Japan, it lies next to what is known as a subduction zone where one of the earth’s plates is subducting or slowly sliding beneath another plate,” he says.
“These massive earthquakes really can only occur around the world’s subduction zones, which we are not in, in the Ottawa area.”