The central and eastern regions of Canada are in good shape when it comes to the earthquake-resistance of their buildings despite the shake-up the regions received Wednesday, say experts.
An earthquake hit at 1:41 p.m. ET south of Echo Lake, Que., 60 kilometres north of Ottawa near the Ontario border. It was felt across southern and eastern Ontario and western Quebec, as well as in some U.S. states, including Michigan, Ohio, Pennsylvania, Vermont, New Jersey and New York.
With a magnitude of 5.0, it caused buildings to shake, leading many to fear that some structures could collapse. Many offices were evacuated as a precautionary measure.
Overall, however, buildings in Quebec and Ontario are safe, said Samir Chidiac, a professor in the department of civil engineering at Hamilton, Ont.-based McMaster University.
"Buildings in Eastern and Central Canada are built to resist earthquakes that are most likely to occur in these regions," he told CBC News Thursday. "The National Building Code of Canada, which prescribes the seismic forces for all regions of Canada, is always being updated to account for new data or knowledge."
The only buildings whose ability to withstand earthquakes is unknown are ones built before 1970, says Glenn McGillivray, managing director of the Institute for Catastrophic Loss Reduction in Toronto.
"Structures built after about 1970 would be able to withstand moderate events, although those built in the Charlevoix region of Quebec would be able to withstand major events," said McGillivray. "The formulas are complicated, but suffice to say that much depends on the region being considered, as requirements change from area to area."
McGillivray said that wood frame structures generally hold up better than masonry buildings and that the older the building, the greater the potential for damage.
"It appears that virtually all structures damaged in yesterday's event were historic in nature, built before — sometimes well before —1970," he said. "This is how we can see that better building codes work."
Seismic activity in region dictates design
The West Coast has different building standards than the eastern and central parts of Canada, said Chidiac, a function of the variety of seismic activity in those regions.
"We don't design buildings to resist major earthquakes unless they are built in regions known or deemed to be shaken by large earthquakes," Chidiac said.
The parts of Ontario and Quebec affected by yesterday's earthquake have not traditionally seen big quakes.
"Historically, we have two other events that had larger magnitudes: the 1988 Saguenay earthquake, with magnitude 5.9, and the 1944 Cornwall-Massena earthquake, with magnitude 5.8," he said.
Nonetheless, McGillivray said, the temblor Thursday served as a reminder to be prepared. He says people have to forget the notion that earthquakes can't happen in their area.
"They need to plan for it, not just wait for it," he said.
Homeowners can help protect themselves and their homes by fastening large shelves, wall units and appliances to walls using brackets or Velcro, as well as fastening doors to shelves or cupboards with claps, McGillivray said.
Placing larger, heavier items on lower shelves and lighter items on top can also help prevent injuries.
People should also take care to protect their gas tanks, said McGillivray. Homeowners might wish to consider installing a natural gas seismic shutoff valve, which automatically shuts gas off in the event of a quake.
"And, if there is a chimney close to the gas main, they may wish to install a protective metal cage on the valve to protect against falling bricks," McGillivray said.
As for personal safety, Chidiac said that staying away from objects in the home that can fall and injure you is critical, as is staying in areas that are structurally reinforced, such as doorways.