If you live on Vancouver Island, you know that earthquakes are a given due to our location near the Cascadia Subduction Zone: where the Juan de Fuca plate subducts beneath the North American. 

Several thousand earthquakes are recorded in B.C. annually, but ClimateReadyBC says only approximately 50 are felt. While those quakes are often relatively safe and do little damage, several seismic threats exist in the area.

First is the possibility of the "Big One", a megathrust along the boundary between the North American and the Juan de Fuca plates – a magnitude of up to 9 which occurs every 200 to 800 years, says Natural Resources Canada (the last occurred in 1700). There's also potential for the Leech River Fault (M7.0) and Intraslab (Deep) Earthquakes (M7.0+).

So, how prepared is British Columbia for one of these quakes? Here's some information on the state of infrastructure in B.C.'s capital region that may make some feel less rattled.

How to know if your building is safe

What may be at the top of some residents' minds is the safety of the buildings they spend time in.

One could consult with a seismic sort of professional engineer – that's the expensive way, said Edwin Nissen, a professor and research chair in seismology at the University of Victoria's School of Earth and Ocean Sciences.

But a general rule of thumb is that wood-frame buildings are generally considered more secure because their flexibility and lighter weight allow them to absorb and dissipate seismic energy, while older highrise concrete buildings and heritage buildings – made out of unreinforced masonry such as brick or stone – are vulnerable. 

That includes red brick heritage buildings around Chinatown and Victoria's inner core, he said, along with the legislature, the Royal BC Museum and Crystal Pool. Though, the new Crystal Pool will be built with advanced seismic design and will likely become a "community safety hub in the event of an earthquake," said Coun. Matt Dell.

In 2017, a study showed that a major earthquake could destroy or severely damage nearly 40 per cent of structures – around 4,000 buildings – in Victoria. "It's going to be a huge housing crisis, basically," Nissen said. It's not just due to buildings being built before proper building codes – many are also built on soft soil, which can amplify the effects of ground shaking.

While there are now "robust building codes", Nissen said, there's a list of previously built buildings that require upgrades. The problem: "It takes a lot of time and money to retrofit all [of them]."

Schools are one priority for seismic upgrades or replacements. Seventy schools across B.C. are currently on that list, and 53 of those projects have already been completed through the Ministry of Education and Child Care's Seismic Mitigation Program.

Minister Kelly Greene told Victoria News that in the past seven years, 42,000 new "seismically safe" student spaces have been built. Plus, the Ministry of Transportation and Transit gives annual funding to strengthen existing structures and new bridges and highways are built to strict standards.

When it comes to seismic safety, new research is always on the horizon, particularly at UBC, a Canadian leader in seismic studies. Dr. Lisa Tobber, an assistant professor at UBC Okanagan's School of Engineering, plus the principal's research chair in resilient buildings, is currently doing interesting research to develop simplified procedures for identifying the highest-risk concrete highrise buildings and simple solutions to reduce their risk.

Building codes are also periodically being updated: the latest seismic standards that B.C. builders must follow were just updated on March 10.

Colleen Ferguson, a realtor with Victoria Homes Group, said some builders will even go "above and beyond, adhering to higher step codes" as this can have financial incentives.

That doesn't mean building to code doesn't go without its challenges. Ferguson pointed out that complications can arise when building codes are changed, specifically mid-build. She knew of one such building already approved under a previous seismic standard, where the building code was changed mid-build. This "affected the owner's values and insured mortgages were not permitted on this building," she said.

But, in the end, the upgrades are ultimately a good idea, as Nissen said most upgraded buildings "should be fine" in a severe earthquake.

Actions taken by the City of Victoria

In B.C., all three levels of government – municipal, provincial, and federal – are involved in earthquake safety efforts.

The City of Victoria is responsible for preparedness, including building codes, retrofitting high-risk structures and public education, but often requires support from higher levels of government for funding.

There are several recent actions the city has taken to improve seismic safety, says Colleen Mycroft, manager of intergovernmental and media relations for the City of Victoria.

The city has upgraded "most of its underground infrastructure" to be seismically resilient using money from the Disaster Risk Reduction Grant, she said.

It also moved the Number 1 fire hall into a new post-seismic building which serves as the new emergency operations centre, installed an NRCAN earthquake early warning sensor in one of the fire halls and started implementing a Resilience Hubs program in existing community centres, intending to secure a resilient facility in each neighbourhood for emergencies.

There is also a tax incentive program for heritage buildings that undergo alterations for seismic upgrading work.