INNOVATION March-April 2016

Share in the Discussion S hare your expertise and views on “How APEGBC members can help improve BC’s earthquake preparedness, resistance and resiliency, and what would be required to make that happen” by writing to innovation@apeg.bc.ca. Letters should not exceed 300 words and are published as space permits. Innovation reserves the right to edit, condense or reject any contribution.

Exploring BC's Earthquake Preparedness, Resistance and Resilience

Earthquake preparedness, of course, has many dimensions—for example, public education, emergency response after a severe quake, survival of critical infrastructure, and the integrity of building stock. Engineers play an important role in ensuring our infrastructure suffers as little damage as possible from a major earthquake. This matter is of critical importance, because we must retain a functioning economy and experience minimal social disruption after an earthquake. Regional geography, older buildings, and the likelihood of widespread liquefaction and amplification of seismic ground motions pose challenges to engineers tasked with ‘hardening’ our building stock to withstand seismic ground motions. In this context, we can take some comfort that considerable progress has been, and is being, made. Consider, for example, the program being carried out by the BC Ministry of Education in partnership with UBC and APEGBC to upgrade seismically vulnerable schools. Consider also the improvements to seismic provisions in our building code and the seismic retrofits that have been completed to most of the area’s bridges. In terms of response to a damaging earthquake, Emergency Management BC (EMBC) is the lead provincial agency responsible for managing disasters and supporting other authorities within their areas of jurisdiction. The Government of BC has charged the agency to develop a comprehensive provincial earthquake plan. The BC Earthquake Immediate Response Plan ( IRP ), released in July 2015, is the first component of that larger plan and sets the conditions for subsequent planning efforts centred on sustained response and recovery. It details how the Province will lead and coordinate during a post-earthquake response phase, and

Since its founding 130 years ago, Vancouver has yet to experience a damaging earthquake. Yet geophysicists and geologists have shown that such an earthquake is inevitable, although they cannot tell us when it will happen. On average, every 500 years, the BC south coast is rocked by a magnitude 8 to 9+ earthquake caused by rupture of the megathrust fault separating the subducting Juan de Fuca plate from the overlying North America plate. What would be the consequence of such an earthquake today? A report by the Insurance Bureau of Canada in October 2013 concluded that it would cause about $74 billion in damages due to the ground shaking, a tsunami, landslides, fire, and business and service interruptions. The south coast is also at risk from two other types of earthquakes—so-called ‘slab events’ at depth within the subducting Juan de Fuca plate, and shallow earthquakes on faults that cut the crust of North America. Both types of earthquakes are far more common than great subduction- zone earthquakes, although they are smaller in magnitude and have smaller damage ‘footprints.’ The 2011 Christchurch earthquake, which was a shallow crustal earthquake, is enlightening—even though it was of only moderate size (magnitude 6.3) and its strong shaking lasted only 10 seconds, the earthquake seriously damaged many of Christchurch’s downtown buildings and claimed 185 lives. The most recent estimate of the cost of rebuilding the city is NZ$40 billion (CDN$37 billion), equivalent to nearly $10,000 for every New Zealand citizen. Metro Vancouver is a rapidly growing urban centre with a huge concentration of wealth and significant national economic importance. Accordingly, the risk from a damaging earthquake is also growing. Residents want to know how prepared we are to deal with a large earthquake.

Dr. John Clague, P.Geo., FGC, FEC (Hon.)

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P hoto : P aul J oseph , cc by 2.0

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