There’s been a lot of talk about the earthquake that’s expected to hit the Pacific Northwest, and while locals prepare for the worst, there’s a lingering question of what will actually happen to our cities.
Carmen Merlo, director of the Portland Bureau of Emergency Management, looks 7,300 miles across the Pacific Ocean to Christchurch, New Zealand as a predictor of what may happen here.
“Christchurch to me always stuck out,” said Merlo. “Both the geography, the population and (the environment) sparked my interest.”
As you may remember, the mid-size city has been struck by thousands of earthquakes since 2010, the most devastating of which hit the Christchurch city center on Feb. 22, 2011, yielding more than 180 causalities and at least 1,500 injuries.
Merlo traveled to New Zealand last October and found the rebuilding city shared many similarities with Portland: The cities have about the same population size and density, and Christchurch has a river running through the city much like Portland — which translates to liquefiable soils.
“When you have heavy ground shaking, the soil behaves like water,” said Merlo. “The soil can no longer support buildings and you have some parts of the city that may never be redeveloped again.”
And prior to the Christchurch earthquakes, Merlo said both cities had passive retrofit policies for unreinforced masonry buildings, which attributed to about 20 percent of the fatalities during the 2011 earthquake.
“For me, what was really shocking is the performance of the buildings,” said Merlo. “I think there’s the misconception that buildings that are built to code are earthquake proof. What we learned in Christchurch is while most buildings did their job — they didn’t collapse, they allowed people to safely evacuate — they were so badly damaged that they could not be reoccupied.”
In preparation for a Portland earthquake, Merlo said the emergency bureau has a few short-term goals already in the works. The city is looking into a new unreinforced masonry retrofit policy, which will likely be considered next year. Local police and firefighters will train neighborhood emergency teams in search and rescue techniques and disaster medicine in case certain areas of Portland are inaccessible to emergency personnel following an earthquake.
“We only have about 1,000 police officers and 700 firefighters,” said Merlo. “That’s one professional for 35,000 to 40,000 people.”
Merlo said a lot of attention has been focused on the Cascadia Subduction Zone, but what Portland should try to prepare for are the unknowns — Christchurch’s earthquakes revealed a number of previously undiscovered fault lines.
“It’s what we don’t know that we should be concerned about,” said Merlo. “These things that can’t be predicted.”