At the same time I have been working in historic preservation projects I have had a parallel interest in preparing for the Cascadia earthquake and tsunami. While thus isn't a topic that is much discussed in the historic preservation community, it should be. The National Trust did a good job mobilizing to save historic structures after Katrina, but this type of work needs to be prepared ahead of time to be really effective.
First, a brief introduction to the Cascadia event. It will be a magnitude 9 earthquake generated along the 800 or so along the Cascadia seduction fault line located off the coast from northern California to southern BC. It will last three to five minutes and will damage buildings and infrastructure all the way to the Cascade mountains. While any pre-1990's buildings are at risk , the large stock of unreinforced masonry buildings, which make up a significant proportion of our historic buildings at particularly at risk. This earthquake will generate a tsunami that will inundate low lying coastal areas in 10-30 minutes.
The last time this event happened was 310 years ago and it happens about every 300 years so we are overdue. In fact, if one uses failure analysis to look at probability, one scientist calculated that we have about a 40% chance of a full rupture in the next 50 years.
So this is something we need to be proactive on. I will touch on areas I think we should be addressing in future posts.
The danger of unreinforced masonry buildings came up many times and retrofitting schools came out as the top priority. Now that the AIA and SEA are becoming more engaged in Cascadia preparation, it is an opportune time for HPLO and the historic preservation community to get engaged as well. The example of Christchurch is especially relevant, since they had a similar historic heritage of buildings similar to Portland, that now has lost. Another reason to engage now is that HR-3 Oregon Resilience Plan passed the House 58-0 and directs OSSPAC to develop a resilience plan to present to the Legislature in 2013. OSSPAC will be talking with stakeholders to develop the resilience plan.
Japan rebuilds, Oregon prepares This is an article from the Seaside Signal that was generated from the last meeting of OSSPAC, which was held in Cannon Beach earlier in July. Three of the OSSPAC members had recently in Japan looking at earthquake/tsunami damage and gave presentations of what they saw and learned.