The devastating results of a 6.7 magnitude quake on the Seattle Fault highlight the importance of disaster preparedness. Using the earthquakes in Christchurch as a case study, the importance of building standards and retrofitting for earthquakes is evident. As a feasible risk management strategy, Seattle’s building codes should reflect the region’s vulnerability to earthquakes. The next section will analyze Seattle’s building codes in relation to its risk for earthquakes.
After the 2001 Nisqually earthquake, 20 of the 31 buildings considered uninhabitable were URM buildings. One out of eight studied URM buildings was damaged. Of those damaged buildings, nearly 48% were considered hazardous. The Nisqually quake demonstrated the vulnerability of URM buildings during seismic events and, therefore, the importance of mitigating risks to protect those inside and outside of the buildings. Demolition is one possible risk mitigation strategy.
Building Standards As demonstrated in Christchurch, buildings, not the earthquake itself, threaten lives. Therefore, when preparing for earthquakes in Seattle, it is important to look at preventative strategies to reduce casualties. One such strategy is to improve building standards. A primary concern in Seattle is the city’s unreinforced masonry (URM) buildings. It is estimated that Seattle has between 850 and 1000 URM buildings, with many of these buildings located in downtown, SoDo, Capitol Hill and Pioneer Square. They are a primary concern because URM buildings do very poorly during seismic events and Seattle has low rates of demolition and retrofitting of these buildings, posing a greater risk to the public than in other earthquake prone areas. Historically, Seattle’s URM buildings have performed poorly during seismic events. 19 | Inhabiting the Quake
Seattle has relatively low rates of URM buildings being demolished or retrofitted, suggesting the need for improved standards in order to protect the public. Seattle has only demolished 2% of its URM buildings since City
1990. When compared with other earthquake prone cities, Seattle has a low demolition rate (David Swanson, 2007). Sara voiced her worries regarding the lack of building demolition during my interview with her: “I go to Seattle and I see all these unreinforced masonry buildings and it makes me quite nervous. And I know that they’ve done some retrofitting. I think Washington State policymakers, politicians, council workers and bureaucrats need to have a really honest discussion with Washington state residents about their building safety. Seattle’s got some serious problems… There needs to be some really tough, honest questions about whether you demolish a building or not” (S. McBride, personal communication, February 20, 2014).
URM Demolitions from 1990 to
URM Seismic Upgrades from
2003
1990 to 2003
San Jose
8%
85%
Oakland
7%
89%
San Francisco
6%
62%
Berkeley
1%
79%
Seattle
2%
5%
A comparison of URM demolition and upgrade rates in several earthquake prone cities (David Swanson, 2007).