Seattle and Portland are two of the fastest growing U.S. cities, and currently have metro-wide populations of 3.7 million and 2.4 million,
ranking as the 15th and 25th largest metro areas nationally. A major earthquake in the Cascadia Subduction
Zone – which stretches for 600 miles – would not necessarily impact either
city. But as Temblor explains, there is
evidence suggesting both cities are in some of the riskiest territory within
the zone, and are prone to particularly dangerous seismic impacts.
According to Temblor, earthquakes within the Cascadia Subduction Zone could
reach Magnitude 9, the same severity as the devastating Tohoku Earthquake off
the coast of Japan in 2011. And certain
indicators studied by seismologists – “locking” and “tremor” – point to Seattle
and Portland as being quite susceptible to just such a severe earthquake
event. Further, downtown Seattle lies in
a lowland basin that makes it particularly vulnerable to shaking damage to
buildings in a major earthquake. It also
features dozens of office and residential towers in the downtown area, with
more being rapidly constructed. In fact,
Seattle claims to have led the nation in the most active construction cranes over the last fewyears.
Temblor cites a study by scientists at the
University of Southern California and the University of Washington concerning
the differences in the degree of swaying or drifting experienced by 4 to 40
story buildings inside the Seattle basin versus outside the basin. Earthquake shaking inside the basin is
expected to be stronger and slower, leading to triple the amount of building
swaying and likely broader and more severe property damage. Similarly, the Oregon Department of Geology
and Mineral Industries posits that a Magnitude 9 earthquake would do at
least some damage to nearly 40% of the buildings in the Portland metropolitan
area.
What does this mean for insurance industry practitioners? On a professional level, they should be
prepared to see a massive volume of property damage claims, including
commercial property insurance claims. On
a personal level, if they are already dealing with insurance claims or disputes
in Portland or Seattle, they should be aware of what to do in an office tower
during an earthquake event. Consider
these tips from https://www.ready.gov/earthquakes:
Prepare NOW
- Practice
Drop, Cover, then Hold On with family and coworkers. Drop to your
hands and knees. Cover your head and neck with your arms. Crawl only as
far as needed to reach cover from falling materials. Hold on to any sturdy
furniture until the shaking stops.
Survive DURING
- Drop, Cover, then Hold On like you practiced. Drop to your hands and knees. Cover your
head and neck with your arms. Hold on to any sturdy furniture until the
shaking stops. Crawl only if you can reach better cover without going
through an area with more debris.
- If inside, stay there until the shaking
stops. DO NOT run outside.
- If you are in a high-rise building, expect
fire alarms and sprinklers to go off. Do not use elevators.
Be Safe AFTER
- Expect
aftershocks to follow the largest shock of an earthquake.
- Check
yourself for injury and provide assistance to others if you have training.
- If in a
damaged building, go outside and quickly move away from the building.
- Do not
enter damaged buildings.
- If you
are trapped, cover your mouth. Send a text, bang on a pipe or wall, or use
a whistle instead of shouting so that rescuers can locate you.
- If you
are in an area that may experience tsunamis, go inland or to higher ground
immediately after the shaking stops.
