Thirteen years ago today, a Magnitude 9.2 earthquake struck off the west coast of Sumatra, producing the single-most devastating tsunami in recorded history. The tsunami that swept across the Indian Ocean killed more than 230,000 people and left more than 1.7 million homeless.
The megathrust earthquake initiated from the Sunda trench subduction zone off the west coast of Sumatra.
This devastation is a strong reminder that Washington state is also vulnerable to this type of event. Closer to home, other reminders are tsunami deposits, drowned shorelines, and buried trees from the 1700 A.D. Magnitude 8.8–9.2 megathrust earthquake along the Cascadia Subduction Zone. These clues have been located in numerous places along the Washington, Oregon, California, and Vancouver Island coasts.
Planning for tsunamis here
The Washington Geological Survey, is helping Washington communities identify how they are vulnerable to similar tsunami events and how they can craft innovative strategies for dealing with those threats.
More work needed
Though we have mapped tsunami inundation for some communities, many along the coast have either outdated tsunami inundation maps – or no maps at all.
In addition, Washington faces the second highest risk from earthquakes in the U.S., and one of the highest for tsunamis, yet remains the only west coast state that does not have an inventory of the seismic hazard for critical infrastructure.
That’s why this year, we’re is asking the legislature for funding to hire geologists to identify and map tsunami hazards in more of our coastal communities.
The Washington Emergency Management Division says the best way to survive any type of disaster is to have a plan, keep informed, and have a mobile survival kit. Find out if you are in a tsunami inundation zone. Download a tsunami evacuation brochure for your community.