Maps lay out tsunami evacuation walking routes in the event of aCascadia subduction zone earthquake
OLYMPIA – Knowing where to walk and how long it might take to get there can be one of the most important pieces of information for anyone in Washington’s coastal communities when a tsunami strikes.
That’s why the geologists at the Washington State Department of Natural Resources (DNR) have published evacuation walk time maps for Port Angeles, Bellingham, Anacortes, Aberdeen, Hoquiam, and Cosmopolis.
These maps, produced by DNR’s Washington Geological Survey, show the time it would take to evacuate on foot from the tsunami inundations zones of a Cascadia subduction zone earthquake.
“A tsunami could be devastating to our communities. That’s why our geologists work every day to make sure people in coastal areas have the information they need to prepare and be ready,” said Commissioner of Public Lands Hilary Franz. “These maps put vital information in the hands of people who live, work, or play in these coastal communities so they know where to go, and how long it might take to get there, in the event of a tsunami.”
Using models of a Cascadia earthquake, the maps use colors to indicate how many minutes it would take to walk to safety at a moderate pace within these communities. Waves from a Cascadia earthquake-induced tsunami could reach Aberdeen in as soon as 15 to 20 minutes.
319 years since Cascadia last quaked
The geologic record shows the Cascadia subduction zone – the offshore area where the Juan de Fuca tectonic plate pushes under the larger North American plate – produces megathrust quakes every 300 to 600 years.
These maps are modeled on a magnitude 9 Cascadia earthquake. The geologic record shows earthquakes of this size occur approximately every 2,500 years, with the last striking in 1700. By using the models for larger Cascadia events, the maps provide a “worse case” scenario that is useful for smaller events as well.
Models, maps available online
The new pedestrian maps and maps for other communities are available through an interactive map on the DNR web site: https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/tsunamis/evacuation
The interactive map also provides access to tsunami evacuation brochures for areas that do not have walk time maps yet.
Other information about impacts from earthquakes to Washington communities is available on DNR’s Geologic Information Portal at: https://geologyportal.dnr.wa.gov
Geologists to discuss tsunami hazards at coastal Road Show next week
Washington Geological Survey geologists will present evacuation information and more with tsunami and earthquake experts from the Washington Emergency Management Division, the National Weather Service, Washington Sea Grant and local officials at next week’s Tsunami Road Show.
These experts will give 90-minute public presentations and answer questions at:
- 10 a.m., Tuesday, April 9 at Pacific County PUD Auditorium, 405 Duryea Street, in Raymond, WA
- 7 p.m., Tuesday, April 9 at Chautauqua Lodge, 304 14th St NW, in Long Beach, WA
- Noon, Wednesday, April 10 at Ocean Shores Convention Center, 120 W. Chance a La Mer, Ocean Shores, WA
- 6:30 p.m., Wednesday, April 10 at Aberdeen (J.M. Weatherwax) High School,410 N. G. St., Aberdeen, WA
- 10 a.m., Thursday, April 11 with the Makah Tribe at Makah Tribal Community Hall, 81 3rd Ave. Neah Bay, WA
- 6:00 p.m., April 11 at Peninsula College in The Little Theater, 1502 E. Lauridsen Boulevard, Port Angeles, WA
- 10 a.m., Friday, April 12 with the Lower Elwah Klallam Tribe at Tribal Center, 2851 Lower Elwha Road, Port Angeles, WA
Geology in the Public Interest
Under the guidance of Commissioner of Public Lands Hilary Franz, the Washington Geological Survey works to ensure the safety and economic well-being of Washington’s citizens from geologic events. The Survey is the primary source of geological products and services for Washington’s government agencies, businesses, and the public.