Did the Alaska earthquake and tsunami on October 19 have you wondering how you’ll be alerted if a tsunami is about to strike Washington?
Watch our Nov. 19 WEBINAR.Join experts from the Washington Geological Survey and Washington Emergency Management Division in this FREE webinar to learn about how tsunamis can impact Washington's inner and outer coasts and what to do before, during and after a tsunami.Download the slides here.
- The U.S. National Tsunami Warning Center issues tsunami information for the continental U.S. and Canada. They have a Twitter account where they post official notices at https://twitter.com/NWS_NTWC. You can follow their account on Twitter. To receive notifications when a tweet from @NWS_NTWC is sent, you must choose to be notified within the Twitter app on your mobile device and/or through the twitter.com website. For instructions on how to set up tweet notifications (also known as “push” notifications) to your device, check out this help menu.
- The United States’ National Weather Service provides InteractiveNWS (iNWS), an application suite able to send NWS products to local partners in multiple ways, including as emails and texts. Visit https://inws.ncep.noaa.gov/ to learn more or to sign up for the service. Once your registration has been accepted you can go onto the site and set up text alerts by county/parish, lat/long, or street address. You can also draw a polygon on the map provided to set up a custom alerting area.
- For an interactive geology map, visit https://www.dnr.wa.gov/geologyportal
- For geologic hazard maps, visit https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/geologic-hazard-maps
- For tsunami information, visit tsunami.gov
- Preparedness and Emergency Information on Social Media: https://twitter.com/waEMD & https://www.facebook.com/washemd
What's a tsunami?
The Pacific Coast, Strait of Juan de Fuca, Puget Sound, and large lakes are at risk from tsunamis, which are trains of waves that threaten people and property along shorelines. Sudden raising or lowering of the earth’s crust during earthquakes generally causes a tsunami, although landslides and underwater volcanic eruptions also can generate them. Movements of the sea floor or lake bed, or rock fall into an enclosed body of water, displace the water column, setting off a series of waves that radiate outward like pond ripples.
Only as a tsunami approaches land does it become a hazard; in shallow water, it gains height as its waves slow and compress. Tsunamis do not resemble their usual icon, a towering wave with a breaking crest. Instead, they come onshore resembling a series of quickly rising tides, and they withdraw with currents much like those of a river. Swift currents commonly cause most of the damage from tsunamis. A Pacific Ocean tsunami can affect the entire Pacific basin, while a tsunami in inland waters can affect many miles of shoreline.
Tsunamis typically cause the most severe damage and casualties near their source. There, waves are highest because they have not yet lost much energy. The nearby coastal population often has little time to react before the tsunami arrives. Persons caught in the path of a tsunami often have little chance to survive; debris may crush them, or they may drown. Children and the elderly are particularly at risk, as they have less mobility, strength, and endurance.
If you live on the coast, you might be curious about the Tsunami All-Hazard Alert Broadcast (AHAB) and its pole-mounted siren system deployed throughout the coast. During a routine TEST of the system, which is conducted on the first Monday of every month at noon, the sirens will play the Westminster Chimes (click here to listen to what it sounds like). Upon the issuance of a TSUNAMI WARNING, the siren will play a wail sound (click here to listen to what it sounds like) and a voice message will follow the siren. This map shows the locations for tsunami sirens as of Oct. 15, 2020.
- Tsunami Warning: Take Action—Danger! A tsunami that may cause widespread flooding is expected or occurring. Dangerous coastal flooding and powerful currents are possible and may continue for several hours or days after initial arrival. Follow instructions from local officials. Evacuation is recommended. Move to high ground or inland (away from the water).
- Tsunami Advisory: Take Action—A tsunami with potential for strong currents or waves dangerous to those in or very near the water is expected or occurring. There may be flooding of beach and harbor areas. Stay out of the water and away from beaches and waterways. Follow instructions from local officials.
- Tsunami Watch: Be Aware—A distant earthquake has occurred. A tsunami is possible. Stay tuned for more information. Be prepared to take action if necessary.
- Tsunami Information Statement: Relax—An earthquake has occurred, but there is no threat or it was very far away and the threat has not been determined. In most cases, there is no threat of a destructive tsunami.
Note: Tsunami warnings, advisories and watches may be updated or cancelled as information becomes available. Advisories, watches and information statements may be upgraded if the threat is determined to be greater than originally thought.
Tsunami warnings are broadcast through local radio and television, marine radio, wireless emergency alerts, NOAA Weather Radio and NOAA websites (like Tsunami.gov). They may also come through outdoor sirens, local officials, text message alerts and telephone notifications. Learn how to get tsunami warnings here.
There may not always be enough time for an official warning, so it is important that you understand natural warnings. If you are at the coast and feel a strong or long earthquake, see a sudden rise or fall of the ocean or hear a loud roar from the ocean, a tsunami may follow. This is your warning. Take action and move to a safe place. Do not wait for official instructions.
Tsunami Evacuation and Inundation Maps
Partnering with local communities, Washington’s Emergency Management Division and Department of Natural Resources helps develop evacuation maps based on known inundation zones. These maps along with additional area specific information can be found by following this link.
Tsunami Warnings and Information
- Current Tsunami Alert Status (NOAA - National Tsunami Warning Center (NTWC))
- International Tsunami Information Center (ITIC)
- Washington State Department of Natural Resource (DNR - Tsunami Evacuation Map Portal)
- The Great Washington ShakeOut
- Learn more about tsunamis in Washington State (PDF)
- Tsunami Emergency Resource Guide Sheet (PDF)
- Tsunami Basics (in Spanish -- PDF)
- Tsunami Basics (PDF)
- Tsunami All-Hazard Alert Broadcast brochure (PDF)
- National Weather Service Tsunami outreach and education resource
Tsunami Education Materials
- Looking for local evacuation maps and materials? Try this link.
- Tsunami Preparedness Videos
- Tsunami Preparedness Along the West Coast (USGS) (Video)
- Media Guidebook - Tsunamis, Volcanoes, Earthquakes 2013 (PDF)
- Tsunami Trivia (PDF)
- Surviving a Tsunami - Lessons from Chile, Hawaii, and Japan (USGS)
- Sobreviviendo a un Tsunami (USGS)
Tsunami and earthquake experts talk about what to do (and what not to do) before and during a tsunami alert. Watch the presentation here. We talk about community-wide alerts, the science and dynamics of tsunamis and how to prepare you and your loved ones for tsunamis.
Our team also recently did a workshop that talked about tsunami vertical evacuation structures in Ocean Shores. Watch the presentation here, courtesy of TVW.
Tsunami Vertical Evacuation
We are consistently working with local governments and tribes on grants for tsunami vertical evacuation structures. We can help you. Download our Tsunami Vertical Evacuation Manual:
Project Safe Haven
Project Safe Haven is a grassroots, community driven, public process currently taking place on the Washington Coast to identify areas for future vertical evacuation structures. Partnering with local residents, its mission is to develop a community responsive vertical evacuation strategy along the Washington coast.
- Clallam County
- Grays Harbor County
- Pacific County
Final Report Cost Breakdown
- Pacific County Cost Estimates - Appendix A (PDF)
- Grays Harbor County Cost Estimates - Appendix B (PDF)
- Four Select Vertical Evacuation Site Estimated Costs - Appendix C (PDF)
2016 Final Report