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Tsunami


Washington is tsunami country

Washington state has more than 3,000 miles of shoreline — this makes Washington tsunami country! Tsunamis can happen at any time and can impact any stretch of Washington’s shoreline, posing a major danger to people, infrastructure, and the environment. Washington State’s Emergency Management Division is dedicated to increasing the resilience of Washington’s residents, visitors and infrastructure to damaging tsunamis.

Here are easy steps you can take ahead of time to protect yourself, your family and your friends from tsunamis.

  • Learn if you live, work or spend time in a tsunami inundation zone and make sure you know where the closest high ground is and the quickest route to get there.
  • Learn about natural tsunami warning signs. Ground shaking may be your first, best and potentially only warning of an approaching tsunami.
  • Sign up for tsunami alerts to be warned about distant tsunamis, as well as alerts from your local emergency management.
  • Make sure you and your loved ones have a go bag ready in case you need to evacuate quickly.
  • Check out mil.wa.gov/preparedness to learn about how you can prepare yourself and loved ones for tsunamis and all of Washington’s hazards.
  • If you spend time on the water, learn what to do if a tsunami occurs while you’re on a vessel or at the marina.

What is a tsunami?

Washington’s Pacific Coast, Strait of Juan de Fuca, Salish Sea, Puget Sound and large lakes are all at risk from tsunamis. Tsunamis are a series of extremely long waves usually caused by the sudden raising or lowering of the earth’s crust during underwater earthquakes, although landslides and underwater volcanic eruptions also can generate them. Movements of the sea floor or lakebed, or rocks falling into an enclosed body of water, displace the water column and set off a series of waves that radiate outward like pond ripples. A Pacific Ocean tsunami can affect the entire Pacific basin, while a tsunami in inland waters can affect many miles of shoreline.

In the deep ocean, tsunami waves are relatively harmless. 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 are more like a moving wall of water, crashing into and lifting up everything in their path.

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. People 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.

Tsunami Evacuation and Inundation Maps

Washington’s Emergency Management Division (WA EMD) and the Department of Natural Resources (WA DNR) develop maps based on tsunami modeling data. These maps include Pedestrian Evacuation Walk Time maps, Tsunami Inundation maps, and Tsunami Current Velocity maps. You can find these maps, along with additional area-specific information, at our Tsunami Resources page.

Tsunami Alerts and Sirens

Because tsunamis can be so destructive, advanced warning is vital for ensuring communities have time to evacuate to high ground before the first waves arrive. The closer someone is to the source of a tsunami, the less time they have to receive that warning. It is therefore important to both be familiar with natural tsunami warning signs and know how you will receive official tsunami alerts.

Natural Warning Signs

There may not always be enough time for you to receive an official tsunami alert before the first waves arrive, so it is important that you understand natural tsunami warning signs. If you are at the coast and you …

• 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 very soon. This is your warning! Take action immediately by moving inland to high ground. Do not wait to receive an official alert or other instructions.

Official Tsunami Alert Methods

Official tsunami alerts are broadcast through local radio and television, marine radio, Wireless Emergency Alerts (WEA), NOAA Weather Radio and NOAA websites like Tsunami.gov. They may also come through outdoor sirens, local officials, text message alerts and telephone notifications

The U.S. National Weather Service (NWS) operates two Tsunami Warning Centers which are staffed 24/7. The main mission of the warning centers is to help protect life and property from tsunamis. The National Tsunami Warning Center (NTWC) in Palmer, Alaska is responsible for monitoring and alerting the coastlines of Alaska, Canada, the continental United States, Puerto Rico, and the Virgin Islands. Tsunami messages are issued by the Tsunami Warning Centers to notify emergency managers, the public, and other partners about the potential for a tsunami following a possible tsunami-generating event. Initial tsunami messages include alert level(s), preliminary information about the earthquake, and an evaluation of the threat. If a tsunami is already suspected, the message may also include wave arrival times, recommended life safety actions, and potential impacts. Subsequent messages, including both updates and cancellations, may feature more refined, detailed, and targeted information.

For the United States, Canada, and the British Virgin Islands, there are four levels of tsunami alerts: warning, advisory, watch, and information statement.

For the United States, Canada, and the British Virgin Islands, these messages include alert levels. There are four levels of tsunami alerts: warning, advisory, watch, and information statement.

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  • 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 inland to high ground immediately.
  • 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. Prepare to take action if necessary.
  • Tsunami Information Statement: No Action Needed—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.


There are many ways you can receive tsunami alerts. To learn more, visit mil.wa.gov/alerts and sign up for your local alerts system, as tsunami alerts may come through these avenues also.

Tsunami Sirens

Tsunami sirens are an important aspect of alerting for distant tsunami events where approaching waves will not be preceded by ground shaking. The Washington Emergency Management Division maintains a network of 121 state-of-the-art All-Hazard Alert Broadcast (AHAB) tsunami sirens (PDF) in high-risk locations throughout the inner and outer coasts. These sirens are intended to act as an OUTDOOR alerting method for people and communities on/near the beach who may not otherwise have access to other official alerting methods. They have an audible range of approximately 1 mile, though this varies depending on environmental factors like topography, wind direction, and physical barriers (trees, buildings, etc). The sirens are not intended to be heard indoors. This outer coast siren map shows the locations of AHAB tsunami sirens located on Washington’s outer coast and this inner coast siren map shows the locations of AHAB tsunami sirens located on the inner coast.

Upon the issuance of a TSUNAMI WARNING, the sirens play a wail sound (click here to listen to what it sounds like) followed by a voice message in English and Spanish instructing listeners to evacuate immediately to high ground.

During a routine TEST of the AHAB tsunami siren system, which is conducted on the first Monday of every month at noon, the sirens play the Westminster Chimes (click here to listen to what it sounds like). The sirens are also tested once a year with the actual wail sound on the third Thursday in October in conjunction with the Great Washington ShakeOut. For this yearly test, the wail sound is followed by a voice message in English and Spanish explaining that it is only a test.

Tsunami Education and Outreach Materials

Outreach and education are a major focus for WA EMD’s tsunami program. Below are links to tsunami education resources, including external sites, materials available for download, and educational videos. More materials are available upon request. Send an email to Public.Education@mil.wa.gov for more information.

  • Public Education Materials


Maritime Guidance

Spend time on the water? Do you know what to do if a tsunami occurs while you’re on a boat or at the marina? Washington’s complex inner coast and high-risk outer coast require different kinds of protective actions, so it’s important to understand what to do based on your location. On the outer coast you may have time to take your boat to deep water, where tsunami waves are smaller and can be more easily navigated. However, Washington’s inner coast lacks large enough areas of sufficiently deep water to provide this level of safety. See below for protective action guidance based on where you are when you experience ground shaking or receive a tsunami alert.

Tsunami Maritime Protective Actions

If you’re at a marina or out on the water when you experience ground shaking or receive a tsunami advisory or warning message, immediately put on your Personal Floatation Device. Your following response actions will depend largely on where you are.

If you are on land or tied up at the dock:

  • DO NOT take your boat offshore. Leave your boat and go inland to high ground on foot as soon as possible. You may not have time to save your boat and you could put your life at risk.

If you are in deep water or very close to deep water on the OUTER COAST of WA:

  • Take your boat to at least 100 fathoms or to the deepest water you can find straight out from the shoreline. Sail directly into the waves but be careful because tsunami currents can make them bigger. Stay as far away as you can from other boats and work together to avoid crashing into each other. Waves can last more than 24 hours.

If you are on the water but very near shore or on the INNER COAST of WA:

  • Use your best judgement and consider the following before taking protective action:


Your harbor master, port captain, the United States Coast Guard, and local emergency management are the best sources for tsunami safety information and regulations for boaters in your area. Learn more about how to prepare for a tsunami when you’re on your vessel with Washington’s Boaters Guide on Tsunamis (PDF)

Tsunami Maritime Response and Mitigation Strategies

Ports, harbors and marinas across Washington face increased risk from tsunamis due to their positioning along the coast. These facilities are central to the maritime community and are an integral part of the Washington economy. As part of its work to help mitigate tsunami risk to the maritime community, Washington Emergency Management Division works with local ports and critical tsunami response partners to develop Tsunami Maritime Response and Mitigation Strategies. We partner with the Department of Natural Resources to model site-specific tsunami impacts that are used to determine the feasibility of more than two dozen response and mitigation actions based upon established maritime guidance from the National Tsunami Hazard and Mitigation Program and international partners. These strategies are designed to be used as a template for other Washington maritime communities to evaluate their tsunami risk, improve their tsunami response and identify projects to help mitigate the impacts of tsunamis. These strategies will help the maritime communities in Washington understand the tsunami risk they face and assist them in their tsunami planning efforts in the future.

Five strategies have been completed as of 2025: Port of Bellingham, Westport Marina (Port of Grays Harbor), Port of Anacortes, Neah Bay, and the Eagle Harbor Marina (City of Bainbridge Island) with an ongoing strategy for the Port of Port Angeles that is expected to be completed in Fall 2025. Copies of those strategies can be found below.

Bainbridge Island's Eagle Harbor

    Port of Neah Bay

    Port of Anacortes

    Port of Grays Harbor's Westport Marina

    Port of Bellingham


    Tsunami Vertical Evacuation

    Could your community survive a tsunami? For Washington’s outer coast, where a tsunami could arrive just 10-20 minutes after a major earthquake, survival depends on multiple factors—including clearly designated evacuation routes, wayfinding signage, and access to high ground. But what if there is no high ground nearby?

    That’s where Tsunami Vertical Evacuation Structures (VES) come in. These purpose-built structures provide safe refuge above the waves, offering a life-saving evacuation option for communities where traditional escape routes are not viable. These structures can be standalone towers or incorporated into new buildings, providing a reliable evacuation option where none exist. They have proven successful in Japan and have also been built in Oregon and New Zealand.

    Vertical Evacuation Structures are specifically engineered to survive:

    • Strong earthquakes, aftershocks, and liquefaction
    • Multiple tsunami waves
    • High-impact debris and extreme water forces

    With over 175,000 people in Washington’s tsunami inundation zone, the need is urgent. To protect at-risk communities, Washington will require at least 58 to 80+ VES structures in key locations to ensure everyone has a place to evacuate in time.

    Washington is Leading the Way

    Planning a VES? Funding and Resources Explored

    VES projects require strong community leadership, planning, and funding. These structures aren’t typical building projects—they require specialized engineering, partnerships with local, state, and federal agencies, and careful site selection.

    To help communities navigate the process, WA EMD has developed a step-by-step guide with lessons from Washington, Oregon, and beyond. Here’s how to get started:

    Tsunamis are unpredictable—but preparing for them doesn’t have to be. Start the conversation today.

    Connect With Us

    Twitter: @waEMD

    Facebook: WashEMD

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    Email: public.education@mil.wa.gov



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