Knowledge

 saves lives!

Tsunami

Awareness & Safety

National Tsunami 

Hazard Mitigation 

Program

How will I be warned about a tsunami?

There are two types of tsunami warnings: official and 

natural. Both are important. You may not get both. 

Respond immediately to whichever you receive first.

Official tsunami warnings are broadcast through 

radio, television, and wireless emergency alerts. They 

may also come through outdoor sirens, officials, text 

message alerts, and telephone notifications.

There may not be time to wait for an official warning. 

A natural tsunami warning may be your only warning. 

Natural warnings include:

• A strong or long earthquake

• A loud roar (like a train or an airplane) from the 

ocean

• Unusual ocean behavior (the ocean could look like 

a fast-rising flood or a wall of water or it could drain 

away suddenly like a very low, low tide)

If you experience any of these natural warnings, even 

just one, a tsunami could be coming.

How do I respond to a tsunami warning?

If you are in a tsunami hazard zone and receive an 

official warning:

• Stay out of the water and away from beaches and 

waterways.

• Get more information from radio, television, or your 

mobile device (text or data). 

• If officials ask you to evacuate, move quickly to a 

safe place. Follow evacuation signs or go as high or 

far inland (away from the water) as possible.

If you are in a tsunami hazard zone and receive a 

natural warning, a tsunami could arrive within minutes:

• In case of an earthquake, protect yourself. Drop, 

cover, and hold on. Be prepared for aftershocks. 

Each time the earth shakes, drop, cover, and hold on.

• Take action. Do not wait for an official warning or 

instructions from officials.

• As soon as you can move safely, move quickly to a 

safe place. Follow evacuation signs or go as high or 

far inland (away from the water) as possible. 

• If there is earthquake damage, avoid fallen power 

lines, and stay away from weakened structures.

• When you are in a safe place, get more information 

from radio, television, or your mobile device (text

or data). 

If you are on the beach or near water and feel an 

earthquake of any size and length, move quickly to high 

ground or inland (away from the water) as soon as you 

can move safely. Get more information from radio, 

television, or your mobile device (text or data). 

If you are outside of the tsunami hazard zone and 

receive a warning, stay where you are unless officials 

tell you otherwise.

If you live, work, or play at the coast, you should 

prepare for tsunamis. Tsunamis do not occur very 

often, but they pose a major threat to coastal 

communities. While they cannot be prevented, 

there are things you can do that could save your 

life and the lives of your loved ones.
December 2015

How can I prepare for a tsunami?

It is easy to prepare for a tsunami. Many preparedness 

actions are common across hazards. If your home, 

school, workplace, or other places 

you visit often are in tsunami hazard 

zones: 

• Ensure you have multiple ways 

to receive warnings. Get a NOAA 

Weather Radio, sign up for text 

message alerts from your local 

government, and verify that your 

mobile devices receive wireless 

emergency alerts.

• Make an emergency plan that includes

 plans for family communication and evacuation.

• Map out routes from home, work, and other places 

you visit often to safe places on high ground or 

inland (away from the water) and outside the 

tsunami hazard zone. Your community may already 

have identified evacuation routes and assembly 

areas. Plan to evacuate on foot if you can; roads 

may be impassable due to damage, closures, or 

traffic jams. 

• Practice walking your routes, even in darkness and 

bad weather. This will ease evacuation during an 

emergency. 

• Put together a portable disaster supplies kit with 

items you and your family (including pets) may need 

in an emergency. Prepare kits for work and cars, too.

• Be a role model. Share your knowledge and plans 

with others.

If you have children in school in a tsunami hazard zone, 

find out the school’s plans for evacuating and keeping 

children safe. 

If you are visiting the coast, find out about local tsunami 

safety. Your hotel or campground should have this 

information.

What should I do after a 

tsunami?

• Stay out of the tsunami 

hazard zone until officials say 

it is safe. The cancellation 

of a warning does not mean 

danger has passed.

• Stay out of any building with 

damage or water around it 

until a professional or official 

says it is safe.

• Get updates and safety instructions from radio, 

television, or your mobile device (text or data). 

Where can I learn more?

Tsunami safety: www.weather.gov/tsunamisafety

Tsunami alerts: www.tsunami.gov

Emergency planning: www.ready.gov

Information provided by the National Tsunami Hazard Mitigation 

Program (http://nws.weather.gov/nthmp/), a partnership of 

the National Oceanic and Atmospheric Administration, Federal 

Emergency Management Agency, U.S. Geological Survey, and 28 

U.S. states and territories. 

What is a tsunami and where do they happen?

A tsunami is a series of waves caused by a large, sudden disturbance of the sea. Undersea earthquakes are 

the most common cause, but landslides, volcanic activity, certain types of weather, and near-earth objects 

(e.g., asteroids, comets) can also cause tsunamis. 

Most tsunami waves are less than 10 feet high. In extreme events, they can exceed 100 feet. Large 

tsunamis can flood more than a mile inland. The first wave may not be the largest or most damaging, 

and the danger may last for hours or days. Tsunamis are a serious threat to life and property. Even small 

tsunamis can be dangerous, especially to swimmers, surfers, and boats in harbors.

Tsunamis can strike any U.S. coast, but risk is greatest for states and territories with Pacific and Caribbean 

coastlines. Low-lying areas such as beaches, bays, lagoons, harbors, river mouths, and areas along rivers 

and streams leading to the ocean are the most vulnerable. Tsunamis can happen any time, any season, and 

during any weather. They can be generated far away (across the ocean) or locally. Local tsunamis can arrive 

just minutes after a disturbance. 

FEMA