When a Tsunami Threatens: What Citizens Can Do to Stay Safe

A tsunami is a series of large ocean waves caused by underwater earthquakes or landslides. These waves can travel across the ocean at high speeds and cause severe flooding and damage when they reach the coast.

While tsunamis are rare, they can be deadly—especially for communities located near the shoreline or in low-lying areas. Your quick actions, staying informed, and following safety guidelines can protect you and your loved ones.

What Is a Tsunami and Why Is It Dangerous?

The word "tsunami" comes from Japanese, meaning "harbor wave." It’s important to know that tsunamis are not the same as tidal waves. They are often mistaken for a big wall of water, but they are actually a series of waves that can arrive minutes or hours apart.

Major hazards include:

• Flooding: Widespread and fast-moving water inundates coastal areas.

• Contamination: Saltwater and debris can pollute water supplies.

• Fires: Ruptured gas lines and tanks can cause fires.

• Property and Infrastructure Damage: Buildings, roads, and utilities can be destroyed.

• Drowning: Most fatalities happen when people are caught in the waves or try to escape on foot or by boat.

How Citizens Can Stay Safe

1. Know Your Risk 

• Find out how high your street is above sea level and how close you live to the coast.

• Learn if your community is at risk for tsunamis and where safe evacuation zones are located—preferably 100 feet or more above sea level or at least two miles inland.

• Practice your evacuation route—day or night, in good weather or bad.

2. Recognize Warning Signs 

• The ocean water may suddenly recede far out to sea—don’t go near the water in this case.

• If you see a rapid rise or fall of water, or hear an earthquake, evacuate immediately.

3. Prepare in Advance 

• Discuss tsunami plans with your family so everyone knows where to go and how to get there quickly.

• Have an emergency kit ready: include bottled water, non-perishable food, a flashlight, batteries, and a battery-powered radio.

• Know your local warning system—many communities use NOAA Weather Radio and sirens to alert residents.

4. If a Tsunami Warning Is Issued or You Recognize Signs: 

• Evacuate immediately—do not wait or try to watch from the shore.

• Move quickly to higher ground or inland—preferably at least two miles away from the shoreline and to an area 100 feet or more above sea level.

• Use routes you’ve practiced. If you’re in a car, follow designated evacuation routes and avoid bridges or areas that could be flooded or damaged.

5. If You Are Already on the Water: 

• Move your boat away from the shore and out to deep water as quickly as possible to avoid being caught by the waves.

After the Tsunami

• Stay away from flooded areas, downed power lines, and damaged buildings—these can be dangerous.

• Continue listening to your radio or other alerts for updates.

• Avoid driving in debris-covered roads or in areas with flooding.

• Help neighbors, especially those who may need assistance, like seniors or disabled persons.

• Be cautious of aftershocks, which can trigger additional waves or cause structural damage.

Common Myths About Tsunamis

• Myth: Tsunamis are giant walls of water.
  Fact: They often look like a fast-moving flood that rises and falls. Sometimes, they form a tall wall, but most are just a series of waves.

• Myth: The first wave is always the biggest.
  Fact: The initial wave is often not the largest. The biggest wave may arrive hours later.

• Myth: Boats should hide in bays or harbors during a tsunami.
  Fact: Tsunamis are most destructive in bays and harbors. If you are out at sea, move away from the coast and into deep water as quickly as possible.

Remember: Your Safety Comes First

You don’t need special training to stay safe during a tsunami. Your quick thinking, calm actions, and following official guidance are your best tools. Know the signs, have an plan, and evacuate immediately if instructed or if signs appear.

Together, we can protect ourselves and our community from tsunamis—until professional responders arrive.