A tsunami is a huge ocean wave that can hit coastal areas and move inland. The series of enormous waves are made by an underwater disturbance such as an earthquake, underwater landslide or meteorite. A tsunami can move at speeds of 600 miles per hour across the open ocean and smash into land with waves as high as 100 feet or more. The debris-filled water can cause great damage and loss of life within minutes.
From the area where the tsunami begins, waves travel outward in all directions. Once the wave nears the shore, it builds in height. The features of the coastline and ocean floor will impact the size of the wave. There may be more than one wave. The wave(s) that follow the first one may be larger than the one before. That is why a small tsunami at one beach can be a giant wave a few miles away.
About 85 percent of tsunamis occur in the Pacific Ocean. North Carolinians living or vacationing at the beach still need to be ready. In fact, NOAA has placed tsunami-detecting buoys about 1,000 miles off the North Carolina and Virginia coast and three in the Caribbean. The buoys will spot monster waves better than the current gauges used on land or close to the shoreline.
The NOAA Weather Radio System also gives direct broadcast of tsunami information to the public. When you hear a tsunami warning, move at once to higher ground and stay there until you are told that it is safe to return home.
Before a Tsunami
If you feel an earthquake or hear a sizable ground rumbling and you see a noticeable rapid rise or fall in coastal waters, those are good warning signs for a tsunami. Seek higher ground instantly. Don't wait for orders to leave your home or office.
The International Tsunamis Information Center gives the helpful tips below.
Tsunamis can be detected by use of our human senses:
- Feel the ground shaking severely? Instantly leave low-lying coastal areas and move inland to higher ground.
- See - As a tsunami comes near shorelines, water may recede from the coast, showing the ocean floor and reefs. If you see an unusual disappearance of water, quickly leave low-lying coastal areas and move inland to higher ground.
- Hear a loud “roaring” sound similar to that of a train or jet aircraft? The odd ocean activity, a wall of water and oncoming tsunami waves create the roar. Instantly leave low-lying coastal areas and move inland to higher ground.
During a Tsunami
- Follow the order to leave as it was issued by authorities.
- Leave immediately. Take your animals with you.
- Move inland to higher ground quickly. Pick areas 100 feet above sea level, or go as far as 2 miles inland, away from the coastline. If you cannot get this high or far, go as high or far as you can. Every foot inland or upward may make a difference.
- Stay away from the beach. Never go down to the beach to watch a tsunami come in. If you can see the wave you are too close to escape it.
- CAUTION - If there is noticeable recession in water away from the shoreline this is nature's tsunami warning. Pay attention to it! You should move away immediately.
- Save yourself – not your possessions.
- Help your neighbors who may need special assistance – infants, elderly people and individuals with access or functional needs.
After a Tsunami
- Return home only after local officials or police tell you it is safe. A tsunami is a series of waves that may continue for hours. Do not think that after one wave the danger is over. The next wave may be larger than the first one.
- Go to an assigned public shelter if you have been told to leave or you feel it is unsafe to remain in your home.
- Stay away from disaster areas. You being there might get in the way of what fire fighters, police and medical staff are doing. Going into an area that has been impacted by a tsunami can put you at risk from the left over effects of floods.
- Stay away from debris in the water. It may pose a safety danger to people or pets.
- Check yourself for wounds. Get first aid as needed before helping hurt or trapped people.
- If someone needs to be rescued, call trained people with the right equipment to help. Many people have been killed or hurt trying to rescue others.
- Help people who require special assistance—infants, elderly people, those without transportation, people with access and functional needs, and large families who may need extra help in an emergency.
- Continue using a NOAA Weather Radio. Tune to a Coast Guard station or a local radio or television station for the latest news.
- Stay out of any building that has water around it. Tsunami water can cause floors to crack or walls to collapse.
- Use caution when re-entering buildings or homes. Tsunami-driven floodwater may have damaged buildings where you least expect it. Watch every step you take.
- Wear protective clothing and be cautious when cleaning up so that you don’t get hurt.
More information on how to plan and get ready for a tsunami can be found at:
Listen to Local Officials
Learn about the emergency plans that have been made in your area by your state and local government. In any emergency, always listen to the orders given by local emergency management officials.