Tsunamis are a series of hazardous, large, long ocean waves caused by earthquakes or volcanic eruptions under the sea. You cannot swim or surf tsunamis because they flood the land like a rushing river (or fast-rising tide) rather than curling and breaking like a regular surfing wave. A tsunami picks up and carries debris, significantly increasing the chance of injury, property destruction, and death. Emergency officials will be holding events around the state this month to raise awareness of the risks posed by tsunamis and how to prepare.

Gov. Josh Green proclaimed April as Tsunami Awareness Month in Hawaii, the same day that representatives from the Hawaii Emergency Management Agency and county emergency management agencies gathered on Oahu to discuss tsunami alert and warning protocols, as well as the 2022 tsunami generated by the massive volcanic explosion in Tonga and other tsunami hazard concerns.

The month marks the anniversary of the deadly April Fools’ Day tsunami in 1946, which arrived without warning and killed 158 people, most of them on Hawaii island and around Hilo, according to the Hawaii Emergency Management Agency. Since 1900, a total of 293 people have been killed by tsunamis in Hawaii. The 1946 tragedy led to the development of the Pacific Tsunami Warning Center as the first tsunami warning system in the U.S.

Tsunamis can produce a wall of water 50 feet high or more, and travel hundreds of yards inland when they reach shore. Hawaii faces hazards both from distant tsunamis, which take hours to reach the state, and local tsunamis, which can arrive in minutes after an earthquake within the state.

Be prepared to evacuate

When there is a Tsunami Siren Warning, immediately turn on a radio and or TV and listen to local news. The public will be advised which evacuation zone to leave. Don’t wait to evacuate. It can take time to clear an evacuation zone, so go as quickly and safely as possible. How do you know if you are in an evacuation area? Here is NOAA’s tsunami evacuation map, if you allow it to know your location it reduces the need to search and guess.

If you need to evacuate:

Plan ahead to be able to grab what you need. Keep items together as you may only have moments to leave. Create list and a place to keep together:

  • valuables and documents and essential medications
  • nonperishable food and drink, a flashlight and blanket, beach chairs or padded mats
  • grab your wallet/ID, close windows and lock your home
  • head out of the evacuation zone
  • on Maui shelters do NOT provide anything besides a roof and bathrooms. You will need to bring all your own supplies
  • do not return into the evacuation area until officials give the go-ahead. Remember, it isn’t just one tidal wave, they come in sets for several hours. If there is damage, it may not be safe to go back – so please wait

If you are not in the evacuation zone

  • avoid unnecessary driving (the roads get really clogged)
  • ensure you have working flash lights and your phones are charged (there is always the possibility of a power outage)
  • make sure you have lots of drinking water and also water to wash (clean and fill the bathtub, sinks, pots for non-drinking water purposes)
  • listen to the local news – before the tsunami wave is expected to arrive, the County shuts down the sanitary sewer system. Avoid using the toilet once that happens.

Find Maui specific information.

It can be very difficult to find local Maui specific tsunami information. Most of the news will be about Oahu. Best Maui news sources online:

Overall Hawaii news

Or, tune into local radio stations.

Please do not put your life and that of others (who may have to save you) at risk by going to the beach to watch!

As part of Tsunami Awareness Month, events are scheduled in each of the counties, including a Maui County tsunami brief on April 11 and a Maui Emergency Preparedness Fair on April 29.

The Hawaii Emergency Management Agency will also be running a public service announcement campaign to remind people of the natural warning signs — strong shaking, a roaring noise from the ocean and water receding from the beach — that may indicate that a tsunami is approaching even before sirens sound. Anyone who notices these signs should immediately move away from the coast or seek shelter in a sturdy building on the fourth floor or higher.

For more information on upcoming events or preparing for a tsunami, visit hawaiitsunami.org or contact the International Tsunami Information Center at itic.tsunami@noaa.gov.