The State of Hawaii named April as Tsunami Awareness Month in the 1990s. On April 1, 1946 a tsunami from the Aleutian islands surprised the State. At the time, the Hawaiian Islands did not have a tsunami warning system. The death toll climbed to 159 people with many more injured. As a result, the US Seismic Sea Wave Warning System was started in 1949. Today, it is known as the Pacific Tsunami Warning Center. The last tsunami that caused significant damage in Hawaii was the Great East Japan tsunami in 2011. This tsunami event caused $30 million in damage statewide.
The 2018 Tsunami Awareness Month theme comes from a Hawaiian proverb (ʻŌlelo Noʻeau) written by Mary Kawena Pukui. “ʻIliki ke kai i ka ʻopeʻope lā, lilo; i lilo no he hāwāwā.” The literal translation is; “The sea snatches the bundle, it is gone; It goes when one is not watchful.” The purpose of tsunami awareness month is to raise awareness and educate the public about tsunamis.
What is a tsunami?
A tsunami is ALWAYS a series of waves. The first wave may not be the largest in the series. They are created when an abrupt disturbance displaces a large amount of water. The entire column of water from the surface to the ocean floor is set into motion. This vast volume of water can travel at speeds of up to 600 mph in deep water. In the open ocean, the waves are only one to two feet tall. As they approach land and move over shallower water, they slow down, build up and the height increases dramatically. A tsunami “wave” looks more like a flooding wall of water than an ocean wave. The wavelength is so long that the distance from one wave crest to the next can be 100 miles away.
There is no “tsunami season”. They can occur at any time and have nothing to do with the tides. Coastal features and the underwater topography affect the size and impact of tsunami waves. One coastal area may experience catastrophic damage, while a nearby community may experience no damage at all. Tsunami flooding, also known as inundation, can extend inland by half a mile or more. History has shown, water height have risen to more than 50 feet from tsunamis of distant origin and more than 100 feet for locally generated tsunamis.
What causes a tsunami? Click, HERE.
What are the different alert levels and what do they mean?
*Tsunami Information Statement: There is no tsunami threat.
*Tsunami Watch: You should prepare and be ready to act because a tsunami may occur.
*Tsunami Advisory: You should move away from beaches and low-lying coastal areas and evacuate harbors/marinas. Move boats and ships to deep water if there is time. You can expect strong currents and dangerous waves in coastal areas and waterways. But significant land flooding is not expected.
*Tsunami Warning: Quickly leave Red Tsunami Evacuation Zones to Green Safe Zones as indicated on the Tsunami Evacuation Map.
*Extreme Tsunami Warning: Quickly leave Yellow Extreme Tsunami Evacuation Zones and Red Tsunami Evacuation Zones to Green Safe Zones as indicated on the Tsunami Evacuation Map. A very large magnitude 9+ earthquake may cause an extreme tsunami. There may only be 3.5 hours to evacuate before the first wave arrives.
*Find out if you are in an evacuation zone! Tsunami Evacuation Maps for Hawaii County can be found HERE.
Upcoming Tsunami Awareness Events in Hawaii County:
Saturday, April 21: Waimea Keiki Fest, All-hazards disaster preparedness, Contact: David Carvalho, Univ of Hawaiʻi, Hilo, Center for the Study of Active Volcanoes (CSAV), firstname.lastname@example.org
Tuesday, April 24: Waiakea Elem Big Brothers Big Sisters After School Program, Volcano and Tsunami Presentation, Contact: David Carvalho, Univ of Hawaiʻi, Hilo, Center for the Study of Active Volcanoes (CSAV), email@example.com
Saturday, April 28: Pacific Tsunami Museum Open House (Childrenʻs Day), 10:00 AM – 4:00 PM, Event will feature games, songs, stories and tsunami educational activities. Contact: Pacific Tsunami Museum www.tsunami.org
*Frequently Asked Questions about tsunamis, click HERE.
*For a map showing run-up from past events here on the Big Island, click HERE.