Tsunami Safety & Preparedness in Hawai`i

Tsunami Evacuation Zone Maps

Tsunamis in Hawai`i

Hawai`i is at risk from tsunamis caused by both distant ("teleseismic") and local sources. PTWC issues different messages types for tsunamis generated by these two types of sources. In either case, a large, shallow earthquake originating beneath the ocean floor has the potential to generate a tsunami.

• Tsunamis from Distant Sources: Most tsunamis that affect Hawai`i originate from seismically active areas around the Pacific. In particular, areas where tectonic plates are in collision (subduction zones), such as Alaska's Aleutian Island chain and the west coast of South America, generate most of the world's tsunamigenic earthquakes. When this occurs, residents of Hawai`i have ample time to prepare for an incoming tsunami (4 hours if it's from Alaska, 10 hours from Chile). In this case people should stay tuned to local radio and TV to determine when and if they should evacuate to higher ground. Distant tsunamis with runups in Hawai`i exceeding 3 meters have occurred in 1868 (Chile), 1877 (Chile), 1896 (Japan), 1906 (Chile), 1923 Kamchatka, 1933 (Japan), 1946 (Aleutians), 1952 (Kamchatka), 1957 (Aleutians), 1960 (Chile), 1964 (Alaska).
  
   
• Tsunamis from Local Sources: Because Hawai`i is seismically active, a shallow undersea earthquake can reach sufficient size to generate a local tsunami. While destructive local tsunamis are less frequent, there is little time to react to such an event. Waves from the tsunami caused by the 1975 Kalapana earthquake killed two campers in the Halape area about a minute after they experienced the strong shaking. Therefore, if you feel strong shaking and are near the water, you should immediately move to higher ground. For example, a tsunami generated from the southeast coast of the Big Island will only take 5-10 minutes to reach Hilo or Kona, so you should act fast. Residents of Maui have about 15-20 minutes, and Oahu has about 30-40 minutes warning. Local tsunamis with runups exceeding 3 meters have occurred in 1868 (Ka`u) and 1975 (Kalapana).

More Resources

• Hawai`i State Civil Defense
• Hawai`i County Civil Defense
• Maui County Civil Defense
• O`ahu Civil Defense
• Kaua`i County Civil Defense
• Pacific Disaster Center
• International Tsunami Information Center
• Pacific Tsunami Museum
• Natural Hazards in Hawai`i
• USGS Tsunami History on the Island of Hawai`i