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Writer's pictureSeaside Sustainability
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The 1946 Aleutian Tsunami

Isabella Deza



for this newsletter, we wanted to take you back in time in climate history to learn about the 1946 Aleutian Tsunami. In the late night of April 1st, an 8.1 magnitude earthquake struck the Aleutian Islands of Alaska at 2:29AM. The earthquake generated one of the most destructive Pacific-wide tsunamis in history and the most severe in the Hawaiian islands (Dr. George Pararas, n.d.) The tidal waves reached an estimated 115 feet in Alaska and averaged 30 feet in Hawaii. The earthquake triggered a tsunami that resulted in the deaths of 159 people in Hawaii and caused over $26 million in damage in 1946 dollars.

In Hawaii’s history, this tsunami is classified as the greatest in damage and numbers of deaths – this led to the creation of the United States’ first tsunami warning system. The official tsunami warning capability began in 1949, in response to the tsunami and because of the devastation that it caused Hilo, Hawaii. The most damage was done to the town of Hilo once the Island of Hawaii was hit. This town was struck with a series of 6 to 7 large tsunami waves, in intervals of 15-20 minutes. The highest waves “had a run up height of 8.1 meters above sea level.” The tsunami arrived in Hilo after 4.9 hours and a total of 96 people lost their lives. Houses that faced the Hilo Bay were ripped off its foundation and were smashing against buildings on the other side of streets. The tsunami was very powerful in size and left scientists baffled by the discrepancy between the size of the tsunami and relatively low surface wave magnitude.

This event also led Hilo to designate “a section of the bayfront as a buffer zone where no businesses could be built. The highway along the waterfront was raised as a barrier, and a warning system with sirens was put in place.” This system is beneficial to Hawaii now since the waves of the tsunami in 1946 topped over 50 feet (HN Staff, 2021). If this system was put in place prior to the tsunami, the damage could’ve been minimal to none, but many people did not know the signs of tsunami natural cues.

Now that the warning system is in place, it is capable of providing early tsunami warning and tsunami awareness is practiced. During the time of the event, many residents didn’t know that receding water signaled an incoming tsunami wave. The warning system was tested four times over the decades of 1950–1960’s. In each case, the system would accurately predict the arrival times of waves in Hawaii. The tsunami left “a permanent imprint on the consciousness of Hawaii residents.” It is recalled to be one of the darkest moments in Hawaiian history.


Citations

  1. 1946 Aleutians tsunami. Western States Seismic Policy Council. (2014, April 5). Retrieved April 25, 2023, from https://www.wsspc.org/resource...;

  2. The April 1, 1946 earthquake and tsunami in the aleutian islands - by dr. George Pararas-Carayannis. (n.d.). Retrieved April 25, 2023, from https://www.drgeorgepc.com/Tsu...;

  3. History.com Editors. (2020, March 30). Alaskan earthquake triggers massive tsunami. History.com. Retrieved April 25, 2023, from https://www.history.com/this-d...;

  4. 1946 aleutian tsunami. (n.d.). Retrieved April 25, 2023, from https://earthweb.ess.washingto...;

  5. Tsunami historical series: Aleutian islands - 1946. Science On a Sphere. (2022, August 24). Retrieved April 25, 2023, from https://sos.noaa.gov/catalog/d...;

  6. Service, N. W. (n.d.). National Weather Service - Tsunami Hazards. U.S. Tsunami Warning Centers. Retrieved April 25, 2023, from https://www.tsunami.gov/?page=...(PTWC)&text=Official%20tsunami%20warning%20capability%20in,house%20the%20Honolulu%20Geomagnetic%20Observatory.

  7. Fukuji, T. (n.d.). 1 April 1946 - International Tsunami Information Center. Retrieved April 25, 2023, from http://itic.ioc-unesco.org/ind...;

  8. McDaniel, J. (n.d.). "like the whole ocean was coming at you". Hawaii Sea Grant. Retrieved April 25, 2023, from https://seagrant.soest.hawaii....;

  9. Staff, H. N. N. (2021, April 1). 75 years ago, the most destructive tsunami in Hawaii's modern history devastated Hilo. https://www.hawaiinewsnow.com. Retrieved April 25, 2023, from https://www.hawaiinewsnow.com/...;

  10. Schmidt, L. J. (2016, July 6). Benchmarks: April 1, 1946: Hawaii tsunami ushers in a Pacific-wide warning system. Retrieved April 25, 2023, from https://www.earthmagazine.org/article/benchmarks-april-1-1946-hawaii-tsunami-ushers-pacific-wide-warning-system/

  11. Shute, M. (2022, July 31). On this day in 1946, the unthinkable happened in Hawaii. OnlyInYourState®. Retrieved April 25, 2023, from https://www.onlyinyourstate.co...



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