1946 Aleutian Islands earthquake facts for kids
Fleeing an approaching tsunami in Hilo, Hawai'i
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| UTC time | 1946-04-01 12:29:01 |
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| ISC event | 898313 |
| USGS-ANSS | ComCat |
| Local date | 1 April 1946 |
| Local time | 03:29 |
| Magnitude | 8.6 Mw |
| Depth | 15 km (9.3 mi) |
| Epicenter | 53°29′N 162°50′W / 53.49°N 162.83°W |
| Areas affected | Hawaii, Alaska United States |
| Max. intensity | VI (Strong) |
| Tsunami | Yes |
| Casualties | 165–173 |
The 1946 Aleutian Islands earthquake occurred near the Aleutian Islands, Alaska on 1 April 1946. The shock had a moment magnitude of 8.6 and a maximum Mercalli intensity of VI (Strong). It resulted in 165–173 casualties and over $26 million in damage. The seafloor along the fault was elevated, triggering a Pacific-wide tsunami with multiple destructive waves at heights ranging from 45–130 ft (14–40 m). The tsunami obliterated the Scotch Cap Lighthouse on Unimak Island, Alaska among others, and killed all five lighthouse keepers. Despite the destruction to the Aleutian Island Unimak, the tsunami had almost an imperceptible effect on the Alaskan mainland.
Waves reportedly traveled across the ocean at 500 miles per hour (800 km/h) and measured 55 feet (17 m) high, crest to trough, according to the USGS. The wave reached Kauai, Hawaii 4.5 hours after the quake, and Hilo, Hawaii 4.9 hours later. In Hilo, the death toll was high: 173 died, 163 injured, 488 buildings were demolished and 936 more were damaged. Witnesses told of waves inundating streets, homes, and storefronts. Many victims were swept out to sea by receding water. The tsunami caused much damage in Maui as well. Waves there demolished 77 homes and many other buildings. The residents of these islands were caught off-guard by the onset of the tsunami due to the inability to transmit warnings from the destroyed posts at Scotch Cap, and the tsunami is known as the April Fools' Day Tsunami in Hawaii because it happened on 1 April. The effects of the tsunami also reached Washington, Oregon, and California.
The tsunami was unusually powerful for the size of the earthquake. The event was classified as a tsunami earthquake due to the discrepancy between the size of the tsunami and the relatively low surface wave magnitude. The large-scale destruction prompted the creation of the Seismic Sea Wave Warning System, which became the Pacific Tsunami Warning Center in 1949.
See also
In Spanish: Terremoto de las Islas Aleutianas de 1946 para niños
