August 21, 1951 Earthquake: Hawaii, United States

1951, August 21, 0:57 local time. This was the strongest earthquake since 1868 on the Hawaiian Islands. Its source was located at sea off the western coast of Hawaii Island, within Kona district. The earthquake lasted 3 minutes near the epicentre and had magnitude of about 8 degrees (by different estimates, from 7 to 9 degrees). The greatest destruction occurred from Kealakekua to Hookena. Here 200 out of 1000 homes suffered damage. At Hookena, 8 frame homes collapsed and 30 homes, a school and a warehouse were damaged. In the pleistoseismic zone, about 50 water reservoirs were destroyed and 150 were damaged; the power telephone networks were put out of commission; two small fires broke out. Two persons were injured. Cracks formed in the ground. A large avalanche fell into the water from a cliff at Napoopoo. There were many other avalanches, not so large. The earthquake was felt with a force of 4 degrees on the opposite, eastern side of Hawaii Island, 2 degrees at Honolulu. It was also felt on Maui Island. After the earthquake many recurrent shocks occurred. Thus at Keei, 109 tremors were felt in the first 8 hours after the main earthquake. [21.VIII; 10h 57m; 19.2 N, 156.1 W; M=6.9] (Reference #415).