Hawaii–Aleutian Time Zone Hawaii–Aleutian Time Zone The Hawaii–Aleutian Time Zone observes Hawaii–Aleutian Standard Time (HST), by subtracting ten hours from Coordinated Universal Time (). The clock time in this zone is based on the mean solar time of the 150th meridian west of the Greenwich Observatory. The zone takes its name from the two areas it includes: Hawaii and the portion of Alaska's Aleutian Islands west of 169° 30′ W longitude. During daylight saving time, the Alaskan portion observes Hawaii–Aleutian Daylight Time (HDT, ), while Hawaii stays on standard time. From 1900 until 1947, GMT−10:30 was used as standard time in Hawaii. French
1946 Aleutian Islands earthquake 1946 Aleutian Islands earthquake The 1946 Aleutian Islands earthquake occurred near the Aleutian Islands, Alaska on April 1. 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. 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