Alaska Time Zone to 1967 refer to this zone as Central Alaska Standard Time (CAT) or as Alaska Standard Time (AST). In 1966, the Uniform Time Act renamed the UTC−10 zone to Alaska-Hawaii Standard Time (AHST), effective April 1, 1967. This zone was renamed in 1983 to Hawaii-Aleutian Standard Time when the majority of Alaska was moved out of the zone. Prior to 1983, the current Alaska Time Zone (UTC−9) was known as the Yukon Time Zone, observing Yukon Standard Time (YST). This time zone included Canada's Yukon Territory and a small portion of Alaska including Yakutat. The Alaska Panhandle communities were in
Aleutian subduction zone west (Andreanof Island) where LFEs occur at greater depths (~75 km) than in the east where the plate is younger (~45 km near Kodiak Island). This may be because the depths at which the hydrous minerals release water and produce tremors are greater when the plate is older, colder, and subducting faster. Aleutian subduction zone The Aleutian subduction zone is a ~2500 mile-long convergence boundary between the North American Plate and the Pacific Plate, that extends from the Alaska Range to the Kamchatka Peninsula. Here, the Pacific Plate is being subducted underneath the North American plate and the rate of