The watch was issued at 9:03 p.m. after a 7.4 magnitude earthquake off Russia’s Kamchatka Peninsula, but canceled after there was no threat to Hawaii.

Completion of mass production of the Poseidon nuclear torpedo marks a shift in strategic deterrence and maritime warfare doctrine. Developed under Russia’s 2018 “Invincible Weapons” initiative, Poseidon combines a compact nuclear reactor for years-long autonomous operation,