New Delhi, July 30 -- A massive 8.8 magnitude earthquake struck off Russia's Kamchatka Peninsula on Monday evening, prompting widespread tsunami warnings across the Pacific - including in Hawaii, where residents and tourists braced for possible waves with surprising calm.

The quake hit at approximately 7:24 p.m. ET, southeast of Petropavlovsk-Kamchatsky. Its powerful tremors triggered immediate tsunami alerts from Japan to California, with Hawaii placed on high alert due to its central Pacific location.

In Honolulu's Waikiki district - a major tourist hub - emergency officials urged people to stay away from the shoreline and prepare to move to higher ground if necessary. Tsunami waves of several feet were later observed in some areas of...