A massive magnitude 8.7 earthquake struck off the coast of Russia Tuesday, sparking tsunami warnings in Alaska and Hawaii and alerts for other areas of the West Coast.
The earthquake occurred about 85 miles off the east coast of Russia’s Kamchatka Peninsula with a depth of nearly 12 miles, according to the U.S. Geological Survey.
A warning was announced for Alaska’s Aleutian Islands and Hawaii. California, Oregon and Washington are under a tsunami watch, as well as the U.S. territory of Guam, while the threat is being evaluated.
MORE: 7.3 magnitude earthquake rattles Alaskan island, prompting tsunami advisory
The first tsunami wave is forecast to reach Hawaii just after 7:15 p.m. local time. Destructive tsunami waves are expected, according to Oahu Emergency Management.
People are urged to evacuate coastal areas, according to officials. All shores of the island are at risk because tsunami waves wrap around islands, according to the National Weather Service.
“The danger can continue for many hours after the initial wave as subsequent waves arrive. Tsunami heights cannot be predicted and the first wave may not be the largest,” the NWS said in an alert.
An advisory was also issued for Japan’s Pacific Coast regions from Hokkaido to Kyushu.
MORE: 6.2 magnitude earthquake near Istanbul rattles Turkey
Japan’s meteorological agency warned that a tsunami about 1 meter (3 feet) high is expected to reach Hokkaido in the north around 10:00 a.m., local time, with waves arriving later in the day along parts of eastern Honshu and Kyushu in the south.
People are warned to stay away from the coast and river mouths and not to approach the water to observe.
A tsunami warning means that a tsunami that could cause widespread, dangerous flooding and powerful currents is expected. A tsunami watch means a distant earthquake has occurred and a tsunami is possible.
ABC News’ Bonnie Mclean, William Gretsky and Anthony Trotter contributed to this report.
This is a developing story. Please check back for updates.
