Alerts for a potential tsunami were issued for coastlines in North America, Hawaii, Russia and Japan after a powerful 8.8-magnitude earthquake struck in the North Pacific Ocean off Russia’s northern Pacific coast, according to the U.S. Tsunami Warning System, which is part of the National Weather Service.

The 8.8 magnitude megaquake is the joint-sixth largest earthquake ever recorded and the first tsunami waves have already hit Oahu, Hawaii.

A powerful earthquake off Russia’s east coast triggered tsunami waves across the Pacific, prompting alerts in Hawaii and California.

Hawaii officials say the timing of the tsunami warning and evacuation orders following this week's massive earthquake off Russia helped make for severe traffic congestion in some areas.