Smaller — but still substantial — quakes were recorded before and after. Russian state media said, citing local geologists, that over two dozen aftershocks had hit Kamchatka. It added their strength was gradually receding.
The PTWC initially said there was a danger of major tsunami waves but later downgraded its warning before finally saying the danger had passed.
Russia's Emergencies Ministry also issued a tsunami warning following the largest quake, urging residents of coastal settlements to stay away from the shore.
There were no immediate reports of casualties or damage, and the ministry said it had no plans to evacuate residents. Just over two hours later, it reported that the danger had passed.
On Nov. 4, 1952, a magnitude 9.0 quake in Kamchatka caused damage but no reported deaths despite setting off 9.1-meter (30-foot) waves in Hawaii.