Authorities in the eastern province of Sakhalin initially issued a tsunami warning but this has now been lifted.
The US Geological Survey said the earthquake was of a magnitude of 8.2, but Russian authorities estimated the size of the earthquake at 6.7.
Soon after the earthquake, tremors were felt across Russia but it is unclear if they were linked.
The tremors reached as far as the capital Moscow, some 7,000km (4,500 miles) to the west. The last time tremors were felt in Moscow was some 30 years ago.
The epicentre of the quake, which struck at 15:44 local time (05:44 GMT), was in the Sea of Okhotsk to the west of the Kamchatka peninsula, around 600 km (380 miles) under the sea.
The area is sparsely populated. The most significant population centre is the city of Petropavlovsk-Kamchatskiy on the Kamchatka peninsula, famous for its active volcanoes.
Residents of Petropavlovsk-Kamchatskiy, around 400 km from the epicentre, briefly ran out of buildings and schoolchildren were evacuated, the Associated Press reports.
However, there are no reports of casualties or significant damage.
The strength of the earthquake is very unusual, even on Russia’s most active geological fault.