The quake hit 111 kilometres (69 miles) east of the Russian city of Petropavlovsk-Kamchatsky.
The administrative centre of the Kamchatka region, at a depth of 39.5 kilometres, according to the USGS.
The survey earlier gave a magnitude of 7.5 before downgrading it.
The Pacific Tsunami Warning Center said "hazardous" waves of up to one metre (3.3 feet) were possible along some nearby Russian coasts.
Japan, Hawaii and other islands in the Pacific may see waves of less than 30 centimetres, the centre said.
In July, one of the strongest earthquakes ever recorded struck off the Kamchatka peninsula, triggering tsunamis up to four metres high across the Pacific and sparking evacuations from Hawaii to Japan.
The magnitude 8.8 quake was the largest since 2011, when a magnitude 9.1 tremor off Japan caused a tsunami that killed more than 15,000 people.
July's quake prompted authorities in Japan to order almost two million people to head to higher ground.
Tsunami warnings were also issued across the region, before being rescinded or downgraded.