The explosions causing the craters to open up could potentially pose risks to vessels travelling on Barents Sea, scientists say.
It could also possibly explain the loss of ships and aircraft in the controversial area referred to as the Bermuda Triangle, according to the experts.
The area stretches from the British Overseas Territory in the North Atlantic Ocean to the Florida coast, to Puerto Rico.
Russian scientist Igor Yeltsov, the deputy head of the Trofimuk Institute, said last year: "There is a version that the Bermuda Triangle is a consequence of gas hydrates reactions.
"They start to actively decompose with methane ice turning into gas. It happens in an avalanche-like way, like a nuclear reaction, producing huge amounts of gas.
"That makes the ocean heat up and ships sink in its waters mixed with a huge proportion of gas."
Huge craters on the sea floor, found off Norway, suggest giant blowouts of methane