Bubbling water of the East Siberia Sea. Picture: Tomsk Polytechnic University

Unexpectedly high level of subsea permafrost degradation was recorded by a Russian-led scientific expedition that spent more than a month in the seas of the eastern Arctic.

A record high methane gas emission in a shape of an underwater ‘fountain’ was registered at the beginning of October east of Bennett island in the East Siberian Sea.

‘It was a needle in a haystack chase, to find an exact place of a methane seep in dark sea waters, but we found it!

'Just right off the Academician Keldysh scientists noticed a spot of emerald-coloured water, with gas rushing to surface in thousands of bubble threads’, said expedition member Sergey Nikiforov, a communications experts of the Tomsk Politechnical University.

The area of the fountain covered about five metres, with water ‘so violently boiling with methane bubbles’ that scientists skipped using plastic cones for sampling and instead collected the gas in buckets.

‘This was the most powerful seep I have ever observed. No one has ever recorded anything similar’ said head of the expedition Igor Semiletov, who has participated in 45 Arctic expeditions.



Bubbling water of the East Siberia Sea. Pictures: Tomsk Polytechnic University

Unexpectedly high speed of degradation of subsea permafrost has been recorded.

'In some areas the roof of subsea permafrost thawed to the stability horizons of gas hydrates. Moreover, it has been proved that over the past 30 years speed of vertical degradation of subsea permafrost doubled compared to previous centuries and reached 18 centimetres per year which is significantly higher than in earlier estimates', said professor Semiletov.

'This result makes us reconsider the belief that subsea permafrost is stable and can only thaw by a few metres by the end of 21st century', he stressed.

First video of the largest methane seep (fountain) so far discovered in the Arctic Ocean, credit Tomsk Politechnic University

KEY FACTS

Expedition set off from Arkhangelsk, northwest Russia, on September 17.

It was organised by Shirshov Institute of Oceanography (Moscow) with the Ilyichev Pacific Ocean Institute of Oceanography (Vladivostok).

65 scientists from 12 research organisations across 7 countries (Russia, Sweden, Norway, Netherlands, Italy, UK, USA) were on board of Academician Keldysh research vessel.

Researchers studied seas of the eastern Arctic: East Siberian sea, Laptev sea and Kara sea.

Aims of the expedition were

To study state of subsea (underwater) permafrost;

To study flows of greenhouse gases in the Arctic atmosphere;

To study ecological state of waters and seabed sediments along the Northern Sea Route (NSR).

What they actually established

High levels of degradation of subsea permafrost.

Speed of vertical degradation of subsea permafrost has doubled compared to previous centuries and turned out to be higher than earlier estimates.

Microplastic has been discovered in seas of the eastern Artic thousands miles away from residential settlements.

What else did researchers say?

Elena Kudryashova, rector of Northern Federal University, Arkhangelsk: 'Another important subject of our research was study of various types of microplastic in the seas of the eastern Arctic.

'It is important to compare and analyse results of all expeditions because microplastic represents a serious threat to organisms and sea ecosystems as a whole.'

Pictures of the methane gas seep credit Tomsk Polytechnic University