More than 400 sealed ‘craters’ are ticking time bombs from a total 7000+ Arctic permafrost mounds

There are 17 identified funnels of exploded so-called ‘heave mounds’ recorded on the Yamal and Gydan peninsulas since the first ’crater’ known as C1 started the history of observations in summer 2014.

They are believed to be caused by the build up of methane gas in pockets of thawing permafrost under the surface; these swollen pingo-like formations then erupt with gas blowing off thick caps of soil, shooting out chunks of ice and soil as large as 150 cubic metres as happened in 2017 when the Seyakha pingo erupted.

The newest - number 17 on Russian scientists’ list - ‘crater’ appeared earlier this summer in an undisclosed location on the Yamal peninsula. 

It is currently 31 metres (102 ft) deep, although scientists believe that it was about 40 metres (131 ft) deep at the moment of eruption, with the bottom of the crater quickly covered by collapsing soil.

‘It was in our database as one of 7,185 permafrost heave mounds on the Yamal and Gydan peninsula.

'Five to six per cent of them are really dangerous’, said Professor Vasily Bogoyavlensky, who has recently returned from a major scientific expedition to study the recently erupted mound. 

The new Yamal peninsula's 'crater' was registered in summer 2020. The process of these mounds forming and exploding is now mostly clear to science, with researchers focusing on how to distinguish the dangerous mounds from the non-explosive ones, and, most importantly, on how to prevent future eruptions. Pictures: Andrey Umnikov, Vesti Yamal

The massive database of pingos is getting compiled thanks to satellite monitoring and regular helicopter expeditions. 

Currently several areas in the Arctic - namely the Seyakha area, the North-Tambey area, the South-Tambey field close to the village of Sabetta, and the West-Seyakha gas field - are on the list of ‘the most dangerous sites’ with the highest concentration of the pingo-like mounds.

The process of these mounds forming and exploding is now mostly clear to science, with researchers focusing on how to distinguish the dangerous mounds from the non-explosive ones, and, most importantly, on how to prevent future eruptions.

‘They can be cut open with gas being pumped out. It must be done very carefully, it is sappers’ work, as these phenomena can be called ‘gas mines’, Dr Bogoyavlensky told The Siberian Times. 

Pictures and video of the new Yamal peninsula's 'crater' by Andrey Umnikov

At the Seyakha crater, a local woman became fascinated with the bulging mound and visited it daily, he said. 

‘But on the day of explosion she felt some tremor, she described it las if the earth was breathing.

‘She quickly left the place just in time before it exploded. If she had shown more curiosity, she would have been killed by this explosion and we would have the first victim.’

At least three of the recorded eruptions had witnesses, who reported seeing the ignition. 

These were the Antipayuta crater (C3), the Seyakha crater (C11) and the Yerkuta crater (C12) eruptions. 

‘We believe the ignition was caused by electrostatic discharges, which adds to the danger of the mounds’, Vasily Bogoyavlensky said.  

The 2014 'crater' on the Yamal peninsula known as C1. Pictures: Vladimir Pushkarev

According to Professor Bogoyavlensky and his team, the exploding mounds described as ‘pingo like features’ differ from classic pingos or bulgunnyakhs. 

Pingos usually form in the depressions of dried up lakes (khasyrei) and have an ice core which expands and makes them grow. 

In the formation of the pingo-like features in northern Siberia, the methane migrates from deeper layers through sub-vertical faults in thawed zones (cryopegs) to fill a cavity formed in permafrost. 

Usually such cavities are covered by a 7 to 9 metre thick seal of permafrost.

The volume of the chamber increases under the growing pressure from the gas and eventually blows up the seal with massive chunks of frozen rock and soil thrown as far as 900 metres from the epicentre. 

Video filmed by Anton Sinitsky in 2017 shows the Seyakha 'crater' with gas emission continuing months after the eruption

Yamal LNG plant in Sabetta, north-east of the Yamal Peninsula. Picture: Yamal LNG

Such mounds grow faster than ‘classic’ pingos. 

For example the Seyakha pingo-like feature  (C11) developed in approximately three and a half years, with an average rate of its growth being over 80cm a year. 

This rate is more than three times higher than that of the Riverbed Pingo (Canada), and other pingos in the north of Canada.

In some cases emission of gas continue long after the eruptions, as it was recorded in Bovanenkovo, Antipayuta, Seyakha 'craters' and lake Otkrytie.

The August 2020 Yamal peninsula research expedition was organized by the Institute of Oil and Gas Problems of the Russian Academy of Sciences, with support from the Government of the Yamalo-Nenets Autonomous Okrug and the Russian Center for Arctic Development.

Specialists from the Skolkovo Institute of Science and Technology were involved in the final stage of the expedition.