Measuring methane samples from Yamal Peninsula
© Anton Sinitsky, The Siberian TimesMeasuring methane samples from Seyakha crater, Yamal Peninsula
Gas bubbles from waters filling crater hole on Yamal peninsula two months after volcanic-style explosion in thawing permafrost.

Fresh analysis of a new geological phenomenon shows how gas is still gushing from a submerged crater caused by a fierce methane gas explosion in northern Siberia in June.

A 'pillar of fire' from the eruption was caused by stones and pebbles being thrown together as they were thrust out of the ground, sparking the swoosh of gas, like in an oven, a leading expert believes.

Reindeer and dogs from a nearby nomadic encampment fled in terror at the fireball, with some debris thrown as far as 200 metres from the epicentre.

A 50-metre deep funnel or crater was immediately filled by water from the Myudriyakha River flowing beside the site of the explosion.

The video shows Dr Anton Sinitasky, director of the Arctic research Centre in Yamalo-Nenets region, in a small boat measuring gas - previously trapped in the frozen permafrost ground - which continues to leak from under the murky waters.

The scientist said: 'I can confirm that there was really a fire burning over the Seyakha funnel. We need to rely on the words of eyewitnesses. It lasted for one or one-and-a-half hours.

'Everything depended on the gas jet power.

'We think that the cause of the ignition was pebbles thrown by the eruption.

'The pebbles collided and struck a spark.

'It was like in gas oven - one spark was enough to set the gas on fire.

'When the power of gas jet began to decrease, the burning stopped.

'But the methane continues to leak from the funnel, so we have been able to take samples.'

Scientists say it is 'clean' methane but they are now analysing whether it comes from deep in the earth or nearer the surface, perhaps through existing fissures and faults.

The Seyakha eruption is the most recent of a series of crater or funnel formations recently noticed in northern Siberia. It was the only one witnessed at close hand by humans. Some 700 sites in the region are reported to be vulnerable to eruptions.

The phenomenon is seen as highlighting the release of greenhouses gases due to thawing permafrost which under relatively recent global warming capped the methane beneath the surface.

A key concern is the impact of such eruptions on industrial facilities including pipelines in the Yamal region, one of the world's largest natural gas supply locations.

'We have gathered some charred sand and grass from Seyakha, but actually no analysis is needed to confirm what is obvious: there definitely was burning.

'We did not find any similar traces of burning at the Yerkuta funnel, but here the eruption was in winter, so pieces of ice, soil and ground fell onto the snow, it melted in spring and all traces might just disappear.

'We found pebbles there, but we cannot say 'yes' or 'no' regarding burning.

'The same is true about the Bovanenkovo funnel.'

This is the most famous and spectacular of the craters found in recent years.

'We found pebbles, but no traces of burning,' he said.

This means that burning may occur - or not - during such eruptions.

'What is important - we now know for sure that the gas can burn during such eruptions,' he said.

Such 'burning' increases the risk for industrial energy facilities.

Gas companies are monitoring sites vulnerable to such eruptions.

These are believed to be geological phenomenon known as pingos where beneath which permafrost is thawing.

'It is all about monitoring,' said Dr Sinitasky.

'I know that oil and gas producing companies have maps of such objects and monitor them constantly.

'I have heard that for example Gazprom-Dobycha Yamburg make punctures and release gas to avoid eruption risk.

'When I was working at VNIIGAZ, I made a map of such objects for Gazprom.'

He said: 'The companies are very interested in minimising risks, they do not need any accidents, so they make maps and observe these objects very closely.

'As for the general map of such objects... The Institute of Oil and Gas Problems keeps a database on sites being discovered using satellite data.

The Earth Cryosphere Institute probably has its own database.

'We provide them with data on new palaeo-craters because it is important to study these things in an historical context.'

He believes that the phenomenon is 'unique' the the geological conditions on the Yamal and Taimyr peninsulas, where .

'We now know that these objects form when there is a coincidence of a thick layer of permafrost and thick sedimentary cover of 3.5 to 5 kilometres,' he said.

'This is why we can observe pingos in Yakutia or Alaska, but they do not explode.'

He told The Siberian Times: 'We are observing such a phenomenon for the first times in history, that is why we call them new,...

'I do not exclude that such objects could form earlier, it's just that they were not observed.

'For example ornithologist Alexander Sokolov has an old picture, showing geologists sitting on a breastwork.

'It is similar to what we see on the Bovanenkovo and Yerkuta funnels.

'Why were they not observed earlier?

'First of all there was no such (industrial) infrastructure as we have now.

'But also we see now how they change their shape very fast - turning to lakes, are covered with plants, so maybe geologists or locals just did not have a chance to see them soon after the eruption.

'Perhaps they just did not pay attention.

'In addition, I suppose that now, because of climate change, such objects appear more often then previously.'

A herdsman told how reindeer and dogs 'fled in terror' from the eruption at Seyakha.

He was left clinging to a new-born deer after its mother bolted in fear.

The sudden and deafening bang shook the ground and sent flames shooting into the sky after the explosion

Mikhail Okotetto told TV channel Yamal-region of a fellow herder who was close to the eruption.

'The reindeer fled to the south, but he had newborn calf (in his hands),' he said.

'So the reindeer and dogs all ran away, and he was just left there standing with the newborn calf.'

Another local said: 'It was like a new volcano exploding. Of course there was no lava, but the rocks are singed from the extreme heat.'

Dr Vasily Bogoyavlensky, deputy director of the Moscow Oil and Gas Research Institute, believes the explosions are similar to the under-ocean eruptions of methane that caused the so-called Bermuda Triangle.

Such 'degassing' is happening in many locations but uneven thawing in permafrost regions means methane is not released evenly and can collect in pockets, eventually exploding.

'Strong degassing is occurring in the Arctic,' he said.

'But what we have just seen is a drop in the ocean of this global degassing of subsoil.'

The latest explosion is around 140 kilometres south of Russia's new state-of-the-art Arctic port of Sabetta, used to export natural gas.

A second new crater - also formed this year - was created after an explosion on bulging ground around 500 km north of the town of Salekhard.

It was located this month by a group of scientists led by Dr Aleksandr Sokolov, deputy head of the ecological research and development station of the Institute of Ecology of Plants and Animals, in Labytnangi, Tyumen region.

'This plot of land was absolutely flat just two years ago,' he said.

'A year ago in 2016 it bulged and we could see that soil has cracked there.'