New footage emerges from deep within the strange structure
Enormous crater appeared suddenly in part of Russia, Yamal, where name translates as 'the end of the world' Some thought the rare and unusual structure, which was up to 300ft (70 metres) deep, was caused by a meteorite
Andrei Plekhanov from Scientific Research Center of the Arctic says crater was formed due to rising temperatures One theory is that a chunk of ice that is located underground that created a hole in the ground when it melted Another is that the crater was formed by a mixture of water, salt and gas igniting an underground explosion
Recent expedition revealed that the crater has an icy lake at its bottom, and water is cascading down its walls
By Will Stewart In Moscow and Jonathan O'Callaghan and Ellie Zolfagharifard and Steph Cockroft
Footage has emerged from deep inside the mysterious crater that has suddenly appeared in Siberia.
The crater on the Yamal Peninsula - known as the 'end of the world' to locals - was caused by aliens, a meteorite, a stray missile, or an explosive gas cocktail released due to global warming, according to theories last week.
Russian scientists recently returned from the first expedition to look inside the giant hole which was previously spotted by helicopter. Scroll down for video
Footage from inside the crater showed that there is a lake at its base
Their footage highlights a darkening around the rim which was earlier seen as evidence of heat possibly from an explosion during the crater's creation.
'They found the crater - around up to 300ft (70 metres) deep - has an icy lake at its bottom, and water is cascading down its eroding permafrost walls,' said The Siberian Times.
It is not as wide as aerial estimates which earlier suggested between 164ft and 328ft (50 and 100 metres).’ Andrey Plekhanov, senior researcher at the Russian Scientific Centre of Arctic Research, revealed that satellite mapping imagery is being used to establish when the phenomenon was formed, thought to be in the last year or two.
This giant crater measuring around 262ft and found in far northern Siberia is believed to have been caused by rising temperatures in the area - not a meteorite
Andrei Plekhanov, a senior researcher at the Scientific Research Center of the Arctic, who travelled to investigate the crater, said there were no traces of an explosion
The discovery eliminates the possibility that a meteorite had struck the region in the Yamal Peninsula - the name of which translates as 'the end of the world'
Mr Plekhanov said the enormous crater appears to be made up of 80 per cent ice which adds to the theory that it was caused by the effects of global warming
The darkening around the inner rim of the crater also indicates 'severe burning' which scorched the crater's edges, researchers said
The darkening around the inner rim of the crater indicates 'severe burning' that scorched its edges
'The crater has more of an oval than a circular shape, it makes it harder to calculate the exact diameter,' he said. 'As of now our estimates is about 98ft (30 metres). If we try to measure diameter together with soil emission, the so-called parapet, then the diameter is up to 197ft (60 metres).
The structure is so fragile that the scientists could not climb deep into the lake and had to send a camera down instead. One theory is that the feature is a ‘pingo,’ reports the Sunday Morning Herald.
A pingo is a large chunk of ice that is located underground that can create a hole in the ground when it melts.
‘Certainly from the images I’ve seen it looks like a periglacial feature, perhaps a collapsed pingo,’ Dr Chris Fogwill of the University of New South Wales said.
‘This is obviously a very extreme version of that, and if there’s been any interaction with the gas in the area, that is a question that could only be answered by going there.’
Dr Plekhanov added the hole was most likely the result of a 'build-up of excessive pressure' underground, due to the region's changing temperatures.
He said 80 per cent of the crater appeared to be made up of ice and that there were no traces of an explosion.
The discovery eliminates the possibility that a meteorite had struck the region.
'Could it be linked to the global warming? Well, we have to continue our research to answer this question,' said Dr Plekhanov.
'Two previous summers - years 2012 and 2013 were relatively hot for Yamal, perhaps this has somehow influenced the formation of the crater
Perma frost is seen near the hole in this photo. Some said the hole could have been formed by a meteorite striking the spot, but that no longer seems to be the case
Scientists working at the site measure some of the soil and debris around the crater
Until the expedition took place, shown, scientists had been baffled by the appearance of the giant hole
Thanks to their readings (shown) the team now believes the cause was increasing temperatures
It's not yet known if this event, which scorched the ground nearby (shown), could occur again in the area
Very remote: The crater has appeared in Yamal - a large peninsula jutting into Arctic waters, which is Russia's main production area for gas supplied to Europe
The Yamalo-Nenets Autonomous Region is area known for its permafrost and pingos
The mysterious hole is in the Yamalo-Nenets Autonomous Region, some 20 miles from the Bovanenkovo gas field
'But we have to do our tests and research first and then say it more definitively.' After the hole was discovered, there was speculation online about the crater indicating 'the arrival of a UFO craft'.
Ruling out extra-terrestrial intervention, Dr Plekhanov said: 'We can say for sure that under the influence of internal processes there was an ejection in the permafrost.
'I want to stress that was not an explosion, but an ejection, so there was no heat released as it happened.'
The latest expedition organised by the Yamal authorities included experts from Russia's Centre for the Study of the Arctic, and also the Cryosphere Institute of the Academy of Sciences.
They took samples of soil, air and water from the scene and were accompanied by a specialist from Russia's Emergencies Ministry.
Anna Kurchatova from the Sub-Arctic Scientific Research Centre, previously said the crater was formed by a mixture of water, salt and gas igniting an underground explosion, a result of global warming.
Gas accumulated in ice could have mixed with sand beneath the surface, and then mixed with salt.
Global warming may have caused an 'alarming' melt in the under-soil ice, released gas and causing an effect like the popping of a Champagne bottle cork, Ms Kurchatova suggests.
Yamal, a large peninsula jutting into Arctic waters, is Russia's main production area for gas supplied to Europe.
Dr Plekhanov said: 'I've never seen anything like this, even though I have been to Yamal many times.'
The crater is different from others on Yamal. The experts say the phenomenon maybe a restarting of a process not seen for 8,000 years when the lake-pocked Yamal landscape was formed on what was once a sea.
This maybe 'repeating nowadays', he said. 'If this theory is confirmed, we can say that we have witnessed a unique natural process that formed the unusual landscape of Yamal peninsula.'
The predominant theory so far is that the feature is a 'pingo'. This is a large chunk of ice that is located underground that can create a hole in the ground when it melts
