An urgent expedition will leaves tomorrow to probe a giant crater that has appeared in gas-rich northern Siberia.

Extraordinary aerial images show a mysterious hole which experts say may be up to 262 feet wide, in the Yamal Peninsula of northern Russia.'A scientific team has been sent to investigate the hole and is due to arrive at the scene on Wednesday,' The Siberian Times has reported.The cause of the hole's sudden appearance in Yamal - which translates as 'the end of the world' - in the far north of Siberia is not yet known.There has been web speculation about the crater indicating 'the arrival of a UFO craft'.But one Russian expert says the cause is more likely to be global warming releasing gases under the surface, which then explode like a champagne cork.Experts say that the darkening around the inner rim of the crater indicates 'severe burning' which scorched its edges.Another theory is that the hole was formed by a meteorite striking this lonely spot in the Yamalo-Nenets Autonomous Region, some 20 miles from the Bovanenkovo gas field.'There is agreement that soil around the hole was thrown out of the crater, large enough for several Mi-8 helicopters to fly into it,' The Siberian Times reported - before adding 'not that they have.'The expedition organised by the Yamal authorities includes experts from Russia's Centre for the Study of the Arctic, and also the Cryosphere Institute of the Academy of Sciences.They plan to take samples of soil, air and water from the scene.They will be accompanied by a specialist from Russia's Emergencies Ministry.A spokesman for the ministry's Yamal branch has ruled out a meteorite, but says it is too early to say what caused the hole.'We can definitely say that it is not a meteorite,' he says.Anna Kurchatova from the Sub-Arctic Scientific Research Centre, thinks 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.Some 10,000 years ago this area was a sea.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.(dailymail.co.uk)Bakudaily.az