Oblique view of crater shows an elevated rim but around a deep hole. This morphology is indicative of a methane explosion, not a meteorite impact or surface collapse into a sink hole.
A mysterious crater almost the size of a football field discovered in a remote part of Siberia's Yamal peninsula known as the end of the world
may have profound implications about the stability of Arctic methane and catastrophic climate change.
The striking puncture in the earth is believed to be up to 80 metres wide but its depth is not estimated yet. A scientific team has been sent to investigate the hole and is due to arrive at the scene on Wednesday.
The cause of its sudden appearance in Yamal - its name means the 'end of the world' in the far north of Siberia - is not yet known, though one scientific claim is that global warming may be to blame.
Russian experts have ruled out speculation that meteorite impact might have caused the crater. The crater was certainly not caused by a meteorite because it has no central crater but instead has a deep hole. Meteorite impacts have far too much energy to leave an open hole. (Note: I studied meteoritics for my first year of graduate school.) Likewise any other extraterrestrial source would have far too much energy to leave an open hole. The impact site would be filled with ejecta.
It doesn't appear to be a sink hole because the hole is surrounded by a rim of ejected material. Genarally, sink holes don't have elevated rims because they are produced by collapse of surface material into a preexisting covered hole. The ejecta appears to have been produced by an explosion. This crater formed in one of Siberia's largest natural gas producing regions. Permafrost in this area is melting in response to the rapid warming of the Arctic. The most likely cause of this crater is a methane explosion. See the update at at the end for a discussion that this crater was caused by the melting and collapse of an ice dome called a pingo. An Australian expert on Arctic landforms suggested pingo collapse created this crater, but Russian experts have not yet commented on his hypothesis.
Strait down view of mysterious Siberian Crater likely caused by a massive methane explosion.
Anna Kurchatova from Sub-Arctic Scientific Research Centre thinks the crater was formed by a water, salt and gas mixture igniting an underground explosion, the result of global warming. She postulates that gas accumulated in ice mixed with sand beneath the surface, and that this was mixed with salt - some 10,000 years ago this area was a sea.
If Dr Kurchatova's explanation is correct, the consequences are profound. It means that There are vertical structures where salt accumulated as methane ices formed in permafrost. Layers of permafrost may have salty vertical zones of weakness in them that will allow sudden release of methane trapped below the permafrost layer as the climate warms. Vast quantities of methane trapped in river deltas in the Arctic ocean on the Siberian shelf may be unstable. This crater appears to be evidence that the methane is not protected by a very slowly melting solid layer of permafrost. Methane bubbles recently observed in the Laptev Sea, reported on by the National Science Foundation, could be the beginning of the release of an enormous amount of subsea methane.
Methane is escaping from shallow subsea sediments on the Siberian platform. This National Science Foundation diagram shows Siberian platform methane bubbles rising to the surface and entering the atmosphere.
The concerns of a methane catastrophe expressed by scientists who have discovered large amounts methane escaping from the Laptev Sea may reinforced by this land based observation of methane instability in Siberian sediments of marine origin. Extraordinarily high methane levels were observed over the Laptev sea in fall 2013.
Harold Hensel, who generated this graphic of methane levels over the Laptev sea in November 2013, expressed alarm:
Very high methane levels were observed over a 30 day period over the Laptev sea, November, 2013.
"I am fighting for the lives of my children, grandchildren, and great grandchildren who's lifespan will extend 30 to 40 years from now. I am also fighting for all children of the world, animals, whales, dolphins, flowers and all living things. They are all in peril and we are the ones that may have a chance of doing something about it now. The threat of what is coming must sink in."
I have been waiting for independent evidence of methane instability in Siberian sediments to validate the concerns that the Siberian platform could produce a rapid release of methane, a far more potent greenhouse gas than CO2, that could destabilize the climate. I am afraid that it has just been found.
One proposed explanation for this mysterious crater is that it was created from the collapse of a soil covered dome of ice called a pingo.
Pingo on the Tuktoyaktuk Peninsula, Mackenzie River delta, N.W.T., Canada
A team of Russian scientists have been dispatched to investigate the crater but University of New South Wales polar scientist Dr Chris Fogwill says it’s likely to be a geological phenomenon called a pingo. “Certainly from the images I’ve seen it looks like a periglacial feature, perhaps a collapsed pingo,” Dr Fogwill said.
USGS illustration of the life cycle of a pingo
Read more: http://www.smh.com.au/...
The U.S. Geological Survey illustrated the process of pingo formation and collapse. The ice dome typically forms in a former lake bottom. Freezing of lake water generates pressure which pushes water upwards, forming a dome. Eventually solar heating of the sides of the dome causes it to melt and collapse.
The problem with the pingo collapse explanation is that most collapsed pingos form ponds or lakes in the collapse center. This crater has a deep pit with no visible water. Because pingos are formed by the upward movement of water, the ground below the pingo is typically saturated with water. For this deep pit with no visible water to form the water table would have had to suddenly drop when the pingo collapsed. That is a possibility, but on this wet, low peninsula that juts into the Arctic ocean there appears to be no place for the water to drain to allow a sudden drop in the water table.
The Russian expert's suggestion of a gas explosion is consistent with the missing mass in the deep pit. Gas would have escaped to the atmosphere but water would have likely filled the pit.
For all those who are skeptical of the possibility of a natural gas eruption or explosion creating this mystery crater, look at this National Geographic photo (Click link for video) of Turkmenistan's methane-burning Darvaza crater. The Darvaza crater was caused a blow out of a gas well. It caught fire years later. They mystery crater in Russia could have been caused by a natural blow out, when melting weakened its icy cover, without catching fire.