Build-up and release of gas from thawing permafrost most probable explanation, says Russian team.

© Yamalo-Nenets Autonomous Okrug Governor
The crater in the Yamal peninsula in Siberia is 30-metres wide.
A mystery crater spotted in the frozen Yamal peninsula in Siberia earlier this month was probably caused by methane released as permafrost thawed, researchers in Russia say.
Air near the bottom of the crater contained
unusually high concentrations of methane - up to 9.6% - in tests conducted at the site on 16 July, says Andrei Plekhanov, an archaeologist at the Scientific Centre of Arctic Studies in Salekhard, Russia. Plekhanov, who led an expedition to the crater, says that
air normally contains just 0.000179% methane.
Since the hole was spotted in mid-July by a helicopter pilot, conjecture has abounded about how the 30-metre-wide crater was formed - a gas or missile explosion, a meteorite impact and alien involvement have all been suggested.
But Plekhanov and his team believe that it is linked to the abnormally hot Yamal summers of 2012 and 2013, which were warmer than usual by an average of about 5°C. As temperatures rose, the researchers suggest, permafrost thawed and collapsed, releasing methane that had been trapped in the icy ground.
Comment: If researchers would only pay attention to what is going in the planet, then they will realize that we are hardly on a "long-term global warming" phase as the article suggests.
For an explosion you need two things: an igniter and combustible material. The Arctic, as with many other places on Earth is outgassing methane at never-before-seen rates. Lightning discharge events are also increasing in intensity and frequency because
the solar wind is being grounded while comet dust loading of the atmosphere increases nucleation and resistance, leading to greater precipitation and greater charge-rebalancing respectively.
These 'crater-holes' are not an indication of global warming. They're another indication of the planet opening up.
See
Earth Changes and the Human Cosmic Connection: The Secret History of the World - Book 3 where this is explained in greater detail.
Comment: If researchers would only pay attention to what is going in the planet, then they will realize that we are hardly on a "long-term global warming" phase as the article suggests.
For an explosion you need two things: an igniter and combustible material. The Arctic, as with many other places on Earth is outgassing methane at never-before-seen rates. Lightning discharge events are also increasing in intensity and frequency because the solar wind is being grounded while comet dust loading of the atmosphere increases nucleation and resistance, leading to greater precipitation and greater charge-rebalancing respectively.
These 'crater-holes' are not an indication of global warming. They're another indication of the planet opening up.
See Earth Changes and the Human Cosmic Connection: The Secret History of the World - Book 3 where this is explained in greater detail.