basil_hayden wrote:similar structures are all around this one
No they're not. These kinds of huge pits surrounded by ejected debris are something new. Nothing like this has ever been found before.
basil_hayden wrote:If ... pingo ice melts, a hole forms, with water at the bottom.
Pingos don't melt in a single summer. Its simple physics...look at the size of the hole, calculate the amount of solar insolation, and you'll find its impossible to melt that much ice in one summer season in the Arctic.
In order to convert 1 g of ice at 0 ºC to 1 g of water at 0 ºC, you have to add 334 J of heat energy. Do the math dude---its impossible to quickly melt a hole that large during the brief Arctic summer. And as Cid points out above, the local observations suggest the hole actually formed in a single day...you can't melt all that ice in a single day just from sunlight.
Nope....the gas expulsion idea is the only plausible explanation.

Do the math, dude. It takes a lot of energy to melt ice.