[Smokin' Joe]

But I didn’t know that surface tundra could blow up.

After all those UFO sightings were blamed on "swamp gas"?

Actually, we don't know that it did, it is one possibility.

BTW, coal seams were drilled in the 90s for the methane (natural gas) present in them, and that may still be going on.

[zeestephen]

Thanks - I didn’t know that coal seams were a commercially viable source for gas.

I assumed they just flared the gas off to prevent mine explosions.