We used to go over to the sand near Lido Sands in Newport Beach California during the late sixties and light the methane gas percolating up through the sand.
It always produced a light blue gas stove type of flame that danced around on the sands surface at night.
Steve Parkford first introduced me to this mysterious sand one night while we were stoned ( come on it was the 60's and all of us stupid kids smoked pot)
But these guys have taken the methane gas lighting ritual to new heights.
From the laughter they may be like we were when we played with methane.
They light a small pilot hole that they have made in the ice first and once it is going they sledge hammer the ice to quick release the methane.
I don't thing too many kids will be doing this, mainly because there are not that many places where methane is either trapped under the ice or percolating up through sand so parents not to worry.