"pingo" yes when I looked in to it these features seemed quite different, so I guess there must be various types, or some authority called them this and no-one is rude enough to gainsay them?
It's quite interesting that they blame human activity, I'm assuming the release of pressure begins the process of gas release, too late not to interfere now, both here and below the ocean. When did those kettle lakes form? and are they founded below sea level, like the 'pingos' on Yamal peninsular?
john
And Sebastion
The local kettle lakes were formed as the glacier retreated leaving a huge block of ice behind. It was buried and all the silt that flowed out from under the still retreating glacier built up the land all around it.
At some time the ice melted and the ground subsided and filled with water. The largest here. Puslinch Lake has an outlet, but many others are essentially gigantic puddles that wax and wane with precipitation, runoff and evaporation.
Nothing to do with methane release so I probably shouldn't have mentioned them in this thread. I'd lived my adult life where glaciers never existed and I'm still excited when I discover another aspect of the local geography that was carved, or impacted by glacial action.
The methane explosion I referenced was a large geyser that erupted at a golf course not far from here. No gas lines in the vicinity nor any landfill sites.
I snuck in a week after the event and did a little poking about. The methane tunneled up through a minimum of 22 feet of very dense clay. No idea how any more feet of clay it may have migrated through.
Terry
