Geography Question

[arcylon]

I've just posted the location of some strange circular lakes in the random files section. Anybody know what they are?

http://www.googleearthhacks.com/forums/downloads.php?do=file&id=51

[Mickey]

Wow, good find. I have no idea what they are, but maybe someone else will be able to help out.

[GeoDave]

The circular depressions are thermokarst lakes formed by melting permafrost. There is a useful account of these at:

http://users.skynet.be/ougseurope/surface/thermokarst.html

[arcylon]

Thanks very much! Thought they might have been maars, but they're too widespread. Looks like permafrost does some interesting stuff!

[Mickey]

Nice work, GeoDave! I've edited the listing on that file (http://www.googleearthhacks.com/forums/downloads.php?do=file&id=51) to include this new information.

Mickey