found whils stumbling the interweb...is this a geyser?
http://www.subtire.com/i.php?n=mg.jpg (http://www.subtire.com/i.php?n=mg.jpg)
I don't know. It does look like a sinkhole...or something like a sinkhole.
Hello! I believe that is a picture of Morning Glory Pool in Yellowstone. If so, they say it has behaved like a geyser once in a while, but usually just sits there as a place for folks to admire.
looks really cool, I wonder how deep you could dive there in the middle..!??!?
You also see all colors in their vibratory order going from red to orange, to yellow to green to blue ;D
Cool! Haven't been there but have read about it - I wouldn't go diving there as the water is around 60 degree celsius! The colouration is from bacteria and the colours have changed over time due to the gradual cooling of the pool (it used to be around 100 degrees), which has altered the type of thermophilic bacteria that live there.
Still beautiful though.
Adam