Geyser Watch

On our trip at the end of September, we (of course) stopped by at West Thumb Geyser Basin to check to see what had changed. Walking past the Yellowstone Association Book Store (the small log cabin) and out to the overview from the top everyone stopped, often gasped and commented on that BLUE. Yep, the pools closest to the top have recharged and bring that glacial blue in part of them. I’m guessing that iridescent blue comes from the water hitting a pocket of glacial rock flour. (If you have better info/more info or ideas about how this color happens, leave a comment – please.) Overflowing and stunningly beautiful, everyone had to get photos of them.  Here are the comparison photos from August to September of this year. Click on it to bring it up a bit larger.

More observations to come…

I’ve seen the upper pools of West Thumb referred to as both the Painted Pools and the Mimulus Pools – and these names also applied to the ‘left’ and ‘right’ sections. Personally, I’m not quite sure (still looking for the original sources of these names), so just refer to them as the Upper Pools. My visit earlier this month showed a change even from June – an increase in water level  in the ones closest to the upper boardwalk. The ones in the middle of the first two photos are now overflowing into a lower pool seen from the middle boardwalk.

Upper Pools at West Thumb Geyser Basin 4 June 2011

Upper Pools at West Thumb Geyser Basin 9 August 2011

Upper Pools 9 Aug 2011

And the ones on the “Abyss side” have also increased in temperature. I missed a photo of them in June, so last fall is the latest comparison photo I have.

Upper Pools 24 July 2010

Upper Pools 9 Aug 2011