West Thumb Geyser Basin Update Mid May 2018

Change is normal in Yellowstone and there have been changes over at West Thumb Geyser Basin. I got a chance to visit earlier this month on the 15th to see what might be happening. An early report on Facebook showed photos of Abyss Pool and Black Pool both looking vastly cooler than when we left them last fall.

GENERAL IMPRESSIONS

Overall at West Thumb, the thermal energy has waned in the central section where we had the energy surge in 2016-2017. Ledge Spring and Collapsing Pool are both half full of water rather than full and overflowing. Percolating Spring is also nearly empty. While the central section has poor water levels, the edges most of the way around have decent water levels. Down on the lake, the water is already rising and by the 15th, had already covered Lakeshore Geyser. The level of the lake water was also part way up on Fishing Cone – whose side vent had some orange microbes, indicating at least a bit of activity.

 

ABYSS POOL AND BLACK POOL

As I walked down the boardwalk toward Abyss, I noticed water running under the boardwalk that came from the culvert in the Roadside Steamer area. This appeared to be cooler water as it didn’t damage the grass it flowed over while coming out of the culvert.

 

When I arrived in the Abyss Pool area, it was clear that both Abyss and Black Pools have cooled. But the source of that cooling appears to be snowmelt. Abyss Pool had a dirty look to it more than the dark microbe look it has when the crater is lined with yellow microbes (which mix with the blue color water normally is to give you the green color).

On this day, in the afternoon, the snow melt water flowed down just below the vents above Abyss Pool and stopped short of the boardwalk spur to Abyss (where ranger led talks are held). But there was quite a channel also carved down to Black Pool.

 

Abyss was lined with orange microbes that showed in the shallower edges. Yet in the time spent there, bubbles rose along the edge occasionally as well as out in the middle over the vent and there was one good welling up of water.
 
Black Pool, while a green color, did not have microbes along the shallower edges that I found interesting and possibly suggests the influx of runoff might be the cause for the color change rather than a decrease in thermal energy. From the north edge of Black Pool, there was a distinct convection seen, but no bubbles rose.
 

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