Abyss Pool Heating Up – July 2017

Just a quick post here to share some comparison photos of the heating up of Abyss Pool at West Thumb Geyser Basin. While there haven’t been any reports of “Waterfall Geyser” in quite awhile, it seems the whole geyser basin is just slowly heating up. Which thermal feature will receive the most benefit from this is yet to be seen.

However, my hope is that Abyss Pool will become active again. Abyss Pool has behaved as a geyser in the past with heights reaching from 50 to 100 feet where the whole pool lifts. That’s an eruption I’d like to see!

On July 8, I spent 5 to 10 minutes just watching the surface of the water and the bubbles rising in steady streams as well as many sections of water welling up. It seems there might be a pattern to it. There were periods of complete calm, then bubbles rising in a couple of spots followed by bubbles rising throughout the pool accompanied by welling up of water. But that would take some time to observe to see if that one sequence I observed actually repeats.

I spent a bit of time today pulling together the photos I took of the overflow channel that gives a better indication of the pool’s temperature based on the microbes seen.

So how hot is it?

Since the actual temperature of the water is not currently taken by the Park Service, I’ve pulled together some observations from the NPS Thermal Log kept by rangers in the past when they did record those temperatures and added helpful descriptions:

154° F – Dark, greenish look – orange algae lining interior, peeling off NW side and falling into pool. (June 27-28, 1989)
162° F – Emerald-greenish tint, yellowish algae lining pool; clear, bottom visible. (February 1990)
174° F – Bluish-green, orange rim, clear (Sept 22, 1990)
190° F – Brilliant aqua blue color – no yellow or orange in bowl – bright orange mats around pool, bubbles in vent areas. (Aug 15, 1990)
200° F – Clear blue, boiling. (Sept 1993)
205° F – Active geyser, pool full and overflowing, extensive super-heated boil around perimeter. (January 1992)

So this lets us know more of what we’re seeing. By looking at this, I’d say it’s hovering around 190° F. Deeply grateful for the time and effort put in by the rangers that entered (and those who still enter) information into the log book.