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Observations for 2020 August 01

First up was a visit to Mugwump and friends. Spent about three-fourths of an hour there, seeing three eruptions. The last was much larger than the first two, in that only the last one put water down the runoff between the pool and the roadway.

Before each eruption, Three Crater started up. A number of the bursts seemed larger than in the previous visit. The activity there stopped with the Mugwump eruption, only to start back up again about six to eight minutes later.

When saw the activity the previous visit, in late June, there was one time when I waited in the evening when there was no breeze but still warm. The pool was dead quiet at times, and it was possible to see convection and upwelling from and area in front of Mugwump's vent. Today, before the last, large eruption I saw, this area boiled heavily and had several bursts to about 25cm. This activity was seen about the time Three Crater started and lasted for a couple of minutes. It was seen again just before the Mugwump eruption.

Over that Grand, all the sputs were quiet prior to the One Burst Eruption. There were consecutive Turban delays. The Grand pool filled slowly during the second delay. There was never a time it looked really good, then dropped. The progression was just extremely slow. So much, that Grand started having heavy boils and even boops nearly two minutes before the eruption finally started.

Down basin, Solstice Geyser is quiet. From what I could tell, the runoff channel was dry and the slime mat was drying out, implying it's been that way for several days. During the days prior to this visit, I'd seen reports of it being both active and quiet, so will be interesting to see if it is becoming intermittent, with long durations and intervals.

At Giant there was no evidence of change or increase in activity. The platform was nearly dry, with just the usual puddle next to Giant's cone that could have been rainwater. At Oblong, I did walk up to it slightly below overflow. That restarted a few minutes later, obvious from the steam coming from the catch basins near the vent.

Conditions in the morning were clear, sunny and almost too hot. That changed by the time it was time to head out to Grand. There had been distant thunder for about an hour before that, and it was mostly cloudy with occasional sprinkles as I headed out. After a couple of Turban intervals I finally had to put on the rain gear.

While the rain stopped by the time the eruption started, the wind shifted and it got more humid. That meant that when Grand started, the northern benches got wet and there was so much steam it was difficult to see much of the eruption. So it was a bit of a surprise when finally, after a minute of waiting, there was the first surge of the start of the second burst. And thanks to that amount of time and the wind direction, it was possible to see the full water column.

I made it as far as the bridge before I had to wait at Castle for a lull in the rain to bicycle back to my cabin.

Today I noticed that the Firehole River is as low as I ever see it, with the ledge at the Sawmill runoff channel completely exposed. But I also noticed some fresh, clean gravel has been washed below it, creating a debris fan. I expect that when Sawmill reactivates, it will create a huge delta, but what caused this small one? Closer examination shows that the area around "Snake Eyes" & SG-#8 is exceptionally clear of debris, as well as the runoff channel, as the photos here show. I suspect there was an eruption there. I didn't notice this when I left in early July.