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Observations for 2021 May 20


Went to Norris because it has been 39 years since Suzanne first saw a Steamboat eruption. That was at 11:55, so we left at noon, after seeing no real change from yesterday. At this point it seems just stuck, and could erupt tonight or weeks from now.

On the drive out, encountered a herd of a couple of dozen bison at the exit to Firehole Canyon Drive about to make their trek up river. The line of traffic behind them was just forming. Since we were headed in the opposite direction, we had no trouble getting through. Coming back from Norris, we only saw a few bison at a distance, so the drive was one of the first in a while that wasn't delayed.

Back in the Upper Basin, went out to see Grand and instead saw that something had happened in the Sawmill Group. Over the past few years, within a narrow range how the group looks hasn't change much. Churn is always in overflow, for example, except when it erupts. Then it's below overflow for a short period of time.

This time, we walked up on Churn down at least 30cm. Tardy was out of sight. Sawmill had a few puddles in the damp runoff channel. It did rain overnight, but the day has been dry, and the puddles shouldn't have been there just because of rain.

Churn Geyser

Over at Oval Spring, it was down at least a meter, and erupting up to a meter above the rim from the north vent. Belgian was also down at least 3cm and Spasmodic was mostly quiet and in a deep drain. Definitely would be keeping an eye on the area for a while.

Oval Spring in Eruption

Over at Grand, we got a long, slow fill that at the 30 minute mark had Grand have a low boiling boop lasting about 30 seconds. Then the pool slowly drained. Four minutes later Turban started, and then the pool started its refill. That took a bit over two minutes, and following another quick Boop, Grand started erupting.

At a little over eight minutes, Grand quit. The vent was quite steamy, but water could be seen sloshing in it for 1m08s. The second burst itself was also just long enough to earn a "Long" designation. It was obvious that there wasn't going to be a third.

During Grand, West Triplet started, and Bulger continued a series of minor eruptions.

So after Grand, it was time to reexamine the Sawmill Group. Now Slurp was erupting. Over the next hour and a half, watched the pool levels all rise. It took an hour and a half from when we first saw it low for Churn to reach overflow. When I left the area, two hours after walking up, the area was pretty stable. The minors series from Bulger was continuing, with durations ranging from splashes for a few seconds to one almost a minute long. Oval stopped erupting, but was having heavy convection over the north vent. Slurp continued to erupt, occassionally become just steam as Crystal stopped overflowing. Sawmill rose up to about 10cm above the top of the orange band in the vent. The wetness and puddling in its runoff channel was no longer visible.

About an hour and a half later, we got a radio call from Todd Singleton that Tardy was in overflow, and having small eruptions. That is the first time in years that I've heard of any activity there. Whenever I've gone by, Tardy may have been in overflow, but it would be totally calm. So went on out, and got to see activity for well over half an hour. About every 65 to 70 seconds, Tardy would splash for a couple of seconds. Some of the eruptions had hints of the Tardy activity when active, and reached a height of a couple of meters.

Tardy Geyser in Eruption

At the same time, Sawmill had been high, and was slowly dropping. It was hard to tell, but it might have overflowed slightly. Spasmodic was also high and overflowing heavily. The end of the Tardy series came abruptly. After taking a break in timing, I came back to Tardy to catch the last two eruptions. There was no slowdown or smaller eruption, as the last eruption was one of the taller ones. Within ten minutes Spasmodic had quit and dropped below overflow, and the drop in Sawmill increased.