Observations for 2021 September 11


If we had gone up to Norris, we would have probably been exiting the Gibbon Canyon when New Crater/Steamboat erupted. I had just arrived at Fan & Mortar, and it was a relief to get the message from Suzanne, knowing we didn't need to worry about Norris for the rest of the trip.

It had rained overnight, and was still mostly overcast. Cool and damp, as it didn't have a chance to get cold overnight.

As it was, I was on the phone with her when suddenly Upper Mortar had a nice rumble. The High and Gold Fan vents were looking good when the call started, and now, moments later, they looked great. I hung up and actually got on the radio to issue a "heads up" call.

The activity looked a lot like the previous eruption, but Angle was not active, and Bottom vent had been splashing when I arrived. Even if it was early in a cycle, people needed to be informed. Over the next ten minutes, the vents only waned a couple of times, then immediately came back strong. Finally, Angle joined in, and by then High was as high as last eruption's preliminary activity. When the Frying Pan finally started, there was little doubt that something was going to happen.

Upper Mortar never really surged until, suddenly, East Vent took off like last time. Unlike last time, the other vents quickly joined in. Unfortunately, the wind, which had been blowing the steam toward the river, shifted and was now toward the benches. So Mortar was clearly visible, but Fan was lost in a mass of steam.

After the eruption, a quick check at East Sentinel showed no real change, other than the one overflow I saw was not followed by any boiling from the South Rim.

The morning Grand was the second observed two burst eruption in a row. It started three Turban intervals after a Turban Delay Interval. There was a definite false pause about 1/2 minute before the end of the first burst, and the whole eruption lasted just over ten minutes.

Later in the day, came out to a Sawmill Group that had relatively high water. Slurp was completely quiet. Penta was splashing slightly, and Belgian and Crystal were both down about 5cm. West Triplet, Percolator and Sput D were also in eruption as I arrived.

The first Turban eruption I saw had an unusual explosive start. Suddenly a thin jet of water was propelled about three meters above the rim, followed by several seconds of quiet before the usual boiling surges began.

Another fifteen minutes after that, Rift started. At that point Grand was full, but stalled out for the next fifteen minutes, giving us another Turban Delay Interval. Fortunately, Grand had its third consecutive observed two burst eruption just two Turban eruption intervals later. At first it was hard to see the pool as Grand paused, then the steam parted with the pool full of churning water. As with this morning, the second burst was short.

Following that, spent some time in a Sawmill Group that still had high water. It had been higher earlier, as the runoff from Spasmodic was still wet. Watched Penta splash around for a while.

Finally, from the bike rack, watch a Bulger major eruption, but no indication of any activity out of Bulger's Hole.

Went out to illuminate a nighttime Grand. It was a One Burst Eruption after Delay that cause the eruption to be two Turban eruption intervals later, and the eruption lasted less than 9-1/4 minutes.