Posted on

Observations for 2018 September 17


Arrived back in the cage at midnight. It wasn't quite as cold as we'd expected, but still down near freezing. After an hour and a half we got the hot period we'd been expecting. It was a strong one, that did not include a Feather restart, instead Feather stayed on for 14m23s. But no Giant eruption. More than a little disappointing.

We'd already planned on getting up at 03:00 to leave for Norris and New Crater/Steamboat. But there wasn't much point in trying to get another nap, so instead we loaded up the truck and hit the road. Driving at that time of night can be interesting, as we found out when we came across a bison jogging north just inside the right late line, just south of the exit from the Firehole Lake Drive. Really glad I was doing Pacman and not strictly staying in my lane. (I figure if I don't see the center line when I should, it's because there's something there.)

Arrived at Norris at 04:00, and learned that a set of strong minors was in progress. It turned out that we witnessed the last of that series. By then it was really cold, but we settled in to wait for dawn and a day of waiting. Some folks who arrived later said that their vehicle thermometers were in the mid to upper 20s.

At around 06:30, suddenly the four of us had a large number of companions, all there to see New Crater/Steamboat. Most of whom I had never seen before, and from the way they were talking, they were there to add another checkmark to their personal lists. The noise level got pretty intense for that time of day.

All this time, there was nothing happening other than a lot of slopping around. It wasn't until 09:30, about 5 hours after we arrived, that we saw the next minor eruption. This was followed almost immediately but several more in quick succession, culminating with an eruption of New Crater/Steamboat at 09:36. That sudden onset was just like the previous eruption we'd seen 10 days ago.

This was a powerful eruption, but what was most notable was how it was still in water phase an hour into the eruption. That's when the North Vent shut down, followed within moments by the South vent. It was absolutely quite out there. Then just as sudden, both vents exploded upward. The North Vent looked almost as tall as the start of an eruption. South Vent was as brown as North for a few seconds,

We got 4 of these shutdowns. Then, finally, the transition to pure steam started. The water columns cleared up, but every time it looked like it was pure steam, they'd throw out some spray.

The drive back was uneventful until we got to the Mary Mountain trailhead. There traffic came to a complete stop for the better part of an hour because of a bison herd near the Kaleidoscope Group. It was really frustrating because we wanted to get back to see what had happened with Giant.

Turns out, not much. A couple of weak hot periods were inferred from the resulting puddles and pools on the platform, or from dry areas. This was interesting news. As the afternoon went on, and there wasn't any event there, it started to look like we might have a chance for an eruption.

After a bathtub, I decided that we probably had at least a couple of hours until the next event. Time to head in and start packing up to leave tomorrow. But as I was riding in, it occurred to me that if Giant was setting up to erupt, it might shorten things up. So decided I should be heading back out in about one and a quarter hours. Besides, I've been consistently overestimating how much time is available between hot periods.

The call that water was rising in Mastiff came in just as I was about to head out. I wasn't sure what to expect, so I packed for a long wait, including light and multiple layers. I quickly lightened my load and headed out. I got to the Cage in plenty of time to see the start of Giant.

The conditions were almost perfect. It was a little windy, but it was in the right direction, away from the platform, and not enough to really to chop off any height. With the low sun, there was a rainbow that was a full arc, and here the wind helped by moving spray well to the north of Bijou.

Again I tried to measure the height. This time I was back on the boardwalk, but not at the marker. That meant, at least, I didn't have to force my way to far to get there (and the decreased crowds helped.) And again I got a disappointing reading: 65%, which translates into about 130feet. The scary thing is, from that perspective, I tried to compare the height to what I remember of big (150+ ft) Grand eruptions from the same distance, and it did look comparable. Not sure what to think about this. Ideally I will try next time (and I do expect a next time or two) to be exactly at the marker and try and catch the maximum starting surge.

And Fan & Mortar erupted in the morning. No one saw it, and we probably wouldn't even have known about it if Suzanne hadn't gone down there to check on it before going to Giant. She noticed that the activity there was even worse than the last few days.