As yesterday, we arrived at Norris at dawn. From early on it appeared that the activity in New Crater/Steamboat had picked up a little. As the morning progressed, there were surges about an hour apart. Finally, at around 10:40, there was a surge that couldn't be ignored, and it was followed up within moments by another, just as large. As in the other eruptions I've seen this year, there was an obvious change in behavior. There was activity stronger than anything seen up to that point, and it didn't diminish.
As soon as the eruption started I moved quickly up the mostly empty walkway to the bench. I wanted to get a height measurement, and this was the perfect time to do it. The only problem was that I had to look into the sun to get the readings, and a third hand to help shield the glare would have helped. In any case, the best measurements I got were 95% of the distance, which I measured on a satellite map as being 130 meters. That comes out to 123.5 meters, or 405ft. I'm pretty sure I saw some higher jets before I got out the clinometer. Even factoring in the uncertainties in my measurements, that eruption was well over 350 feet, and could have been as much as 450ft.
I took a video of my walk back, and the height was still obvious as I went back. It was only a few minutes later that north vent turned a dirty brown, and started chugging away like it was going to choke. This lasted quite a while, with water pouring off the hillside behind the vent into the vent and then down the runoff channel. It looked like we were going get a choke, but it never quite made it. But the behavior tended to confirm my contention that they are because of the water running back into the vent off the hillside.
This time the transition from water to steam was fairly easy to see and feel, at least from the vantage point of the lower platform.
I also went down to the bridge over the runoff, just to see how it compared to the last time I was there during an eruption. This time the boards were wet. I stood there, to take a video of the eruption looking up when I noticed that I was standing in water. I moved over to the side, and a small flood washed a bunch of peachpit sized rocks onto the walkway.
It wasn't until much later in the eruption that the wind shifted and we got a soaking. Got wetter trying to get into raingear which wasn't really needed after about five minutes. On the whole, this was one of the more powerful eruptions I've experienced. The pounding feeling against my body was especially strong around the time of the transition to steam.
Decided to take the opportunity to visit Porcelain Basin for the first time this century. It was as I remembered, and in other way completely different. There seems to be no mention of Ebony or Bear Den Geysers, while the flat on the east side and many more geysers and eruptive features than I remember. Took the trail to the Back Basin, and don't remember Minute Geyser looking like that.
When we arrived at Cistern, it was already below overflow, and there was a five dollar bill lying on the boardwalk. So I actually made a profit today.
From there it was back to the lower platform one last time. Where we saw three people making there way down through the trees behind the eruption. I made a radio report of this, then noticed a naturalist at the upper platform with his NPS radio out, and figured they were already repoerted. The three then cut over to get closer to the geyser at about then, when the naturalist yelled at them, then ran down the walkway to intercept them.
Of course I had to revisit the bridge at bottom again, where we found three people dejectely standing next to the naturalist. A bit later, as we were loading the truck and as I was taking the following photo, I noticed them being escorted out of the basin by a ranger with a gun. I sure do hope they got more than a reprimand.
As we were leaving the basin, I noticed a sign that hadn't been there when we arrived or when we made a plumbing run about an hour before the eruption. While it intention seems to be good, perhaps it would be better to have this up before the eruption? After all, the most likely time to get slimed in the parking lot is during the water phase.
So after our return to the Old Faithful area, there was time to unload (and dry out) all the stuff from the back of the truck. I headed out to Grand at about the five hour mark, only to see from the boardwalk by Castle that Beehive's Indicator was in eruption. With no radio call. So I had to make one. I also had to make some calls at the five and ten minute mark, as the indicator was a fairly long one. I waited around in the Sawmill Group for the eruption to finally start.
I finally made it to Grand just as Daisy erupted Grand was not particularly cooperative, at least until the end. I arrived to a series of Turban eruption intervals with short eruption durations. There was some activity from Sput D, but not with every interval, and it seemed not accompanied by any West Triplet overflow. So Grand was kind of stalled out, and the 7-1/2 hour interval was not because of any sort of delay. But when Grand finally did erupt, the first burst quit well before 8 minutes. Then Grand reverted to form, with a second burst lasted well over 2-1/2 minutes. It went into full "Big Sawmill" mode about a minute into the burst, with what seemed like pauses only to have a tall jet rocket out of the vent. But it was probably the last Turban eruption before sunset, so the lighting was ideal, especially for the start of the second burst.