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Grand Complex, Upper Geyser Basin, 2019


Grand Complex, Upper Geyser Basin, 2019. Video by H.Koenig.
Sput D & Belgian Pool

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Back Basin, Norris Geyser Basin, 2019 August 27/September 01


Back Basin, Norris Geyser Basin, 2019 August 27/September 01. Video by H.Koenig.

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Observations for 2019 September 18


This morning there was the thickest fog I've seen in years. It was still forming as we went out before dawn for a Grand eruption. Were surprised to see a large tour on the boardwalk at Castle. Must've been a photo tour, as everyone had their camera on a tripod pointed to the east. Castle had erupted several hours earlier, so assumed they weren't there for that. Over at Grand, the steam looked like Rift was erupting, but had to get to Old Tardy to confirm.

The fog actually cooperated with the Grand eruption. It was fairly clear to the north. Although it was raining enough that umbrellas were needed, we could see the jets of water and Vent easily. The photo tour, for some reason, decided to stay shrouded in the thick fog generated by the runoff channels.

As we left the area, Bulger started erupting. About three minutes later Bulger's Hole suddenly filled with clear water that started surging and got murky. Bulger's Hole was strong and continued about a minute after Bulger ended.

After the One Burst Grand eruption, headed over to Geyser Hil just to check things out, and enjoy the thick fog. It appeared we had missed Aurum and not by much. Over at Beehive, it was totally dead. From there we heard a radio call of Lion erupting. We couldn't see or hear it until we were past Arrowhead Spring. Shortly afterward, noticed a rising steam column over the general fog to the northwest. Had to be Castle, so walked over there and again didn't see anything until up close. The view was interesting, as the sun was visible, but not bright enough for a true backlit steam column. Also noted, as we walked by, that Rift was still erupting two hours after we had seen it earlier.

The fog cleared out, so that for the next eruption, it was clear and a bit breezy. Shortly before noon arrived back out at the Grand Group to find Sput D erupting weakly, while Rift was off but steaming heavily. That ended a few minutes later, and was the last activity seen from that end of the group. Saw several eruptions of Turban, and the last two intervals were well over 24 minutes long, but not long enough to be a Delay by definition.

Grand finally erupted one second after 13:00. The wind and steam cooperated so that it was easy to see the starting events. At around the seven minute mark it looked like Grand was trying to transition into Big Sawmill mode, when instead it quit. The pause was short, and so was the second bursts. The total eruption at that point was just over 8-1/2 minutes. There have been eruptions that short, but this wasn't one of them. The water in the pool was hard to see, but it was there, and it didn't drain. The total duration was just over ten minutes, so we had greedy hopes for a fourth, but Grand didn't even try.

It also didn't try to have an afterburst, even though Vent & Turban continued. It was about 15 minutes before the first splashes were observed, and they weren't all that strong.

Went out before sunset for one final Grand eruption. About 15 minutes after we arrived, was surprised by a West Triplet start. Almost immediately Sput D joined in, and eventually Percolator filled and added to the noise. But as with the other day, all this activity acted more like an indicator, and despite the steamy low light conditions, we could see the pool filling nicely and then Vent overflowing.

Grand started almost immediately, and the burst lasted about 9-1/2 minutes. This seems to be about the upper limit for any chance of a second burst, and fortunately, we got one. When Grand ended, I noticed that West Triplet was also quiet. So it appears that things are changing in the area again.


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Observations for 2019 September 17


It was a gray, cold dreary morning. Went out to Grand a bit early because the weather forecast said the rain was about to start. Instead it was blustery with only the occasional sprinkling that was just enough to need the umbrella, but it never lasted long.

Arrived to find West Triplet drained. It was even rumbling down deep a bit. The area with the sputs looked totally dead, with little steam. No change in Belgian or Crystal, but it seemed fairly obvious that there had been a Rift eruption. The longer double interval from Grand overnight tended to confirm this. I suspect it was after midnight, and lengthened the second interval.

Ended up waiting an hour through several Turban eruption intervals. Finally we got a Delay, which never looked like it wanted to erupt. The following Turban interval was promising, with Grand's pool quickly refilling. With the steam and wind, it was hard to see any waves, but when Grand had a couple of large boops similar to the other day, but not as tall, it was obvious it was going to erupt.

The first burst started to go into Big Sawmill mode, then quit with a duration of 8m45s. Have seen One Burst Grand eruptions that short in the past, but not this time. The water column easily outraced the steam column in the cold air.

Went back out in the late afternoon. Again, the forecast rain really hadn't materialized, but the wind and cold did. While waiting at Grand, the wind was usually to toward the north, but every so often the pool would become visible as the wind shifted to the south. Arrived to find West Triplet back to its normal water level, but there was no evidence of recent runoff as the channel was dry.

Shortly after arrival, West Triplet started to erupt. About 5 minutes later, Sput D joined in and both were erupting when Grand started about 16 minutes after West Triplet. This was another shorter first burst that stopped instead of going into Big Sawmill mode. And again the height of the second burst was well above the steam clouds, easily visible.

I don't know when Sput D ended, but West Triplet's last splash was seen late in the first burst. Percolator joined in during Grand's second burst, and quit shortly thereafter.

This behavior doesn't exactly fit what I was expecting. Previously, once the area recovered from Rift, the area would go into having frequent Sput D eruptions and West Triplet overflows. When West Triplet started, I was wondering if we were about to get another Rift eruption. The area is in flux, here at the end of the summer season when observers are few.


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Observations for 2019 September 16


The previous night had high cloudiness, enough that I decided I'd rather get some sleep. But this night was clear. Got out to Grand in time to catch a full Turban eruption interval before the main event, and as I noted yesterday, there was an eruption of Sput D a few mnutes before Grand started. There was also a loud eruption of Old Faithful, almost as loud as the eruption of Daisy a few minutes later. The boardwalk north of Grand was starting to ice up after the One Burst Eruption.

The sky was clear and the moon was obviously less than full. As we were untying our bikes, realized that it was time for an eruption of Castle. So waited a bit in the cold, with an elk bugling somewhere for at least 1/2 hour. There were a few splashes, and I was feeling the cold and had decided to head in when the eruption started. For the first eight minutes or so there were lots of short pauses as if it was trying to stop. Then the water play became continuous. When the steam phase started, a low moonbow was visible at the top of the cone if you stood directly between the geyser and the moon.

The morning warmed up nicely, considering how cold it had been a few hours earlier. As I walked toward Crested Pool, it had one of its huge boils, easily 3-4 meters high, lasting only a few seconds. I was wondering if I should get out my camera, but it ended before I could move.

I got to the Grand Group just I received a radio call that Beehive's Indicator was showing water. I decided to stay put, and was rewarded a few minutes later with an eruption of Oblong. Apparently it has been seen via the webcam just after midnight, so this was around an eight hour interval. It was still pretty steamy, but I could see bursts in there, but none of them were particularly big. The duration seemed normal, too.

Grand was again preceeded by Sput D, and it had a fairly long burst, about 9m45s. So it was a pleasant surprise to see water in the pool. Was to the north of the geyser, where the eruption had been backlit,and it was easy to see the sun's reflection on the swelling water. Was quiet strong burst with the small breeze pushing the steam toward the west. As I was leaving the area, the breeze turned into wind.

At the five hour mark, I wasn't thinking about going out to Grand because it had started raining, with lightning and dark skies. A half hour later, the rain had stopped and there was even some sunshine between the clouds. So I headed out, since waiting in the rain is much easier than heading out in it.

The rain never returned, and it was another One Burst Grand eruption, but still nice to see. Was a bit of a surprise, as the Turban interval was exactly 20 minutes, which is short for this year. But a couple of boops got my attention just before the start.


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Observations for 2019 September 15


Was mostly a day of One Burst Grand eruptions. The first one took its time, and we may have walked up on a Delay Turban interval, based on the long Turban eruption duration,

Stopped by down at Grotto to catch a start. Grotto Fountain went about 3-5 meters high, and preceeded Grotto by about two minutes, so nothing out of the ordinary there. At Giant, nothing happened much there either, other than for a moment I thought I was actually seeing a Bijou pause.

While waiting in the early afternoon, we were treated to having an eagle flying low over the river, then perching on a dead tree. After a while, it took off and slowly circled its way higher and off to the north.

The eruption itself was preceeded by an eruption of Sput D, which did not erupt during the previous Turban eruption interval. I've been seeing a number of cases like this, where Sput D acts almost like a sort of indicator or pressure guage to the system. Also, the new normal seems to be that West Triplet overflows heavily for several minutes after Grand erupts.

The last Grand eruption of the day was the had two bursts, with the second lasting well over two minutes. Fortunately, much of the eruption was through a hole in the high, thin cloudiness .


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Observations for 2019 September 14


With a full moon and no clouds, it was time to catch Grand again. Only had to wait a couple of Turban intervals before Grand erupted. While waiting, could hear an elk bugling off in the distance.

We had just gotten back to the cabin, and hadn't even started to strip off the layers, when there was a call of "Beehive's Indicator" over the radio. So there no reason not to go over there for the eruption. Just barely made it, but the lighting was excellent with the moon behind the water column.

The next Grand eruption was interesting. It looked like we had arrived in the middle of a delay overflow, one of those early in the interval that lead to a Delay of more than just two Turban intervals. So it was a pleasant surprise when we heard an explosive start from Grand. Except that was it, no followup. It was perhaps the highest (two to three meters) and loudest boop I've seen. The pool then dropped, and three minutes later, Turban started. Again, this was early in the interval, so expecting to wait. So it was a bit of a surprise when the pool rose back up, and within a minute the real eruption started.

In the afternoon, it was back out for a third Grand eruption for the day. This time also it felt like we'd walked upon a Delay, but nothing happened this time. Two Turban intervals later we got the Grand eruption, so it was still a nice short interval. And we got a second burst. It was long, but not long enough to be noted. Most of that burst consisted of Big Sawmill activity, too.

Decided after that to do another bicycle visit, this time to Black Sand Basin. Well, we biked as far as Punch Bowl, and then went on foot past Black Sand Pool. It was pretty quiet, with only one large boil, and minutes between the superheated sizzles. At the basin proper, things seemed pretty normal. We arrived to an empty Cliff Geyser, which started erupting for real as we crossed the bridge over the creek. That eruption lasted long enough that we were able to walk back to the overlook there. There was also continuous play from what I believe was Handkerchief Pool, and from Spouter Geyser. On the way back we arrived at Daisy just as it was starting.

Finally went out one last time for another Grand in the dark. There were several groups of people already waiting, but fortunately, when Grand did erupt, it wasn't until well into the eruption that anyone tried to illuminate it. This was despite the fact that the moon had disappeared behind some thick clouds, and it wasn't that bright out. Of course as we were walking away, the clouds parted enough that we could get a backlit Old Tardy eruption.


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Observations for 2019 September 13


With a full moon and clear skies, it was time to head out to Grand in the dark. Castle was slopping gently, and the walkway wasn't very wet, so it looked like there had been a minor eruption. At Grand, things were pretty normal. Heard an eruption of Sput D, but there was no overflow from West Triplet to accompany it. It was humid enough that everything was steaming heavily. I thought at one point Oblong was starting to erupt, but after a couple of minutes, no increase and no noise meant I was wrong.

It was only two Turban intervals before Grand started to erupt. The first burst lasted almost nine minutes, so wasn't surprised that there was a second burst, and that everything was quiet after that.

It was foggy for the next Grand eruption, which came after a couple of Turban eruptions. By that time the fog had cleared enough that it was possible to see the water column backlit.

With the day clear and warming, it was time to do something a little different. Did a bicycle ride down to Biscuit Basin. Was surprised when we arrived to find that there was actually a bike rack there. Getting across the bridge was a bit fun, because instead of a shoulder, there's a raised walkway, so a bike as to ride along the white stripe.

Did the Biscuit Basin loop, and got to see several eruptions of both Mustard Spring and Jewel Geyser. Not much else going on during the time we were there.

In the early after noon spent a couple of hours watching Turban. For the second hour, Turban and Sput D alternated, and the latter started just before the Grand eruption. This eruption had a long second burst, over two minutes long, with much of that time in Big Sawmill mode where it looks like it's stopping, only to have a jet rocket out. It's the kind of behavior the crowd loves, not knowing that it's keeping them from seeing another burst start.

There was one more eruption to attend after dark. The moon was out, but unforunately, there were clouds coming in, so that by the time Grand started, the lighting was subdued. The first eruption of Turban I saw while waiting lasted seven minutes, which was a pretty good indication that I was seeing the end of a Turban Delay. So I wasn't surprised to have Grand erupt two Turban intervals later. Again we got two bursts, the third such eruption of the day.

Also, for all four eruptions of Grand, it was followed by heavy overflow from West Triplet. It's beginning to appear that this is the normal mode, except when recovering from the weekly Rift eruption.