Posted on

Observations for 2020 May 27


A day spent at Norris, where nothing much happened. Steamboat/New Crater looked pretty much the same when we left at 19:20 as when we arrived at 05:50. Seemed like good water coming from the South vent, but North vent was initiating most of the activity, and only once, in the middle of the day, did we see anything approaching vertical.


Posted on

Observations for 2020 May 26


Had decided to not come out for the pre-dawn Grand eruption, so it was a bit of a surprise to find it erupting shortly ater 08:00. That meant that most likely that there were two long intervals overnight. It also meant that I wouldn't be getting out until later.

Did go out after noon, and watched a series of similar Turban eruption intervals. Unlike previous days, there was no hint of any sort of delay. So it was nice to also be rewarded with a second burst, although the eruption was just under ten minutes long and Vent & Turban did quit.

Went on over to Geyser Hill again, to check on Beehive but not stay. It was having minor splashes, but nothing that looked imminent. Over by Aurum and watched and felt a episode of thumping by Doublet Pool. With few people on the boardwalks, it was easy to feel them. Then Aurum erupted just as I was getting ready to leave. Better behaved than in my previous attempt at seeing an eruption.

The day ended with a report of Beehive's Indicator starting. It was a long one, giving us plenty of time to get within view. And again, the area was far quieter than usual. Old Faithful had just erupted, so there were a few families wandering about


Posted on

Observations for 2020 May 25


The weather was finally clear and sunny. So went down basin to watch and wait for something. Ended up being Daisy, where it was the middle of the interval. Splendid was calm for the hour or so I waited there. I did see a couple of Pyramid eruptions, too. The duration of the Daisy eruption was only 3m10s, which seems to be continuing the trend of shorter durations. In years past it seemed like Daisy was regularly 3m40s.

After that, it was to Castle, since it was well over 13 hours since the major eruption last night. Only waited about five minutes for a start. It was strong the whole time, except for a series of pauses between four and six minutes.

Then it was over to Grand. Arrived to a full, steamy pool that slowly dropped. The Turban duration was well over six minutes, which makes me suspect we missed a Delay. That the next Turban interval had almost no overflow tends to confirm that.

Grand erupted on the next opportunity, with Turban taking almost a minute to join in. After yesterday, we couldn't be sure what would happen when Grand quit after 9-1/4 minutes, but through the steam we could see the water over the vent, and we were finally, on the tenth try, rewarded with a second burst. Of course that meant that Vent & Turban had to quit.

West Triplet was overflowing heavily by then, and I did catch weak eruption, with lots of thumps, that lasted five minutes. Then it was a Bulger major eruption, and by the time that finished, it was only a few minutes until Vent & Turban restarted.

So because of that, I ended up seeing Beehive start as I passed by Sawmill. I didn't notice any steam to the left as Beehive was climbing in height, so I'm almost certain there was no Indicator. What isn't know is was that really an interval pushing four days, or were there some missed nighttime eruptions? In any case, the days of multiple Beehive eruptions in a day seem to gone for a while.

It was pointed out to us yesterday by Rebecca Roland that one of the vents at Spasmodic had a strange purple color to it. In the bright sunlight of this morning, this coloration was obvious. I think I walked past there once during the last few gray days, and I don't remember seeing anything like this. It looks like some sort of dye. It might be from some trash, as there is what appears to be paper right up next to the vent. In any case, I doubt it is natural, as that pool is intermittent, and when not empty, it's near boiling.

The wait for the next Grand eruption was similiar to the morning. Arrived to a heavily overflowing pool and the subsequent Turban eruption was a long one. The next Turban eruption had no overflow. Unfortunately, the One Burst Grand eruption lasted just under 10 minutes.


Posted on

Observations for 2020 May 24


No new snow overnight, and since it didn't clear, the temperature stayed just below freezing. So the snow on the walkway out to Grand was mushy and sloppy from all the footsteps from yesterday, most of them being ours.

For the first time it appeared that the water level in Belgian was at the rim, instead of being just below it (or even lower). West Triplet was in intermittent overflow. No delays, but we did end up waiting an hour for a double interval of just under 12-1/2 hours, which isn't at all bad.

The eruption of Grand ended at 8m36s, and didn't even try for a second burst, so that made for the eighth consecutive One Burst Grand of the trip. As we left, West Triplet started to actually burst, but weakly. Then as we passed Bulger, Churn started. I managed to get the rest of the eruption on video. It was a nice solid, typical Churn that resulted in the pool dropping about 5cm or so. It took about fifteen minutes to get back to overflow, and we finally left after twentyfive when the occasion boils didn't result in anything looking like an eruption.

Since was early and nice, for once, decided to visit the Lower Geyser Basin. The Firehole Lake Drive was two grooves of pavement in the snow much of the way. Great Fountain wasn't anywhere near overflow, and Fountain didn't look interested either.

At Fountain Paint Pots there were two sets of footprints leading out and back. A Fumarole was completely drown by a large pool, and just bubbling, and not vigorously. Red Spouter was impressively throwing brown soupy mud all over the place. The Paint Pots themselves were so wet that there were bluish pools over some of the area where the mudpots would normally be active.

There were people at the next eruption of Grand, along with some of the Naturalist staff.The wait started out nice, then the snow showers began. They ended well before another One Burst Eruption.

Afterwards another walk around Geyser Hill showed that Beehive was a bit noiser than yesterday, and that there was some slopping, but it just didn't look interested in erupting. Infant Pool being well above the rim was about the only other interesting thing noticed.


Posted on

Observations for 2020 May 23


The snow started just about the time we needed to go out for the morning Grand. We trudged on out there, into the north wind. The temperature was right at freezing, so instead of bouncing off, the snow stuck and accumulated to gloves, hats, coats and packs.

The wait at Grand was uneventful. I did watch a West Triplet overflow early in the wait, then went on down to the main runoff. just before Grand started, a small bird flew up from the runoff channel and tried to land on my notebook pouch. I shooed it away.Because of the wind, the pool was easily visible. Turban Geyser's intervals were consistently about 21 minutes, and the durations just under five minutes.

Then we got a nice fill, and the 21 minute mark passed. At 24-1/2 minutes, Turban started and Grand quickly followed. Thanks to the wind, there wasn't much height to this One Burst Grand eruption which lasted about 10-1/2 minutes.

West Triplet was overflowing as we were leaving, and started to well up and burst. Didn't stay around for the duration, and what we saw of the bursts were pretty weak, so it might have been a short eruption. Bulger did nothing the whole time we were out there.

On the way out, at Castle, we encountered two other people. The guy was wearing shorts, and I overheard him say they wanted to go to Grand.

The snow continued during the day, so when we went back out for the mid-day One Burst Grand, the tracks from our previous visit (and of the other two people) were just barely visible. Again the wind was from the north, so we were able to easily see the water level in the pool.

We had a ten minute wait with a nice full pool when Grand had a boop. Then nothing for almost four minutes other than the pool slowly dropping. A long Turban eruption and this meant we were getting a delay. It was two Turban intervals, another ten minute long eruption where Vent & Turban quit. Afterward West Triplet was in heavy overflow, but all we saw was a single heavy upwelling, no eruption.

Decided that it was time to visit Geyser Hill, to see what it was like. Walk over to Lion under at least four inches of snow, and slow going as the temperature was also just at freezing, making everything mushy. When we got to Aurum, it was having a sequence of nice surges that sucked us in. It continued to do that for the next hour. At some point Castle started, but it was hard to see it. Mostly we could tell it was eruption by the sound.

I finally had enough, and left to look at the rest of Geyser Hill. Lion was quiet, as was Beehive. It was at Beehive where I turned around and saw the large Aurum eruption steamcloud. Went over to Anemone, and then returned back to the vehicle at the store lot via the Sawmill Group.

Went out in the evening and the snow was pretty much ended. There was even, once, a bright spot in the sky to the west where the sun should have been. Also arrived in time for a delay. This time, it took three Turban intervals for the One Burst Grand eruption. If the sun had been visible, it probably would have just set.


Posted on

Observations for 2020 May 22


There was at least an inch of snow that needed removal from the truck before I could drive over to the morning One Burst Grand eruption. But it wasn't cold, as the snow was melting, and the wind was much less than yesterday. But the weather was getting wet as we came back in.

Belgian Pool had recovered mostly, just slightly below the rim. I've seen that variation before.

Did a survey down basin later in the morning. There are new benches at Castle, Riverside and Fan & Mortar, replacing the old ones. Thirty at Riverside, so there will be much less excuse for people sitting on the bumper logs.

Fan & Mortar looked nice at the start of a cycle, with Bottom vent splashing away, and they all quickly died down as Angle started. I doubt there's been any eruption since last year.

Giant didn't look changed much, either. Didn't spend much time there, as the weather was starting to get wet. An extended observation period will have to wait for nicer weather. Oblong has thick black slime filling much of the runoff, so I doubt it has done anything in the last few months, either.

The mid-day One Burst Grand was during a period of snowing, and had a short interval, so we got to see the start from Castle. Waited through the West Triplet activity to catch the first Rift eruption of the season. Again, things seem unchanged there from last year, as Percolator and Sput D were also active until West Triplet ended as Rift started.

The weather cleared a few hours later, so went out to see the Three Sisters activity in person, instead of on the camera. Got confused by which was which, so initially reported Mugwump for what was actually Three Crater. (I think that pool of water has the highest concentration of less than obvious names.) Saw a couple of periods of intermittent splashes to about a foot. The first lasted a bit over 7 minutes, which the second was only four minutes long.

Then it was off to Grand, where we were treated to a 35 minute delay. It was too steamy to see the pool, but on the other hand, the steam was pouring off well below the rim of the crater. Finally, 20 seconds after a couple of boops, the One Burst eruption began. The steam direction was more up the hillside, so was able to catch the starts of Vent and Turban.

Bulger had been having frequent minors before Grand, and the webcam operators had mentioned it looked different. So after Grand, we stuck around for a while to catch one, with no success. The best we got was deep rumbling.


Posted on

Observations for 2020 May 21


The precipitation didn't start until we passed West Thumb, but before that it was gusty head-winds. The notification sign at the junction sound of Lander had "South Pass 50+mph winds".

But it wasn't wet when we went out for the first One Burst Grand of the year. The sun was actually trying to come out. The first geyser I saw was the end of a Tilt eruption. But the interesting thing was that Crystal Spring and Belgian Pool were down about 3cm, and that was higher than earlier. At the same time Slurp was having a wet steam phase eruption-- lots of wet droplets with a hint of the slurping sound.

On the way back, we did get to see the mule deer and bison who have been hanging around together. They were in the trees over by Oval Spring.


Posted on

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.


Posted on

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.


Posted on

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.


Posted on

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 .


Posted on

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.


Posted on

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.


Posted on

Observations for 2019 September 12


Because Grand had some long overnight intervals, didn't get out and about until almost noon. Arrived at the Grand Group to find Belgian and Crystal back to normal. Ended up waiting for quite a while, with occasional activity from Sput D, but not every Turban interval. Then there was a Turban Delay, and we had to wait three more Turban intervals before we finally got the eruption.

It turned out to be a nice three burst eruption. It started out nicely, with the wind pushing the steam toward the south, giving us a clear view of the eruption. The first burst ended at about eight minutes, which was so sort we were almost guaranteed a second burst. But when that one ended just a minute later, the question of getting a third became obvious. Because of the breeze, we could see the pool fill and slosh about. Based on past experience, that doesn't mean anything until the bursting started. Even then, it took several large surges to get the burst started. There was no attempt to fill following that.

The long interval and Delay ended up pushing the next eruption into the dark, which was actually good. It's full moon time, and the moon had cleared the trees by the time we got the eruption. Best of all, the crowd of a couple of dozen people behaved themselves, and no one tried to light it up. It was only one burst, but the breeze again cooperated to make the water column visible the whole time. Even the arm-carried doglet seemed to enjoy it.


Posted on

Observations for 2019 September 11


Decided I'd had enought of Norris, and needed a break. The weather was supposed to be cold and wet, so I decided if I'm going to get soaked, I'd rather do it where I can easily get inside and warm up and dry out.

Based on the weather forecast and maps, I went out to Grand a bit early to get ahead of any rain. Turns out it didn't rain. Instead I arrived to see West Triplet, Sput D, and Percolator all in vigorous eruption. Sputnik was also steaming heavily, but there wasn't any visible water.

About 8 minutes later, Rift started. West Triplet continued for another twenty minutes, and when it quit, the other active features quit too. So for nearly two more hours, it was Rift sputtering away with nondescript Turban eruptions. The first Turban eruption I saw was probably a Delay Interval, as it started almost twenty minutes after I arrived. But with Rift erupting, it really didn't matter.

That situation persisted for over two hours, with occasional weak, independent activity from Sput D and Percolator. The steam from West Triplet seemed to pick up at the same time. Finally Rift quit, but it took two Turban eruptions before Grand was ready. When Turban started the second time, it took Grand nearly a minute to build up and finally start another One Burst Eruption.

I hadn't noticed anything when I left the area, but when I got out ahead of the rain for the next One Burst Grand Eruption, I noticed something I haven't seen since the early 1990s. (I'll have to consult my old notebooks to be sure.) Both Belgian Pool and Crystal Spring were down about 3-4cm. This was in response to the Rift eruption earlier. Back in the 1990s, they'd also get murky, especially Belgian. Also back then Belgian could drop as much as 15cm, completely emptying the non-vent lobe. They may have been lower earlier, before I got there.

The Grand eruption itself was pretty ordinary. It was an interval less than six hours, but erupted on a Turban Delay. If the previous Turban interval had been four seconds longer, it would have been back-to-back Delays. The rain had quit, but it was still steamy, and the prevaling wind was toward where I usually sit. Which meant that by moving north, I had a clear view of Turban and Vent. Which was good, because Turban took nearly a minute to start. Then the One Burst Eruption lasted 12m25s, so it was well short of any record.


Posted on

Observations for 2019 September 10


Another day at Norris watching minor activity that led nowhere. We get strong play from the vents, and the wall of water would start to form, only to have the North Vent stop and the South take over. This would happen every hour or less for most of the day.

The runoff was turning white all day. By late afternoon this had extended all the way down to the bridge over the runoff, and even a couple of areas beyond in the outwash.

Also yesterday we noticed that during the morning rains, it appeared that the dead trees behind the vents looked more green and brown than gray. Wondered if these rains, the first strong and persistent ones in several weeks, had washed some of the silica and minerals off. But in the afternoon, when the rains had stopped, they were back to gray. Also the trees along the walkway have lost a lot of needles, so that only near the ends are there green ones. The ground is covered with a pretty thick coating of these needles. A few of the trees near the runoff are also full of pinecones, but these look old and dried out.