Once again I got to walk up on a Turban Delay Interval, this time 14 hours after the eruption we saw the day before. Tuns out the interval wasn't horrible, and the Delay was only for three Turban eruptions.
That's when we got a nice steady fill in Grand, then a full pool with waves increasing in strength. The start was explosive, and Turban didn't start for nearly a minute. Even though the first burst lasted more than nine minutes, we got a second burst.
Midway through the first burst we started getting radio calls from the Bijou Cage announcing a Bijou pause where Feather was pulsating and overflowing. It made for a significant distraction from Grand's eruption.
2026-Sep-10 : 09:04:35 D3/G2Q 09:04:35 B1 --- d=09m07s 09:05:30 Turban 0m55s 09:08:33 Vent 3m58s 09:13:42 P1 9m07s d=48s 09:14:31 B2 9m55s d=38s 09:15:09 P2 10m34s 09:15:52 V&T Quit 11m17s ΣB=09m45s ΣD=10m34s * * * * * 08:06:37 d=04m34s D0 08:23:42 Int: 17m05s d=03m59s D1 08:41:25 Int: 17m43s d=03m43s D2 09:19:15 West Triplet Grand: 23m10s
Afterwards, Castle started to erupt, and when it didn't turn into a minor eruption, I waited around to watch the major eruption transition into steam.
Returned a few hours later to the Bijou Cage. Nothing much had happened since the last Bijou pause. On the Giant Platform, nothing much happened for the next 3-1/2 hours that I was there. Occasionally we'd get a Mastiff back vent surge followed by water just visible in Mastiff, other times just the Mastiff surge.
Midway through this wait, I glanced over to the south, and noticed a lot of steam coming from Oblong. It was windy, so the steam wasn't rising above the trees, but instead extended to the left over the river. We were seeing the first eruption of Oblong in several days.
I headed over to Grand when its eruption window opened, and saw some Turban eruptions. The third turned into a Delay Interval, and when Turban finally erupted, I turned my attention to tying down my camera tripod, which had moments earlier tried to fall over because of the wind. So I was distracted when Grand started to erupt 1-1/2 minutes later.
Around the 8-1/2 minute mark, there was a false pause and long slowdown in Grand. I figured it was going into Big Sawmill mode and we'd get only a single burst. Instead, after a half minute, Grand quit, and we got a second burst.
2026-Sep-10 : 16:41:05 D0/T2Q 16:39:37 Turban -1m28s 16:41:05 B1 --- d=08m53s 16:43:18 Vent 2m13s 16:49:28 FP 8m23s 16:49:58 P1 8m53s d=19s 16:50:17 B2 9m12s d=48s 16:51:05 P2 10m00s 16:51:51 V&T Quit 10m46s ΣB=09m41s ΣD=10m00s * * * * * 15:32:04 15:50:45 Int: 18m41s d=03m17s 16:06:54 Int: 16m09s 16:48:21 West Triplet Turban: 32m43s
After that, it was back to the Bijou Cage. By this time, it had been seven hours since the last Bijou pause. The only time a length of time like that, without a pause, had been seen had been just before the previous Giant eruption. So it was time to prepare for a long wait. After an hour and a half, I made a quick trip back to the cabin to reconfigure for a nighttime wait.
All during this wait Mastiff would have a surge every 30 minutes or so. Most of the times, Bijou would roar and Catfish splash about three or four minutes later.
Finally, just after 21:00, we got the first Bijou pause in eleven hours. It took a while for Mastiff to show water, and the event proceeded as a Standard Bathtub until Feather filled and started to push water at about 4-1/2 minutes. Almost immediately, Feather started to erupt, and Mastiff overflowed. This was unlike any activity seen since 2018. At this point, the Hot Period behaved much like those of that year. One by one, various vents started to show activity, and Giant began to surge more powerfully.
Ten minutes after Bijou had paused, Bijou began to roar as Mastiff dropped. A minute later, Giant erupted.
I was in the Cage near the benches, and got soaked repeatedly by hot water and hot steam. I made a hasty exit, leaving my pack behind. There were multiple bright lights, so the eruption was easily visible. Ben Vanderlay got a height at the start of 215ft.
As the eruption progressed, more and more people began to appear on both the walkway from Oblong and along the bike trail. At least one NPS vehicle drove down the bike trail, and by then there was a crowd of 30-40 people gathered in the Cage and along the boardwalk.
I recorded the entire start of the Hot Period and most of the Giant eruption, until the battery was drained, for about an hour of video. The timestamps on the Hot Period portion show most of the activity matching the times in my notes. Once the eruption started, the video doesn't show much, because the wind was blowing steam and spray toward the camera, and it seems the camera had a hard time processing what was going on, especially with the sound.
The video is available in a separate posting. It only took 5 hours to process and upload it from the cabin.
21:02:54 Mastiff surge/Bijou pause 21:04:30 Mastiff water visible 21:05:02 SW spits 21:05:12 Catfish splashes 21:06:25 SW vents erupting 21:06:59 Feather water visible 21:07:34 Feather push 21:07:48 Mastiff in overflow 21:07:57 Feather erupting 21:08:13 Mastiff front boil h~1m 21:08:48 Feather Satellite erupting 21:09:21 Catfish splashing 21:09:28 Cave erupting 21:10:10 Bijou erupting 21:10:41 Giant surging 21:11:59 Rust eruption? 21:12:43 Giant surging to top of cone 21:13:04 Bijou roaring 21:13:20 Emerald erupting 21:14:06 Giant start of eruption 22:03:36 Feather restart 22:05:03 Feather Sat. restart 22:17:45 Giant last water seen 22:33:09 Grotto ie