Observations for 2025 September 08


The Beehive's Indicator call came in about an hour before the time the alarm was set. It was hours before dawn, so nicely backlit by the almost full moon.

Took a short nap, then went out for a 2-1/2 hour wait for a One Burst Grand Eruption. At first it was dark and mostly clear, with the moon a couple of hours from setting. As it got lighter, the fog formed so that by the time Grand finally did erupt, it was not possible to see into the Sawmill Group from the trees by Rift. Uncertain erupted, and I couldn't tell that until I got closer.

2025-Sep-08 : 07:26:05 T1Q

 07:25:48	Turban	-0m17s
 07:25:58	Vent Ovfl	-0m07s
 07:26:05	B1	--- d=11m15s
 07:28:40	Vent	2m35s
 07:37:20	P1	11m15s
 07:38:26	V&T Quit	12m21s

				     	ΣD=11m15s
	* * * * *
 05:03:08			d=04m47s 	
 05:20:43	Int: 17m35s	d=03m51s 	
 05:38:39	Int: 17m56s	d=03m47s 	
 05:57:45	Int: 19m06s	d=03m45s 	
 06:15:11	Int: 17m26s	d=03m19s 	
 06:33:11	Int: 18m00s	d=03m51s 	
 06:51:13	Int: 18m02s	d=03m43s 	
 07:09:22	Int: 18m09s	d=03m28s 	
		     Turban: 16m26s

A bit later headed out with the intention of waiting for Oblong. The large steamcloud I saw while riding past the Lodge said that we were a bit late. So instead went Fan & Mortar to see what it wasn't doing.

As I arrived, Bottom was erupting, and Fan's High and Gold vents had high water levels and were erupting vigorously. That activity died down, and over the next couple of hours, there were a series of more ordinary cycles which were never really strong.

Just as about to leave came a radio call about some interesting activity by East Sentinel. The boiling was quite strong, and cyclic. Every fifteen to twenty minutes, the right side would increase in activity and pour water over the side nearest to us. Occasionally the left side would show some activity, but only briefly. It looks like East Sentinel needs to be watched for an eruption.

By then it was time to return to Grand. On the way back, Rocket had a major eruption start just as I rode up. Shortly after, the guy dumping boardwalk pieces fired up his powered wheelbarrow, providing an unwelcome amount of noise. Rather than put up with it, I left.

Arrived at the Grand Group with West Triplet in eruption. Grand spent the next two hours never trying to erupt. Then we got a Turban Delay interval, and four more Turban eruption intervals later Grand finally appeared ready to erupt.

It was a slow start with almost a minute between the start of Turban and the start of Grand. It was a pleasant surprise when the first burst ended at 7m20s. I had just been joking about how we never seemed to get short first bursts any more.

The pause was pretty normal, and Grand didn't play around too much prior to the second burst. That burst wasn't long, and after it quit, it seemed like Grand was sloshing more than normal, with jets of water coming from the vent, when suddenly the pool drained. The eruption lasted less than nine minutes. West Triplet started just before the second burst started.

2025-Sep-08 : 18:12:32 D4/T2C

 18:11:40	Turban	-0m52s
 18:11:43	Vent Ovfl	-0m49s
 18:12:27	Boop	-0m05s
 18:12:32	B1	--- d=07m20s
 18:14:49	Vent	2m17s
 18:19:52	P1	7m20s d=39s
 18:20:31	B2	7m59s d=46s
 18:21:17	P2	8m45s
Vent & Turban continue

				     ΣB=08m06s	ΣD=08m45s
	* * * * *
 14:59:15	West Triplet
 15:00:27			d=03m04s 	
 15:19:21	Int: 18m54s	d=03m38s 	
 15:37:40	Int: 18m19s	d=03m34s 	
 15:56:59	Int: 19m19s	d=03m28s 	
 16:15:47	Int: 18m48s	d=03m29s 	
 16:34:01	Int: 18m14s	d=03m26s 	
 17:03:31	Int: 29m30s	d=04m53s  D0	
 17:20:42	Int: 17m11s	d=03m13s  D1	
 17:36:49	Int: 16m07s	d=03m41s  D2	
 17:54:40	Int: 17m51s	d=03m50s  D3	
 18:20:26	West Triplet
		     Turban: 17m00s

Even with the short eruption duration, Grand didn't seem to have any afterplay.

Did not stick around for the end of West Triplet, or a start of Rift as it was pointed out that this was an ideal time for an eruption of Great Fountain. So left quickly, and when we got over to the cabin to load up the bikes, learned that overflow had started about a half hour prior. So we had plenty of time to drive out and bike over.

The sun was about to set, and it was below the horizon when Great Fountain finally did erupt. But it was still well lit, and after a few preliminary surges, we got a huge burst that sent out multiple waves across the terrace. Not a superburst, but still impressive, and it all showed up nicely in the recording I made. Didn't stick around much longer, as no one wanted to deal with biking back in the dark.

On the drive back, I did get to encounter just over the Biscuit Basin bridge an oncoming van that just had to get in front of someone else even though I was coming right at him. At least I didn't have to deal with any bison on the road.

In the cabin area, the elk continue to bugle off in the distance to the south.