Last Known Eruption
149d 9h 41m ago

Latest Eruptions

Eruption DurationInterval
08 Jul 2022 @ 15419m 1d 3h 0m
07 Jul 2022 @ 1241~1m 4d 19h 58m
02 Jul 2022 @ 16439m 1d 7h 8m
01 Jul 2022 @ 0935 ns9m 18h 6m
30 Jun 2022 @ 15294h 7m
30 Jun 2022 @ 1122 ns8m 1d 19h 51m
28 Jun 2022 @ 1531 ie1d 1h 21m
27 Jun 2022 @ 14106m 2h 0m
27 Jun 2022 @ 12101h 49m
27 Jun 2022 @ 1021~4m 40s 3d 19h 44m
23 Jun 2022 @ 1437 ns9m 1h 52m
23 Jun 2022 @ 12455m 21h 28m
22 Jun 2022 @ 15172d 4h 39m
20 Jun 2022 @ 1038 ie1d 21h 20m
18 Jun 2022 @ 13181h 48m
18 Jun 2022 @ 1130 ie22h 24m
17 Jun 2022 @ 1306 ie10d 1h 57m
07 Jun 2022 @ 11092d 21h 28m
04 Jun 2022 @ 1341 ie33m
04 Jun 2022 @ 1308 ie1d 1h 11m
03 Jun 2022 @ 1157 ie1h 32m
03 Jun 2022 @ 1025~59s 33m
03 Jun 2022 @ 095257s 31m
03 Jun 2022 @ 092157s 2d 21h 19m
31 May 2022 @ 1202 ie49m
31 May 2022 @ 1113 ie5d 21h 6m
25 May 2022 @ 14075m 48m
25 May 2022 @ 13192m 1h 3m
25 May 2022 @ 12164m 2h 1m
25 May 2022 @ 10155m 1d 18h 44m
23 May 2022 @ 15311h 9m
23 May 2022 @ 14223h 6m
23 May 2022 @ 11165m 40s 1h 26m
23 May 2022 @ 0950~5m 30s 1h 37m
23 May 2022 @ 0813 ie3d 19h 47m
19 May 2022 @ 12266m 3d 16h 48m
15 May 2022 @ 1938 ns~4m 7h 4m
15 May 2022 @ 1234 ns~56s 24m
15 May 2022 @ 12101m 20s 1h 26m
15 May 2022 @ 10445m 51m
15 May 2022 @ 09533m 27m
15 May 2022 @ 092630s 13m
15 May 2022 @ 0913<2m 30s 3d 21h 24m
11 May 2022 @ 11494m 18m
11 May 2022 @ 113140s 11m
11 May 2022 @ 1120<2m 1h 1m
11 May 2022 @ 10195m 1h 16m
11 May 2022 @ 0903 ns4d 13h 13m
06 May 2022 @ 1950 ns7h 36m
06 May 2022 @ 12146m 38s 1h 49m
06 May 2022 @ 10255m 7d 23h 17m
28 Apr 2022 @ 11084m 1d 22h 45m
26 Apr 2022 @ 12234m 36s 1h 26m
26 Apr 2022 @ 1056:384m 51s 58m 55s
26 Apr 2022 @ 0957:434m 1d 19h 16m
24 Apr 2022 @ 14414m 6h 39m
24 Apr 2022 @ 08024m 5d 19h 40m
18 Apr 2022 @ 1222 ns5m 1h 22m
18 Apr 2022 @ 11004m 58s 1h 15m
18 Apr 2022 @ 0945 ns5m 168d 22h 10m
31 Oct 2021 @ 1135 ns23h 38m
30 Oct 2021 @ 1157 ie3d 1h 33m
27 Oct 2021 @ 1024 ie7d 22h 18m
19 Oct 2021 @ 1206 ie3d 13m
16 Oct 2021 @ 1153 ie9d 20h 29m
06 Oct 2021 @ 1524 ie24m
06 Oct 2021 @ 1500~11m 23m
06 Oct 2021 @ 1437 ie28m
06 Oct 2021 @ 14093d 22h 24m
02 Oct 2021 @ 154544s 40m
02 Oct 2021 @ 1505<1m 38m
02 Oct 2021 @ 1427<1m 30m
02 Oct 2021 @ 1357~1m 13m
02 Oct 2021 @ 134415m
02 Oct 2021 @ 1329~45s 20h 9m
01 Oct 2021 @ 17201m 1d 30m
30 Sep 2021 @ 16501h 23m
30 Sep 2021 @ 15271h 18m
30 Sep 2021 @ 1409 ie5d 22h 38m
24 Sep 2021 @ 15317m 1h 40m
24 Sep 2021 @ 13517m 1h 31m
24 Sep 2021 @ 12206m 1h 49m
24 Sep 2021 @ 10316m 22h 29m
23 Sep 2021 @ 1201:488m 48s 1h 36m
23 Sep 2021 @ 1025 ns5m 4d 21h 34m
18 Sep 2021 @ 1251 ns10m 2d 2h 50m
16 Sep 2021 @ 100122m 2d 23h 41m
13 Sep 2021 @ 1019:5030m 29s 69d 0m 4s
06 Jul 2021 @ 1019:4627m 2s 11d 42m 1s
25 Jun 2021 @ 0937:45 ns2d 16h 52m
22 Jun 2021 @ 164523m 19s 1d 7h 28m
21 Jun 2021 @ 09177d 21h 12m
13 Jun 2021 @ 120534m 24d 25m
20 May 2021 @ 1140 ns7d 18h 22m
12 May 2021 @ 171813m 15s 4h 22m
12 May 2021 @ 125612m 22s 3d 20h 52m
08 May 2021 @ 1604 ie8d 3h 32m
30 Apr 2021 @ 1232 ie21h 42m
29 Apr 2021 @ 14501h 13m
29 Apr 2021 @ 133719h 57m

Interval Statistics

Interval Count100
Min11m
Max168d 22h 10m
Mean4d 8h 37m
Median12h 51m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
22395 08 Jul 2022 @ 0944 08 Jul 2022 @ 1125 cb low level blips
22243 30 Jun 2022 @ 1052 --- cb start of low level (just visable) blips.
21491 25 May 2022 @ 1007 --- Graham Boiled up but then quit.
20276 03 Nov 2021 @ 0828 03 Nov 2021 @ 1612 MAB morphed between low burps and more robust bursts of maaaybe 15in all day with a few seconds of quiet - may be regular but didn't track it closely
20178 28 Oct 2021 @ 0840 28 Oct 2021 @ 1522 MAB low burble all day - puts out enough water to steam up the runoff channel - a few times it built a few inches higher like typically pre start but no go
20117 24 Oct 2021 @ 0855 24 Oct 2021 @ 0921 MAB Low burbling while in the area
19951 10 Oct 2021 @ 0852 --- MAB low burbling while in the area - didn't build any higher that I saw
18306 07 Jul 2021 @ 0939 --- cb looks recently post eruptive. very wet runoff channel and gently steaming.
18038 22 Jun 2021 @ 1232 --- MAB visible burbles after 0900 which slowed by 1000 - viewed from above 1232 vent area has water but is not overflowing
17717 12 Jun 2021 @ 1900 --- MAB Tiny burbles visible from above - runoff channel damp most of the way to Colloidal
17544 07 Jun 2021 @ 0902 --- MAB Saw Arsenic burbling in the morning but it never progressed - coming back from Nuphar @ 1800 water is visible around the vent and down the channel but no steam
17074 12 May 2021 @ 0936 --- MAB heavy steam in channel all the way to Colloidal- must have just finished
8004 26 Apr 2018 @ 1127 --- Micah Kipple It's having very frequent splashing 10-20 cm but am only entering true jetting eruptions.
4171 31 May 2017 @ 1200 --- kc Arsenic was on and off all afternoon with durations ranging from 1 to 5 minutes.
3987 21 Apr 2017 @ 0956 21 Apr 2017 @ 1022 MAB Appears to start, but never reaches full height. Not closed intervals as it was very steamy and I was walking around the lower loop.
2398 21 Sep 2015 @ 0930 21 Sep 2015 @ 1410 MAB Burbling and looking pre-eruptive for 4 hours, no eruption seen. Same for the afternoon visit from 1641 - 1750
2380 18 Sep 2015 @ 0603 --- MAB I had a good handle on Arsenic pre-disturbance. It has skunked me the last 4 visits, sometimes burbling and looking quite pre-eruptive. Jake may have seen the last one for a while! I will start noting the burbles that are about 4" and see if they fit the interval pattern from earlier this month. I hope I am just unlucky and am missing them.
3756 15 Aug 2015 @ 0941 --- jh23487 Arsenic was either erupting or bubbling a little, not very tall. Possibly at the end of an eruption.
4696 02 Jul 1988 @ 1800 --- research-mab 7/2/1988 Also, Arsenic geyser is erupting this summer.
7638 26 Jun 1986 @ 1800 --- research-mab 6-26-1986 Arsenic Geyser – Active. Clear, full, boiling before eruption. T=201º
7604 11 Feb 1984 @ 1800 --- research-mab 2-11-84 Arsenic Geyser active.
5367 11 Aug 1983 @ 1800 --- research-mab 8/11/1983 Arsenic Fireball Splutterpot in simultaneous eruption {time unknown}
4643 14 Aug 1981 @ 1900 --- research-mab 8/14/1981 Arsenic Geyser is in perpetual spluttering as is Moxie and 2 other small spouters. Fireball is somewhat weak. GS
4644 14 Aug 1981 @ 1900 --- research-mab 8/14/1981 Arsenic Geyser is in perpetual spluttering as is Moxie and 2 other small spouters. Fireball is somewhat weak. GS
4645 14 Aug 1981 @ 1900 --- research-mab 8/14/1981 Arsenic Geyser is in perpetual spluttering as is Moxie and 2 other small spouters. Fireball is somewhat weak. GS
4615 22 Sep 1980 @ 1800 --- research-mab 9/22/1980 Arsenic Geyser – in a low eruption a good share of the day ie 204ºF
4762 22 Jul 1980 @ 1315 22 Jul 1980 @ 1330 research-mab 7/22/80 Porcelain 1:15-1:30 -Arsenic – constant, one to two feet
5133 01 Jun 1980 @ 1800 --- research-mab 06/01/1980 Arsenic was observed in two different eruptions to 5’. (no times)
4989 26 Sep 1979 @ 1800 --- research-mab 09/26/1979 Arsenic and Acute Spouter continue their small, perpetual eruptions. Ledge still puffing away with steam. ‘
5065 21 Sep 1979 @ 1800 --- research-mab 09/21/1979 Africa, Fireball, Arsenic and Geyser north of Constant all perpetual spouters. {probably Acute Spouter?-mab}
5060 15 Aug 1979 @ 1800 --- research-mab 08/15/1979 Five geysers erupted in concert today down in the Porcelain Basin Arsenic, Africa, Fireball, Little Wirlygig, and Constant. A new small geyser (sideways) erupted 1 foot today on the eastern side of Constant. {probably Acute spouter?- mab}
4967 01 Jul 1978 @ 1110 --- research-mab 07/01/1978 Good activity out of Porcelain this morning. Between 1000 am and 1110 am geysers in eruption included Fireball, Africa, Blue, Dark Cavern, Big Whirligig (twice), Constant (twice) and * Arsenic Geyser (10 min+). *Today was the first recorded observation of this geyser in eruption recorded this summer.
5116 19 Aug 1977 @ 1800 --- research-mab 08/19/1977 Arsenic splashing up to 15” high, much as it did for most of last year.
5239 07 Sep 1976 @ 1800 --- research-mab 09/07/1976 Arsenic – mainly steam
5271 28 Jul 1976 @ 0900 --- research-mab 07/28/1976 Ragged & Arsenic both active as usual at 9:00
5554 20 Jul 1976 @ 1800 --- research-mab 07/20/1976 Arsenic & Fireball continue their nearly constant type of activity, but the intensity of the activity varies.
5535 29 Jun 1976 @ 1540 29 Jun 1976 @ 1600 research-mab 06/29/1976 Arsenic, Moxie & Pinto erupting simultaneously from 3:40 -4:00
5863 28 Jun 1976 @ 1550 28 Jun 1976 @ 1610 research-mab Arsenic Geyser erupting constantly during above interval.
5836 21 Sep 1974 @ 1428 --- research-mab 09/21/1974 1428 Africa quits, now only Arsenic {noted as Geezer in log} is erupting (3’)
6203 26 Sep 1973 @ 1800 --- research-mab 09/26/1973 Temperatures taken yesterday Arsenic Geyser 200 – not erupting {included here since it’s not mentioned much this year-mab}
5925 17 Mar 1973 @ 0800 --- research-mab 03/17/1973 Arsenic was in its “steam phase” during all of this time.{written in morning section of log}
5912 12 Mar 1973 @ 1200 12 Mar 1973 @ 1815 research-mab 03/12/1973 Arsenic The water level was seen throughout the morning and early afternoon to be gradually rising in the vent. Accompanying the filling was continuous minor play with splashing originating at the northeastern end. During the afternoon the minor play became gradually more vigorous with water occasionally splashing out. At 1342 the last 3-4 inches to the top of the vent rapidly filled and was accompanied by the splashing changing into a series of fountain-like jets with massive overflow & runoff. After 9 minutes of play the water bursts became intermittent & more mixed with steam to end the true water phase. At 1445 the “steam phase” was still in progress with occasional bursts up to 2-3 feet, while at 1610 all play had ceased. A second phase of activity began sometime between 4:30 and 4:40, with the new “steam phase” beginning at approximately 4:45 and running to approximately 6:15.
5910 10 Mar 1973 @ 1635 --- research-mab 03/10/1973 At 4:35 Feisty, dark Cavern, Africa, Little Whirligig, Fireball, Blue, Arsenic, and Constant Geyser were all seen to be playing at the same time. (for 10-15 seconds due to the very short duration of Constant) Four playing together is not unusual but 8 is.
6489 11 Sep 1972 @ 1200 --- research-mab 09/11/1972 Bear Den, Dark Cavern, Africa. L. Whirligig, Blue, Fireball & Arsenic all have been observed in eruption this morning. {generic a.m. time}
6428 19 Aug 1972 @ 1800 --- research-mab 08/19/1972 Little Whirligig, arsenic, & Africa are still playing continuously. Ledge still has intermittent spray type minor play.
6398 15 Aug 1972 @ 1800 --- research-mab 08/15/1972 Arsenic – still in constant eruption, spraying water to a height of 5-7 feet.
6396 14 Aug 1972 @ 1800 --- research-mab 08/14/1972 L. Whirligig & Arsenic are still in continuous eruption.
6387 12 Aug 1972 @ 1800 --- research-mab 08/12/1972 Arsenic & Little Whirligig have not been observed to quit yet.
7866 09 Aug 1972 @ 0800 09 Aug 1972 @ 1800 research-mab 8/9/1972 Arsenic Geyser in constant 2-8’ eruption all day (before 8:00am to after 6:00 pm) normal 3-4 hours
6350 23 Jul 1972 @ 1400 --- research-mab 07/23/1972 At the end of the 1:30 walk there were 6 geysers in simultaneous eruption – Blue, Iris, Fireball, Arsenic, Africa and Little Whirligig.
6334 08 Jun 1972 @ 1548 --- research-mab 06/08/1972 Africa, Bear Den, Ledge, L. Whirligig, Arsenic and Possibly Blue (crossed out “Iris”) were all erupting at the same time at 3:48
6498 15 May 1972 @ 1800 --- research-mab 05/15/1972 Arsenic geyser – have not noticed an eruption 148º
7670 12 Aug 1970 @ 1800 --- research-mab 08/12/1970 Much activity in Porcelain in late pm (6-7) Arsenic, Fireball, and Fan went off in succession. 8/12/1970 Dark Cavern had extended eruption also.
7088 28 Jun 1966 @ 1800 --- research-mab 06/28/1966 Fireball & Arsenic both active this afternoon.
6797 24 Oct 1964 @ 1800 --- research-mab 10/24/1964 Arsenic is sloshing around but not erupting over the lip.
6775 17 Oct 1964 @ 1800 --- research-mab 10/17/1964 Fan {FIREBALL} & Arsenic are weak.
6772 16 Oct 1964 @ 1800 --- research-mab 10/16/1964 Fan {FIREBALL} & Arsenic are occasionally quiet & very weak.
6747 09 Oct 1964 @ 1800 --- research-mab 10/09/1964 The small geysers (Fan, Arsenic, Fireball {PINTO} etc) are still continuously active but are weak.
6710 05 Oct 1964 @ 1800 --- research-mab 10/05/1964 Porcelain Basin observed from 3:30 pm to 4:30 pm Arsenic & Fan are continuously active but weak.
6705 04 Oct 1964 @ 1800 --- research-mab 10/04/1964 Arsenic, Fan and Fireball {PINTO} are still steadily active.
6789 03 Oct 1964 @ 1800 --- research-mab 10/03/1964 The little geysers within the boardwalk loop (Arsenic, Fan {today’s FIREBALL}, Fireball {today’s PINTO}) have been continuously active all day.
EntrySourceLinkComment
09 Aug 2014 @ 1554 JSJ https://www.youtube.com/watch?v=2gpPvJbTC3g#t=1m47s Video clips (time stamp 1:47 to the end) of Arsenic Geyser's 3:54 to ~4:10 PM eruption on 9 August 2014.
07 Jul 2014 @ 1432 JSJ https://www.youtube.com/watch?v=2gpPvJbTC3g Video clips (beginning to time stamp 1:46) of Arsenic Geyser in eruption from 2:32 to ~2:45 PM on 7 July 2014.
Baseline does not exist.