Last Known Eruption
4d 17h 25m ago

Latest Eruptions

Eruption DurationInterval
23 May 2023 @ 1037 ie203d 21h 59m
31 Oct 2022 @ 1238 ie20m
31 Oct 2022 @ 1218 ie39m
31 Oct 2022 @ 11395m 13s 37m
31 Oct 2022 @ 1102 ns4m 57s 40m
31 Oct 2022 @ 10224m 40s 39m
31 Oct 2022 @ 0943 ns4m 22s 14m
31 Oct 2022 @ 0929 ns1m 18s 1h 2m
31 Oct 2022 @ 0827 ns4m 2d 14h 18m
28 Oct 2022 @ 1809 ie18m
28 Oct 2022 @ 1751 ie10m
28 Oct 2022 @ 1741 ie19m
28 Oct 2022 @ 1722 ie21m
28 Oct 2022 @ 1701 ie23m
28 Oct 2022 @ 1638 ie23m
28 Oct 2022 @ 1615 ie55m
28 Oct 2022 @ 1520 ie12m
28 Oct 2022 @ 1508 ie5m
28 Oct 2022 @ 1503 ie9m
28 Oct 2022 @ 1454 ie10m
28 Oct 2022 @ 1444 ie7m
28 Oct 2022 @ 1437 ie5m
28 Oct 2022 @ 1432 ie14m
28 Oct 2022 @ 1418 ie13m
28 Oct 2022 @ 1405 ie8m
28 Oct 2022 @ 1357 ? ie5m
28 Oct 2022 @ 1352 ie9m
28 Oct 2022 @ 1343 ie15m
28 Oct 2022 @ 1328 ie11m
28 Oct 2022 @ 1317 ie24m
28 Oct 2022 @ 1253 ie6m
28 Oct 2022 @ 1247 ie5m
28 Oct 2022 @ 1242 ie10m
28 Oct 2022 @ 1232 ie3m
28 Oct 2022 @ 1229 ie8m
28 Oct 2022 @ 1221 ie15m
28 Oct 2022 @ 1206 ie11m
28 Oct 2022 @ 1155 ie11m
28 Oct 2022 @ 1144 ie23m
28 Oct 2022 @ 1121 ie32m
28 Oct 2022 @ 1049 ie23m
28 Oct 2022 @ 1026 ie14m
28 Oct 2022 @ 1012 ie20d 21h 35m
07 Oct 2022 @ 1237 ns64d 22h 18m
03 Aug 2022 @ 1419 ie6d 22h 42m
27 Jul 2022 @ 1537 ns~8m 5d 22h 53m
21 Jul 2022 @ 1644 ie7h 29m
21 Jul 2022 @ 09158m 18h 59m
20 Jul 2022 @ 141611m 1d 2h 14m
19 Jul 2022 @ 12028m 3h 47m
19 Jul 2022 @ 0815 ie1d 21h 19m
17 Jul 2022 @ 1056 ns6m 40s 19h 35m
16 Jul 2022 @ 15218m 2d 35m
14 Jul 2022 @ 1446 ns22h 48m
13 Jul 2022 @ 1558 ie~7m 4h 56m
13 Jul 2022 @ 11029m 19h 28m
12 Jul 2022 @ 15349m 3h 44m
12 Jul 2022 @ 11502d 2h 2m
10 Jul 2022 @ 0948 ie1d 18h 7m
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

Interval Statistics

Interval Count100
Min3m
Max203d 21h 59m
Mean3d 17h 31m
Median1h 17m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
25527 18 May 2023 @ 0905 --- MAB 0905 thru 1500 - burbling varying in intensity - at the peak bursts could be nearly 12in - hard to discern if it ever actually stopped - even harder to see once the day warmed up
25060 27 Feb 2023 @ 1400 --- MAB approx time - seen from various vantage points appeared to have low burbles but hard to see with steamy conditions - never saw anything more than a few inches in height if that
24588 30 Oct 2022 @ 1828 --- MAB briefly big @1827-1828 but won't enter others - see Friday 28th Note
24526 29 Oct 2022 @ 1811 --- MAB same deal as yesterday low play then ~30s of bigger bursts near end then repeat but I'm not writing them down
24507 28 Oct 2022 @ 0836 28 Oct 2022 @ 1838 MAB Definitely Periodic! Thought I heard splashes in the morn but couldn't see a thing. Low burbles then were observed to pause every ~5m. As visibility improved I could see some decent height bursts some as much as 4ft, full bodied and wide. Those best-bursts lasted 30s or less then the flow {and steam} flowing into Colloidal would cease. Some of the low play would not evolve into the larger bursts but no way to know which would or would not, and finding an actual start to time was a problem, so I collected times of the biggest bursts as 'IE near end' because I wanted these intervals saved for the record. Some are obviously not Closed Intervals as Constant or Whirligig took my attentions but you get the idea.
24393 15 Oct 2022 @ 1842 --- MAB still burbling as high as 8in as seen the last 2 days
24267 05 Oct 2022 @ 1434 05 Oct 2022 @ 1600 cb continuous small low level blips observed from the Constant bench
23884 17 Sep 2022 @ 1715 17 Sep 2022 @ 1830 MAB steady low play from 1-4in
23563 04 Sep 2022 @ 1245 --- cb barely visable splashes in the vent observed above with binoculars
23373 23 Aug 2022 @ 1030 23 Aug 2022 @ 1825 MAB burbling to a few inches during most of my time today - some up to 8in - some pauses - repeat
23253 18 Aug 2022 @ 1852 --- MAB seen burbling 6in or so from above until it was out of sight
23227 16 Aug 2022 @ 1703 16 Aug 2022 @ 1723 MAB small burbling barely visible - stopped 1723
23053 05 Aug 2022 @ 1120 05 Aug 2022 @ 1314 cb a steady blipping boil ~2"-5"
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.