Last Known Eruption
23y 186d 13h 47m ago

Latest Eruptions

Eruption DurationInterval
27 Aug 1995 @ 10207m 333d 23h 5m
27 Sep 1994 @ 111519d 30m
08 Sep 1994 @ 1045106d 15h 45m
24 May 1994 @ 1900 min

Interval Statistics

Interval Count3
Min19d 30m
Max333d 23h 5m
Mean153d 5h 6m
Median106d 15h 45m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
9519 07 Aug 2018 @ 1147 --- bbev Water in crater is clearer than I have seen this year, no change in runoff.
3227 24 Jun 2016 @ 1113 --- David level high. bubbling in larger pool, left side of island. see photo:
1577 11 May 2015 @ 1308 --- MAB heavy overflow
4722 23 Jun 1994 @ 1800 --- research-mab June 23 1994 – Monarch having series of eruptions then days of nothing
5687 07 Sep 1975 @ 1800 --- research-mab 09/07/1975 A new spring has opened up in the runoff channel of Emerald due north of Monarch Geyser Crater. All water from Emerald drains down vent.
5655 24 Aug 1975 @ 1800 --- research-mab 08/24/1975 Monarch Geyser – boiling has decreased in vent lying between the 3 large rocks. Is back to normal. Same with front vent.
5644 21 Aug 1975 @ 1800 --- research-mab 08/21/1975 Monarch Geyser – looks almost the same as it did immediately after the June 30th quake. Material of a deep charcoal gray color now covers the pool area, runoff channels. & makes the water in the vents quite cloudy. Great increase in activity in vent lying between the 2 large rocks. Large boiling spot located near edge of pool is perhaps 2’ in diameter & 6” high. Scattered bubbles rising in rest of vent. In “front” vent, (main pool area), boiling has also increased in size of area boiling as well as vigor.
5664 05 Aug 1975 @ 1800 --- research-mab 08/05/1975 Monarch Geyser Crater producing some kind of film on the water.
5647 21 Jun 1975 @ 1530 21 Jun 1975 @ 1630 research-mab 08/21/1975 What’s Going On? Monarch is spouting steam bubbles from its quiet side as much as it does from its active side. Cistern appears to be more violent, and Emerald has gone crazy. (Observed in Walk 6, 3:30 to 4:30)
6525 10 Sep 1971 @ 1800 --- research-mab 09/10/1971 Monarch Geyser Crater – the water is still a yellow-green in color, apparently from the sulphur down below but today has started to become slightly turbid from the boiling activity; it has been increasing in vigor very slowly over the past 3-4 weeks.
7408 21 Jul 1968 @ 1800 --- research-mab 07/21/1968 Monarch – H2O from vents surging 5-6 inches. Temp 199.7F
7329 08 Sep 1967 @ 1800 --- research-mab 09/08/1967 Monarch Geyser Whereas Monarch appeared to be a quiet, almost stagnant, pool early this summer, it is now a very clear green color and boiling vigorously. Two vents boiled continuously on the east side of a rock that extends across the pool dividing it into two large rifts. The vents are 198.8ºF and boil up 3-4 inches. No record was made of Monarch early this summer because it showed very little activity. Correction: Ed Leigh recorded 194º on June 22 and ph5 at 140º
6764 16 Oct 1964 @ 1800 --- research-mab 10/16/1964 Monarch is clear & there is very little agitation at 187º
No attachments for this geyser.
Baseline does not exist.

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