Kilauea is one of three American volcanoes the USGS has on advisory tonight

Kilauea’s summit eruption is on pause, and the USGS Hawaiian Volcano Observatory has the volcano at alert level ADVISORY with aviation color code YELLOW. Its status went out at 19:05 UTC on October 29, with the next burst of lava fountaining forecast for November 1 through 7. Two other American volcanoes hold the same rating, Shishaldin in Alaska and Ahyi Seamount in the Mariana Islands.

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Episode 55 of the Halemaʻumaʻu eruption lasted under six hours on October 17. The pause since then has lasted nearly two weeks.

Two weeks of recharge after episode 55

The observatory’s daily update for October 29 says episode 55 ran from 3:19 to 9:03 a.m. Hawaii time on October 17, throwing fountains about 720 feet high from the north vent and a plume to roughly 25,000 feet. The buildup before it was unusually long, with 39 days of overflows and a shallow dike under the caldera that the observatory calls Kaluapele. The south vent was buried during the episode and is dark. Glow persists at the west vent, strong, and at the north vent, weaker and steady.

Instruments show a volcano refilling. Tilt at the Uēkahuna station has recovered about 14.9 microradians since episode 55, including a 0.4 microradian gain in the last day. Seismicity is background tremor with periodic stronger pulses, which the update calls typical of pauses, plus three earthquakes below magnitude 1.5 in 24 hours. Sulfur dioxide is running within the 1,000 to 5,000 tonnes per day that the observatory expects between episodes, with winds carrying the gas north toward the community of Volcano.

An eruptive volcano on the lowest elevated tier

Under the USGS definitions explained on its page on alert levels at American volcanoes, ADVISORY covers unrest above background and also activity that has fallen after a higher level but remains under observation for a renewed rise. Kilauea belongs to the second group. The November 1 to 7 window is the observatory’s estimate of when the next episode of fountaining begins.

The rift zones, the two long fractures that run away from the summit, are quiet. The update reports low seismicity and deformation in both the East and Southwest Rift Zones, and sulfur dioxide from the East Rift is below the level instruments can detect. Hazards the observatory lists for the summit are volcanic gas, tephra, lava flows and ground cracks, and its notice names Hawaiʻi Volcanoes National Park and the Hawaiʻi County Civil Defense Agency among the organizations it references.

The window moved. The observatory pushed the forecast for episode 56 back because of a recent tilt decline, a reminder that the timing rests on how fast the summit inflates, which the instruments measure daily and the volcano does not promise.

The other two volcanoes on advisory

Kilauea’s company comes from the USGS elevated-volcanoes feed, which lists four entries. The Alaska Volcano Observatory’s update places Shishaldin, a 9,373-foot peak, at ADVISORY and YELLOW with low-level unrest, elevated seismic activity, small earthquakes and tremor, and weak steaming seen on clear webcam views. The fourth entry, Great Sitkin, is higher at WATCH and ORANGE, because lava has been erupting slowly there since July 2021.

Great Sitkin has its own observatory page dated October 30, which reports minor growth of the lava dome over the past week, a south flank creeping slowly southward with occasional small rockfalls, and only low seismicity. The contrast with Kilauea is one of rhythm. Great Sitkin erupts continuously and slowly, and Kilauea erupts in short, violent episodes separated by weeks of quiet, which is how the same eruption can read as WATCH at one volcano and ADVISORY at the other.

Ahyi Seamount is the odd one out. In the USGS Northern Mariana Islands update, its summit lies 180 feet under the sea, discolored water appeared over it on October 16 and 21, and the agency says it cannot forecast or warn of an eruption without local real-time data. A hazard to mariners, not to residents, is the stated concern. The update recounts the seamount’s history of shocks and sulfur-bearing upwelling in 1979, explosive eruptions in 2001 and 2014, the second of which carved a new crater and a landslide chute on the southeast flank, and renewed eruptive activity beginning in 2022. Distant monitoring showed nothing notable in the past week, and satellite data showed no sign of unrest. The notice points to the greenish water as the recent sign of activity.

That leaves a count of three at ADVISORY out of four on the list, with Kilauea the only one whose next eruptive episode comes with a date range attached. Whether the November 1 to 7 estimate holds depends on tilt readings that gained only 0.4 microradian in the latest day, and the observatory has already moved the window once. Anyone downwind in the community of Volcano is the first to feel the difference, since the same observatory notes that gases from the summit were drifting north toward that town on October 29.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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