(BIVN) – The ongoing eruption at the summit of Kilauea remains paused following Saturday’s eruptive episode.
Episode 55 began on October 17th, and ended the same day after 5.7 hours of high lava fountaining.
21 microradians of deflationary tilt was measured at Uēkahuna during the event. When the episode ended, tilt switched to inflation. The UWD tiltmeter has since recovered at total of 7.1 microradians.
Due to northeast winds, the gas plume at the summit is being pushed to the southwest over the Kaʻū Desert.
From the USGS Hawaiian Volcano Observatory:
Summit Observations:
Glow continued to be observed overnight from the north and west vents in Halema’uma’u. No glow was visible from the south vent, which was covered in a layer of tephra during episode 55. In the past, summit vents have re-established themselves over the course of days to weeks following similar tephra coverage. Slow movements from cooling lava flows and gravity induced slumps on the vents are expected to continue in the coming days and nights. Points of incandescence from the cooling lava flow in the crater were much reduced overnight.
Low-level seismic tremor with periodic seismic pulsing continues this morning, which is typical during inter-episode pauses. One earthquake was recorded in the summit area in the past 24 hours.
Inflationary tilt resumed immediately upon cessation of fountains and steady tilt continues this morning. The UWD tiltmeter has recovered at total of 7.1 microradians of inflationary tilt since the end of episode 55. Deflationary tilt measured at a summit tiltmeter at Uēkahuna (UWD) totaled 21 microradians during episode 55.
During inter-episode pauses, the sulfur dioxide (SO2) emission rate from the summit typically varies between 1,000 to 5,000 tonnes per day. Winds are forecast from the northeast, which are pushing the gas plume to the southwest over the Kaʻū Desert this morning.
Rift Zone Observations:
Rates of seismicity and ground deformation remain low in the East Rift Zone and Southwest Rift Zone. SO2 emissions from the East Rift Zone remain below the detection limit. No significant ground deformation was recorded in either rift zone.
Analysis:
Kīlauea has been erupting episodically between December 23, 2024, and August 25, 2026, from two vents (north and south) in Halema‘uma‘u at the summit. Lava fountaining episodes generally lasted for less than 12 hours and were separated by pauses of two or more weeks. The onset of episode 55 departed from the pattern established from previous episodes, with summit tiltmeters recording inflationary tilt indicating additional pressurization of the summit magma chamber beyond levels typically seen before fountaining. The prolonged period of inflationary tilt was not steady, being marked by extended periods of irregular deflationary tilt or no tilt. The episode was also preceded by 39 days of intermittent overflows, a record for the length of precursory activity prior to fountaining. During this prolonged interval, a series of short-lived vents opened within Halemaʻumaʻu and a shallow dike was emplaced beneath Kaluapele. More data is needed to make a forecast for episode 56, but the initial reinflation follows the normal, predictable pattern seen after most fountain episodes. However given the differences in episode 55, there is uncertainty in whether future episodes will return to the regular, predictable patterns that allowed them to be forecast with reasonable precision.
HVO continues to closely monitor Kīlauea and is in contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency about eruptive hazards. Kīlauea volcano alert level and aviation color code remain at ADVISORY/YELLOW.
