(BIVN) – Low-level eruptive activity continues at the summit of Kīlauea, where scientists say another episode of high lava fountaining remains a possibility.
The USGS Hawaiian Volcano Observatory reported on Monday that small overflows continue to occur at the north vent within Halemaʻumaʻu crater. All vents have strong glow and intermittent spatter.
“The summit tilt has remained relatively flat over the past 24 hours, and continuous tremor remains the dominant seismic signal across the summit,” the Observatory says.
Scientists say there is no anomalous activity outside of the summit.
From the USGS HVO on Monday morning:
Summit Observations:
Precursory overflows from the north vent resumed on Tuesday night, September 22, beginning at 10:10 p.m. HST. Since then, there have been 63 overflows, most of them from the north vent, although several small overflows occurred from the south vent yesterday. Most of the overflows have lasted about 5-35 minutes and produced lava flows that traveled a few hundred meters (yards) from the vent. Many of the overflows were fed by vigorous fountains that rise 15-30 feet (5-10 meters) above the small 30-50 foot (10-15 meter) cone that has built up at the north vent. The north, south, and west vents continued to glow strongly overnight, and emit flames and intermittent spatter. No other areas of incandescence were observed across the summit region last night.
Continuous tremor is the dominant seismic signal across the summit. There were nine small and shallow earthquakes located across the summit region in the past day. Four of these clustered around the “outlet” area at the south end of Kaluapele, the summit caldera.
Summit tilt has remained relatively flat over the past day, with no overall inflation or deflation. The current total inflation since the end of episode 54 is about 16.6 microradians, which is about 4 microradians greater than what was lost during episode 54 fountaining.
During inter-episode pauses, the sulfur dioxide (SO2) emission rate from the summit typically varies between 1,000 and 5,000 tonnes per day. Winds are currently forecast from the northeast.
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:
The north vent resumed precursory overflow activity on Tuesday night, September 22. In addition, the south vent produced several small overflows yesterday. The north, south, and west vents continued to glow, and emit flames and intermittent spatter overnight. Strong continuous tremor dominates the seismic signal within the summit. Forecast windows for this episode can no longer be modeled due to the irregular changes in inflation and deflation. Since reaching a peak inflation of 16.8 microradians (UWD tilt post episode 54) on Saturday, September 27, the summit deflated slightly yesterday and is currently at 16.6 microradians. Current eruptive activity is focused on the north vent, which has produced the last 11 high fountain events (episodes 44-54). However, it is not possible to say with certainty that this activity will lead to the onset of another fountain event at this time, although conditions remain favorable.
Because the summit system remains active and highly pressurized, the two most likely possibilities are that activity continues at the north-south-west vent complex, or it activates another existing weak crack system in the summit region. Neither of these events are likely to produce a strong seismic precursor, so the alert levels have been left at ORANGE/WATCH as the volcano continues to “exhibit heightened unrest with an increased potential for eruption”. For further details about potential scenarios see the September 15 Status Report.
Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses of two or more weeks.
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.
