USGS photo by K. Lynn

Kīlauea Volcano Update for Monday, September 21

Big Island Video News

Sep 21, 2026

STORY SUMMARY

HAWAIʻI VOLCANOES NATIONAL PARK - Scientists say resumed activity is possible in a few days, as the summit could return to the peak pressurization.

(BIVN) – The ongoing eruption at the summit of Kīlauea remains paused, with a potential resumption of activity in a few days, if the volcano reaches peak pressurization. 

“The system is within 1-2 days at the current rate of inflation of reaching the maximum inflation of 16 microradians of tilt recovered since episode 54 fountaining ended,” reported the USGS Hawaiian Volcano Observatory. “When this peak pressurization is reached, it is possible that activity will resume at the north-south-west vent complex, or reactivate the vent 1-6 system, or intrude another weak area in the summit region.” 

“None of these events are likely to produce a strong seismic precursor,” the Observatory stated, as it kept the Volcano Alert Level at WATCH and the Aviation Color Code at ORANGE. 

Overnight, glow with intermittent spatter was visible at the north, south and west vents in the existing complex within Halemaʻumaʻu crater. There is no anomalous activity outside of the summit, scientists reported. 

“Over the past 24 hours strong tremor has become continuous and continues to be the dominant seismic signal across the summit,” the Observatory reported. 

USGS webcam view of the new, inactive vents on Monday

From the USGS HVO on Monday morning:

Analysis

The north, south, and west vents continued to glow and sporadically emit flames, with minor intermittent spatter from the north vent last night. 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 microradians (UWD tilt post episode 54) on Wednesday September 16, the summit deflated about 2.3 microradians as the new lava flows from vents 1-6 ceased. Slow inflation (recorded on the UWD tiltmeter) started Thursday September 17 and has since recovered about 1.9 of the 2.3 microradians lost to the deflation event.

The system is within 1-2 days at current inflation rates of returning to the peak pressurization that resulted in the opening of vents 1-6 with no seismic precursors. If inflation rates change or deflation occurs, this could change. Because the summit system remains active, the three most likely possibilities are that activity resumes at the north-south-west vent complex, or reactivates the vent 1-6 system, or intrudes another existing weak crack system in the summit region. None 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”.

About The Featured Image

USGS: "Glow and flames were observed in Kīlauea summit webcam imagery overnight, with occasional spatter, but only incandescence was visible within the vent during a USGS Hawaiian Volcano Observatory monitoring overflight the afternoon of September 18, 2026." (USGS photo by K. Lynn)


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