(BIVN) – Low-level, precursory lava activity continued at the summit of Kīlauea over the past day.
Small lava overflows have been occurring from both the north and south vents within Halemaʻumaʻu. Scientists continue to say it is not possible to forecast the onset of episode 55 fountains or if they will occur.
There is no anomalous activity outside of the summit, the USGS Hawaiian Volcano Observatory says.
A weekly Volcanic Activity Notice was issued Tuesday, as required by the International Civil Aviation Organization for all volcanoes in ORANGE alert status. The Notice did not represent a change in activity.
From the USGS HVO on Tuesday:
Summit Observations:
Precursory overflows from the north vent resumed on September 22, beginning at 10:10 p.m. HST, after about 10 days of quiescence at the vent complex. Overflow activity from the south vent began on September 27, however, the north remained dominant until last night when short, rapid cycles of overflows and lava drainback began at 7:44 p.m. HST. The overflows have lasted about 2-5 minutes, with most pauses between each cycle lasting about 5-7 minutes. There have now been 165 overflows since September 22, and about 80 of those occurred during these rapid cycles. The north and south 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 14 small and shallow earthquakes located across the summit region in the past day, but they did not form clusters in time or location.
Summit tilt has been variable over the past day, with overall inflation of about 0.3 microradians. The current total inflation since the end of episode 54 is about 16.8 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 east.
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 September 22. Overflows from the south vent began on September 27, and there have been over 80 short cycles of south vent overflows and lava draining back into the vent since last night at 7:44 p.m. HST. The north and south 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 about 17 microradians (UWD tilt post episode 54) overnight, the summit deflated slightly and is currently at 16.8 microradians. Current overflow activity is focused on the south vent since last night. The north vent has produced the last 11 high fountain events (episodes 44-54). 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.
