(BIVN) – The ongoing eruption at the summit of Kīlauea volcano remains paused, and another instance of deflation has delayed the anticipated next episode of high lava fountains.
Summit inflation paused around 9 p.m. Thursday last night, with minor deflation starting around midnight and continuing until Friday afternoon. Tilt appears to have since leveled off.
“South vent had intermittent glow last night, while north vent had strong persistent glow which weakened starting around 3 a.m. HST this morning,” the USGS Hawaiian Volcano Observatory stated in a Friday update. “These observations have pushed back the modeled forecast time window for episode 52 fountains to between July 26 and July 30.”
From the USGS HVO Friday update:
Degassing continues from both north and south vents .South vent had intermittent glow overnight, while north vent had strong persistent glow which weakened starting around 3 a.m. H.S.T. this morning.
Tremor last night was punctuated by more frequent drops in intensity followed by spikes in tremor typical of gas pistoning. The tremor spikes correlate with periods of brighter glow and occasionally flames from the south vent, presumably due to drainback events. One earthquake was located beneath the summit of Kīlauea summit in the past 24 hours.
Since episode 51 ended, inflation resumed and has recovered 12.0 microradians of tilt at the summit tiltmeter at Uēkahuna (UWD). After nearly two days of steady inflation, inflation paused around 9 p.m. H.S.T. last night, with deflation starting around midnight and continuing. Despite the deflation, in the last 24 hours UWD has recorded a net gain of 0.9 microradians. Kīlauea summit deflation totaled 14.7 microradians during episode 51.
The sulfur dioxide (SO2) emission rate from the summit is likely now varying within a typical range of 1,000 to 5,000 tonnes per day. Degassing plumes from both vents are being blown toward the southwest 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.
Analysis:
The abrupt switch from summit deflation to inflation at the end of episode 51 along with continued glow from the vents indicates that another fountaining episode is likely. Inflation since the end of episode 51 was relatively smooth without significant deflations until very early on Tuesday, July 21, when inflation paused and was flat for over a day. Inflation resumed Wednesday July 22 in the morning, and then paused last night (July 23), with minor deflation starting around midnight. As of this morning, inflation-based models have pushed the forecast window for the start of episode 52 fountains a day later to July 26 through July 30. Future periods of slow inflation or deflation may cause the forecast window to be adjusted.
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 that can be longer than three 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.
