(BIVN) – Precursory lava overflows continue at the summit of Kīlauea, as the volcano slowly builds to its next eruptive episode.
Low-level activity was occurring at the vents within Halemaʻumaʻu on Wednesday morning. USGS webcams now have clear views of the summit, following several days obscured by rain and steam.
The rate of inflation has again slowed, and has been highly variable since Tuesday morning. The tilt appears stalled compared to its previous high rate. Summit reinflation has been very unsteady since lava fountaining episode 54 on August 25.
On Tuesday, the USGS Hawaiian Volcano Observatory said a forecast window of September 8th to 10th is likely for the start of episode 55 high lava fountaining.
UPDATE – (9:30 a.m.) – From the USGS HVO update on Wednesday:
Webcam views over the past several days have been mostly obscured by heavy rain, clouds, and steam from Hurricane Lowell passing west of the Hawaiian Islands but the summit is clearing this morning. Weak spattering from the north vent was first reported at 6:54 p.m. HST on September 6, with the first sluggish precursory overflow from the north vent starting at around 12:45 p.m. HST on September 7. Overflows from the north vent have continued intermittently since then, with a total of 29 so far, lasting from 15 minutes to about 2 hours long and separated by interludes of about 15 minutes to 8 hours. The most recent north vent overflow started at 7:27 a.m. HST this morning. Overflows have become progressively more vigorous and been fed by a dome fountain that reached 15-30 ft (5-10 m) tall. Two main lava flows have formed during these overflows with one making it about a half mile (1 kilometer) to the southwest of the north vent, and the other making it less than half a mile (1 kilometer) to the northeast of the north vent. Between overflows, glow was observed from the north vent in webcam imagery when it was not obscured by rain and steam. No overflows occurred from the south or west vents, but occasional glow and flames were noted from these vents overnight in webcam imagery
Tremor continues across the summit with regular intervals (about 5 minutes) of gas piston activity. In the absence of views from webcams into the vents during overflow activity, changes in tremor signal were used to time the duration of many of the overflows from the north vent. Two small earthquakes were recorded beneath the summit region over the past 24 hours.
Summit reinflation has been very unsteady since lava fountaining episode 54 on August 25. On September 7 around 3:00 p.m. HST, inflation at UWD reached a maximum that was higher than when episode 54 began, approximately 13.2 microradians. Following this inflationary high, UWD recorded around 1 microradian of deflation with the onset of precursory activity. Since then, there has been little change with slow inflation totaling 0.5 microradians. As of this morning, UWD remains at a similar amount of ground tilt it showed yesterday: approximately 12.3 out of the 12.7 microradians lost during episode 54.
During inter-episode pauses, the sulfur dioxide (SO2) emission rate from the summit typically varies between 1,000 and 5,000 tonnes per day. Trade winds have returned but continue to be weak this morning. The degassing plume is being pushed to the southwest of Kīlauea’s summit caldera. Continued trade winds today could blow volcanic gases as well as fine ash and Peleʻs hair to the southwest of Kaluapele if episode 55 begins.
