(BIVN) – The ongoing eruption at the summit of Kīlauea remains paused, with the next lava fountaining episode likely to occur this week. 

The USGS Hawaiian Volcano Observatory says models now show Episode 31 is likely to start between August 18th and August 22nd, with Tuesday, August 19th to Thursday, August 21st the most likely window. The anticipated start of the episode has been pushed back due a decrease in the inflation rate. 

The Uēkahuna tiltmeter recorded about 22.5 microradians of deflationary tilt during the previous episode (Episode 30). Since the episode ended, the summit area has recovered just under 19 microradians of inflationary tilt. However, the rate of inflation “have slowed to less than 1 microradian a day which is slower than the normal inflation rate late in the repose period,” the USGS HVO wrote on Sunday. 

“Periods of no inflation or deflation, as seen prior to episode 30, cannot be forecast and will delay the onset of the next episode,” the scientists stated. 

USGS webcam shows the Kīlauea summit vents on Sunday morning

From the USGS HVO on Sunday:

Moderate to strong persistent glow was visible at both the north vent and the cracks above it overnight. There was no glow from the south vent or the southern fissure. Low to moderate continuous tremor and along with weak low-frequency tremor bursts have been observed over the past 5 days. The low-frequency tremor bursts are characteristic of gas-pistoning of magma. Variations in gas-piston events are consistent with long term variability of shallow seismicity between episodes. The onset and strengthening of glow within the north vent may indicate that magma is slowly getting closer to the surface. Images from an overflight on August 6th showed that episode 30 flows had covered nearly 80% the Halemaʻumaʻu crater floor, which now includes the old down dropped block.

Kīlaueaʻs East Rift Zone continues to contract, indicating no magma is entering that part of the system, the USGS noted.

The USGS Volcano Alert Level for Kīlauea remains at WATCH.