(BIVN) – Episode 20 in the ongoing eruption of Kīlauea paused on Tuesday night, after 4.5 hours of sustained lava fountaining from the vents in Halemaʻmaʻu. 

After 31 hours of precursory low-level activity at the summit, sustained lava fountains began at 5:28 p.m. HST early Tuesday evening. 

“The onset of sustained fountaining was accompanied by a rapid change in summit tilt from inflation to deflation along with a rapid increase in tremor,” the USGS Hawaiian Volcano Observatory reported. “The Uēkahuna tiltmeter (UWD) recorded approximately 8 microradians of inflationary tilt between the end of episode 19 and the beginning of episode 20 sustained fountaining.” 

USGS webcam view of the sustained lava fountains during Episode 20, just aftersunset.

“Fountains from the north vent quickly reached heights of greater than 500 ft (150 m),” the USGS HVO noted. “North vent lava fountains are feeding fast moving lava flows that are covering the floor of Halemaʻumaʻu crater, including a flow that poured over the south vent.” 

Scientists calculated that average eruption rate over the first 30 minutes of sustained fountaining has been estimated to be about 7,000 cubic feet per second (200 cubic meters per second). 

The south vent began generating lava fountains a short time later, reaching heights of up to about 65 feet (20 meters). Scientists estimated that lava flows from Episode 20 covered less than half of the Halemaʻumʻau crater floor. 

USGS webcam view of the end of Episode 20.

Episode 20 then ended at 9:58 p.m. HST. 

“The end of episode 20 fountaining activity was accompanied by a rapid change in summit tilt from deflation to inflation, along with a rapid decrease in tremor,” the USGS HVO said. “The Uēkahuna tiltmeter (UWD) recorded approximately 6 microradians of deflationary tilt between the start and end of episode 20 fountaining.” 

The ongoing eruption at the summit of Kīlauea is now paused. the USGS Volcano Alert Level remains at WATCH.