UPDATE – (3 p.m.) – Episode 12 of the ongoing Kilauea summit eruption transitioned to continuous fountaining at 2 p.m HST, following a sluggish start on Tuesday morning.  

“Inflationary tilt reached just over 10 microradians since the end of the last episode; nearly balancing out the amount of deflationary tilt during episode 11,” the USGS Hawaiian Volcano Observatory reported. “Seismic tremor began increasing and tilt at UWD switched from inflation to deflation at 2:00 p.m. HST, at the same time fountaining began.” 

USGS: “Only weak vent activity was observed on the USGS Hawaiian Volcano Observatory monitoring helicopter overflight of Kīlauea summit at 8 a.m. HST on March 4, 2025. Weak effusive activity continued throughout the day until around 2 p.m., when fountaining started with more vigor, producing a larger flow across the crater floor.” (USGS photo by M. Patrick)

(BIVN) – The pause in the ongoing eruption at the summit of Kīlauea came to an end Tuesday morning, with the sluggish start of Episode 12. 

The USGS Hawaiian Volcano Observatory reported lava began erupting from the south vent within Halemaʻumaʻu crater at 7:30 a.m. HST on the morning of March 4. At the time, no lava was visible from the north vent. Episode 12 was underway. 

About 20 minutes later, scientists noted that lava continued to erupt from only the south vent. “Lava is highly degassed and overflowing the vent with very little fountaining,” the USGS HVO wrote. “High fountains should begin after degassed lava is pushed from the vent.” 

USGS webcam shows sluggish lava flows at the summit of Kīlauea

Shortly after the start of the previous Episode 11, lava fountains grew to heights of hundreds of feet within hours. This did not happen for Episode 12. 

Scientists noted Episode 4 of the eruption was also preceded by several hours of sluggish overflows prior to the onset of fountaining. 

Lava flows from the south vent ended by 8 a.m. HST. 

At 8:04 a.m., scientists noticed spattering within the north vent. Lava began erupting from the north vent at 9:33 a.m. HST. Sluggish lava overflows continued until 9:45 a.m. HST, the USGS HVO reported. 

Then, at 12:45 p.m. HST on March 4, lava began overflowing from the south vent. “Fountains remain very low and within the south cone,” the USGS HVO wrote. 

Scientists say they expect lava fountaining will start later today or tomorrow. 

“The Uēkahuna tiltmeter (UWD) has not yet switched from inflation to deflation but is expected to when fountains begin,” the USGS Hawaiian Volcano Observatory reported. “UWD has recorded just over 10 microradians of inflationary tilt since the end of episode 11. Seismic tremor has increased slightly, but not at levels associated with high fountains. No significant earthquakes were recorded in the summit region over the past 24 hours.” 

Activity remains confined to Halemaʻumaʻu crater. Rates of seismicity and ground deformation remain very low in the East Rift Zone and Southwest Rift Zone with no significant earthquake activity in the past 24 hours, the USGS HVO says.