UPDATE: Episode 29 of the Halemaʻumaʻu eruption abruptly ends after 13 hours

Update at 10 p.m. Sunday, July 20: Episode 29 of the ongoing Halemaʻumaʻu eruption ended abruptly around 6:35 p.m. on Sunday after over 13 hours of continuous lava fountaining.

The north vent stopped erupting around 6:35 p.m., marking the end of the episode; the weakly-active south vent had stopped erupting several hours earlier.

Lava fountains did not exceed 330 feet during this episode, as most lava was sprayed laterally within Halemaʻumaʻu crater. An estimated 1.8 billion gallons of lava erupted during the episode, covering approximately 80% of the crater floor.

Visitors to Hawaiʻi Volcanoes National Park can expect the spatter deposits and lava flows from this episode to exhibit slow movement and incandescence within the southern part of Kaluapele as they cool and solidify over the coming days.

Volcanic gas emissions have greatly decreased since fountaining stopped, and the sulfur dioxide emission rate will likely range from 1,200–1,500 tons per day during the new eruptive pause.

The Uēkahuna tiltmeter recorded approximately 18.5 microradians of deflationary tilt during this episode. The end of the episode was coincident with a rapid change from deflation to inflation at the summit and a decrease in seismic tremor intensity.  

Original story at 12 p.m. on Sunday, July 20: Dome fountains and lava overflows can be observed as Episode 29 of the ongoing Halemaʻumaʻu eruption continues from early Sunday morning.

Precursory low-level activity for Episode 29 of the ongoing Halemaʻumaʻu eruption began around 3:55 a.m. Sunday, July 20, with spattering at the north vent, followed shortly after by dome fountains and lava overflows starting around 4:11 a.m.

According to the National Weather Service, winds are forecast to blow from the north to northeast today, which suggests that volcanic gas emissions and volcanic material may be distributed to the south and southwest.

In previous episodes, low-level precursory activity—eruptive vent spattering, small dome fountains, and lava overflow—has lasted from a few hours to a few days. Due to the heightened level of pressurization reached during the most recent eruptive pause, precursory activity for Episode 29 may be brief, and sustained high lava fountaining may begin soon.

At the start of previous episodes, precursory activity has rapidly escalated into sustained high fountaining over minutes to tens of minutes. During previous episodes, fountains reached heights of more than 1,000 feet and the eruptive plume reached heights of up to 20,000 feet above ground level soon after sustained high fountaining began.

The Uēkahuna tiltmeter at the summit has recorded approximately 17.8 microradians of inflationary tilt since the end of the last episode, during which it recorded 15 microradians of deflationary tilt. Low-level seismic tremor continues beneath the Halemaʻumaʻu crater.

All eruptive activity is confined to the Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park, and airports in Hawaiʻi County will not be affected by the activity.

Three Kīlauea livestream videos can be watched on the U.S. Geological Survey Youtube account.

Most episodes of Halemaʻumaʻu lava fountaining since Dec. 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting at least several days. A timeline of eruptive episodes is available online.

No changes have been detected in the East Rift Zone or Southwest Rift Zone. Another notification will be issued when sustained high lava fountaining begins, marking the start of Episode 29, or earlier if an update is needed.