Episode 52 of Halemaʻumaʻu eruption at Kīlauea ends, marked by 500 foot fountain and 19,000 foot ash plume

Activity Summary:  

• Episode 52 of the ongoing Halemaʻumaʻu eruption began around 7:10 p.m. HST July 28 and ended abruptly at 2:36 a.m. HST on July 29, 2026. 
• The maximum lava fountain height was approximately 500 feet above ground level from the north vent. The south vent never fountained during this episode but did emit flames at the end of the eruption. 
• The maximum plume height was approximately 19,000 feet above mean sea level. 
• Tephra fall was restricted mostly to the closed area of Hawaiʻi Volcanoes National Park to the southwest of the active Halemaʻumaʻu vents.  

Lava fountaining episode 52 in Halemaʻumaʻu at the summit of Kīlauea began around 7:10 p.m. HST July 28 and ended at 2:36 a.m. HST on July 29, 2026, after 7.4 hours of continuous fountaining from the north vent, according to the USGS Hawaiian Volcano Observatory.

The last 4 minutes were marked by gas jetting and flames from the north vent. The south vent never fountained during this episode but did emit flames at the end of the episode, the HVO reports.

The instantaneous effusion rate peaked at about 350 cubic yards per second at approximately 9:15 p.m. HST, with an average effusion rate of 250 cubic yards per second for the entire fountaining episode, according to the HVO.

HVO scientists say an estimated 6.1 million cubic yards of lava erupted and covered about 40-50% of the Halemaʻumaʻu crater floor.

Seismicity followed the normal change in tremor patterns seen after most fountain episodes. The Uēkahuna tiltmeter recorded about 14.4 microradians of deflationary tilt during episode 52, according to the HVO.

Precursory activity began from the north vent on the morning of July 28 with six overflows between 10:22 a.m. and 1:53 p.m., the longest lasting over 30 minutes, the HVO reports.

“The north vent lava fountain reached a peak height of approximately 500 feet around 9:00 p.m. HST and produced significant heat and ash, feeding a plume cloud that reached a maximum height of about 19,000 feet above sea level based on radar data reported by the National Weather Service. The plume track largely remained within Hawaiʻi Volcanoes National Park with most tephra falling in the closed area,” according to the HVO.

Episode 52 ended abruptly at 2:36 a.m. on July 29. Fine ash was noted within public areas of Hawaiʻi Volcanoes National Park. No tephra was reported from any other populated areas. 

The abrupt switch from summit deflation to inflation at the end of episode 52 indicates that another lava fountaining episode is likely, according to the HVO.

More Information:

• Kīlauea webcam images: https://www.usgs.gov/volcanoes/kilauea/webcams
• Kīlauea photos/video: https://www.usgs.gov/volcanoes/kilauea/photo-and-video-chronology
• Kīlauea lava-flow maps: https://www.usgs.gov/volcanoes/kilauea/maps
• Kīlauea FAQs: https://www.usgs.gov/volcanoes/kilauea/faqs
• Meaning of volcano alert levels and aviation color codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes.