Summary of Episode 52

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE U.S. Geological Survey Wednesday, July 29, 2026, 9:10 AM

KILAUEA (VNUM #332010)

19°25’16” N 155°17’13” W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: ADVISORY Current Aviation Color Code: YELLOW

Summary: Kīlauea volcano is not erupting; the summit eruption in Halemaʻumaʻu is paused. Episode 52 ended at 2:36 p.m. HST on July 9. Reinflation indicates another episode is likely but more data are needed to determine the forecast.

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu is paused following 7.4 hours of lava fountaining during episode 52 on July 28-29, 2026. Inflationary tilt measured by tiltmeters around the summit of Kīlauea resumed after episode 52 ended accompanied by continued glow from both vents, suggesting that another episode is likely. More data are needed to determine the forecast.

No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

A summary of episode 52 is posted below.

NOTE: Significant changes in activity between Daily Updates are posted here: https://www.usgs.gov/observatories/hvo/observatory-messages

Summit Observations:

Bright glow and flames were visible overnight from both the north and south vents in Halema’uma’u. Shifting incandescent spots were visible overnight from lava flows that erupted onto the floor of Halema’uma’u crater and the slopes of the active vents during episode 52. Slow movements from cooling lava flows and gravity induced slumps on the vents are expected to continue in the coming days and nights. Winds are currently weak, and degassing plumes are rising vertically this morning.

Low-frequency seismic pulsing began with the cessation of episode 52 and continues this morning, which is typical during the onset of pauses between eruptive episodes. Eight shallow earthquakes, broadly dispersed within the summit, have been recorded since around the end of episode 52. The largest was a magnitude-2.2 at 2:22 a.m. this morning, beneath the eastern edge of Halemaʻumaʻu.

Deflationary tilt measured at a summit tiltmeter at Uēkahuna (UWD) totaled 14.4 microradians during episode 52. Since the episode ended, inflation resumed and the tiltmeter has recovered 1 microradian of ground tilt.

The sulfur dioxide (SO2) emission rate from the summit is likely now varying within a typical range of 1,000 to 5,000 tonnes per day.

Rift Zone Observations:

Rates of seismicity and ground deformation remain low in the East Rift Zone and Southwest Rift Zone. SO2 emissions from the East Rift Zone remain below the detection limit.

Analysis:

The abrupt switch from summit deflation to inflation at the end of episode 52 along with glow from the vents indicates that episode 53 fountaining is likely. More inflationary tilt data are needed to determine the forecast window.

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses that can be longer than three weeks.

HVO continues to closely monitor Kīlauea and is in contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency about eruptive hazards.

Please see the Hawaiʻi Volcanoes National Park website for visitor information: https://www.nps.gov/havo/index.htm

Summary of episode 52:

A detailed account of episode 52 is given in the HVO Status Report issued on July 29: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-29T13:10:51+00:00

*            Episode 52 of the ongoing Halemaʻumaʻu eruption began around 7:10 p.m. HST on July 28 and ended abruptly at 2:36 a.m. HST on July 29, 2026.

*            The maximum lava fountain height was approximately 500 feet (150 meters) 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 (5,800 meters) 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.