USGS Volcano Notice - DOI-USGS-HVO-2026-07-16T19:01:34+00:00

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu is paused following 8.3 hours of lava fountaining during episode 51 on July15, 2026. Inflation measured by tiltmeters around the summit of Kīlauea resumed after episode 51 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 51 is posted below.

NOTE: The V1 camera is on a temporary assignment to watch an area that has displayed persistent subsidence after several fountain episodes. It will return to its "normal" job of keeping an eye on the north vent when the current assignment is completed.

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. Numerous bright, 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 51. Strong glow was visible from cracks and around the edges of these flows and from overturns and breakouts that exposed still-molten lava. Slow movements from cooling lava flows and gravity induced slumps on the vents are expected to continue in the coming days and nights. Degassing plumes from both vents are being blown toward the southwest this morning.

Low-frequency seismic pulsing began with the cessation of episode 51 and continues this morning, which is typical during the onset of pauses between eruptive episodes. There were two shallow earthquakes within Kaluapele (Kīlauea caldera) in the past 24 hours, the largest of which was a M2.0 beneath the southeast corner of Halemaʻumaʻu. 

Kīlauea summit deflation totaled 14.7 microradians during episode 51. Once the episode ended, inflation resumed and has since recovered 2.2 microradians of tilt at the summit tiltmeter at Uēkahuna (UWD).  

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 51 along with glow from the vents indicates that episode 52 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 51:

A detailed account of episode 51 is given in the HVO Status Report issued on July 15: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-16T03:55:25+00:00

• Episode 51 of the ongoing Halemaʻumaʻu eruption began around 8:30 a.m. HST on July 15 and ended abruptly at 4:46 p.m. HST on July 15, 2026.
• The maximum lava fountain height was approximately 950 feet (290 meters) above ground level from the north vent. The south vent never fountained during this episode but did emit flames and gas jets.
• The maximum plume height was approximately 18,000 (5,500 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. A light fall of Peleʻs hair was reported at several sites in the national park outside the closed area, including Uēkahuna overlook and Kaʻu Desert trailhead on Highway 11.

Resources:

NOTE: HVO’s monitoring network is mostly recovered from recent power- and storm-related outages. Several summit stations, including the SDH tiltmeter, will remain offline until we are able to re-establish access across the deep tephra field southwest of the caldera.

The following links provide more information about the current eruption that began on December 23, 2024:

• Eruption resources, including the most recent map and a timeline of eruption episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information
• Short messages tracking the evolution of the lava fountains and eruptive activity can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages
• Three Kīlauea summit livestream cameras that show eruptive lava fountains are available here: https://www.youtube.com/@usgs/streams
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams
• Volcano Watch article on gas pistons: https://www.usgs.gov/observatories/hvo/news/volcano-watch-so-what-earth-or-least-kilauea-a-gas-piston

Hazards:

This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park.

• Volcanic Gas: high levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are continually released during an eruption. Emissions can remain locally hazardous in the areas immediately downwind of the vents, even when the vents are not actively erupting. SO₂ reacts in the atmosphere to create vog (volcanic air pollution) downwind. SO₂ and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
• Tephra: small glassy volcanic fragments—volcanic ash, pumice, scoria, Pele’s hair and reticulite—are created by the lava fountains. A combination of fountaining dynamics and wind conditions determines where tephra fall may occur for any given eruption episode. Larger particles fall near the vents while light particles may be wafted greater distances. These particles may be remobilized during windy conditions following recent eruptive episodes. Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation. More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/
• Lava flows: lava on the floor of Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera, remains hot and may slowly move in the days immediately following an eruptive episode.

Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. Close to the eruptive vents, the tephra material on the crater rim is prone to cracking, slumping, and small landslides that sometimes expose hot and molten material within. This underscores the extremely hazardous nature of Kīlauea's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.