USGS Volcano Notice - DOI-USGS-HVO-2026-07-15T15:48:14+00:00

Overview:

The episodic Halemaʻumaʻu eruption at Kīlauea's summit resumed yesterday with precursory overflows from both vents. This followed a 4-day pause after the initiation of weak precursory spattering and a small overflow from the south vent on Saturday, July 11. Precursory overflows began from the north vent yesterday afternoon but then paused when inflation leveled off. Summit inflation resumed later in the evening and overflows from both vents resumed in the early morning hours. Currently a sustained overflow fed by a dome fountain continues from the north vent. Current observations suggest that lava fountaining episode 51 is most likely to start today, July 15 or possibly Thursday, July 16 if slowed by summit deflation.

The National Weather Service (NWS) this morning reports low level winds from the east-northeast that would move the plume to the southwest towards Pāhala, and high level winds from the south that would move the higher plume over communities adjacent to Hawaiʻi Volcanoes National Park. The NWS has issued a Special Weather Statement regarding potential impacts from wind-blown tephra during episode 51: https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=HFO&wwa=special%20weather%20statement.

The Hawaii County Civil Defense Agency has issued a message regarding potential impacts from episode 51:  https://evb.gg/n#gpyyywtp2io/0lh9DoNe. 

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

A summary of lava fountaining episode 50 is posted below.

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

Summit Observations:

Precursory activity began from the north vent yesterday afternoon with 4 overflows between 3 and 4 p.m. HST, the longest lasting over 30 minutes. Activity then paused when inflation leveled off. Summit inflation resumed later in the evening. Overflows began from the south vent at 2:08 and 2:32 a.m. HST that lasted less than 5 minutes each. After a brief pause, short overflows from the north vent occurred at 4:27 and 4:42 a.m. HST. These were immediately followed by the onset of a vigorous overflow fed by 10-30 foot (3-10 meter) high dome fountains from the north vent at 4:47 a.m. HST that continues at this time.   

Steady, low-level seismic tremor yesterday was replaced by sharp tremor spikes at about 5:30 p.m. HST that continued until just before 3:00 a.m. HST this morning. These occurred roughly every 10 minutes and were correlated with bright glow from the south vent, presumably due to drainback events related to gas pistoning in the vent. After 3 a.m. HST, steady low level tremor returned and continues at this time.

Earthquake activity picked up significantly just before noon yesterday beneath Halemaʻumaʻu and the southern caldera region. There have been 34 locatable earthquakes (and many smaller earthquakes) since then, mostly less than magnitude 1. Activity dropped off just after midnight.

Kīlauea summit has recorded about 16.7 microradians of inflationary tilt since the end of episode 50, exceeding the target inflation of 15.3 microradians lost during episode 50. Tilt has increased in a stair stepped fashion since recovering from the long deflationary trend that began on Saturday morning, July 11. Tilt has been relatively flat since the transition from gas pistoning to steady tremor at 3 a.m. this morning. 

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:

Inflation has exceed the target value by over 1 microradian and inflation based forecast models are no longer valid.  Based on observational data, episode 51 is most likely to begin today from the current long overflow or possibly tomorrow, July 16, if another deflation occurs.

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 50:

A detailed account of episode 50 is given in the HVO Status Report issued on June 27: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-06-28T04:29:55+00:00

• Episode 50 of the ongoing Halemaʻumaʻu eruption at the summit of Kīlauea ended abruptly at 5:10 p.m. HST on June 27, 2026, after 7 hours of continuous lava fountaining from the north vent. The eruption is currently paused.

• 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 from the town of Pāhala in Kaʻū.

   

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.