USGS Volcano Notice - DOI-USGS-HVO-2026-06-02T18:05:14+00:00

Overview:

Lava fountains of episode 48 occurred for 9 hours from 4:40 a.m. to 1:37 p.m. HST on June 1 from within Halemaʻumaʻu in the summit region of Kīlauea volcano. Lava fountains reached a maximum height of almost 650 ft (200 m) and lava flows covered 40% of the crater floor. Light to moderate tephra fall was reported within Hawaiʻi Volcanoes National Park, on Highway 11 near Nāmakanipaio campground, within Volcano village, Mauna Loa Estates, and Ohia Estates. Glow was still visible at the vents and on places on the crater floor overnight as the lava flow cools.

Inflation measured by tiltmeters around the summit of Kīlauea resumed after episode 48 ended, indicating that an episode 49 is likely. Several days of inflationary tilt data are needed for a forecast window.

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

Summary of episode 48:

A detailed account of episode 48 is given in the HVO Status Report Issued June 1: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-06-02T00:33:02+00:00

• Episode 48 of the ongoing Halemaʻumaʻu eruption began at the summit of Kīlauea at 4:40 a.m. HST and ended abruptly at 1:37 p.m. HST on June 1, 2026, after 9 hours of continuous lava fountaining from the north vent. The eruption is currently paused.
• The Halemaʻumaʻu eruption now has the most fountaining episodes ever recorded for an episodic fountaining eruption, edging out the Pu‘u‘ō‘ō eruption which had 47 fountain episodes. Other eruptions have had additional episodes related to changes in vent activity and location, this only applies to episodic fountains.
• Most tephra fell within the closed area of Hawaiʻi Volcanoes National Park, but sparse reticulite up to 1 inch (2 centimeters) in size fell at both the Uēkahuna overlook and on Highway 11 west of Nāmakanipaio campground. Fine ash and Peleʻs hair was reported from Hawaiʻi Volcanoes National Park in communities to the northeast, including Mauna Loa Estates, Ohia Estates, Volcano village, and Royal Hawaiian Estates.

Current Summit Observations:

After episode 48 ended, flames could still be seen sporadically from the vents, as well as continuous glow throughout the night. The crater remains very steamy due to heavy rain this morning. Lava flows on the floor of the crater continued to move through the night but had slowed dramatically by the early morning.  Areas of glow on the crater floor lava flows typically remain for several days after the end of an episode. 

Approximately 50 earthquakes were recorded along the south rim Halemaʻumaʻu in the southern part of Kaluapele (Kīlauea caldera). These started about an hour before episode 48 ended and continued until about 6 a.m. HST this morning, June 2. Most earthquakes were at a depth of less than 0.6 miles (1 km) and magnitude 2 or less.

Kīlauea summit deflation totaled 17.1 microrads during episode 48. Once the episode ended, inflation resumed and has since recovered 2.7 microrads of tilt at the summit tiltmeter at Uēkahuna (UWD). 

With the eruption now paused, 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. Measurements on Friday, May 22, indicated emission rates of about 2,000 tonnes per day. Winds are very light at the summit this morning and the plume is not well defined with all the steaming in the crater. There have been about 3.5 inches (8 cm) of rain since yesterday at the summit.

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 deflation to inflation continued at the end of episode 48 and indicates that an episode 49 is likely. Several more days of inflationary tilt data are needed to create a robust forecast window, but preliminary estimates suggest another fountaining episode is at least 10-15 days away.

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

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.