USGS Volcanoes: Notices released in the last day.

Slow eruption of lava continues. Minor seismicity was detected over the past day. Persistent cloud cover prevented clear satellite and web camera observations of the volcano. 

The current eruption began in July 2021 and, since then, lava flows have filled most of the summit crater and advanced into valleys below. There have been no explosions at Great Sitkin Volcano since an event in May 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data, webcams, and regional infrasound and lightning networks.

Occasional earthquakes continued over the past day. No activity was observed in clear to partly cloudy satellite views of the volcano.  

There is no real-time geophysical monitoring network at Mount Kupreanof. The closest functioning seismometers are approximately 17 miles (27 km) to the east of the volcano as part of the Mount Veniaminof network. Mount Kupreanof is also monitored by satellite data, remote infrasound and lightning networks, and visual observations from pilots and mariners passing by the volcano. 

Unrest continues. Minor seismic activity and infrasound were detected at the volcano. Satellite data from the past day showed typical sulfur dioxide emissions and web camera images showed a steam and gas plume from the summit.   

Local seismic and infrasound sensors, web cameras, and a geodetic network are used to monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lightning data, and satellite images to detect eruptions. 

Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN

Activity Update: All volcanoes monitored by CalVO show normal background earthquake activity and deformation. Monitored volcanoes include Mount Shasta, Medicine Lake Volcano, Lassen Volcanic Center, Clear Lake Volcanic Field, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.

Past Week Observations for June 01 (0000h PDT) to June 07 (2359h PDT):

Typical seismicity was recorded at The Geysers geothermal field south of the Clear Lake Volcanic Field; 125 earthquakes greater than M1 were recorded, with the largest having a magnitude of M2.3.

One earthquake greater than M1 was recorded at Mammoth Mountain, with a magnitude of M1.6.

Five earthquakes greater than M1 were recorded in the Sierra Nevada Block, south of Mammoth Mountain and Long Valley, with the largest having a magnitude of M3.4.

One earthquake greater than M1 was recorded in the Coso Volcanic Field, with a magnitude of M1.0.

Two earthquakes greater than M1 were recorded near the Salton Buttes, with the largest having a magnitude of M1.5.

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu remains paused following the end of episode 48 on June 1, 2026.  Glow was visible at both vents overnight and degassing plumes are visible in Halemaʻumaʻu during the day. Inflation of the summit as measured by tiltmeters slowed overnight and forecast models indicate that the onset of fountaining episode 49 is likely to occur between June 13-15.

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

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

Summit Observations:

Strong glow along with periodic large flames were observed in the south vent overnight. Continuous glow was also visible from the north vent, though weaker than the previous night. Lava was visible in the south vent during a helicopter overflight on Tuesday. Strong degassing plumes are visible rising from both vents in Halemaʻumaʻu during the day. 

Low level tremor related to the active vents continues to be recorded across summit seismometers. There were two small earthquakes less than M1.0 in the summit region in the past 24 hours.

Summit inflation recorded on the UWD tiltmeter slowed overnight, showing only 0.4 microradians of tilt increase and a total increase of 13.8 microradians since the end of episode 48. The UWD tiltmeter recorded a total of 17.1 microradians of deflationary tilt during episode 48.

During inter-episode pauses, sulfur dioxide (SO₂) emission rates from the summit typically vary between 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:

Continued repose period inflation, tremor, and glow from the vents all indicate that episode 49 is likely. The slowing of inflation across the summit of Kīlauea yesterday has pushed the forecast back slightly. Forecast models based on Kīlauea summit region inflation rates suggest that the start of fountaining episode 49 is most likely June 13-15. If slow inflation continues at the summit, it could push the forecast further back.

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 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. Lava fountains reached a maximum height of almost 650 ft (200 m) and lava flows covered 40% of the crater floor. 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.

Resources:

NOTE: Several summit stations, including the SDH tiltmeter, 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.

NORTHERN MARIANAS VOLCANOES
No definitive signs of unrest were detected at any Northern Mariana Island volcanoes during the past week.

Monitoring of Northern Mariana Islands Volcanoes

Northern Mariana Island volcanoes are monitored using seismo-acoustic sensors on Saipan, and by examining satellite imagery. We also use distant seismic stations in Guam and Chichijima, Japan, and hydroacoustic data from Wake Island, when available.

This level of monitoring can detect significant volcanic activity in the CNMI but cannot provide advanced warning of eruptions.

Due to a lack of geophysical monitoring on any of the volcanic islands, the following volcanoes have alert levels of UNASSIGNED: Anatahan, Sarigan, Farallon de Pajaros, Supply Reef, Maug, Asuncion, Agrigan, Pagan, Almagan, and Guguan.

Data feeds from seismic and acoustic sensors on the island of Saipan were restored in late May. These data streams had been unavailable due to infrastructure damage on Saipan following typhoon Sinaku in mid April. The USGS monitors these sensors as well as satellite images, distant hydroacoustic sensors and regional seismic sensors to detect significant volcanic activity in the CNMI. This level of monitoring can detect volcanic activity but cannot provide advance warning of eruptions.

Due to a lack of geophysical monitoring on any of the volcanic islands, the following volcanoes have alert levels of UNASSIGNED: Anatahan, Sarigan, Farallon de Pajaros, Supply Reef, Maug, Asuncion, Agrigan, Pagan, Almagan, and Guguan.