USGS Volcanoes: Notices released in the last day.

Minor earthquakes were detected over the past day, likely associated with rockfall on the growing dome. Clouds obscured visible satellite and webcam images, but a new satellite radar image confirms continued slow growth of the lava dome on the east-southeast side. 

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.

Low-level unrest continues with seismicity at low-levels. Clouds obscured satellite images.

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. 

Minor seismic signals were detected at the volcano. Steam emissions were seen in clear webcam images.

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. 

Activity Summary: 

• 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.

Episode 51 Chronology:

Lava fountaining episode 51 in Halemaʻumaʻu at the summit of Kīlauea began around 8:30 a.m. HST on July 15 and ended abruptly at 4:46 p.m. HST, after 8.3 hours of continuous fountaining from the north vent. The last 2-3 minutes were marked by gas jetting from the north vent. The south vent never fountained during this episode but did emit flames and gas jets. The instantaneous effusion rate peaked at about 370 cubic yards (280 cubic meters) per second at approximately 10:30 a.m. HST, with an average effusion rate of 200 cubic yards (150 cubic meters) per second for the entire fountaining episode. An estimated 6.6 million cubic yards (5.1 million cubic meters) of lava erupted and covered about 50% of the Halemaʻumaʻu crater floor. Seismicity followed the normal change in tremor patterns seen after most fountain episodes. There was one locatable earthquake associated with the eruption: a shallow magnitude-2 event at 14:52:59 HST located beneath the southeast corner of Halema'uma'u crater. The Uēkahuna tiltmeter (UWD) recorded about 14.7 microradians of deflationary tilt during episode 51.

Precursory activity began from the north vent on the afternoon of July 14 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 on July 15, and each lasted less than 5 minutes. 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 which continued until the onset of episode 51 fountaining around 8:30 a.m. HST. The transition was marked by increasing height of the dome fountain, greater eruptive volume, increased deflation and tremor.

The north vent lava fountain reached a peak height of approximately 950 feet (290 meters) around 10:30 a.m. HST and produced significant heat and ash, feeding a plume cloud that reached a maximum height of about 18,000 feet (5,500 meters) above sea level based on radar data reported by the National Weather Service (NWS) and verified by HVO webcam images. Winds were out of the northeast during the initial hours of fountaining and caused the plume to move toward the southwest during the most energetic part of the episode. High level winds from the south blew the upper plume toward the northwest after 10:00 a.m. HST. The NWS issued an updated Special Weather Statement (SWS) at 10:26 a.m. HST indicating that varying levels of ash, Pele`s hair, and other lightweight tephra may fall downwind of the eruption. The plume track largely remained within Hawaiʻi Volcanoes National Park with most tephra falling in the closed area.

Fountain and plume heights gradually decreased in height to about 400 feet (120 meters) AGL and 10,000 feet (3,000 meters) AMSL, respectively, by 4:40 p.m. HST. Then the episode ended abruptly at 4:46 p.m. HST. No tephra was reported from any populated areas.

The abrupt switch from summit deflation to inflation at the end of episode 51 indicate that another lava fountaining episode is likely.

Published Notices about episode 51: 

Volcano Activity Notice at end of episode 51: USGS Volcano Notice - DOI-USGS-HVO-2026-07-16T01:02:30+00:00

Volcano Activity Notice for maximum episode 51 fountain heights and reports of tephra fall in Hawai'i Volcanoes National Park: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-15T20:15:42+00:00

Hawaiʻi County Civil Defense Agency message alerting community to potential ash fall: https://evb.gg/n#ybjxxqeznxi/0lgoRWVn

HVO short messages posted to the HVO website and social media as episode 51 progressed: HVO - Observatory Messages | U.S. Geological Survey

Volcano Activity Notice when episode 51 began: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-15T01:41:41+00:00

Kilauea Daily Update for July 15 prior to the start of episode 51: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-15T15:48:14+00:00

Volcano Activity Notice issued on July 14 when precursory low-level eruptive activity before episode 51 began: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-15T01:00:23+00:00

Hazard Analysis: 

• Volcanic Gas: water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂) are continuously released during an eruption. SO₂ reacts in the atmosphere to create the visible haze known as vog (volcanic smog) downwind, which may cause respiratory and other problems. 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 the links below:
  • https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/  
  • https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf
• Lava flows: generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera. 
• 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 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.

Episode 51 of the ongoing Halemaʻumaʻu eruption ended abruptly at 4:46 p.m. HST on July 15 after 8.1 hours of continuous lava fountaining. The eruptive plume was under 10,000 feet (3,000 m) above sea level when fountaining ended. Tephra that was carried high into the air during fountaining may remain suspended in the atmosphere for some time and may continue to fall even after lava fountaining ended. Additional details on this eruptive episode will be provided in the next official report.

• All eruptive vents and lava flows are confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park. Tephra fall from volcanic ash clouds is greatest within 3 miles (5 km) of the vents, lighter ash and Pele's Hair may stay suspended for large distances from the vents.
• Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information 
• Three Kīlauea summit livestream videos are available here: https://www.youtube.com/@usgs/streams 
• Additional short updates shared during the episode can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages 

Episode 51 of lava fountaining in Halemaʻumaʻu began at the summit of Kīlauea began at 8:30 a.m. HST on July 15 and continues as of this notice. Fountain heights are at 950 feet (290 meters) and effusion rates have reached a peak of about 400 cubic yards per second (300 cubic meters per second) at 10:30 a.m. HST July 15.  

The National Weather Service reports that the plume from this eruption is reaching 18000 feet above sea level. Ground-level sensors near the eruptive vents indicate that light winds are blowing from the northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the southwest direction from Halemaʻumaʻu. At higher altitudes the plume is rising vertically at this time over an area just southwest of the vents. Most tephra fall currently remains within the closed area of Hawaiʻi Volcanoes National Park.  Very light fall of Peleʻs hair was reported from the Kaʻu Desert trail head along Highway 11. No tephra is currrently falling in the town of Pāhala or anywhere outside of Hawaiʻi Volcanoes National Park.

More details of the eruption are found in earlier USGS HVO reports:

Kīlauea Daily Update

Volcanic Activity Notice (VAN) at the start of episode 51

Short Messages on USGS HVO website and social media.

See the Hawaii County Civil Defense Agency message from July 15 to prepare your home by closing windows and disconnecting catchment if necessary.

The NWS has issued a Special Weather Statement regarding potential impacts from wind-blown tephra during episode 51

All eruptive vents and lava flows are confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park. Tephra fall from volcanic ash clouds is greatest within 3 miles (5 km) of the vents, lighter ash and Pele's Hair may stay suspended for large distances from the vents.

• Help support science and community awareness by reporting tephra fall: https://hawaiiash.science/report_form 
• Three Kīlauea summit livestream videos that show eruptive lava fountains are available here: https://youtube.com/@usgs/streams 
• KPcam and MKcam provide views of the plume height for aviation purposes
• Additional short updates as the episode progresses will be posted here: https://www.usgs.gov/observatories/hvo/observatory-messages 
• Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information 

Most lava fountaining episodes since December 23, 2024, have continued for a day or less.

Episode 51 of lava fountaining in Halemaʻumaʻu at the summit of Kīlauea began at 8:30 a.m. HST on July 15. Lava fountains are currently erupting from the north vent and reaching heights of about 160 ft (50 m) above ground level. Peak fountaining typically occurs 1-2 hours after onset. North vent fountains are feeding large lava flows onto the floor of Halema'uma'u crater. No fountains or flows are erupting from the south vent at this time. Precursory activity is summarized in the Kīlauea Update for Wednesday June 15.

Ground-level sensors near the eruptive vents indicate that winds are blowing 5-10 mph (2-5 m/s ) from the east-northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the west-southwest direction from Halemaʻumaʻu. Tephra including ash may be carried by the wind in the direction of communities in the Ka'u District including Pāhala and Nāʻālehu, and on Highway 11 southwest of Volcano. Higher level winds are from the south with the possibility of tephra being dispersed into communities adjacent to and north of Hawaiʻi Volcanoes National Park. See the Hawaii County Civil Defense Agency message from July 15 to prepare your home by closing windows and disconnecting catchment if necessary.

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.

• All eruptive vents and lava flows are confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park. Tephra fall from volcanic ash clouds is greatest within 3 miles (5 km) of the vents, lighter ash and Pele's Hair may stay suspended for large distances from the vents.
• Support science and community awareness by reporting tephra fall: https://hawaiiash.science/report_form 
• Three Kīlauea summit livestream videos that show eruptive lava fountains are available here: https://youtube.com/@usgs/streams 
• KPcam and MKcam provide views of the plume height for aviation purposes
• Additional short updates as the episode progresses will be posted here: https://www.usgs.gov/observatories/hvo/observatory-messages 
• Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information 

Most lava fountaining episodes since December 23, 2024, have continued for a day or less.

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.

Signs of unrest at Ahyi Seamount have been observed in recent satellite images over the past few weeks. Small plumes of discolored water were observed drifting less than 0.3 miles (0.5 km) away from the volcano in satellite images on July 1, 7, and 11. Small plumes have been observed intermittently in clear satellite images over the last few months, but recent images show more discrete plume shapes suggesting more vigorous activity. No significant activity has been detected from the direction of Ahyi Seamount in hydroacoustic array data at Wake Island. 

The plumes are likely the result of gas release into the water column, these could reflect vigorous hydrothermal degassing or be associated with an ongoing effusive eruption. In either case, the observations indicate increased volcanic unrest and potential for activity to breach the ocean surface.

Eruptive activity at Ahyi Seamount may present a hazard to mariners in the water above and near the volcano. The summit has shallowed over the course of previous eruptions to 180 feet (55 m) below sea level, but the lack of local real-time data means we are unable to forecast or warn of impending eruptions. The Aviation Color Code and Volcano Alert Level are being raised to YELLOW and ADVISORY. We will continue to monitor satellite and distal hydroacoustic data for additional evidence for, or escalation of, volcanic activity.