USGS Volcanoes: Notices released in the last day.

Slow eruption of lava within the summit crater continues. Minor earthquakes were detected during the past 24 hours. Slightly elevated surface temperatures from the slowly growing lava dome were observed in satellite data over the past day. Web camera observations were obscured by clouds.

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.

Earthquake activity continues at a variable rate. A newly installed web camera located southwest of the summit showed steam emissions, which have been common during this period of unrest. No activity observed in satellite data.

While a new temporary monitoring station was installed in the last week near Mount Kupreanof, data are not yet available in real-time. The closest functioning seismometers are approximately 10 miles (16 km) to the northeast 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 activity and infrasound were detected at the volcano during the past day. Steam emissions were observed in satellite and web camera images over the past day, and produced a visible plume towards the south. The plume was longer than what has been observed recently, but it does not indicate a significant change in unrest. Typical sulfur dioxide gas emissions were observed in satellite data from yesterday afternoon. 

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. 

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu is paused following 7.4 hours of lava fountaining during episode 52 on July 28-29, 2026. Inflationary tilt measured by tiltmeters around the summit of Kīlauea resumed after episode 52 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 52 is posted below.

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. 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 52. Slow movements from cooling lava flows and gravity induced slumps on the vents are expected to continue in the coming days and nights. Winds are currently weak, and degassing plumes are rising vertically this morning.

Low-frequency seismic pulsing began with the cessation of episode 52 and continues this morning, which is typical during the onset of pauses between eruptive episodes. Eight shallow earthquakes, broadly dispersed within the summit, have been recorded since around the end of episode 52. The largest was a magnitude-2.2 at 2:22 a.m. this morning, beneath the eastern edge of Halemaʻumaʻu. 

Deflationary tilt measured at a summit tiltmeter at Uēkahuna (UWD) totaled 14.4 microradians during episode 52. Since the episode ended, inflation resumed and the tiltmeter has recovered 1 microradian of ground tilt.  

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 52 along with glow from the vents indicates that episode 53 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 52:

A detailed account of episode 52 is given in the HVO Status Report issued on July 29: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-07-29T13:10:51+00:00

• Episode 52 of the ongoing Halemaʻumaʻu eruption began around 7:10 p.m. HST on July 28 and ended abruptly at 2:36 a.m. HST on July 29, 2026.
• The maximum lava fountain height was approximately 500 feet (150 meters) above ground level from the north vent. The south vent never fountained during this episode but did emit flames at the end of the eruption. 
• The maximum plume height was approximately 19,000 (5,800 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.  

   

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.

Activity Summary:  

• Episode 52 of the ongoing Halemaʻumaʻu eruption began around 7:10 p.m. HST July 28 and ended abruptly at 2:36 a.m. HST on July 29, 2026. 
• The maximum lava fountain height was approximately 500 feet (150 meters) above ground level from the north vent. The south vent never fountained during this episode but did emit flames at the end of the eruption. 
• The maximum plume height was approximately 19,000 (5,800 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.  

Episode 52 Chronology: 

Lava fountaining episode 52 in Halemaʻumaʻu at the summit of Kīlauea began around 7:10 p.m. HST July 28 and ended at 2:36 a.m. HST on July 29, 2026, after 7.4 hours of continuous fountaining from the north vent. The last 4 minutes were marked by gas jetting and flames from the north vent. The south vent never fountained during this episode but did emit flames at the end of the episode. The instantaneous effusion rate peaked at about 350 cubic yards (270 cubic meters) per second at approximately 9:15 p.m. HST, with an average effusion rate of 250 cubic yards (190 cubic meters) per second for the entire fountaining episode. An estimated 6.1 million cubic yards (4.7 million cubic meters) of lava erupted and covered about 40-50% of the Halemaʻumaʻu crater floor. Seismicity followed the normal change in tremor patterns seen after most fountain episodes. The Uēkahuna tiltmeter (UWD) recorded about 14.4 microradians of deflationary tilt during episode 52. 

Precursory activity began from the north vent on the morning of July 28 with 6 overflows between 10:22 a.m. HST and 1:53 p.m. HST, the longest lasting over 30 minutes. 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 1:56 p.m. HST which continued until the onset of episode 52 fountaining at 7:10 p.m. HST. The transition was marked by increasing height of the dome fountain, greater eruptive volume, increased deflation and rapidly increasing tremor. 

The north vent lava fountain reached a peak height of approximately 500 feet (150 meters) around 9:00 p.m. HST and produced significant heat and ash, feeding a plume cloud that reached a maximum height of about 19,000 feet (5,600 meters) above sea level based on radar data reported by the National Weather Service (NWS). Winds were out of the northeast during the initial hours of fountaining and caused the plume to move toward the south during the most energetic part of the episode. Later in the evening the lower level winds died and the plume became more vertical but did not spread over populated areas. 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 11:00 p.m. HST July 28. Episode 52 ended abruptly at 2:36 p.m. HST on July 29. Fine ash was noted within public areas of Hawaiʻi Volcanoes National Park. No tephra was reported from any other populated areas. 

The abrupt switch from summit deflation to inflation at the end of episode 52 indicates that another lava fountaining episode is likely. 

Published Notices about episode 52:  

Volcano Activity Notice at end of episode 52:  USGS Volcano Notice - DOI-USGS-HVO-2026-07-29T10:09:27+00:00 

Volcano Activity Notice for maximum episode 52 fountain heights: USGS Volcano Notice - DOI-USGS-HVO-2026-07-29T06:14:51+00:00 

Hawaiʻi County Civil Defense Agency message alerting community to potential ash fall: https://evb.gg/n#wshhhoz1s6h/0llV46JE 

HVO short messages posted to the HVO website and social media as episode 52 progressed: HVO - Observatory Messages | U.S. Geological Survey 

Volcano Activity Notice when episode 52 began: USGS Volcano Notice - DOI-USGS-HVO-2026-07-28T22:59:42+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 52 of the ongoing Halemaʻumaʻu eruption ended abruptly at 2:36 a.m. HST on July 29 after 7.5 hours of continuous lava fountaining. Additional details on this eruptive episode will be provided in the next official report.

• All eruptive vents and lava flows were confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park. A light dusting of fine ash fell along the northern rim of Kaluapele within Hawai'i Volcanoes National Park. Light ash and Pele's Hair may stay suspended for a short time after the eruption ends
• 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 52 of lava fountaining in Halemaʻumaʻu began at the summit of Kīlauea began at 7:10 p.m. HST on July 28, 2026 and continues as of this notice. Fountains are close to peak height of about 500 feet (150 meters) at 9:15 p.m. HST. Effusion rate is also peaking at 350 cubic yards per second (270 cubic meters per second).  

The National Weather Service radar shows the maximum plume height reached 19,000 feet AMSL (above mean sea level) and is currently at about 16,000 feet AMSL. Winds are still below the inversion and the plume is currently rising vertically.  Currently no tephra is falling on the overlooks closest to the Halema'uma'u vents, but it is possible they will experience light fall of ash and Pele's hair later in the eruption.  Above 10,000 feet AMSL, winds are weak buand out of the north. Satellite images indicate that volcanic gas is moving southward from the vent area at high altitudes. Most higher tephra can be expected to fall south of the Halema'uma'u vents within the closed areas of Hawai'i Volcanoes National Park. 

• 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 52 of lava fountaining in Halemaʻumaʻu began at the summit of Kīlauea began at 7:10 p.m. HST on July 28, 2026 with 100 foot (30 meter) fountains. This followed precursory spattering from both vents that began on the night of July 27. Initial precursory overflows began at 10:22 a.m. HST from the north vent. After 6 precursory flows lasting 10-30 minutes, continuous overflows began from the north vent at 1:56 p.m. HST and continued until they transitioned into the start of episode 52 fountains.

Ground-level sensors near the eruptive vents indicate that winds are currently light from the north to northeast. Wind forecast models indicate that similar winds continue up to about 20,000 feet AMSL. Wind directions indicate that much if not all of the tephra fall and volcanic gas emissions will occur within Hawai'i Volcanoes National Park, mainly south of the Halema'uma'u vents.

• 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.

Precursory low-level activity for episode 52 of the ongoing Halemaʻumaʻu eruption at the summit of Kīlauea began around 10:22 a.m. HST on July 28 with an overflow from the north vent. Accordingly, HVO is raising the Alert Level for Kīlauea from ADVISORY to WATCH and the Aviation Color Code from YELLOW to ORANGE. Alert level and aviation color code definitions: https://www.usgs.gov/programs/VHP/alert-level-system. This low-level precursory activity can continue for hours to days before the lava fountaining episode beings. The forecast for episode 52 of lava fountaining to start is between today and July 30. Low level winds are out of the north to northeast at the summit today, with the possibility of tephra and ash being carried in the direction of Pāhala and Nāʻālehu. Higher level winds are variable from the north to northwest, with the possibility of tephra being dispersed into Hawaiʻi Volcanoes National Park. Another VAN will be published when lava fountaining episode 52 begins.

• 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.