USGS HVO Volcanic Activity Notice — Eruption at Kīlauea Volcano summit

HVO/USGS Volcanic Activity Notice 

Volcanic Activity Summary: 

Shortly after approximately 9:30 p.m. HST, the USGS Hawaiian Volcano Observatory (HVO) detected glow within Halemaʻumaʻu crater at the summit of Kīlauea Volcano. An eruption has commenced within Kīlauea’s summit caldera. The situation is rapidly evolving and HVO will issue another statement when more information is available.  

Accordingly, HVO has elevated Kīlauea’s volcano alert level to WARNING and its aviation color code to RED. 

Alert levels and aviation color codes are explained here: https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels…;

HVO continues to monitor the volcano closely and will report any significant changes. 

Stay informed about Kīlauea by following volcano updates and tracking current monitoring data on the HVO web page (https://www.usgs.gov/volcanoes/kilauea/volcano-updates) or by signing up to receive updates by email at this site: https://volcanoes.usgs.gov/vns2/. 

HVO is in communication with Hawai‘i Volcanoes National Park as this situation, which is taking place within the park, evolves. 

HVO is in contact with the County of Hawai‘i Civil Defense Agency.  

Recent Observations:  

For the past several weeks, the USGS Hawaiian Volcano Observatory (HVO) has recorded ground deformation and earthquake rates at Kīlauea Volcano’s summit and upper East Rift Zone that have exceeded background levels observed since the conclusion of the 2018 lower East Rift Zone eruption and summit collapse.  

Beginning in September 2020, increased rates of uplift were observed by GPS stations in Kīlauea’s upper East Rift Zone. In the past month, increased uplift has also been measured at GPS stations in Kīlauea’s summit region. While uplift related to post-collapse inflation of the summit reservoir has been occurring since March of 2019, rates have been steadily increasing in recent months and are currently higher than they have been since the end of the 2018 eruption.  

In late November 2020, increased earthquake rates began when seismic stations recorded an average of at least 480 shallow, small-magnitude earthquakes (97% of which were less than or equal to magnitude-2) per week occurring at depths of less than 4 km (2.5 miles) beneath Kīlauea's summit and upper East Rift Zone. This compares to a rate of fewer than 180 per week following the end of Kīlauea’s 2018 eruption and through early November 2020. 

On December 2, 2020, GPS stations and tiltmeters recorded a ground deformation event at Kīlauea’s summit. Accompanied by earthquake swarms, the patterns of ground deformation observed were consistent with a small dike intrusion of magma under the southern part of Kīlauea caldera. The injection resulted in about 8 cm (3 inches) of uplift of the caldera floor, and modeling suggests that it represented 0.4–0.7 million cubic meters (yards) of magma accumulated approximately 1.5 km (1 mile) beneath the surface. Though the intrusion did not reach the surface and erupt, it represented a notable excursion from trends observed in Kīlauea summit monitoring data streams following the end of the 2018 eruption.  

On December 17, 2020, seismometers detected a notable increase in occurrence and duration of long-period seismic signals beneath Kīlauea’s summit, which are attributed to magmatic activity. Whereas this type of seismicity was observed on average once every few weeks following the 2018 eruption, rates have increased to over a dozen in the past several days.  

Other monitoring data streams including volcanic gas and webcam imagery were stable until this eruption.  

An earthquake swarm began on the evening of December 20, accompanied by ground deformation detected by tiltmeters. An orange glow was subsequently observed on IR monitoring cameras and visually beginning approximately 21:36 HST. 

Hazard Analysis: 

[General hazards]  

HVO is currently assessing the hazards associated with this eruption and will provide updates as information becomes known.   

At the present time, no explosions have been detected. 

For discussion of Kīlauea hazards, please see:  

https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards and 

https://www.usgs.gov/volcanoes/kilauea/frequently-asked-questions-about-k-lauea-volcanos-summit-water 

Remarks:  

Background 

Since the early 1800s, when written records of Hawaiian volcanoes began, Kīlauea has had infrequent periods during which no lava erupted.  

The longest known eruptive pause was in 1935-1952, ending with eruption in the caldera. Neither that 17-year pause, nor any other shorter pause, followed partial collapse of the caldera such as the collapse that occurred in the summer of 2018.  

Following partial caldera collapses, the first eruption outside the caldera took place on the East Rift Zone 17 years after the 1823 collapse, on the Southwest Rift Zone 28 years after the 1840 collapse, and on the Southwest Rift Zone 52 years after the 1868 collapse.  

After partial caldera collapses in 1840 and 1868, lava returned to the caldera within days to a few weeks. The length of the current pause exceeds those earlier post-collapse pauses. 
 
Kīlauea Volcano has maintained a low level of non-eruptive unrest since the end of the 2018 lower East Rift Zone eruption and summit collapse, which deepened Halemaʻumaʻu crater by over 500 meters (1640 feet). Following the 2018 eruption, ground deformation rates have indicated steady inflation of Kīlauea’s summit and at the end of 2018, the HVO monitoring network detected Deflation-Inflation events (DI-events) indicative that the shallow Halemaʻumaʻu magma reservoir, located approximately 1.6 km (1 mile) under Kīlauea caldera, still contained significant amounts of magma.  

In late July 2019, ponded water appeared at the base of the deepest collapsed area of Kīlauea’s summit, within the Halemaʻumaʻu crater. Since then, the body of water has grown into a lake, which continues to rise as it seeks equilibrium with the surrounding groundwater. 

Prognosis 

All communities on or near Kīlauea’s summit and rift zones should be prepared. 

HVO continues to monitor the volcano closely and will report any significant changes. HVO is in close touch with National Park Service and Hawaii County Civil Defense and other agencies responsible for public safety. 

Stay informed about Kīlauea by following volcano updates and tracking current monitoring data on the HVO web page (https://www.usgs.gov/volcanoes/kilauea/volcano-updates) or by signing up to receive updates by email at this site: https://volcanoes.usgs.gov/vns2/. 

The County of Hawai‘i Civil Defense Agency is in constant communications with HVO. If anything develops that may affect your safety, you will be informed.  Please sign up for Civil Defense notifications by visiting the County of Hawai‘i Civil Defense Agency webpage at http://www.hawaiicounty.gov/civil-defense/. 

Contacts: askHVO@usgs.gov 

Next Notice:  Kīlauea updates will be issued weekly on Tuesdays. Should volcanic activity change significantly a new VAN will be issued. Regularly scheduled updates are posted at https://www.usgs.gov/hvo 

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi.