USGS Volcano Notice - DOI-USGS-HVO-2024-07-25T02:17:22+00:00

SUMMARY OF ACTIVITY 

An abrupt increase in seismicity accompanied by local deformation on July 22 at 11 a.m. HST marked the initial stage of magma intruding underground in the upper East Rift Zone (UERZ) of Kīlauea.  This activity is concentrated between Pauahi Crater and Maunaulu along Chain of Craters Road in Hawaiʻi Volcanoes National Park.    

A stronger pulse of seismicity and local deformation began on July 23 at 3:30 a.m. HST and was coincident with deflation of Kīlauea summit.  The summit has been steadily deflating since then as magma moves into the vertical, sheet-like body (dike) beneath the UERZ near Pauahi Crater.   

A third pulse of activity began today on July 24 at 10 a.m. HST as dike emplacement continues.  Each pulse lasted approximately 2–3 hours, but seismicity and deformation continued at levels well above normal between the pulses.   

In total, there have been nearly 1,000 earthquakes located in the UERZ of Kīlauea over the past 3 days; 250 of those earthquakes exceeded magnitude-2 and the largest event was a magnitude-3.6. Earthquakes have remained 1–3 km (0.6–1.8 miles) beneath the surface. As of 4:30 p.m. on July 24, the dike continues to grow, and unrest may continue to wax and wane with changes to the input of magma into the area. An eruption is not currently imminent, but conditions could change rapidly.  

Unrest has been restricted to UERZ; no unusual activity has been noted along Kīlauea’s middle and lower East Rift Zones or the Southwest Rift Zone. The USGS Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea for changes.  

INTERPRETATION 

The rapid onset and concentrated intensity of the July 22–24 UERZ swarm, coupled with abrupt changes in UERZ ground deformation patterns, show that an intrusion of magma is occurring in the area of Pauahi Crater.  Deformation associated with emplacement of this dike is apparent on a satellite interferogram of the area, confirming ground-based observations. Ongoing seismicity, local deformation, and steady deflation of the summit region indicate that magma is continuing to move underground into the UERZ. The pulsing nature of this recent activity may represent fluctuations in the amount of magma moving underground from the summit to the UERZ.  

An interferogram showing recent ground deformation patterns in the UERZ is available here:  https://www.usgs.gov/media/images/july-24-2024-insar-image-kilauea-ground-deformation 

WHAT WE CAN EXPECT  

It is not possible to forecast an exact outcome of this activity. Future eruptions are possible with little warning along the upper portions of Kīlauea’s East Rift Zone. Recent Kīlauea eruptions have occurred with as little as 1 hour or less of advanced warning in the form of accelerated rates of ground deformation and earthquakes.  

Here are some possible scenarios that could play out in the coming days to weeks:    

• The intrusion grows: Magma continues to accumulate below the surface near Pauahi Crater on Kīlauea’s UERZ as an intrusion (similar to what occurred during the January/February 2024 intrusion southwest of Kaluapele). In this scenario, we would expect to see varying rates of ground deformation and earthquakes in the direction of the intrusion as it grows, along with summit deflation.  
• An UERZ eruption occurs: Magma continues to accumulate below the surface near Pauahi Crater on Kīlauea’s UERZ, resulting in an eventual UERZ eruption. In this scenario, we would expect to see accelerated rates of UERZ earthquakes along with increased rates of Kīlauea summit deflation and UERZ inflation before lava reaches the surface.  Based on patterns of past UERZ eruptions, the area most likely for an outbreak would be located between Hiʻiaka crater and Maunaulu.  
• The intrusion moves east: Magma continues to accumulate below the surface near Pauahi Crater on Kīlauea’s UERZ, eventually establishing a path to the east, in Kīlauea’s middle East Rift Zone, as occurred during the Father’s Day intrusion in 2007. In this scenario, we would expect to see earthquake locations migrating east of Maunaulu, followed by accelerating rates of summit and UERZ deflationary ground deformation.  

WHAT WE ARE DOING  
   
HVO briefly raised the alert level/aviation color code for Kīlauea from ADVISORY/YELLOW to WATCH/ORANGE during the most intense recent pulse of UERZ unrest on July 23. HVO continues to closely monitor Kīlauea, watching for any signs of unrest that may precede a new eruption.  

HVO is in frequent communication with Hawai‘i Volcanoes National Park and Hawai‘i County Civil Defense to keep them apprised of the activity. Hawai‘i Volcanoes National Park has implemented temporary closures as a result of the UERZ intrusion: https://www.nps.gov/havo/learn/news/20240722-earthquakes.htm    

With permission from Hawai‘i Volcanoes National Park, the KOcam was deployed to Maunaulu to monitor the upper East Rift Zone in May and is available here: https://www.usgs.gov/observatories/hvo/kocam-live-image-upper-east-rift-zone-maunaulu  

HVO has re-aimed and zoomed the K2cam, located at Uēkahuna bluff, to view the UERZ: https://www.usgs.gov/volcanoes/kilauea/k2cam-kaluapele-kilauea-caldera-uekahuna-bluff  

HVO field crews examined Chain of Craters Road in Hawaiʻi Volcanoes National Park on July 23 and did not observe any major cracks associated with the recent activity. 

HVO will continue to issue daily updates for Kīlauea, and additional notices as necessary.    

RECENT OBSERVATIONS  

Kīlauea erupted most recently for about 8 hours on June 3, 2024, approximately 3 km (2 miles) southwest of Kaluapele (Kīlauea caldera) within Hawai'i Volcanoes National Park. Following that eruption, patterns of seismicity and ground deformation indicated that magma re-accumulated in the storage regions beneath the summit. 

Earthquake activity in the UERZ began to increase in late June, distributed between Keanakākoʻi and Pauahi craters, beneath Chain of Craters Road in Hawaiʻi Volcanoes National Park. A swarm of approximately 1,500 earthquakes occurred in this area between June 27 and July 1, 2024, but was not accompanied by significant changes in ground deformation in the UERZ or summit. For more information about this swarm, see https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2024-07-03T22:26:28+00:00. 

PREVIOUSLY RECORDED ACTIVITY IN THE UPPER EAST RIFT ZONE 

Pit craters and lava flows in the UERZ are evidence of a long history of magma moving along this rift zone pathway. Intrusions of new magma into this region have been monitored numerous times in the past decades, with sparse eruptions. During the past 60 years, there have been approximately 50 intrusions and 5 eruptions in the UERZ region. The most recent UERZ eruption took place in November 1979. That was a brief one-day eruption that occurred in and near Pauahi Crater and was preceded by two months of increased earthquake activity along with inflation at the summit region. Several other UERZ eruptions took place in the late 1960s and early 1970s and lasted from one day to about a month. UERZ eruptions have typically occurred near the southeast margin of Kaluapele, or where the UERZ meets the middle East Rift Zone near Pauahi Crater.    

The most recent significant intrusion in this area took place in 2007. The “Father’s Day” intrusion began on June 17, 2007, with an earthquake swarm centered southwest of Maunaulu. Over the next several hours, ground deformation rates accelerated and during the next two days, earthquakes propagated downrift towards Puʻuʻōʻō in the middle portion of Kīlauea’s East Rift Zone. Cracks formed at multiple locations in the East Rift Zone, and steam vents formed along the western base and slope of Kāne Nui o Hamo. On the morning of June 19, HVO geologists observed a small amount of fresh lava on the north flank of Kāne Nui o Hamo, which had been erupted overnight of June 19, 2007. 

A map showing the located of previous eruptions in the UERZ is available here: https://www.usgs.gov/media/images/kilauea-upper-east-rift-zone-reference-map  

A Volcano Watch article describing past activity in the UERZ is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-cruising-chain-craters-road-recent-earthquakes-and-past