BREAKING: Ongoing Kīlauea Intrusion Causes Tiny East Rift Eruption, September 16, 2024

Following a magnitude 4.3 earthquake beneath Kīlauea’s south caldera on September 14, magma flow increased into the volcano’s East Rift following the pathway of other recent intrusions in August and July. Earthquakes in the area of Makaopuhi and Nāpau craters which have persisted for over a month suddenly intensified about an hour and a half after the summit event accompanied by volcanic tremor, suggesting the onset of another intrusion. 

After a quieter morning, the evening of September 15 brought renewed tremor between 9 and 10pm, at the same time when USGS “infrasound instruments detected a strong signal typical of gas or steam venting”. Volcano area residents reported the strong smell of volcanic gas around the same time despite a locally heavy downpour, which usually mitigates its effects, but that same weather prevented any visual confirmation of a possible eruption. That came as USGS Hawaiian Volcano Observatory scientists conducted an aerial survey as the weather cleared this morning. 

The USGS now confirms the small eruption came from two fissure segments extending 525 yards or 480 meters in length near the Nāpau campsite, putting out about 25,000 cubic yards or 20,000 cubic meters – about 8 Olympic-sized swimming pools worth of new rock. (For comparison, Kīlauea’s last summit eruption in September 2023 output over 18 million cubic meters.) Lava only reached about 100 yards or 90 meters from the fissure vents, all within a remote area of Hawaiʻi Volcanoes National Park, thus posing no threat to people or infrastructure, “however it occurred in close proximity to the Nāpau Trail and cultural resources nearby.”

Although the eruption appears over, the intrusion that caused it is still ongoing as evident on monitoring signals, with the summit continuing to steadily deflate as magma leaves that area headed towards the East Rift. Thus “renewed episodes of intense unrest or eruption are possible and could occur with little warning.” The USGS continues to issue frequent updates and status reports since advising of escalating activity on September 14 and increasing the volcanic alert level just after midnight this morning, noting that “additional ground cracking and outbreaks of lava around the active fissures are possible at any time, or, existing fissures can be reactivated.” We all await what will develop next.

We review the monitoring signals, imagery, and reports available courtesy of the USGS Hawaiian Volcano Observatory, annotating the presentation on screen as we go and discussing live viewer questions. 

To support our productions please like, share and subscribe, and consider making a donation at https://hveri.org/donate .