USGS Volcano Notice - DOI-USGS-HVO-2023-12-28T10:27:48-08:00

Activity Summary:  Kīlauea volcano is not erupting. Over the past day moderate seismicity has been recorded in the summit region, upper East Rift Zone, and Southwest Rift Zone. Unrest may continue to wax and wane with fluctuating input of magma to the area, and eruptive activity could occur in the near future with little or no warning. No unusual activity has been noted along the middle and lower sections of Kīlauea’s East Rift Zone.

Summit Observations:  Moderate seismicity was recorded in Kīlauea's summit region with 25 earthquakes of less than M2.5 over the past 24 hours, mostly beneath and just south of the caldera. The region southwest of the caldera remains quiet. Cycles of rising and falling shallow seismic activity can be expected to continue during repressurization of the summit magma reservoir, which has been ongoing since the end of the September eruption. Seismicity has not reached the levels that immediately preceded recent summit eruptions at Kīlauea.

The summit tiltmeter began recording deflationary tilt yesterday evening associated with a new DI event. Kīlauea's summit region remains at a high level of inflation; relative tilt is above the level reached prior to the most recent eruption in September 2023, and it is higher than at any time since the 2018 eruption.

Sulfur dioxide (SO₂) gas emission rates remain low. Field measurements indicated an SO₂ emission rate of approximately 70 tonnes per day on December 5, which was similar to measurements in October and November.

There are currently no signs of an imminent eruption at Kīlauea, but the volcano's summit region remains unsettled, with a high level of inflation and continued seismic activity. Seismicity and deformation in the area southwest of the caldera between the December 1974 vents and the Koʻae fault has diminished significantly over the past month greatly reducing the likelihood of an eruption in this area. The onsets of previous summit eruptions have been marked by strong swarms of earthquakes caused by magma moving towards the surface 1–2 hours before the appearance of lava. This type of earthquake activity is not being detected at this time.

The information statement released on October 23, 2023, provides additional information and context related to recent unrest at Kīlauea's summit: https://volcanoes.usgs.gov/hans2/view/notice/DOI-USGS-HVO-2023-10-23T22:33:18-07:00

A map summarizing recent unrest around Kilauea’s summit (activity from November 11 to December 12, 2023) can be found here: https://www.usgs.gov/maps/december-12-2023-summary-map-unrest-kilauea-volcano

Rift Zone Observations:  Seismicity in both of Kīlauea's rift zones has remained low over the past day. In the past 24 hours, three total earthquakes M1.5 or less were recorded in the upper and middle East Rift Zone. In the Southwest Rift Zone, nine earthquakes less than M2.0 were recorded. Deep aftershocks, greater than 25 km depth, continue in the region just to the east of Mauna Iki and the Southwest Rift Zone; however, these are unrelated to volcanic activity.

We continue to closely monitor both rift zones, especially near the summit. No unusual activity has been noted along the middle and lower sections of Kīlauea's East Rift Zone. Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone—the site of 1983–2018 eruptive activity—have been below detection limits for SO₂, indicating that SO₂ emissions from Puʻuʻōʻō are negligible.

Hazard Analysis:  Levels of volcanic gases (sulfur dioxide and carbon dioxide) can remain locally hazardous even when Kīlauea is not erupting. Local concentrations of sulfur dioxide (SO₂) and/or hydrogen sulfide (H₂S) may persist in downwind areas, and residents may notice odors of these gases occasionally. Significant hazards also remain around Halemaʻumaʻu from crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. For discussion of Kīlauea hazards, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.

The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea volcano.

Next Notice: HVO will issue daily Kīlauea updates. Additional messages will be issued as needed.