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USGS Volcano Notice - DOI-USGS-HVO-2023-12-02T10:31:14-08:00


U.S. Geological Survey
Saturday, December 2, 2023, 9:24 AM HST (Saturday, December 2, 2023, 19:24 UTC)

KILAUEA (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Activity Summary:  Kīlauea volcano is not erupting. Seismicity increased dramatically in the south caldera region just before midnight and returned to lower levels just after 5 a.m. this morning.  While the volcano tectonic earthquakes have subsided pulses of small, long period earthquakes that cannot be accurately located are occurring beneath Halemaʻumaʻu indicating that unrest continues. Seismicity remains low to the southwest of the caldera and in the upper East Rift Zone. Unrest may continue to wax and wane with changes to the input of magma into 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:  Summit seismicity was elevated over the past 24 hours, with a strong seismic swarm in the south caldera that produced about 90 earthquakes from just before midnight to just after 5 a.m. HST.  Minor small earthquakes also occured in the upper East Rift Zone during this period. Activity this morning has subsided, but bursts of long period activity that cannot be located accurately continue beneath Halemʻaumaʻu. These earthquakes are indicative of continued magmatic unrest.

The seismic swarm in the south caldera was accompanied by strong uplift on the Sand Hill tiltmeter located in that region. Tilt flattened at the Sand Hill tiltmeter just before 5 a.m. and earthquakes began diminshing soon after that. The Uēkahuna summit tiltmeter, located northwest of the caldera, showed mixed signals over the past 24 hours, with the NE component increasing 0.5 microradians and the NW component decreasing 1 microradian. Overall, the summit of Kīlauea remains at a high level of inflation, above the level reached prior to the most recent eruption in September 2023, and the highest level since the 2018 eruption.

Sulfur dioxide (SO2) emission rates remain low. Field observations found SO2 gas emmision of 100 tonnes per day on November 17. This is the same as an observation in October 2023.

There is currently no sign of an imminent eruption, but the summit region remains unsettled with increased unrest continuing as long period earthquakes beneath Halemaʻumaʻu are continuing in pulses. Seismic activity continues at low levels at the summit, upper East Rift Zone, and Southwest Rift Zone after the early morning swarm. The onsets of previous summit eruptions have been marked by strong swarms of earthquakes caused by the emplacement of a dike 1-2 hours before eruptions and these have not been detected at this time.

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

A map summarizing recent unrest southwest of Kilauea’s summit (activity beginning 10/4/23) is seen here: https://www.usgs.gov/maps/november-5-2023-summary-map-intrusive-activity-kilauea-volcano

Rift Zone Observations:  Seismicity in the upper East Rift Zone continues at low levels with 32 events over the past 24 hours, and 18 events over the past 24 hours in the Southwest Rift Zone.

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

Hazard Analysis:  Levels of volcanic gas (sulfur dioxide and carbon dioxide) can remain locally hazardous even though Kīlauea is no longer erupting. Sulfur dioxide (SO2) gas emissions have greatly decreased; however, local concentrations of sulfur dioxide (SO2) 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.

More Information:

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 and American Samoa.



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