USGS Volcano Notice - DOI-USGS-HVO-2024-02-01T19:44:10+00:00

Activity Summary:  Kīlauea volcano is not erupting.  The increase in seismicity and deformation that began early January 31 in the summit region has shifted from the summit to the southwest. Since last night, earthquake activity has concentrated along the Koa‘e fault system southwest of the summit. Kīlauea’s summit remains pressurized; in recent months unrest has escalated quickly, and an eruption could occur in the future with little warning.   

Summit Observations:  As of this morning, seismicity in the south caldera region has quieted, and activity is concentrated 5-7 miles (8-11 km) southwest of the caldera, in the vicinity of Pu‘ukoa‘e. Depths have remained consistent, 1–4 km (less than a mile–2.5 mi) below the surface, and the rates have persisted at 25-30 locatable earthquakes per hour. There have been over 70 locatable earthquakes in this region in the past 3 hours, with magnitudes ranging from a maximum of 3 to less than 1. Some events are large enough to be felt by neighboring communities, though none have been large enough to cause damage.  

Kīlauea's summit region remains at a high level of inflation. Nearly 40 microradians of change have been recorded since 4:00 a.m. HST on January 31 at tiltmeters near Sand Hill and Uēkahuna bluff. Both of these tiltmeters showed highly variable directions and rates of tilt on January 31, typical of shallow crack growth that can precede either an eruption or shallow intrusion.  Since early this morning, these tiltmeters have shown more consistent directions and rates, suggestive of ground inflation to the southwest (in the direction of where earthquakes are occurring). Step-wise offsets in the tilt signal are likely due to the instrument being shaken by nearby earthquakes or rockfalls. 

Sulfur dioxide (SO2) gas emission rates remain low. Field measurements indicated an SO2 emission rate of approximately 70 tonnes per day on January 17, which was similar to measurements in October, November, and early December.  

Patterns of earthquakes and ground deformation since this morning indicate that pulses of magma continue to move beneath the surface of southwest of the summit along the Ko’ae fault zone. The Koa‘e fault system connects Kīlauea’s East and Southwest Rift Zones south of the caldera. Faults here appear as low cliffs, or “scarps.”  Typically, when magma reaches this area earthquakes are concentrated at depths of 3-4 km (2-2.5 mi), but current activity is distributed more evenly from 1-4 km (less than a mile–2.5 mi) depth. Around 7:30 this morning, three magnitude 2.9 earthquakes occurred just south of Puʻukoʻae at very shallow depths. At the time of this report, activity remains elevated; periods of increased earthquake activity and rates of ground deformation can be expected to continue in this region. Based on past historical activity, this event is much more likely to continue as an intrusion, but there is still a possibility of it ending in an eruption.  

• The MITDcam provides views of this area: https://www.usgs.gov/observatories/hvo/mitdcam-kilaueas-upper-southwest-rift-zone-looking-north 

• Please see the official notices published yesterday for more information about recent activity:  

• https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2024-01-31T10:20:40-08:00 

• https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2024-02-01T03:44:28+00:00 

• https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2023-10-06T18:55:23-07:00  

Kīlauea volcano alert level and aviation color code remain at WATCH/ORANGE as the situation remains dynamic. HVO will continue to evaluate alert levels and notices will be issued as activity warrants.  

Please note that upgrades to the network are causing intermittent outages that are affecting public access to monitoring data. HVO maintains internal access to volcano monitoring data and will continue to report on volcanic activity.  We apologize for any inconvenience during this dynamic time.  

Rift Zone Observations:  Seismicity in Kīlauea's East Rift Zone and Southwest Rift Zone remained low in the past 24 hours.  

We continue to closely monitor the summit and both rift zones. 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.