USGS Volcano Notice - DOI-USGS-HVO-2022-10-10T11:37:15-07:00

Activity Summary: Mauna Loa is not erupting and there are no signs of an imminent eruption at this time. However, Mauna Loa continues to be in a state of heightened unrest as indicated by increased earthquake activity and inflation of the summit. The current unrest is most likely being driven by renewed input of magma 2-5 miles (3-8 km) beneath Mauna Loa’s summit. Monitoring data show no significant changes in the past day and conditions remain similar to those reported for the past week.

Observations: During the past 24 hours, HVO located over three dozen small-magnitude (below M3.0) earthquakes 2-3 miles (3-5 km) below Mokuāʻweoweo caldera and 4-5 miles (6-8 km) beneath the upper-elevation northwest flank of Mauna Loa. Both of these regions have historically been seismically active during periods of unrest on Mauna Loa. 

Global Positioning System (GPS) instruments at the summit and on the flanks of Mauna Loa continue to measure inflation at rates elevated since mid-September. However, tiltmeters at the summit are not showing significant surface deformation over the past week. 

Concentrations of sulfur dioxide (SO₂), hydrogen sulfide (H₂S), and carbon dioxide (CO₂), as well as fumarole temperatures, remain stable at the summit and at Sulphur Cone on the upper Southwest Rift Zone. Webcam and thermal camera views have shown no changes to the volcanic landscape on Mauna Loa over the past week.  

Narrative: Heightened unrest began in mid-September 2022 with increased earthquake rates below Mauna Loa summit (from 10-20 per day to 40-50 per day), an increased rate of inflation recorded by GPS stations, and inflation recorded on the MOK tiltmeter. The unrest is likely caused by renewed input of magma into Mauna Loa’s summit reservoir system. As the reservoir expands it is triggering small earthquakes directly beneath Mokuāʻweoweo caldera and in a region just to the northwest of the caldera. Deeper magma input (greater than 2 miles, 3 kilometers) is detected by the continued increase in upward movement and extension measured between GPS stations located on the ground surface. Shallower magma input (less than 2 miles, 3 kilometers) was likely responsible for inflation recorded on the summit tiltmeter during the last two weeks of September. The current locations of earthquakes and deformation do not necessarily mean that the next eruption will occur there. Mauna Loa remains at an elevated alert level of ADVISORY/YELLOW. The current increase in activity does not suggest that a progression to an eruption is certain, and there are no indications that an eruption is imminent. 

HVO will continue to closely monitor Mauna Loa for changes.  

HVO will continue to issue daily Mauna Loa Volcano updates until further notice. Additional messages will be issued as needed.

For more information on current monitoring of Mauna Loa volcano, see: https://www.usgs.gov/volcanoes/mauna-loa/monitoring.

Related Volcano Watch from October 6, 2022: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-events-mauna-loa-remind-us-be-prepared-quick-changes

Hawaiʻi Volcanoes National Park: https://www.nps.gov/havo/

County of Hawaiʻi Civil Defense Agency: https://hawaii-county-civil-defense-agency-hawaiicountygis.hub.arcgis.com/

Activity Summary: The summit eruption of Kīlauea Volcano, within Halemaʻumaʻu crater, continued over the past 24 hours. All recent eruptive activity has been confined to the crater. No significant changes have been observed at the summit or in either rift zone.

Halemaʻumaʻu Lava Lake Observations: Eruption of lava from the western vent into the active lava lake and onto the crater floor continued over the past 24 hours. The active part of the lava lake has been steady over the past 24 hours. Overflight measurements from October 5, 2022, indicated that the crater floor had seen a total rise of about 143 meters (469 feet), and that 111 million cubic meters (29.2 billion gallons) of lava had been effused since the beginning of this eruption on September 29, 2021.

Summit Observations: Summit tiltmeters recorded nearly zero deformation over the last 24 hours. Volcanic tremor remains above background levels. A sulfur dioxide (SO₂) emission rate of approximately 1,800 tonnes per day (t/d) was measured on September 30, 2022.

Rift Zone Observations: No unusual activity has been noted along the East Rift Zone or Southwest Rift Zone; low rates of ground deformation and seismicity continue along both. Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone remain below detection limits for SO₂, indicating that SO₂ emissions from Puʻuʻōʻō are negligible.

Hazard Analysis: This eruption at Kīlauea's summit is occurring within a closed area of Hawaiʻi Volcanoes National Park. High levels of volcanic gas are the primary hazard of concern, as this hazard can have far-reaching effects downwind. Large amounts of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are continuously released during eruptions of Kīlauea Volcano. As SO₂ is released from the summit, it reacts in the atmosphere to create the visible haze known as vog (volcanic smog) that has been observed downwind of Kīlauea. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock. For more information on gas hazards at the summit of Kīlauea, please see: https://pubs.er.usgs.gov/publication/fs20173017. Vog information can be found at https://vog.ivhhn.org. 

Additional hazards include Pele's hair and other lightweight volcanic glass fragments from lava fountains that will fall downwind and dust the ground within a few hundred meters (yards) of the erupting fissure vent(s). Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation. 

Other significant hazards also remain around Kīlauea caldera  from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. This underscores the extremely hazardous nature of the rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since early 2008. 

For discussion of Kīlauea hazards, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.

Please see the Hawaiʻi Volcanoes National Park website for visitor information: https://www.nps.gov/havo/index.htm. Visitors to Hawaiʻi Volcanoes National Park should note that under southerly (non-trade) wind conditions, there is potential for a dusting of powdery to gritty ash composed of volcanic glass and rock fragments. These ashfalls represent a minor hazard, but visitors should be aware that such dustings at areas around the Kīlauea summit are possible. 

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

HVO will continue to issue daily Kīlauea Volcano updates until further notice. Additional messages will be issued as needed.