Mauna Loa volcano in heightened unrest, national park closes summit

• The Mauna Loa does not erupt and the USGS Volcano Alert Level/Color Code remains at ADVISORY/YELLOW.
• While there are currently no signs of an impending eruption, scientists say Mauna Loa is currently experiencing heightened civil unrest.
• As a precaution, Hawai’i Volcanoes National Park is closing the backcountry of Mauna Loa’s summit until further notice.
• Beginning tomorrow, October 6, the USGS Hawaiian Volcano Observatory will provide daily updates on Mauna Loa activity reflecting the increased level of civil unrest.

From a USGS Mauna Loa status report Wednesday evening:

Mauna Loa is not erupting and there are currently no indications of an impending eruption.

However, Mauna Loa is currently experiencing heightened civil unrest. Earthquake activity has increased from 5–10 earthquakes per day since June 2022 to 10–20 earthquakes per day in July and August, reaching around 40–50 earthquakes per day in the last two weeks. Peak numbers of over 100 earthquakes per day occurred on September 23rd and 29th.

Mauna Loa summit inflation, or expansion, accompanies earthquake activity and has also increased over the past two weeks. The last time Mauna Loa experienced similar increased earthquake activity and an expansion of the summit region was in late January through late March 2021. Additional periods of increased earthquake activity have also occurred in the 38 years since Mauna Loa last erupted in 1984.

Mauna Loa alert level remains at ADVISORY/YELLOW.

Beginning tomorrow, October 6, HVO will be changing UPDATES for Mauna Loa from WEEKLY to DAILY to reflect the increased level of concern.

HVO continues to carefully monitor the Terms and will issue appropriate updates as the Terms change.

From the Hawaiʻi Volcanoes National Park press release:

Due to increased seismic activity on Mauna Loa and as a precautionary measure, Hawai’i Volcanoes National Park is closing the Mauna Loa summit hinterland until further notice. Mauna Loa Road and the Mauna Loa Lookout at 6,662 feet remain open to the public.

Mauna Loa does not erupt. The Vulcan alert level remains on recommendation and the aviation color code remains on yellow. Scientists from the US Geological Survey Hawaiian Volcano Observatory (HVO) will notify the park if conditions change.