USGS graphic shows locations of earthquakes under Mauna Loa during the past week.

• Mauna Loa is not erupting and the USGS Volcano Alert Level / Color Code remains at ADVISORY / YELLOW.
• While there are no signs of an imminent eruption at this time, scientists say Mauna Loa is currently experiencing heightened unrest.
• As a precautionary measure, Hawai‘i Volcanoes National Park is closing the Mauna Loa summit backcountry until further notice.
• Beginning tomorrow, October 6, the USGS Hawaiian Volcano Observatory will be providing daily updates on Mauna Loa activity, reflecting the heightened level of unrest.

From a Wednesday evening USGS Mauna Loa Status Report:

Mauna Loa is not erupting and there are no signs of an imminent eruption at this time.

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

Inflation or expansion of Mauna Loa’s summit is accompanying the earthquake activity and has also increased in the past two weeks. The last time Mauna Loa displayed similar elevated earthquake activity and expansion of the summit region was late-January to late-March of 2021. Additional periods of increased earthquake activity have also occurred during the 38 years since the last eruption of Mauna Loa in 1984.

The Alert Level for Mauna Loa remains at ADVISORY/YELLOW.

Beginning tomorrow, October 6, HVO will be changing UPDATES for Mauna Loa from WEEKLY to DAILY, reflecting the heightened level of unrest.

HVO is continuing to monitor conditions carefully and will issue appropriate updates if conditions change.

From the Hawaiʻi Volcanoes National park news release:

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

Mauna Loa is not erupting. The volcanic alert level remains at advisory, and the aviation color code remains at yellow. U.S. Geological Survey Hawaiian Volcano Observatory (HVO) scientists will notify the park if conditions change.