Beginning at 2:30 a.m. HST on March 29, 2021, the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded over 130 earthquakes beneath the northwest side of Mauna Loa’s summit, beneath the northeast flank, about 42 km (26 miles) WNW of Volcano. Mauna Loa is not erupting and other monitoring data streams currently show no signs of increased activity.

Most of these earthquakes are occurring in a cluster about 2 km (1 mile) wide and 6–8 km (3.5–5 miles) below the surface.

The largest event was a magnitude-2.7 earthquake, with the bulk of the events being less than magnitude-2, with a maximum Intensity of II on the Modified Mercalli Intensity Scale:

Clustering of shallow earthquakes in this region does not mean an eruption is imminent. HVO has recorded shallow earthquakes in this area for many decades across several eruptive cycles at both Kīlauea and Mauna Loa. These earthquakes may result from changes in the magma storage system and/or may be part of normal re-adjustments of the volcano due to changing stresses within it. Other monitoring data streams for Mauna Loa and Kīlauea, including ground deformation, gas, and imagery, show no significant changes in activity.

HVO continues to closely monitor geologic changes, seismicity, deformation, and gas emissions at Mauna Loa and Kīlauea volcanoes. .

For information on recent earthquakes and eruption updates, visit the USGS Hawaiian Volcano Observatory website at: https://www.usgs.gov/observatories/hawaiian-volcano-observatory.