The Hawaiian Volcano Observatory (HVO) reported that a small seismic swarm is occurring beneath the summit of the volcano.
At about 02:00 local time starting on 23 September, the seismic network recorded over 38 earthquakes beneath the summit caldera region with most earthquakes in a cluster about 3.1 mi (5 km) wide and -1.2 to 0.6 mi (-2 to 1 km) below the surface. 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.
According to HVO Scientist-in-Charge Ken Hon, „Seismic activity beneath Mauna Loa has been gradually increasing over the past two months. Small earthquake swarms are considered a normal part of this increase in activity. Currently, there are no indications that magma is moving toward the surface and other monitoring systems are displaying normal behavior. Levels of seismicity and deformation remain below those recorded during the winter of 2021.“
Source: Hawaiian Volcano Observatory volcano activity update 25 September 2022