On Thursday, March 18, 2021, the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded over 40 earthquakes beneath the upper Ka‘ōiki seismic zone, under Mauna Loa’s southeast flank and northwest of Kīlauea’s summit about 21 km (13 mi) WNW of Volcano. The earthquakes, which began at 1 a.m, are occurring in a cluster about 2 km (1 mi) wide and 0.5–6 km (0.5–4 mi) below the surface. Despite these earthquakes, Mauna Loa is not erupting
The largest event in the sequence, so far, was a magnitude-3.5 earthquake, with the bulk of the events being less than magnitude-2 and not widely reported by residents.
These earthquakes do not show any signs of magmatic involvement and are part of normal re-adjustments of the volcano due to changing stresses within it. Other monitoring data streams for Kīlauea and Mauna Loa, including ground deformation, gas, and imagery, show no signs of increased activity.
HVO continues to closely monitor changes, seismicity, deformation and gas emissions at Kīlauea and Mauna Loa Volcano’s. HVO will issue additional messages and alert level changes as warranted by changing activity.
For more information on recent earthquakes and eruption updates, visit the USGS Hawaiian Volcano Observatory website at https://www.usgs.gov/observatories/hawaiian-volcano-observatory.
