MAUNA LOA, Hawaii – A sudden swarm of earthquakes on the rift of Mauna Loa caught the attention of scientists with the USGS Hawaiian Volcano Observatory last week.

The small earthquake swarm occurred beneath Mauna Loa’s west flank from Saturday, May 28 through Tuesday, May 31. The USGS reported that most of the earthquakes occurred at depths between 3 to 5 miles below the surface. The largest quake was a magnitude 2.8.

“This activity is part of the expected range of behaviors for Mauna Loa and does not represent a significant change,” USGS wrote in a June 2 update. “Seismicity rates have since decreased, though are nonetheless elevated above the long-term background.”

Scientist-in-charge Tina Neal told Sherry bracken during a June 3 interview that the event was a reminder that the world’s largest volcano is in a period of unrest.

In addition, measurements continue to show deformation related to inflation of a magma reservoir beneath the Mauna Loa summit and upper Southwest Rift Zone, with inflation recently occurring mainly in the southwestern part of the magma storage complex.