(BIVN) – Seismic activity under Mauna Loa increased slightly over the past month, the USGS Hawaiian Volcano Observatory reported in its monthly update on the massive Hawaiʻi island volcano, published Thursday. 

A total of 123 earthquakes were detected beneath Mauna Loa’s summit region in the January reporting period, the Observatory said, while the prior month had 94 earthquakes. There was “a tight clustering of events under Mokuʻāweoweo and upper Southwest Rift Zone early in the month”, which was a continuation of the elevated earthquake activity from the end of the previous month. 

“Data from Global Positioning System (GPS) instruments on Mauna Loa show variable rates of inflation at the summit over the past six months,” the USGS HVO stated. “This is associated with refilling of the summit reservoir system following the 2022 eruption, as well as recent refilling of a magma chamber under the southern caldera region.” 

USGS: “At the end of their Mauna Loa summit overflight on December 23, USGS Hawaiian Volcano Observatory geologists passed the 2022 Northeast Rift Zone eruption site. In this photo, an older vent known as Steaming Cone is visible in the lower-left of the frame (red and white colors), with the 2022 fissure 3 cone just to the right of it (black and brown colors). 2022 lava channels leading down toward the Humu‘ula Saddle are also visible in the right side of the frame, along with Mauna Kea in the distance.” (USGS photo by M. Zoeller)

Little change was seen in the gas and temperature data from a station on Mauna Loa’s Southwest Rift Zone, scientists say, with values at background levels. 

Mauna Loa is the largest active volcano on Earth, and last erupted in late 2022.