USGS Elevates Mauna Loa Alert Status To Advisory

The largest active volcano on earth, Mauna Loa, has given the USGS reason to elevate the alert status from normal to advisory.

Activity Summary: Mauna Loa is not erupting. Seismicity rates have decreased significantly since the earthquake activity recorded in late-May, but they remain above previously established baselines. Global Positioning System (GPS) measurements continue to show ground surface deformations related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone, with recently inferred inflation concentrated mainly in the southwestern part of this magma storage complex.

Mauna Loa

Background: Mauna Loa is the largest active volcano on our planet, rising gradually to 4,170 m (13,681 ft) above sea level. Its long submarine flanks descend an additional 5 km (3 mi) below sea level to the ocean floor. The ocean floor directly beneath Mauna Loa is, in turn, depressed by the volcano’s great mass another 8 km (5 mi). This places Mauna Loa’s summit about 17 km (56,000 ft) above its base. The enormous volcano covers half of the Island of Hawaiʻi.

Mauna Loa has erupted 33 times since its first well-documented historical eruption in 1843. Its most recent eruption was in 1984.