HVO Upgrades Mauna Loa to ‘Advisory’ Level

Mauna Loa volcano has been upgraded to an alert level of advisory following continuous summit unrest.

Hawaiian Volcano Observatory says that the unrest has been recorded for the past year and that ground deformation measured is consistent with a recharge of Mauna Loa’s shallow magma storage system. However, HVO urges that the increase in alert level does not mean that an erruption is imminent of that it is certain that a progression will occur.

Seismic stations at various locations, including beneath Mauna Loa’s summit, upper Southwest Rift Zone, and west flank have recorded shallow, small-magnitude earthquakes which have varied, but overall remained above the long-term average.

A combination of the continuous seismic activity, along with the measurements of ground formation, have caused the advisory level, which was previously listed as normal.

“The alert level change at Mauna Loa reminds us that it is an active volcano that will erupt again someday, so we should be prepared,” said Frank Trusdell, an HVO geologist who has extensively studied and mapped Mauna Loa.

According to HVO, the earthquakes are occurring in locations similar to those that happened before Mauna Loa’s two most recent eruptions in 1975 and 1984. Although similar, HVO notes that the energy of the recent earthquakes are comparatively low and the current rate and pattern of ground deformation is similar to what was measured in 2005 during Mauna Loa inflation that did not end up causing an eruption.

“It’s possible that the increased level of activity at Mauna Loa could continue for many months, or years, without leading to an eruption,” said Tina Neal, HVO’s Scientist-in-Charge. “It is also possible that the current unrest could be a precursor to the next eruption of Mauna Loa. But at this early stage, we cannot determine precisely which possibility is more likely.”

Within the new advisory level, the aviation color has changed from green to yellow.

Big Island Now will continue to monitor Big Island volcanoes, including Mauna Loa and Kilauea, and bring you all the latest.