Media release

From: Springer Nature

Earth Sciences: Investigating the 2022 eruption of Mauna Loa

The 2022 eruption of Mauna Loa, Hawaiʻi, was preceded by a two-month long period of magma intrusion below its caldera, a study published in Nature Communications indicates. The findings provide further insights into the mechanism of the volcano and could help aid scientists in forecasting volcanic activity more accurately worldwide.

Mauna Loa, one of the five volcanos that make up the Island of Hawaiʻi, is Earth’s largest active volcano. After 38 years of repose, the volcano began erupting on 27th November 2022, with activity continuing for 13 days. The volcano had shown intermittent unrest in the decades before the new eruption; however, it proved challenging to differentiate this unrest from signals that preceded and eventually escalated to the volcanic eruption. Interpretation of the months-long precursory unrest was complicated by the fact that the last eruption, which occurred in 1984, occurred prior to the installation of the modern monitoring network.

Kendra Lynn and colleagues used multidisciplinary datasets to provide new insights into how the 2022 eruption took place. They tracked the spatio-temporal evolution of Mauna Loa’s precursory unrest by studying the composition and formation of the erupted lavas, making gas plume measurements, and monitoring seismic data and ground deformation. The authors suggest that prior to the 2022 eruption, a large volume of magma migrated from depths of 3-5km up to 1-2km below the caldera (a large depression formed when a volcano erupts and collapses), which increased the stress on the shallow magma reservoir until it erupted. Such an intrusion was not seen during the previous decades of inactivity and the results may provide a new model of the plumbing network of this high-risk volcano.

The findings suggest that eruptions might be preceded by trackable signals that all reflect magma migration into shallow storage areas. Using these combined indicators may improve our ability to forecast an eruption with more lead time than the minutes to hours of intense pre-eruptive seismicity typical for Mauna Loa eruptions.