Volatile resorption expedites eruption onset in large silicic systems.

Keller, Franziska; Townsend, Meredith; Troch, Juliana; Huber, Christian · Nat Commun · 2026

basic_science · Level V

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Abstract

Silicic caldera-forming eruptions are among the most hazardous natural phenomena on Earth, yet their triggering mechanisms remain poorly understood. While volatile exsolution is widely recognized as a potential eruption driver in large silicic systems, we find that volatile resorption can, counterintuitively, promote chamber pressurization faster than volatile exsolution. Using a thermo-mechanical magma chamber model, we show that resorption is a common process in rapidly recharged systems, driven by pressure increase and crystal melting. The Aso-4 eruption offers a natural case where volatile resorption may have occurred, with model results predicting resorption at recharge rates >10<sup>-2.4</sup> km<sup>3</sup>/yr. Through reducing bulk magma compressibility, resorption amplifies pressurization, driving chamber destabilization and potentially expediting eruption onset. Here, we propose that volatile resorption is a natural process both accommodating and promoting rapid chamber pressurization, fundamental to destabilizing large-scale silicic systems. Detecting its signatures in monitoring signals could provide early warning of imminent eruption.