Toba caldera, Indonesia

Understanding resurgence after voluminous explosive eruptions remains one of the greatest challenges in volcanology (Acocella, 2014), as essentially all calderas currently experiencing unrest in the world are in this state (Newhall & Dzurisin, 1988; Acocella et al., 2019). Thus, constraining the timescales, conditions, and extent over which magmatic processes are occurring in resurgent reservoirs becomes fundamental for eruption forecasting, especially when geophysical approaches have difficulties to characterize melt-containing reservoirs at high resolution (Lowenstern et al., 2017).