A synergistic thermal framework for monitoring, quantifying, and classifying volcanic activity from space

Satellite-based monitoring of volcanic thermal activity commonly relies on Mid-InfraRed Volcanic Radiative Power (VRP MIR ), sensitive to high-temperature (≳600 K) surfaces, or on Thermal InfraRed Volcanic Radiative Power (VRP TIR ), which captures lower-temperature (≲600 K), spatially diffuse emissions. Because these approaches sample different portions of the volcanic thermal spectrum, each alone provides an incomplete view of volcanic heat release. We present a unified thermal framework that integrates these parameters with two new complementary metrics, namely the Total Volcanic Radiative Power (VRP Tot ), derived from combined MIR and TIR signals, and the VRP Ratio (VRP MIR / VRP TIR ), a dimensionless proxy for effective temperature, capturing thermal structure independently of the feature's size. Synthetic modelling and satellite observations show that this integrated approach enables discrimination between different types of volcanic activity and suggest that existing MIR-only inventories underestimate total heat release by factors of 2–20, implying substantial upward revisions to global volcanic heat budgets. Application of the framework at Sabancaya volcano reveals precursory evidence months before the November 2016 eruption that is invisible in single-band observations. We envisage that this simple, transferable methodology will enable a revision of global volcanic thermal budgets and will provide enhanced capability for volcano monitoring and detection of thermal precursors.