Thermal Emissions of Active Craters at Stromboli Volcano: Spatio‐Temporal Insights From 10 Years of Satellite Observations

Abstract

AbstractOpen‐vent volcanoes continuously emit magmatic products and frequently feature multiple adjacent craters. Temporal shifts of thermal emissions between craters are especially detectable by InfraRed satellites. Here, SENTINEL‐2 and LANDSAT‐8/9 Short Wave InfraRed (SWIR) high‐spatial resolution satellite data, are combined to investigate 10 years (2013–2023) of thermal activity at Stromboli volcano (Italy). The correlation between Volcanic Radiative Power (VRP, in Watts) and Volcanic Radiative Energy (VRE, in Joules), retrieved by moderate MODIS and VIIRS Middle InfraRed (MIR) data, with the Thermal Index SWIR (TISWIR) data, allows us to quantify long‐term series of heat fluxes (VRPSWIR) and energy (VRESWIR). Combining moderate and higher spatial resolution data and fitting cumulative trends of TISWIR with VREMIR allows to measure thermal activity sourced by single craters during Strombolian activity. Long‐term results highlight that thermal emissions are clustered in the northern and southern parts of the crater terrace, with total energy emitted (∼12 × 1014 J) equally distributed. The thermal increase since April 2017 marked a reactivation of shallow magma transportation and an intensification of the activity after the 2014 eruption. Distinct thermal behaviors are shown by the NE, C, and SW craters, related to mechanisms of explosions. We found that short‐term thermal variations match well those resolved by ground‐based signals, and the NE crater as the most sensitive to the transition to higher‐intensity activity. Our multispatial/multisensory investigation allows, for the first time, the long‐term quantification of heat flux from Stromboli's craters, with an improved understanding of open‐vent dynamics and a new approach to monitor multiple active craters.