Volcano hazard monitoring using remote sensing techniques during the Cumbre Vieja volcano 2021 eruptive crisis

On 19 September 2021, after about 50 years of quiescence, a new eruption started at Cumbre Vieja volcano (Canarias, Spain). The onset was preceded by a series of seismic swarms, the last one of which occurred on 11 September 2021. A system of eruptive fissures opened and multiple vents produced lava fountains, sustained ash columns, and lava flows that travelled over 5 km W to the sea, damaging hundreds of properties along their path. The eruption forced the evacuation of over 7,000 people and destroyed nearly 3,000 buildings, ending on 13 December, after 85 days.

We here detail the different phases of the eruption and describe and discuss the lava flow field structures and emplacement dynamics by using ground- and air-based thermal camera data as well as using multispectral satellite images. Indeed, the high temporal resolution of SEVIRI images - i.e. an image every 15 minutes - allowed tracking the lava flow development and provided an estimation of the effusion rate. Sentinel 2, Landsat 8 and PlanetScope images enabled mapping the active areas of the lava field and, thus to clearly depict the formation of lava tube systems promoting lava flow lengthening to the sea. Moreover, the satellite-derived data were used as input to the GPUFLOW model to produce near real time, short-term lava flow hazard maps.