Combination of geodetic techniques for deformation monitoring during 2021 La Palma eruption  

Abstract

<div> <p><span>Surface deformation is considered one of the most important parameters in volcano monitoring. That was shown during the recent Cumbre Vieja eruption (La Palma, Canary Islands) which started on 19th September 2021 and lasted almost three months. Several days after the beginning of the unrest, on 11th September, deformation data were able to confirm the depth of the volcanic intrusion and constrain an approximate volume.Maximum deformation of 20 cm were measured prior to the beginning of the eruption pointing to the area were the dike finally reached the surface.</span><span> </span></p> </div><div> <p><span>After the eruption onset, deformation monitoring resulted essential to understand eruption dynamics. This work is focused on results obtained by the geodetic techniques operated by Instituto Geográfico Nacional (IGN) during the three months of volcanic activity. </span><span> </span>This system includes GNSS permanent stations, InSAR processing, tiltmeters and a GNSS-RTK periodic measurements on benchmarks around Cumbre Vieja. It allowed to measure displacements with different temporal and spatial scales providing a complete picture of the deformation, which, together with other geophysical parameters, helped to manage the volcanic crisis and interpret the magmatic processes.</p> </div>