Crustal structure of La Palma Island inferred from 3D aeromagnetic modelling

Abstract

Abstract La Palma, the second youngest island in the Canary archipelago, has been the subject of numerous geophysical studies. This study aims to use a new approach in the Island to unravel its crustal structure: 3D inversion of aeromagnetic anomalies. We analyze the magnetic anomaly map through standard data processing techniques and present the first 3D magnetic susceptibility model of La Palma. Our results suggest that the strongest magnetic signal in the North is attributed to the uplifted seamount dyke complex. The South of the island is characterized by three central bodies of high magnetic susceptibility up to 5 km depth comprising the bulk core material of the Cumbre Vieja volcano, in agreement with previous geophysical studies. We additionally identify lateral magnetic structures likely compatible with ancient volcanic structures that had not been inferred before. Both flanks of the Cumbre Vieja ridge are characterized by magnetic susceptibility lows compatible with hydrothermal alteration processes as previous studies suggested. This study demonstrates that the magnetic method and 3D magnetic susceptibility maps are valuable tools for initial geothermal and structural exploration in volcanic environments, such as La Palma, providing extensive spatial coverage and critical insights.