First Onset of Unrest Captured at Socompa: A Recent Geodetic Survey at Central Andean Volcanoes in Northern Chile

We report the first detection of unrest at Socompa volcano during our recent survey Central Andean volcanos in Northern Chile using Interferometric Synthetic Aperture Radar measurements spanning January 2018 to October 2021. find that volcano, whilst initially undeforming and no recorded eruptions for 7.2 kyr, shows a steady uplift (17.5 mm/yr) from November 2019, independently by near-field continuous Global Positioning System data. The deformation pattern can be fitted with pressure increase an ellipsoidal source region stretching 2.1 10.5 km, volume change rate ∼6.2 × 106 m3/yr. Our observations onset suggest it is unlikely nearby Mw 6.8 deep intraslab earthquake on 3 June 2020 triggered unrest. signal we detect indicates initiation Socompa, after least two decades without measurable deformation, many thousands years volcanic activity.