Unrest at the Laguna del Maule volcanic field 2005–2020: renewed acceleration of deformation

Abstract

The Laguna del Maule volcanic field in Chile has been exhibiting unrest since 2005. New GPS and InSAR data reveal a second episode of accelerated deformation beginning in late 2016 and continuing through May 2020, with an uplift rate > 290 mm/year between 2019 and 2020. To explain the spatial and temporal pattern of deformation, we apply a dynamic model of viscous magma flowing through a conduit into a fluid-filled reservoir surrounded by a heterogeneous, viscoelastic crust. A Monte Carlo procedure optimizes the ellipsoid reservoir geometry and the inlet pressure history. The two episodes of accelerating uplift are each modeled with a pressure increase rate of ∼ 9 MPa/year. Since 2016, 0.10 km3 of magma was injected into the system for a total of 0.37 km3 since 2005.