Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations

摘要

Nevado del Ruiz is part of a large volcano complex in the northern Andes of Colombia. Interferometric synthetic aperture radar observations from the RADARSAT-2 satellite since 2011 show steady inflation of the volcano since 2012 at 3-4cm/yr. The broad (>20km) deformation pattern from both ascending and descending track data constrain source models for either point or spheroidal sources, both located at >14km beneath the surface (mean elevation 4.2km) and 10km SW of Nevado del Ruiz, below nearby Santa Isabel Volcano. Stress change computations for both sources in the context of a compressive regional stress indicate that dikes propagating from the source should become trapped in sills, possibly leading to a more complex pathway to the surface and explaining the significant lateral separation of the source and Nevado del Ruiz Volcano.