Large earthquakes provoke unrest in volcanic areas hundreds of kilometres away from their epicentre. For example, earthquakes can induce ground deformation, thermal anomalies, additional earthquakes, hydrological changes or eruptions in volcanic regions. Two earthquakes in the Chilean subduction zone, in 1906 and 1960, triggered eruptions in the Andean southern volcanic zone within one year, yet no significant eruptions in the past three years are clearly associated with the 2010 M w 8.8 Maule, Chile earthquake. We use satellite Interferometric Synthetic Aperture Radar (InSAR) and night-time thermal infrared data to analyse subtle changes in ground deformation and thermal activity at volcanoes in the southern volcanic zone since 2010. We document unprecedented subsidence of up to 15 cm in five volcanic areas within weeks of the earthquake, but no detectable thermal changes. We suggest that the deformation is related to coseismic release of fluids from hydrothermal systems documented at three of the five subsiding regions. The depth and shape of these hydrothermal reservoirs can also be constrained by our deformation data, implying that coseismic volcano subsidence could be used to prospect for geothermal resources. Similar subsidence observed at Japanese volcanoes following the 2011 Tohoku earthquake suggests this phenomenon is widespread.
Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853, United States; Servicio Nacional de Geología y Minería, Volcano Hazards Program, Santiago 8320119, Chile
Recommended Citation:
Pritchard M.E.,Jay J.A.,Aron F.,et al. Subsidence at southern Andes volcanoes induced by the 2010 Maule, Chile earthquake[J]. Nature Geoscience,2013-01-01,6(8)