Co-eruptive subsidence and post-eruptive uplift associated with the 2011-2012 eruption of Puyehue-Cordón Caulle, Chile, revealed by DInSAR

EUILLADES, PABLO A.; EUILLADES, LEONARDO; BLANCO, MAURO; VELEZ, MARÍA LAURA; GROSSE, PABLO; GUSTAVO SOSA

JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 344 p. 257 - 269

0377-0273

The 2011-2012 eruption of the Puyehue-Cordón Caulle volcanic complex, southern29 Andes (Chile), was associated with complex surface deformation affecting an area of30 roughly 50 by 50 km. We report here differential SAR interferometry (DInSAR) results31 of pre-, co- and post-eruptive deformation from ENVISAT ASAR, COSMO-Skymed,32 and ALOS-2/PALSAR scenes acquired between early 2011 and early 2017. No clear33 pre-eruptive deformation is observed during five months before the eruption, although34 some patterns could be interpreted as showing inflation occurring between April and35 May 2011. Co-eruptive interferograms show a complex deformation pattern consisting36 in a huge deflation lobe (120 cm LOS lengthening) centered 10 km NW of the emission37 vent accompanied by smaller uplift and subsidence regions in the vicinity of the vent.38 Re-inflation began immediately after the end of the eruption. A first pulse lasted 3 years39 between 2012 and 2015, accumulating ~70 cm uplift. We detect here a second pulse,40 beginning in middle 2016 and still ongoing in February 2017, reaching 12 cm in half a41 year. Inverse modeling with spherical cavity and spheroidal sources locates re-inflation42 sources at a depth ranging between 8 and 11 km under the surface. It suggest re-filling43 of a deeper reservoir occurring after the emptying of a shallow magma chamber during44 the 2011-2012 eruption.