The 2012 Eruption

Abstract

This contribution is a detailed description of the precursory activity and theeruptive events that took place during July and December 2012 at Copahue volcano, based on field observations and geophysical and geochemical monitoring. After the Mw 8.8 Chilean earthquake on February 27th 2010, several signals of anomalous behavior were detected at Copahue, revealing the instability of the volcanic system. Starting from July 2012 a phreatic activity occurred with emission of a low amount of material mainly constituted by rocks from the volcanic conduit and sediments from the bottom of the crater lake. Seismic activity and degassing continued until December 22nd when the eruption started with an opening phreatic event that rapidly evolved to a phreatomagmatic, and finally a magmatic eruption.