Chronology and impact of the 2011 Cordón Caulle eruption, Chile

We present a detailed chronological reconstruction of the 2011 eruption of the Cordón Caulle volcano (Chile) based on information derived from newspapers, scientific re- ports and satellite images. Chronology of associated volcanic processes and their local and regional effects (i.e. precursory activity, tephra fallout, lahars, pyroclastic density currents, lava flows) are also presented. The eruption had a severe impact on the ecosystem and on various economic sectors, including aviation, tourism, agriculture and fishing industry. Urban areas and critical infrastructures, such as airports, hos- pitals and roads, were also impacted. The concentration of PM10 (particulate matter ≤ 10 μm) was measured during and after the eruption, showing that maximum safety threshold levels of daily and annual exposures were surpassed in sev- eral occasions. Probabilistic analyses suggest that this com- bination of atmospheric and eruptive conditions has a prob- ability of occurrence of about 1 %. The management of the crisis, including evacuation of people, is discussed, as well as the comparison with the impact associated with other recent eruptions located in similar areas and having similar char- acteristics (i.e. Quizapu, Hudson and Chaitén volcanoes). This comparison shows that the regions downwind and very close to the erupting volcanoes suffered very similar prob- lems, without a clear relation to the intensity of the eruption (e.g. health problems, damage to vegetation, death of ani- mals, roof collapse, air traffic disruptions, road closure, la- hars and flooding). This suggests that a detailed collection of impact data can be largely beneficial for the development of plans for the management of an eruptive crisis and the miti- gation of associated risk of the Andean region.