Carbon Dioxide Diffuse emissions at the Planchón ? Peteroa Volcanic Complex, Southern Andes, Argentina - Chile

NOGUÉS V; CHIODINI G; AGUSTO M; CARDELLINI C; LAMBERTI M C

Workshop; 13th WORKSHOP CCVG-IAVCEI; 2017

Instituto Geofísico - Escuela Politécnica Nacional (ECUADOR)

ThePlanchón ? Petoroa Volcanic Complex (PPVC) is in the Andean range shared byArgentina and Chile, comprised in the Transitional Southern Volcanic Zone(Stern, 2004). Fluid emissions occur from the caldera of the Peteroa volcano,and from hydrothermal peripheral areas, such as the Baños del Azufre and thePeñón valleys. Surveys of CO2 diffuse degassing were carried out atthese three sites of the PPVC and in a tributary valley to (of) theValenzuela river, not characterized by thermal emissions. About the hydrothermal sites, diffuse emissions of CO2are poorly spread and are mainly linked to the thermal springs. The GraphicalStatistical Approach method was used to investigate the origin of the CO2in each site: two CO2 populations correspond to background fluxes, whilea third population only present in the valleys of Baños del Azufre and Peñón, canbe related to volcanic ? hydrothermal CO2 degassing. The SequentialGaussian Simulation method (SGS) was used to map the CO2 flux and toestimate the CO2 release and it revealed that Baños del Azufre, Peñónand the tributary valley emit 3.7, 4.7, and 0.64 tons/day of CO2 respectively.About the Peteroa caldera, both diffuse CO2and temperature anomalies were detected. The occurrence of two CO2flux populations characterize Peteroas?s data. Due to the total absence ofvegetation, both can be interpreted as due to volcanic CO2degassing. The CO2 flux map of the Peteroa caldera highlights twodistinct areas of emission. The SGS analysis allowed to estimate that about 6.5tons/day of CO2 are released from the surveyed area of the Peteroa caldera.