AUTOMATIC DATA ACQUISITION SYSTEM TO MEASURE DISSOLVED CO2 (CO2 METER): Data obtained during measurements performed in Ecuador and Argentina

AGUSTO, M.; HIDALGO, S.; TASSI, F.; CÓRDOBA, J.; LAMBERTI, M.C.

Nápoles

Congreso; Cities on Volcanoes 10; 2018

IAVCEI

After water, carbon dioxide (CO2) is the main gas dissolved in magma. Being easily exsolved compared to more soluble gas species, CO2 is one of the main components of volcanic emissions both during quiescence and periods of unrest. Carbon dioxide is released from magma at depths and can condense and/or become dissolved in shallows aquifers existing around the volcano. Changes in the concentration of dissolved CO2 in spring water can therefore be related to volcanic activity, especially when related to other parameters such as (water?) temperature and seismicity for example. For the purpose of continuous monitoring of dissolved CO2 in spring water, an Automatic Data Acquisition System (CO2 METER) has been developed.The work presented here, comprises data collected during several campaigns at spring waters in Ecuador and Argentina between 2015-2017, performed in order to verify the reliability of CO2 METER system. For the majority of obtained data there is strong agreement between concentrations of dissolved CO2 and temperature when compared with existing data. At Palmira spring, a natural water source in close proximity to Guagua Pichincha volcano (Ecuador), CO2 METER registered a CO2 concentration of 22.6%, comparable to similar concentrations acquired by Inguaggiato et al. 2010. In another campaign performed at Las Maquinitas hot spring near to Copahue volcano (Argentina) the CO2 METER registered an average dissolved CO2 concentration of 1.4% and a temperature of 83ºC. These data compare well with measurements performed by Augusto et al. 2017 (not published). These first results provide validation for the CO2 METER as an accurate means by which to measure dissolved CO2 at spring waters. This fully automated system provides a promising tool for volcano observatories to provide real time continuous data, reducing timely dependence of routing measurements.