Continuous monitoring of hydrogen and carbon dioxide at Mt Etna

This study assessed the use of an H2 fuel cell as an H2-selective sensor for volcano monitoring. The resolution,repeatability, and cross-sensitivity of the sensor were investigated and evaluated under known laboratoryconditions. A tailor-made device was developed and used for continuously monitoring H2 and CO2 at Mt Etnathroughout 2009 and 2010. The temporal variations of both parameters were strongly correlated with theevolution of the volcanic activity during the monitoring period. In particular, the CO2 flux exhibited long-termvariations, while H2 exhibited pulses immediately before the explosive activity that occurred at Mt Etna during2010.