Continuous monitoring of hydrogen and carbon dioxide at Mt Etna

- We assess the use of an H2 fuel cell as an H2 selective sensor.
- We develop a new device for the continuous monitoring of soil H2 and CO2.
- H2 and CO2 provide complementary information for monitoring volcanic activity.

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 laboratory conditions. A tailor-made device was developed and used for continuously monitoring H2 and CO2 at Mt Etna throughout 2009 and 2010. The temporal variations of both parameters were strongly correlated with the evolution of the volcanic activity during the monitoring period. In particular, the CO2 flux exhibited long-term variations, while H2 exhibited pulses immediately before the explosive activity that occurred at Mt Etna during 2010.