Deep versus shallow sources of CO and Rn from a multi-parametric approach: the case of the Nisyros caldera (Aegean Arc, Greece).

Estimating the quantity of CO diffusively emitted from the Earth's surface has important implications for volcanic surveillance and global atmospheric CO budgets. However, the identification and quantification of non-hydrothermal contributions to CO release can be ambiguous. Here, we describe a multi-parametric approach employed at the Nisyros caldera, Aegean Arc, Greece, to assess the relative influence of deep and shallow gases released from the soil.