Diffuse magmatic soil degassing at Soufriere of Guadeloupe, Antilles

A soil gas profiling made along the southern basis of Soufriere summit lave dome, in Guadeloupe, reveals the existence of diffuse emanations of magma-derived CO2 in coincidence with a major volcanic (Ty) fault, where CO2 concentrations at 70 cm depth in the ground reach 35-96 % and are associated with a thermal convective cell. Outside, a few 'cold' gaseous anomalies of volcanic origin (lack of methane) provide reliable conditions for continuous radon monitoring of soil degassing. (authors)