RADON MIGRATION IN THE SOLFATARA CRATER, CAMPI FLEGREI

S. De Martino, M. Mattera, G. Monetti, C. Sabbarese 

(Dipartimento di Fisica, Universita' di Salerno, I-84081 Baronissi, Salerno, Italy)

Radon migration was studied in the soils of the Solfatara Crater, Campi Flegrei (Southern Italy) using radioactive disequilibrium between Ra-226 and Pb-210. Vertical profiles of soil (as far as 5 m long) were investigated. Radon migration parameters were studied as function of physical characteristics of soil (density, porosity, grain size, water content) and also by considering the fumarolic emissions, the small crater of hot mud and the small fault present in the crateric area. Results show:
1) the good sensitivity of disequilibrium method at the physical variations of the soil;
2) the influence of the transport velocity as function of the distance from the fumarolic emissions, from the small fault and from the hot mud;
3) a global model of radon migration in the soils of the crateric area, which presents interesting results respect to the temperature and permeability gradients.