Soil thermal gradient at Solfatara during 2016-2017 (Campi Flegrei, south Italy)

The monitoring of energy fluxes associated with diffuse degassing may bean important tool in the surveillance of volcanic activity. In a purely conductive regime, the heat flux is a linear function of the soil thermal gradient with a slope proportional to the thermal conductivity of the medium. For that reason, soil temperatures were continuously measured during two years (january 2016 to january 2018) within the crater of Solfatara using an automatic station. The station was equipped with a Gigalog mod.F data logger that acquires, at 1-hour time intervals, the soil temperature along a vertical profile at 0.1, 0.2, 0.3 and 0.4 m depth, The measurements, expressed in degrees centrigade, made with n.4 Resistance Temperature Detector "RTD" PT100 in platinum class B with a tolerance of ±0.3 °C at 0°C. The coordinates of the instrument are 33T 427461.48m E 4520150.14m N