RADON, PH AND TEMPERATURE MONITORING IN WATER WELLS AT CAMPI-FLEGREI CALDERA (SOUTHERN ITALY)

Monitoring of the Campi Flegrei caldera has been undertaken since 1983 by measuring radon content (by track etch method), pH and temperature in three thermal water wells. Collection of data started after the ar ea was affected by a dramatic phase of volcano unrest, with a high rat e of uplift and increased seismicity. Results show that the radon cont ent is different from well to well; low in the cold well and at least one order of magnitude greater in the two hot wells. Variations in rad on content in the three wells sometimes occurred simultaneously and in dicate an influence from the same phenomena and feeding source. Three main events, (i) rain fall, (ii) seismic activity and (iii) volcano un rest have been identified to correlate with variations in the radon co ntent, with pH and temperature changes at the same time.