LONG-TERM TEMPERATURE MONITORING OF ACTIVE VOLCANIC AREAS BY DISTRIBUTED OPTICAL FIBER SENSORS

We present the first results of long- term monitoring of temperature profiles at the Campi Flegrei caldera (Italy). The measurements were carried out along a 76 meters-deep borehole already equipped with a borehole strain-meter. We installed a cable containing a loop of optical fiber in order to use a fiber-optics distributed sensor based on stimulated Brillouin scattering. The obtained data are consistent with results of both deep and surface geothermal explorations and indicate that geothermal gradient can be efficiently measured and monitored by the proposed technique.