Self-potential anomaly generation in volcanic areas. The Mt. Etna case-history

We propose a mechanism for self-potential (SP) anomaly generation in volcanic areas related to the rise of a magma intrusion towards the Earth's surface. To this scope, we take profit by a series of SP measurements carried out along a profile crossing the fracture system, located in the south-eastern part of Mt. Etna (Sicily, Italy), which are presented and discussed beforehand. A new processing method of the observed SP anomalies, for a ready recognition of the source pattern, according to a tomographic representation, is adopted for outlining, as realistically as possible, the time evolution of the impending risk.