Gravity changes and present-day dynamics of the island of Pantelleria (Sicily Channel—Italy)

Abstract

The island of Pantelleria is an active volcano located in the Sicily Channel (southern Italy), occurring in the middle of a continental rift system. Since the 1980's the island has been periodically surveyed by means of geodetic and geophysical methods to monitor the regional and local volcanic dynamics. Also, high-precision gravity measurements were started in 1990. The present paper is an analysis of the time-space gravity changes. Gravity measurements were carried out on a network presently formed by twenty stations. The gravity network was fully surveyed in June 1990 and June 1995 and partially surveyed in September 1993. Two absolute gravity stations were established in 1993 to provide a reference system and to check for long-term variations. The areal distribution of the gravity changes during the 1990–1995 time interval, obtained in the thirteen stations of the 1990 network, is strongly similar to the Bouguer anomaly field and to the large-scale features of the basement of the island. Otherwise, gravity changes are directly correlated with the Bouguer anomaly and inversely correlated with the altimetric variations. Comparison with the geological setting suggests that the present activity may be ascribed to the influence of the geodynamics of the Sicily Channel.