Three years of gravity continous obsevations in the Calabria Arc System: a model of the gravity tide and the tidal field

Abstract

Remarkable mass displacements of different origin and nature are currently active in the geological domain known as Calabrian-Peloritani Arc and in the adjacent Tyrrhenian and Ionian Seas. Geophysical, geological and archeological evidence exists that the Ionian coasts are interested by intense subsidence phenomena(e.g. Marino et al., 2010; Minelli et al., 2013; Stanley and Bernasconi, 2012). However, over geological times, the whole Calabrian region has been rapidly rising relatively to the sea level. The region can be subdivided into several blocks that move upwards with different mean vertical velocities, estimated in some areas up to about 2 mm/yr in the last 700,000 years (e.g. Sorriso-Valvo, 1993; Westaway, 1993; Antonioli al., 2006). Finally, as shown by the intermediate and deep local seismicity the subduction under the Tyrrhenian Sea is still active and should be taken into account, whatever its stage of development (e.g. Monna et al., 2013; Piana Agostinetti et al., 2009, and reference therein). Although since over a century the Calabrian region is going through a period of relative seismic quietness, its seismic hazard is at the highest levels in the Mediterranean basin due to several catastrophic earthquakes present in the historical records.