HAS THE MEDITERRANEAN SEA FELT THE MARCH 11th, 2011, M 9.0 TOHOKU-OKI EARTHQUAKE (JAPAN)?

Sea level recordings from about 200 available tide gauge stations located along the coast of Japan and elsewhere in the world, including the Mediterranean basin, were analysed to investigate the far field effects of the giant tsunami caused by the March 11th, 2011, M 9.0 Tohoku-Oki earthquake. The tsunami was generated offshore the Honshu island (Japan) and propagated in the Oceans. While the near field tide gauge stations show a saturated signal due to the very high tsunami waves, the Mediterranean tide gauge stations have likely recorded a weak signal that disturbed the daily tidal trends. In this report we briefly show and discuss the analysis of tidal data from some selected tide gauge stations located in the Mediterranean sea, including the Italian tide gauge network consisting in 30 stations. Global sea level data were retrieved by internet from IOC (http://www.ioc-sealevelmonitoring.org/) and ISPRA for the Italian region(http://www.mareografico.it/). Tidal data were reduced for inverse barometric correction and analyzed by an advanced filtering technique that decomposes a non-stationary time series X(t) through oscillating modes, identifying the contributions at different timescales of the tidal variations. Finally, we focused on the dynamical behavior of low-frequency processes and trends.