Morfologia e dinamica delle frane sottomarine potenzialmente tzunamogeniche del margine meridionale sardo (Progetto MAGIC)

Tsunamis are tipically related to several triggering events including earthquakes generated along subduction zones extending up to several hundreds kilometers in lenght, the gravitational massive collapse of volcanic buildings, cliffs or submarine landslides (TINTI ET ALII, 1999; FRYER ET ALII, 2004; MCADOO &WATTS, 2004). Until recent years, tsunamis associated with gravitational events, have been considered very rare, restricted to limited areas and with less energy than the earthquakes generated tsunamis. Recent studies show that the landslides produced tsunamis can be frequent as much as those induced by earthquakes and are also able to generate extreme waves that may affect coastal areas (MCMURTHY ET ALII, 2004; LEE ET ALII, 2007). Considering the actual population growth and industrialization of coastal areas, these are important data implying that tsunami hazard should be studied not only in tectonically active areas, but also in passive margin contexts where gravitational processes can frequently occur (GARZIGLIA ET ALII, 2007). Within the MAGIC project (Marine Geohazard Along the Italian Coast) during the “Sardegna 2009” and “Sardegna 2010” cruises, carried out with the R/V “Universitatis”, multibeam surveys with RESON 8160, high resolution seismic surveys by CHIRP Subbottom ( 500Hz/13,5kHz) and sparker surveys APPLIED ACOUSTICCSP2200 (10/2000 J) were carried out in the southern and western Sardinian margin at depths between -50 and -2200 m. In this work several complex landslides, detected in the upper Sulcis slope and in the Cagliari gulf were analyzed.