The Augias megaturbidite in the central Ionian Sea (central Mediterranean) and its relation to the Holocene Santorini event

A thick mud turbidite, up to 24 m in thickness (termed the “Augias turbidite”) is decribed from the Ionian and Sirte Abyssal Plains and the adjacent slopes of the Calabrian Rise and the Mediterranean Ridge. The material of the megaturbidite is derived from the Gulf of Sirte (revealed by its high aragonite content) and, through erosion, from the Sirte Rise. The shallow water sediments making up the turbidite were probably mobilized by a tsunami caused by the Minoan Santorini collapse around 3500 yr B.P. The volume of the mobilized sediments is calculated as a minimum of 65 km3. Isolated turbidites of the same age deposited on the upper slope of the Mediterranean Ridge may consist of tsunami-mobilized shallow water material as well as of earthquake-triggered sediment from the flanks of local depressions.