GEOLOGICAL AND GEOPHYSICAL EVIDENCE FOR A HOLOCENE TSUNAMI DEPOSIT INTHE EASTERN MEDITERRANEAN DEEP-SEA RECORD

Extended geological and geophysical exploration of basinal settings in different areas of the eastern Mediterranean demonstrate the existenc e of a Holocene mud layer several metres in thickness (up to more than 20 m) and typically showing a graded basal part. The event producing this peculiar deposit is correlated with the gigantic 'Bronze Age' or Minoan eruption of the Santorini volcano (3500 years BP), which result ed in caldera collapse and supposedly produced a strong seismic sea-wa ve, that is a tsunami. Order of magnitude calculations demonstrate tha t the wave speed was sufficient to induce erosion and liquefaction of the soft unconsolidated sediments draping the deep-sea floor. The even t is recorded in over 50 deep-sea cores recovered in the last 20 years which contain the fine grained 'Homogenite' layer starting with a fin ing-upwards sandy base and having a thickness of more than 24 m in the Sirte Abyssal Plain area. Several depositional models related to sett ing and source areas and based on thickness, composition, carbonate co ntent and sedimentary structures of the deposits have been proposed. ( C) 1997 Elsevier Science Ltd.