June 21, 1978 Tsunami: Eastern Italy, Adriatic Sea

Ref #4139:

On June 21 (tsunami intensity iv, max horizontal inundation 800 m) some anomalous coastal oscillations of the sea along the central Adriatic coast between Giulianova and Bisceglie. No earthquakes recorded to justify the anomalous event. Bedosti (ref #9286) hypotesises that a possible cause is a submarine landslide beneath the 200 m isobath more or less between Termoli and Vasto. Mosetti (anonymous)also suggests the occurrence of a submarine landslide in the Adriatic sea. The following information is taken from Bedosti (ref #9286). The oscillations period was about 10-15 minutes. At Giulianova the sea withdrew by about 50 m at 11h 59m am and it came back 6 min later surpassing the normal level by about 60 cm. Oscillations repeated many times with period of 15 min and amplitude of 60 cm in the harbour until 5h 30m pm. At Ortona only one oscillation observed, starting at 11h 30m am with a withdrawal of 15 m. The water came back at 12h. At Bisceglie the sea withdrew by 2-3 m at 6h 30m and then it flooded the beach by 200 m. The maximum height was 50 cm. Two fishing boats broke their mooring. At Molfetta at 5.00 am 10 m of withdrawal. The period was 5 min. Anomalous oscillations also observed at Fossacesia, Vasto, Termoli, Campomarino and Trani at different times. Some newspapers report detailed description of the phenomenon: At Termoli the sea withdrew for tens of metres leaving the harbour dried and then violently came back; some swimmers referred that the sea water suddenly became cold and immediately after became also turbolent and strongly agitated (Anonymous). At Bari the sea water suddenly witdrew many times leaving the seafloor dried; some moored ships in the harbour went aground and some fish was found on the beach (Anonymous). Parenzan (ref #9287) reports that at Bari and Vieste the sea suddenly withdrew for about 50-100 m leaving boats aground and after a few minutes the sea violently inundated the shore with very high waves, causing damage to the boats and some injured people. The sea water swept away the beach-umbrellas. In many islands and places along the Yugoslavian coasts the sea water suddenly rose; at Vela Luka (Cursola island) the waves was 8 m high inundating the first floors of all the buildings on the shore. Many ships suffered severe damage and the sea water flooded the cost for 650 m inland (Anonymous) Also at Dubrovnick, Caltaro and at the Iissa island anomalous waves were observed (Anonymous).

Ref #9531:

21 June 1978, weather conditions were favourable for the formation of such air-pressure disturbances […] Thus, the dramatic waves at Vela Luka on 21 June 1978 were a [...] meteotsunami. Another recent work (Vucetic et al. 2009) also classified this event as a meteotsunami. Hence, the 21 June 1978 (Antonopoulos 1990, and Soloviev et al. 2000, where it is noted as 22 June 1978) event may be removed from the list of Adriatic tsunamis-the existence of the underwater landslide was not supported by evidence, while the Thessaloniki earthquake is an unlikely source because the shallow-water waves would have reached the Middle Adriatic in 3.6 h, i.e. several hours before the flooding at Vela Luka, and moreover, the earthquake epicentre was 30 km inland

Ref #10285:

No earthquake was recorded in that day to justify the anomalous event. Bedosti (ref #9286) hypothesises that a possible cause was a submarine landslide beneath the 200m isobath more or less between Termoli and Vasto. We remark that in the Italian Tsunami Catalogue this event was attributed an unknown cause, and we still persist in this position since new investigation is needed to unveil the real cause [...] if the tsunami was induced by a submarine landslide, the source can very unlikely be located in the place suggested by Bedosti

Ref# 13742:

material damage was approximately 7 m Euro [USD 9.5 m]