October 30, 1930 Tsunami: Central Adriatic, Italy

October 30, 1930, 07:13 UTC, 43 deg 40 min N, 13 deg 16 min E, magnitude 5.9, earthquake intensity VIII, tsunami intensity 4. This earthquake (I=VIII-IX, M=5,9) called the "Senigallia earthquake" hit the coastal area in the central Adriatic, with maximum effects at Senigallia. Here the shock caused severe damage and the total destruction of many buildings. 18 victims (14 at Senigallia). Some sources mention a strong tsunami in the harbour of Ancona. A sudden high tide was noted, the sea boiled. An American steamship, moored in the "molo della Sanita'", broke its moorings because of the waves and it was slammed against the dock, suffering heavy damage. The railing of the harbour office was almost completely pulled off. The docks in the harbour were broken with large cracks. Many fishermen that were on their ships in the harbour quickly came back to the beach , frightened by the extraordinary movement of the water. (reference #4139)

On 30 October 1930, a strong earthquake (I = VIII–IX, M = 5.9), called the ‘Senigallia earthquake’, struck the coastal area around Ancona (Boschi et al. 1995), with maximum effects at Senigallia. It was accompanied by a strong tsunami in the harbour of Ancona (Boschi et al. 1995): Suddenly, high tide impinged on the coast, and the sea boiled. The tsunami waves broke off the moorings of an American ship and slammed it against the dock. The fence of the harbour office was almost completely pulled out, and the docks were heavily damaged. Many fishermen who were on their vessels in the harbour quickly disembarked, frightened by the extraordinary movement of the water (Il Corriere Padano 1930; Il Messaggero 1930) (Fig. 10). Croatian journals supplied extensive accounts of the catastrophic earthquake in Italy and the tsunami in the harbour of Ancona (Jutarnji list 1930). We have examined marigrams from the tide gauge at Bakar, close to Rijeka, which began operating several months before the earthquake. The instrument registered moderate high-frequency variability throughout 30 October, starting several hours prior to the earthquake (Archives of Geophysical Institute, Faculty of Science, University of Zagreb) but showing no enhancement at the time of the expected arrival of the tsunami waves. Thus, any sign of a weak tsunami on the eastern side of the Adriatic would have been masked by meteorologically induced sea-level oscillations. (reference #9531)