May 22, 1980 Tsunami: Azores, Portugal

On 22 May 1980 a large landslide occurred on the southern coast of Flores Island (39°22′ N, 31°13′ W), between Lajedo and Faja de Lopo Vaz. This event became known as the ‘Quebrada da Rocha Alta’ (Fig. 10).

The monthly newspaper As Flores (1980) contains references to this event, in which it is mentioned that the landslide occurred at dusk and many fishermen at the Lajes pier were perplexed to see the sea rise above its normal level, submerging stranded boats, the pier itself and the walls of coastal protection. This phenomenon was interpreted by some as a result of seismic activity, while others thought it was a landslide causing the sea-level rise. No damage was reported nor was anyone injured as a result of this event. As in the 1847 event (Quebrada Nova), this was a rotational slip landslide (Pacheco et al. 2006) triggered on a hillside c. 300 m high. The associated deposit has already suffered marine erosion and is currently c. 1000 m in length along the coast and about 400 m wide. The waves will preferably have displaced to the south and the only report of their lateral propagation along the coastline is that which mentions the Lajes pier. There are no reports regarding the maximum amplitude of the waves. (reference #13057)