July 26, 1691 Tsunami: Azores, Portugal

Note: this event is likely referencing the event of 1591 July 26. See comments by reference #13057.

Sea disturbance (reference #4139)

1691 July 26. According to Mendonca (1758) and Padilla (1751), a violent seismic shock was felt throughout the Island of Terceira on 26 July 1691. Both accounts are poor in details which, nonetheless, agree with the description of a tsunami associated with that shock: " ... [both] the ships sailing 20 leagues away from that island and moored ashore were in risk of wrecking due to the large disturbance of the sea." (Mendonca, 1758). " ... the air and sea raged ... and the ships, not only those anchored ashore but also those sailing as far as 20 leagues offshore, were in risk of wrecking ... " (Padilla, 1757). (reference #5046)

1691 July 26. Improbable tsunami. (reference #11164)

1691 July 26. This tsunami is listed as an erroneous entry by ref #13057. Based on these descriptions, Andrade et al. (2006), Borges et al. (2008) and Baptista (1998) assumed the occurrence of a tectonic triggered tsunami on Terceira Island. However, the transcription of Mendonca (1758) about the 1691 event is identical to that of Buffon ([1707–1788] 1853) regarding the 1591 seismic crisis in S. Miguel Island, presented earlier in this paper. In fact, there are several coincidences, such as the dates (1591/ 1691), the mention of the destruction of Vila Franca do Campo and the reference to the earthquake effects felt at sea on ships 20 leagues offshore. Most of all, the same comparison had already been made by Canto (1880), who stated that ‘all this is a manifest error, arising from the confusion of the date of 1591, with that of 1691; as can easily be seen, seeing what was said of the phenomena of that year’ (vol. III, p. 495). (reference #13057)