The 7.9 magnitude quake occurred during the early hours of 28 February 1969 and was the biggest earthquake registered in Europe since the Lisbon 1755 quake.

Its epicentre was 180km southwest of Sagres and was felt mostly in the Algarve, Madeira, Spain, Morocco and France, causing 13 deaths.

The online project aims to determine just how dangerous earthquakes are to Portugal.