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.
My family were living in the Algarve when the 1969 earthquake struck I was 7 at the time. And I recall the whole house shaking a big crack appearing in our hallway ceiling and I could hear the bells swinging in the nearby church due to the quake. We got in the car and for some reason my dad drove us to the beach!
By She lomas from UK on 24 Nov 2019, 15:03
Living in the Algarve in 1969 I was 10 , remember waking up early hours of the morning with the doors rattling. We thought it was the dog leaning against it and having a scratch. We knew something was wrong as cracks began to appear on the walls. My dad gathered us all up and I remember as we got outside, the church in the square falling down, which is not there now. My dad drove us to the beach ,which we now know was the wrong thing to do.
By Louise Sparham from UK on 25 Nov 2019, 16:45