For decades, geologists have struggled to explain the massive earthquakes which struck Lisbon in 1755 and 1969. Now a fissure in the tectonic plate 200 kilometres off the coast of Cabo de São Vicente (Sagres) may finally offer a clue to the forces behind earthquakes in the Portuguese capital.
This fissure, which has only just been discovered, has been forming for at least five million years, according to a study by the Faculty of Sciences of the University of Lisbon recently published in the journal Nature Geosciences.
