Monday, 14. April 2008, 08:02:09
I am back home from a week in Lisbon, where I was several times reminded of the
Great Lisbon Earthquake.
On 1 November 1755 Lisbon was shaken by a violent earthquake. It occurred at 9:40 in the morning during High Mass - a mass to celebrate All Saints' Day, also known as All Hallows or Hallowmas, an important religious holiday in this strong Roman catholic country.

Geologists today estimate the Lisbon earthquake approached magnitude 9 on the Richter scale, with an epicentre in the Atlantic Ocean about 200 km west-south-west of Cape St. Vincent (See map). Estimates place the death toll between 60,000 to 100,000 people, making it one of the most destructive earthquakes in history.
More than 20 churches collapsed, and due to the candles lit for the celebration fire quickly broke out, and flames raged for five days. Gigantic fissures up to five metres wide appeared in the city centre. Survivors rushed to the open space of the docks for safety and watched as the water receded revealing the sea floor. Approximately forty minutes after the earthquake, an enormous tsunami engulfed the harbour and downtown, rushing up the Tagus river. It was followed by two more waves.
Many people at the time saw the disaster a God’s punishment - because the town was too rich, because of the inquisition (the Spanish Inquisition was established in 1478), because of idolatry or other sins? Apart from theological, philosophical (including work by Voltaire), and literary discussions, however, scientists got involved. It was the first earthquake studied scientifically for its effects over a large area, and it led to the birth of modern seismology.
I stayed at a hotel a few hundred metres from the
Santa Justa Lift (also known as the Carmo Lift). The Santa Justa Lift was designed by an apprentice of Gustave Eiffel (the one with the Eiffel Tower). The iron lift is 45 metres tall and it brought me from the downtown streets to the uphill Carmo Square. From the roof of the lift construction (with a bar, where I had an espresso) there is a nice view over downtown Lisbon and the
Carmo Convent. This mediaeval convent was ruined in the Earthquake, and the ruins of its Gothic church are the main trace of the great earthquake still visible in the city. The ruins were preserved to remind Lisboners of the destruction.
I went down to the docks and took the train to see one of the most impressive monuments in Lisbon, the
Jeronimos Monastery. The vaulting in the church withstood the earthquake of 1755, which probably says something about the architecture. In the same district - called Belém, which is in fact Portuguese for Bethlehem, and pronounced more or less as “blem” - there is an old tower, the
Torre de Belém. The tower was built in the same style as the Monastery between 1515 and 1519 in the middle of the river Tagus to defend Lisbon and the monastery. Today, however it stands on the water’s edge practically moored to the north bank, the river having altered course during (and after) the earthquake and tsunami of 1755.
From there the train moves on to the romantic fishing port - and holiday resort with yacht harbour - of
Cascaias, about half an hour’s ride from Lisbon (30 kilometres west of Lisbon). A large portion of the village was destroyed during the earthquake in 1755. But today it is bustling, and I had a nice evening meal at the beach with cockles and local wine.

PS of 17 April 2008
The position of the epicentre is disputed (See comments). The source mechanism seems to require generation at a subduction zone, but where would that be?