Main Page | See live article | Alphabetical index

1755 Lisbon earthquake

The 1755 Lisbon earthquake took place on November 1, 1755 at 9:20 in the morning. It was one of the most destructive and deadly earthquakes in history and had a strong impact in the 18th century society. Modern geologists estimate that the Lisbon earthquake approached magnitude 9 on the Richter scale.

Table of contents
1 The earthquake
2 The day after
3 Social implications
4 The birth of seismology
5 External link

The earthquake

The earthquake struck in early morning of November 1, the All Saints Day Catholic holiday. Contemporary reports state that the earthquake lasted for three-and-a-half minutes, causing gigantic fissures five meters wide to rip apart the city centre. The survivors rushed to the open space of the docks for safety and watched as the water receded, revealing the sea floor, littered by lost cargo and old shipwrecks. Moments later an enormous tsunami engulfed the harbour, and the city downtown. In the areas unaffected by the tidal wave, fire quickly broke out, and flames raged for five days.

Lisbon was not the only Portuguese city affected by the catastrophe. All the South of the country, namely Algarve was affected and destruction was generalized. The shockwaves of the earthquake were felt throughout Europe and North Africa. Tsunamis up to twenty meters in height swept the coast from North Africa to Finland and across the Atlantic to Martinique and Barbados.

Of a population of 275,000, about 90,000 were killed. Another 10,000 were killed across the Mediterranean in Morocco. Eighty-five percent of Lisbon's buildings were destroyed, including its famous palaces and libraries. Several buildings which had suffered little damage due to the earthquake were destroyed by the fire. The brand new Opera House, opened only six months before, was burned to the ground. The Royal Palace stood just beside the Tagus river in the modern square of Terreiro do Paço, and was destroyed by the earthquake and the tsunami. Inside, the 70,000-volume library and hundreds of works of art, including paintings by Titian, Rubens, and Correggio, were lost. The precious royal archives concerning the exploration of the Atlantic and old documents also disappeared. The earthquake destroyed also the major churches of Lisbon, namely the Cathedral of Santa Maria, and the Basilicas of São Paulo, Santa Catarina, São Vincente de Fora, and the Misericordia. The ruins of the Carmo convent can still be visited today in the centre of the city. The Royal Hospital of All-Saints was consumed by fire and hundreds of patients burned to death.

The day after

Due to a strike of luck, the royal family escaped unharmed from the catastrophe. King Joseph I of Portugal and the court had left the city, after attending mass at sunrise. The reason was the will of one of the princesses to have a holy day away from the city. The king was very fond of his four daughters and decided to oblige her wishes. After the catastrophe, Joseph I developed a fear of living within walls, and the court was accommodated in a huge complex of tents and pavilions in the hills of Ajuda, then in the outskirts of Lisbon.

Like the king, the prime minister Sebastião de Melo (the Marquis of Pombal) survived the earthquake. With the pragmatism that characterized his rule, the prime minister immediately started to organize the reconstruction. He was not paralysed with shock and is reported to have answered: Now? We bury the dead and take care of the living. His quick response put fire-fighters in the city and teams to remove the thousands of corpses. Thanks to this, no major epidemic followed the earthquake.

As for the city itself, the prime minister and the king hired architects and engineers and less than a year later, Lisbon was already free from the debris and being reconstructed. The king was keen in having a new, perfectly ordained city. Big squares and rectilinear, large avenues were the mottos of the new Lisbon. At the time, somebody asked the Marquis of Pombal what was the need of such wide streets. The Marquis answered: ''one day they will be small...'\' And indeed, the chaotic traffic of Lisbon reflects the wisdom of the reply.

The new downtown, known nowadays as the Pombaline Downtown, is one of Lisbon's attractions. These buildings are also among the first seismic protected constructions in the world. Small wooden models were built for testing and the earthquake was simulated by marching troops around them.

Social implications

The earthquake shook a lot more than a city and its buildings. Lisbon was the capital of a devout catholic country, with a history of investments in the church and evangelisation of the colonies. Moreover, the catastrophe struck in a catholic holiday and destroyed every important church. For the religious minds of the 18th century, this manifestation of the anger of God was difficult to explain. In the following days, priests roamed the city hanging people suspected of heresy on site, blaming them for the disaster. Many contemporary writers, such as Voltaire, mentioned the earthquake on their writings. The Lisbon earthquake made many people wonder about the existence of a God who permitted these events to happen.

In the internal politics, the earthquake was also devastating. The prime minister was the favourite of the king, but the high nobility despised him as an up-start. The feelings were returned and a constant struggle for power and royal favour was taking place. After November 1, the competent response of the Marquis of Pombal severed the power of the aristocratic faction. Conflicts were constant and silent opposition to king Joseph I started to rise. This would end in an attempted murder of the king and the elimination of the powerful Tavora family. See Tavora affair for the whole account.

The birth of seismology

The competent action of the prime minister was not limited to the practicalities of the reconstruction. The Marquis ordered a query to be sent to all parishes of the country, regarding the earthquake and its effects. Questions included:

The answers are still archived in the Tower of Tombo, the national historical archive. Studying and cross-referencing the priests accounts, modern scientists were able to reconstruct the event in a scientific perspective. Without the query designed by the Marquis of Pombal, the first attempt of a seismological, objective description, this would be impossible. This is why the Marquis is regarded as the precursor of seismological sciences.

The geological causes of this earthquake and the seismic activity in the region of Lisbon are still being discussed by modern scientists. Since Lisbon is located in a centre of a tectonic plate, there is not a obvious reason for the event. Portuguese geologists have suggested that the earthquake is related with the first steps of development of an atlantic subduction zone.

Note: Despite the fact that the prime minister Sebastião de Melo is mentioned here as Marquis of Pombal, the title was only granted in 1779.

See also: List of earthquakes

External link