1755 Lisbon earthquake

2007 Schools Wikipedia Selection. Related subjects: General history

This 1755 copper engraving shows the ruins of Lisbon in flames and a tsunami overwhelming the ships in the harbor.
This 1755 copper engraving shows the ruins of Lisbon in flames and a tsunami overwhelming the ships in the harbour.

The 1755 Lisbon earthquake took place on November 1, 1755, at 9:40 in the morning. It was one of the most destructive and deadly earthquakes in history, killing between 60,000 and 100,000 people. The quake was followed by a tsunami and fire, resulting in the near-total destruction of Lisbon. The earthquake accentuated political tensions in Portugal and profoundly disrupted the country's eighteenth-century colonial ambitions.

The event was widely discussed by European Enlightenment philosophers, and inspired major developments in theodicy and in the philosophy of the sublime. As the first earthquake studied scientifically for its effects over a large area, it signaled the birth of modern seismology. Geologists today estimate the Lisbon earthquake approached magnitude 9 on the Richter scale, with an epicenter in the Atlantic Ocean about 200  km (120  mi) west-southwest of Cape St. Vincent.

The earthquake

The ruins of the Carmo Convent, which was destroyed in the Lisbon earthquake.
The ruins of the Carmo Convent, which was destroyed in the Lisbon earthquake.

The earthquake struck on the morning of 1 November, the Catholic holiday of All Saints' Day. Contemporary reports state that the earthquake lasted between three-and-a-half and six minutes, causing gigantic fissures five  metres (16 ft) wide to appear in the city centre. The survivors rushed to the open space of the docks for safety and watched as the water receded, revealing a sea floor littered by lost cargo and old shipwrecks. Several tens of minutes after the earthquake, an enormous tsunami engulfed the harbour and downtown, rushing up the Tagus river. It was followed by two more waves. In the areas unaffected by the tsunami, fire quickly broke out, and flames raged for five days.

Lisbon was not the only Portuguese city affected by the catastrophe. Throughout the south of the country, in particular the Algarve, destruction was general. The shockwaves of the earthquake were felt throughout Europe as far as Finland and North Africa. Tsunamis up to 20 metres (66 ft) in height swept the coast of North Africa, and struck Martinique and Barbados across the Atlantic. A three-metre (ten-foot) tsunami hit the southern English coast. Galway, on the west coast of Ireland, was also hit, resulting in the partial destruction of the " Spanish Arch".

Estimated epicentre of the 1755 Lisbon earthquake.
Estimated epicentre of the 1755 Lisbon earthquake.

Of a Lisbon population of 275,000, up to 90,000 were killed. Another 10,000 were killed in Morocco. Eighty-five percent of Lisbon's buildings were destroyed, including famous palaces and libraries, as well as most examples of Portugal's distinctive 16th-century Manueline architecture. Several buildings that had suffered little earthquake damage were destroyed by the subsequent fire. The brand new Opera House, opened only six months before (under the ill-fated name Phoenix Opera), was burned to the ground. The Royal Ribeira Palace, which stood just beside the Tagus river in the modern square of Terreiro do Paço, was destroyed by the earthquake and tsunami. Inside, the 70,000-volume royal library as well as hundreds of works of art, including paintings by Titian, Rubens, and Correggio, were lost. The precious royal archives disappeared together with detailed historical records of explorations by Vasco da Gama and other early navigators. The earthquake also damaged major churches in Lisbon, namely the Lisbon Cathedral, the Basilicas of São Paulo, Santa Catarina, São Vicente de Fora, and the Misericordia Church. The Royal Hospital of All Saints (the biggest public hospital at the time) in the Rossio square was consumed by fire and hundreds of patients burned to death. The tomb of national hero Nuno Álvares Pereira was also lost. Visitors to Lisbon may still walk the ruins of the Carmo Convent, which were preserved to remind Lisboners of the destruction.

It is said that many animals sensed danger and fled to higher ground before the water arrived. The Lisbon quake is the first documented reporting of such a phenomenon in Europe.

The day after

The Ruins of Lisbon.  Survivors lived in tents on the outskirts of the city after the earthquake, as shown in this fanciful 1755 German engraving.
The Ruins of Lisbon. Survivors lived in tents on the outskirts of the city after the earthquake, as shown in this fanciful 1755 German engraving.
Detail from above: Executions in the aftermath of the Lisbon earthquake.  At least 34 looters were hanged in the chaotic aftermath of the disaster.  As a warning against looting, King Joseph I of Portugal ordered gallows to be constructed in several parts of the city.
Detail from above: Executions in the aftermath of the Lisbon earthquake. At least 34 looters were hanged in the chaotic aftermath of the disaster. As a warning against looting, King Joseph I of Portugal ordered gallows to be constructed in several parts of the city.

Owing to a stroke 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, fulfilling the wish of one of the king's daughters to spend the holiday away from Lisbon. 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 on the outskirts of Lisbon. The king's claustrophobia never waned, and it was only after Joseph's death that his daughter Maria I of Portugal began building the royal Ajuda Palace, which still stands on the site of the old tented camp. Like the king, the prime minister Sebastião de Melo (the Marquis of Pombal) survived the earthquake. "Now? Bury the dead and feed the living," he is reported to have said, and with the pragmatism that characterized his coming rule, the prime minister immediately began organizing the recovery and reconstruction. He sent firefighters into the city to extinguish the flames, and ordered teams to remove the thousands of corpses before disease spread. Contrary to custom and against the wishes of representatives of the Church, many corpses were loaded onto barges and buried at sea beyond the mouth of the Tagus. To prevent disorder in the ruined city, and, in particular, as a deterrent against looting, gallows were constructed at high points around the city and at least 34 people were executed. The Portuguese Army surrounded the city to prevent the able-bodied from fleeing, so that they could be pressed into clearing the ruins.

Not long after the initial crisis, the prime minister and the king quickly hired architects and engineers, and less than a year later, Lisbon was free from debris and undergoing reconstruction. The king was keen to have 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 about the need for such wide streets. The marquis answered: one day they will be small. Indeed, the chaotic traffic of Lisbon today reflects the wisdom of his reply.

Pombaline buildings are among the first seismically-protected constructions in the world. Small wooden models were built for testing, and earthquakes were simulated by marching troops around them. Lisbon's "new" downtown, known today as the Pombaline Downtown (Baixa Pombalina), is one of the city's famed attractions. Sections of other Portuguese cities, like the Vila Real de Santo António in Algarve, were also rebuilt along Pombaline principles.''''

Social and philosophical implications

The earthquake shook much more than cities and buildings. Lisbon was the capital of a devout Catholic country, with a history of investments in the church and evangelism in the colonies. Moreover, the catastrophe struck on a Catholic holiday and destroyed almost every important church. For eighteenth-century theology and philosophy, this manifestation of the anger of God was difficult to explain.

The earthquake strongly influenced many thinkers of the European Enlightenment. Many contemporary philosophers mentioned or alluded to the earthquake in their writings, notably Voltaire in Candide and in his Poème sur le désastre de Lisbonne ("Poem on the Lisbon disaster"). The arbitrariness of survival motivated Voltaire's Candide and its satire of the idea that this was the " best of all possible worlds"; as Theodor Adorno wrote, "[t]he earthquake of Lisbon sufficed to cure Voltaire of the theodicy of Leibniz" (Negative Dialectics 361). In the later twentieth century, following Adorno, the 1755 earthquake has sometimes been compared to the Holocaust as a catastrophe so tremendous as to have a transformative impact on European culture and philosophy.

Jean-Jacques Rousseau was also influenced by the devastation following the earthquake, the severity of which he believed that was due to too many people living within the close quarters of the city. Rousseau used the earthquake as an argument against cities as part of his desire for a more naturalistic way of life.

The concept of the sublime, though it existed before 1755, was developed in philosophy and elevated to greater importance by Immanuel Kant, in part as a result of his attempts to comprehend the enormity of the Lisbon quake and tsunami. Kant published three separate texts on the Lisbon earthquake. The young Kant, fascinated with the earthquake, collected all the information available to him in news pamphlets, and used it to formulate a theory of the causes of earthquakes. Kant's theory, which involved the shifting of huge subterranean caverns filled with hot gases, was (though ultimately shown to be false) one of the first systematic modern attempts to explain earthquakes by positing natural, rather than supernatural, causes. According to Walter Benjamin, Kant's slim early book on the earthquake "probably represents the beginnings of scientific geography in Germany. And certainly the beginnings of seismology."

Werner Hamacher has claimed that the earthquake's consequences extended into the vocabulary of philosophy, making the common metaphor of firm "grounding" for philosophers' arguments shaky and uncertain: "Under the impression exerted by the Lisbon earthquake, which touched the European mind in one [of] its more sensitive epochs, the metaphor of ground and tremor completely lost their apparent innocence; they were no longer merely figures of speech" (263). Hamacher claims that the foundational certainty of Descartes' philosophy began to shake following the Lisbon earthquake.

In Portuguese internal politics, the earthquake was devastating. The prime minister was the favorite of the king, but the aristocracy despised him as an upstart son of a country squire. (Although the Prime Minister Sebastião de Melo is known today as Marquis of Pombal, the title was only granted in 1770, fifteen years after the earthquake.) The prime minister in turn disliked the old nobles, whom he considered corrupt and incapable of practical action. Before November 1, 1755 there was a constant struggle for power and royal favour, but afterwards, the competent response of the Marquis of Pombal effectively severed the power of the old aristocratic factions. Silent opposition and resentment of King Joseph I began to rise. This would culminate in an attempted assassination of the king, and the elimination of the powerful Duke of Aveiro and the Távora family.

The birth of seismology

The prime minister's response was not limited to the practicalities of reconstruction. The marquis ordered a query sent to all parishes of the country regarding the earthquake and its effects. Questions included:

  • how long did the earthquake last?
  • how many aftershocks were felt?
  • what kind of damage was caused?
  • did animals behave strangely? (this question anticipated studies by modern Chinese seismologists in the 1960s)
  • what happened in wells and water holes?

The answers to these and other questions 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 from a scientific perspective. Without the query designed by the Marquis of Pombal, this would have been impossible. Because the marquis was the first to attempt an objective scientific description of the broad causes and consequences of an earthquake, he is regarded as a forerunner of modern seismological scientists.

The geological causes of this earthquake and the seismic activity in the region continue to be discussed and debated by contemporary scientists. Some geologists have suggested that the earthquake may indicate the early development of an Atlantic subduction zone, and the beginning of the closure of the Atlantic ocean. Indeed, the only other recorded earthquakes of this size have been megathrust earthquakes involving subduction, making it all but certain that the Lisbon event was a megathrust earthquake as well.

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