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, killing well over 100,000 people. The quake was followed by a tsunami and fire, resulting in the near total destruction of Lisbon. The earthquake had a strong impact on 18th century society. It accelerated a political conflict in Portugal and became the subject of the first scientific study of an earthquake's effect over a large area. Modern geologists estimate that the Lisbon earthquake approached magnitude 9 on the Richter scale.

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 between three-and-a-half and six minutes, causing gigantic fissures five meters wide to rip apart the city center. 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. About 30 minutes after the earthquake, an enormous tsunami engulfed the harbor and the city downtown, 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 generalized. The shockwaves of the earthquake were felt throughout Europe and North Africa. Tsunamis up to twenty meters in height swept the coast of North Africa. Waves struck Finland and hit across the Atlantic in Martinique and Barbados.

Of a Lisbon 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, as well as nearly every example of Portugal's distinctive 16th century Manueline architecture. 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 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 also destroyed 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. Detailed historical records of explorations by Vasco da Gama and Christopher Columbus were destroyed. The tomb of national hero Nuno Alvares Pereira was also lost.

Many animals sensed danger and fled to higher ground before the water arrived. The Lisbon quake is the first documented case of such a phenomenon in Europe.

The day after

Due 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. 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? Bury the dead and feed the living. His quick response put fire-fighters in the city to extinguish the flames, and sent in teams to remove the thousands of corpses, quelling fears that corpses would lead to an epidemic.

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 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 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 on 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.

Many contemporary philosophers mention or allude to the earthquake in their writings, notably Voltaire in Candide and in his Poème sur le désastre de Lisbonne (Poem on the Lisbon disaster). Voltaire's Candide might be read as a satire upon the arbitrariness of survival. Thinkers of the European Enlightenment drew varied inspiration from the Lisbon earthquake. The concept of the sublime, as described by philosopher Immanuel Kant in the Observations on the Feeling of the Beautiful and Sublime, took inspiration in part from attempts to comprehend the enormity of the Lisbon quake and tsunami. (In turn, theories about the sublime would inspire artists as diverse as Turner and the Impressionists, and poets from Blake to Whitman. The Lisbon earthquake arguably precipitated a sea change in European aesthetic thought, with a ripple effect which would not be fully appreciated until the late 19th century.)

Although Portugal, with Spain, had led Europe in the first centuries of maritime exploration and colonialization, the earthquake and tsunami effectively ceded the 19th Century colonial scramble to England, France, and later, to Germany and Italy. In the generation following the earthquake many colonial Portuguese, including some who had intermarried with Africans and Brazilians, returned to Lisbon. The darker hue sometimes seen in Portuguese skin tones today -- by comparison to Spanish neighbors -- is popularly credited to the 18th century genetic commingling that came with the ritornados following the 1755 earthquake.

In Portuguese internal politics, the earthquake was devastating. The prime minister was the favourite of the king, but the high nobility despised him as an upstart. (Although the prime minister Sebastião de Melo is known as Marquis of Pombal, the title was only granted in 1770). 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.

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:

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

and many others. 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 scientists.

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 are no obvious reasons for the event. Portuguese geologists have suggested that the earthquake is related with the first steps of development of an Atlantic subduction zone.

See also: List of earthquakes

External link

• Historical Depictions of the 1755 Lisbon earthquake (http://nisee.berkeley.edu/lisbon/)

pt:Terramoto de 1755