lisbon quake 1755

Today is the 258th anniversary of one of the most astounding environmental catastrophes in recorded history: the Great Earthquake of Lisbon. At about 9:40 in the morning of Saturday, November 1, 1755, the ground in Lisbon, Portugal began to shake violently. As buildings began to wobble apart and stone cornices fell into the streets, the tremors lasted, by some accounts, for six minutes–an absolute eternity in the realm of earthquakes. By contrast, the main thrust of the San Francisco earthquake of 1906 lasted only 42 seconds. In a sprawling 18th century city made mostly of wood, plain brick and non-reinforced masonry, six minutes of shaking was enough to reduce the entire city to rubble. But the worst was yet to come.

Terrified citizens rushed out of the crumbling hills of Lisbon to the city’s waterfront. There, they saw an eerie and inexplicable sight: the waters of Lisbon Harbor were receding, pulling back toward the horizon. The mud flats that opened up where the harbor had been were littered with wrecked ships, cargo and trash that had been accumulating on the sea bottom for decades. Forty minutes after the earthquake, the reason for the receding waters became clear: a gigantic tsunami was headed for Lisbon. When it crashed into the city, it destroyed most everything the earthquake itself had left intact. Anywhere from 10,000 to 100,000 people died in the disaster.

Modern seismologists peg the Lisbon quake of 1755 at approximately 8.5 to 9.0 on the modern Richter scale, an extraordinarily powerful quake. It probably happened along the Azores-Gibraltar Transform Fault which runs under the sea near the coast of Iberia. None of this, of course, was known at the time. The world of the Enlightenment, which in 1755 was just getting started in European thought, was rocked to its foundations by the disaster. Scientific thought as a discipline was just beginning to come into its own, and study of the Lisbon quake and its aftermath had a great impact on influencing philosophers such as Voltaire and Rousseau to urge people to turn their thoughts toward a more systematic and rational explanation of the universe. It can be argued that the modern study of earthquakes began in 1755.

voltaire candide

Voltaire mentions the 1755 Lisbon quake in his seminal work “Candide,” pictured here.

The quake’s effect on Lisbon’s churches and religious life is equally great, and points in the same direction. Nearly every church in Lisbon was razed either by the quake or the tsunami. In this deeply Catholic country, parishioners buried their dead and asked the inevitable question: why did this happen to us? Religion could not provide those answers. A crisis of faith helped increase the momentum of the move toward rational and scientific thought that the Enlightenment represented. This increasing emphasis on reason percolated down through all of European civilization, manifesting itself both in scientific and technological developments–the seeds of the Industrial Revolution that were beginning at the time–and political ones, such as the American and French Revolutions. All were deeply influenced by Enlightenment thought.

There are plenty of physical traces left of the quake in Lisbon today–monuments, as well as buildings constructed in the grand new style that arose after the quake–but a curious physical memorial to the disaster exists across the ocean, in Rio de Janiero, Brazil. The famous wave-shaped tile pattern at the edge of Copacabana Beach is said to have been created to evoke the tsunami of 1755; Brazil, of course, was a Portuguese colony. I doubt many visitors to the beach know much about the environmental disaster that inspired this curious memorial.

copacapana beach

The image of Copacabana Beach tiles is by Laszlo Ilyes and is used (and relicensed) under Creative Commons 2.0 (attribution) license.