The 1755 Lisbon Earthquake

On November 1, 1755, a catastrophic earthquake struck Lisbon, Portugal, marking one of the deadliest and most destructive natural disasters in European history. The event had profound effects not only on the city but also on the broader cultural and philosophical landscape of the time.

Context and Background

Lisbon, the capital of Portugal, was a thriving city in the mid-18th century, known for its wealth derived from colonial trade. The city was densely populated, with a significant number of buildings constructed in close proximity, many of which were not designed to withstand seismic activity.

The Earthquake

• Time and Magnitude: The earthquake occurred in the morning, around 9:40 AM local time, on All Saints’ Day, a major religious holiday. Modern estimates suggest the earthquake had a magnitude of 8.5 to 9.0 on the Richter scale.
• Epicenter: The epicenter is believed to have been in the Atlantic Ocean, approximately 200 kilometers southwest of Cape St. Vincent.

The Tsunami and Fires

• Tsunami: Following the earthquake, a massive tsunami struck the Portuguese coast, with waves reaching heights of up to 20 meters (65 feet). The tsunami affected not only Lisbon but also other coastal areas in Portugal, Spain, and even as far as North Africa and the Caribbean.
• Fires: In the aftermath of the earthquake and tsunami, fires broke out across Lisbon, fueled by candles and cooking fires that had been left unattended during the chaos. These fires raged for several days, causing further destruction.

Casualties and Damage

• Death Toll: Estimates of the death toll vary, but it is widely believed that between 30,000 and 50,000 people perished in Lisbon alone. The total number of casualties, including those in other affected areas, may have been higher.
• Destruction: Approximately 85% of Lisbon’s buildings were destroyed, including many iconic structures such as the Royal Ribeira Palace and the Carmo Convent.

Aftermath and Impact

• Reconstruction: The Marquis of Pombal, Sebastião José de Carvalho e Melo, led the reconstruction efforts. He implemented innovative architectural and engineering techniques, including the use of earthquake-resistant structures known as “Pombaline buildings.”
• Philosophical and Cultural Impact: The disaster had a significant impact on European Enlightenment thought. It challenged existing theological and philosophical ideas about divine intervention and the nature of evil. Notably, it influenced the writings of philosophers like Voltaire, who referenced the earthquake in his satirical novella “Candide.”
• Scientific Inquiry: The event spurred early scientific inquiry into seismology and the study of earthquakes, as scholars sought to understand the causes and effects of such natural disasters.

Broader Historical Significance

The 1755 Lisbon earthquake is remembered not only for its immediate devastation but also for its lasting influence on urban planning, architecture, and the intellectual discourse of the Enlightenment. It serves as a poignant reminder of the vulnerability of human societies to natural forces and the resilience required to rebuild in the aftermath of disaster.