Lisbon earthquake and the birth of seismology
Terremoto de Lisboa y nacimiento de la sismología
- Date
- 1 de noviembre de 1755 · confidence high
- Place
- Lisbon, Portugal
- Credited to
- Marquis of Pombal (survey), John Michell (seismic waves, 1760)
- People
- 👤 John Michell1724–1793👤 Marqués de Pombal1699–1782
- Field
- Cosmos & Earth
What was discovered
The earthquake, tsunami and fire destroyed Lisbon. Pombal sent a questionnaire to every parish, the first seismological survey; Michell deduced that earthquakes are waves propagating from a focus and estimated their speed. It also shook Enlightenment theodicy (Voltaire, Kant).
Coordinates of Lisbon, the city destroyed; the epicentre was in the Atlantic, southwest of Cape St Vincent.
What it led to
- Seismology as a science
- Earthquake-resistant construction (the Pombaline 'gaiola')
- Philosophical debate over natural evil
- Concept of disaster management
Built on
- Aristotelian theories of underground winds
- The Enlightenment
Made possible
- Pombaline cage (anti-seismic timber frame)1755-1777
- Horizontal-pendulum seismograph1880
- Earthquake-resistant urban planning
- Macroseismic surveys