1755 Lisbon Earthquake - Development of Seismology

Development of Seismology

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

• At what time did the earthquake begin and how long did the earthquake last?
• Did you perceive the shock to be greater from one direction than another? Example, from north to south? Did buildings seem to fall more to one side than the other?
• How many people died and were any of them distinguished?
• Did the sea rise or fall first, and how many hands did it rise above the normal?
• If fire broke out, how long did it last and what damage did it cause?

The answers to these and other questions are still archived in the Torre do 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.