#3 on Joe’s Most Interesting Natural Disasters List: The Lisbon Earthquake

One thing I forgot to mention about the Hieronymites Monastery is that it somehow managed to survive the Lisbon earthquake of 1755, an event that ranks among the most devastating natural disasters in recorded history. The interesting thing about the Lisbon earthquake — though I’m certainly no seismologist — is the type of motion the city was subjected to. The way I understand it, most earthquakes are strong in just one type. The Lisbon earthquake was notable in that it started with jostling up-and-down primary waves which were then followed up by even stronger shimmying, side-to-side secondary waves. Again, as I understand it, many buildings, even those built in the 1700’s, could withstand one of those two forces. But the combination of the up-and-down and side-to-side knocked down virtually every building in Lisbon.

Now I don’t know about you, but starting in grade school I wondered why the Portuguese were so dominant during the Age of Discovery (Henry the Navigator, Vasco da Gama), but then seemed to drop off the face of the Earth, as it were, in the Colonial Era. There were several contributing factors. Competition from other nations, wars and a gold rush in Brazil that concentrated their energies. However if you could reduce their lack of competitiveness in the eighteenth century to just one event, it would be the Lisbon earthquake. That quake, combined with the ensuing tsunami and 3-day fire, killed upward of 60,000 people, many of them sailors, soldiers, merchants and administrators. In other words, a whole lot of the people Portugal needed to expand and maintain its empire.

I’m fascinated by natural disasters that have world-historical consequences like that. Oh, and if you’re curious which other ones beat out the Lisbon earthquake on the Joe Scale of Interestingness (JSOI), they are the Krakatoa eruption of 1883 and the eruption of Santorini.