October 31, 1542 Earthquake: Uruguay

Reference #14020 (unofficial translation):

A group of Spaniards leaving Buenos Aires and heading for Asuncion in 1542, on what would be the current coast of Colonia, in Uruguay, in the ravines near the mouth of the San Juan River, experienced an earthquake and probably a seiche that caused the death of at least fourteen people.

[…] anchored off the coast of Uruguay, at the mouth of the San Juan River, Colonia, with its coastal ravines.

On Saturday 31 October 1542, the eve of All Saints' Day, something disastrous happened to Captain Goncalo de Mendoca. He lost a ship loaded with goods and provisions and many people died. He writes that something strange happened while they were sailing. That day before, his ships were anchored on the river bank. Among them was a galley tied to a tree. He says that the earth shook, and the earth itself came down like a blow from the sea into the ravine. The trees fell into the river, and the ravine struck the brigantines, and the tree where the galley was tied gave such a blow to the galley that it pushed the ship upside down. And so it was dragged more than half a league (approximately two kilometres), with the mast underneath and the keel on top. In this event, fourteen people, including men and women, drowned in the galley and in the other boats.

It is difficult to estimate the magnitude of the earthquake from this information, but it is certainly the strongest earthquake ever recorded in the region.

And if it happened once, it is possible that one of similar magnitude could happen again. The fact that at least fourteen people died, in an open field, at a time when the region was virtually unpopulated, speaks to the significance of this event.

Note: epicentral area uncertain