The southern part of Cuba was struck by a major earthquake on 12 June 1766 at midnight local time.

It had an estimated magnitude of 6.8 Ms and a maximum felt intensity of IX (destructive) on the MSK scale.

[1] The southernmost coast of Cuba lies adjacent to the southern margin of the North American plate.

[1] The intensity of shaking was at a maximum at Morro Castle and La Socapa Fort, with an estimated value of IX (Destructive), due to their proximity to the epicentre and the presence of thick alluvial deposits.

Levels of VIII (Damaging) were reached in the cities of Santiago de Cuba and Bayamo.