Earthquake struck Machu Picchu in 1450 study concludes
Peruvian Times ^ | December 13, 2018 | Andean Air Mail and Peruvian Times
Construction of Machu Picchu was interrupted around 1450 by a powerful earthquake, leaving damage still evident today and prompting the Inca to perfect the seismic-resistant megalithic architecture that is now so famous throughout Cusco, according to a major new scientific study revealed by Peru’s state-run news agency Andina...
The Cusco-Pata Research Project determined that a temblor of at least magnitude 6.5 struck during the reign of the 9th Inca Pachacutec while he was building his now iconic summer estate atop the saddle-ridge between two craggy mountain peaks.
As a result, the Inca moved away from using smaller stones, assembled in a more rustic cellular architecture, and continued to develop and perfect seismic-resistant trapezoidal structures, with giant stone blocks at the base with narrower upper walls.