The 1563 MI 8 Puerto de la Navidad Subduction‐Zone and 1567 Mw 7.2 Ameca Crustal Earthquakes (Western Mexico): New Insights from Sixteenth‐Century Sources

The A.D. 1563 Puerto de la Navidad subduction‐zone earthquake and the A.D. 1567 Ameca crustal earthquake in the Trans‐Mexican volcanic belt are the earliest earthquakes in west‐central Mexico documented in historical sources. The 27 May 1563 earthquake destroyed the shipyards at the Pacific harbor settlement of Puerto de la Navidad and caused severe damage to structures up to $∼100km$ from the coast. The macroseismic intensity distribution for the 1563 earthquake is practically identical to that of the 3 June 1932 $Ms$ 8.2 earthquake, which ruptured the Rivera–North America plate interface over a length of $∼220km$⁠. This suggests that the 1563 earthquake had comparable rupture location and dimensions and was of comparable magnitude.

The origin of the $Mw$$7.2±0.3$ Ameca crustal earthquake can now be pinpointed to 28 December 1567 at dawn, relying on information from sixteenth‐century documents not incorporated in previous studies. These new sources also permit defining more precisely its damage area, which in the north likely included the region of sixteenth‐century Lake Etzatlán but did not reach as far south as Zapotlán el Grande and Tuxpan as reported in the A.D. 1653 chronicle by Antonio Tello, who partly confused the A.D. 1563 and 1567 earthquakes.