March 28, 1787 Earthquake: San Marcos, Oaxaca, Mexico

1787, March (mistakenly April) 28 (mistakenly 14 and 18), at 11:30 [local time]. There was a large earthquake with source near San Marcos, affecting the coast of the states of Oaxaca, Guerrero and Michoacan and causing much destruction. In Mexico City, an oscillatory movement lasting 6 minutes was felt; buildings were damaged. At Igualapa, it was felt for 7 minutes. Three churches were almost totally ruined in Teuchitlan. Reports about the earthquake arrived from Morelia, Oaxaca, Chilapa, Chiautla, Tlapa, Ayutla, Cuatla, Acapulco, Ometepec, Veracruz and Tehuantepec. The earthquake was not so strong at Ulua and Tulacingo. It was felt at San Luis Potosi and Valladolid. Thirty-five recurrent shocks were counted until April 3. The earthquake also generated a tsunami. (reference #415)

1787, March 28. The earthquake of magnitude 8.0, was generated at 11:30 local time near San Marcos and affected the coasts of the states of Oaxaca, Guerrero and Michoacan. It was felt in Mexico City for 6 minutes and damaged a few buildings. In Teuchitlan, three churches were destroyed. In Oaxaca City many buildings collapsed. (reference #369)

1787, March 28-April 3. Mexico, centre near San Marcos, Acapulco, Ayutla, Igualapa, Tcotillan in Oaxaca, Michoacan and south to Tehuantepec; sea waves. Intensity III which corresponds to an earthquake which destroyed towns and devastated districts. (reference #1055)

[…] as is generally the case for large and great earthquakes in Mexico, that the fault rupture of the 1787 earthquake encompasses the areas where intensities greater than VIII were reported and where a strong tsunami invaded land, the estimated length of the rupture is approximately 450 km long. This fault length would correspond to an earthquake of approximately Mw 8.6 […] The sequence initiated with a very large earthquake on 28 March, which we interpret here to be the main event. It was followed by three large shocks on 29 March, 30 March, and 3 April […] the earthquake of 1787 produced important damage and the collapse of wellconstructed buildings and structures, such as churches, convents, government houses, and private dwellings (García Acosta and Suá\arez, 1996). The observed intensity for the main event in 1787 in Oaxaca City (MMI = IX) has never been observed in the historical record for other events occurring along the subduction zone to the south of the city. (reference #14084)