The Big Mexican Tsunami

Do you remember the last time there was a tsunami in Puerto Escondido? Of course, you don’t. The last (and only) recorded event occurred almost 230 years ago on March 28, 1787 at around 11 a.m.

The tsunami was set off by an 8.6 earthquake, called the San Sixto for the pope on whose saint’s day it fell. Mexico City shook for seven minutes causing major damage there and in Oaxaca. The quake occurred along a 450 km subduction zone that parallels the Oaxaca coast, and the tsunami destroyed churches in the Jamiltepec village of Ometepec in the southwest of the state and in Salina Cruz in the southeast. It also entered Puerto Angel, Pochutla. The rest of the coast was sparsely populated at the time, and there were no other reports of damage.

Although the tsunami did not reach Acapulco, it did set off large waves that bounced around the bay for 24 hours and wreaked havoc with the port. Fishermen on horseback who had been tending their nets in the Corrolero Lagoon (Alotengo), 27 km south of Pintotepa Nacional, reported that the tsunami reached six km inland leaving ranchers and fishermen hanging from trees. This has been backed up by recent geological studies of the area. The maximum height of the wave is estimated at 18.5 meters.

Computer models, however, show that in Puerto the waves maxed out at under two meters, which would have resulted in the sea invading only a few hundred meters of land.

There have been around 90 tsunamis in Mexico in the past 250 years, but none to compare with the San Sixto event.

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