On September 19th, 1985 an earthquake of magnitude 8.0, hit the city of Mexico City, killing 5,000. September 19, 2017, the anniversary of the 1985 quake event, a devastating blow was witnessed, so far totaling, 200+ deaths. The 1985 earthquake’s center was in the south-east of Mexico City. The 2017 earthquake seemed to be in a direct south vicinity.
The seismic activities originate from the movement of the North American tectonic plate, grinding against the Cocos/Pacific plates. It is one of the most active in the world. Tremors average about 90+ per year.
Unfortunately, Mexico City had developed from a historic lake and the “prevailing silt and volcanic clay sediments amplify seismic shaking”. As the tremors are amplified, the damage to structures are amplified, as well by the ‘liquefaction’ that occurs during the event.