1985 Mexico City Earthquake

Looking for statistics on the 1985 Mexico City earthquake? Want to know what caused the earthquake and what its effects were? Our guide gives you the facts & information you want to know.

A massive and devastating earthquake at 8.1 magnitude on the Richter Scale hit Mexico City more than two decades ago. Of a population of 18 million in 1985, an estimated 10,000 people were killed and 50,000 more suffered from injuries. That fateful day made 250,000 people homeless and left an estimated amount of $9-12 billion of damaged properties. Over 800 buildings crumbled down including hospitals, hotels, and business structures on that tragic day.

Causes of 1985 Mexico City Earthquake

Mexico City is said to be located in a broad basin formed around 30 million years ago by faulting of an uplifted plateau. Some volcanic activities closed the basin and resulted in the formation of a Lake. There are geological reasons why the city is vulnerable to earthquakes. Along the west coast of Southern Mexico and Central America lies the Cocos Plate beneath the North American Plate producing an active seismic zone. Since the start of the 20th Century there have been around 35 earthquakes with magnitude over 7.0 that have occurred on this zone. The epicenter of the earthquake on that unfortunate day of September 19, 1985 was at the border between the states of Michoacan and Guerrero. It is also said that the lack of enforcement of building codes have added to the cause of damage.

Tremendous Earthquake Damage

The epicenter of the earthquake was more than 300 kilometers away from Mexico City yet it suffered the most damage. The quake which lasted for about three to four minutes made buildings of 6-15 stories in height fall apart in an instant. Electricity lines were destroyed for days as well as communications. The Central Communications Center building collapsed isolating Mexico City from the immediate help and assistance of neighboring countries. Water and the sewage systems were seriously damaged, thus, contaminating the water supply in the city. About a hundred thousand housing units were destroyed as well as government buildings, schools and other infrastructure. Three of the largest hospitals in the city collapsed burying some 1,200 people alive. The loss of hospitals crippled the city’s ability to help injured victims. An aftershock of 7.5 magnitude was felt 36 hours later causing widespread panic. Countries around the world responded sending relief and assistance in the form of cash.

The disaster that happened in 1985 is still remembered by Mexicans up to this date. The government has funded a state-of-the-art alert system with the help of planted sensors in Guerrero and another is being constructed in Oaxaca. The alert system will send warning messages to city residents when seismic activity is detected.