1985 Mexico City earthquake
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The 1985 Mexico City earthquake was one of the most devastating earthquakes in the history of the Americas. On Thursday, September 19, 1985, at 7:19 AM local time,Mexico City was struck by an earthquake of magnitude reached 8.1 on the Richter scale. The epicenter of the earthquake was off the Pacific coast of Mexico, a distance of 350 km, in the Cocos Plate]] subduction zone. Shaking lasted two to three minutes and was felt over 825,000 square kilometers. The most damaged zones in the city were those in the bed of the historic Lake Texcoco, where the prevailing silt and volcanic clay sediments amplified the shaking. Building damage was worsened by soil liquefaction liquefaction which causes the loss of foundation support and contributes to dramatic settlement of large buildings.
As a result of the earthquake, according to official government statistics, at least 9,000 people were killed, 30,000 injured, and 100,000 left homeless. 412 buildings were destroyed and over 3,000 seriously damaged.
Many residents of Mexico City dispute these statistics, and believe that deaths exceeded 60,000 and more likely approached 100,000.
One hundred thousand housing units were destroyed, together with many government buildings, schools, housing units, parts of the Televisa Chapultepec campus, the famous Cafeteria Superleche restaurant, the two buildings of the Nuevo León section of the Plaza de las Tres Culturas Tlatelolco housing development (where relatives of Placido Domingo perished) and at least three large hospitals. Between $9-12 billion dollars of damage were caused in just over three minutes.
There was an additional magnitude 7.5 aftershock 36 hours later (the evening of Friday, September 20), which caused widespread panic among the already battered population of the city. a magnitude of 7.5 is enough to destroy buildings severel kilometers away.
[edit] Later effects
In an effort to be better prepared for future devastating earthquakes, the Mexican government funded a state-of-the-art alert system, Sistema de Alerta Sísmica (SAS) [1] that sends early-warning messages to Mexico City electronically from sensors located along the coastal
The last considerable earthquake in Mexico City had a magnitude of 7.4 Richter, in September 30, 1999 at 11:27 am. Only one person died because of the fall of a pipe.