*Ground motion*
- Strong ground motion: The 1985 Mexico City earthquake was a magnitude 8.1 earthquake, and the ground motion it produced was extremely strong. The shaking was particularly intense in the city's downtown area, where many buildings were located.
- Long duration: The earthquake's ground motion lasted for over two minutes, which gave buildings more time to be damaged.
*Soil conditions*
- Soft soil: The soil in Mexico City is very soft and unstable. This type of soil can amplify seismic waves, making the ground motion even stronger.
- Liquefaction: Liquefaction is a phenomenon that occurs when loose, water-saturated soil loses its strength and behaves like a liquid. Liquefaction can cause buildings to settle or sink, which can lead to severe damage.
*Building design and construction*
- Weak building codes: At the time of the earthquake, Mexico City's building codes were not as strict as they are today. This meant that many buildings were not designed to withstand a strong earthquake.
- Poor construction practices: Many buildings in Mexico City were constructed with poor quality materials and workmanship. This made them even more vulnerable to damage from the earthquake.
As a result of these factors, the 1985 Mexico City earthquake caused widespread damage to buildings. Over 10,000 buildings were destroyed, and many more were severely damaged. The earthquake also caused a large number of casualties, with over 10,000 people killed and over 30,000 injured.
