Understand why buildings in São Paulo "trembled" after earthquake in Chile

The 6.9 magnitude earthquake that hit northern Chile this Monday (25) had repercussions felt in the city of São Paulo.

Residents from different regions, especially the West zone of the capital and cities like São Bernardo do Campo, reported vibrations in apartments. The information was confirmed by the Brazilian Seismographic Network (RSBR) and the USP Seismology Center.

Despite the reports, the Fire Department reported that there was no record of incidents related to victims or immediate material damage.

Building resistance and safety
Experts explain that in modern engineering, buildings are designed to withstand different types of dynamic loads, including winds and vibrations.

Seismic engineering uses concepts of redundancy and controlled deformation, which means that if one element fails, other components maintain support to allow the safest possible evacuation of occupants.

In construction, the use of structures that use flexible connections and a consistent capacity for balanced deterioration, such as quality steel, can dissipate the energy of the tremor without suffering ruptures.

Countries with high seismic activity often adopt vibration dampers and counterweights on top of buildings to reduce oscillation, ensuring the main structure.

Why does São Paulo feel distant tremors?
The perception of tremors occurring in the Andes on São Paulo soil is explained by local geology. According to RSBR, São Paulo is located on a sedimentary basin, a characteristic that has the property of amplifying seismic waves.

Depending on the magnitude and depth of the original earthquake, these waves travel long distances and become noticeable in tall buildings.

However, the agency reinforces that it is "very unlikely" that earthquakes of this type will cause serious structural damage in the city.

What to do in case of structural doubt
Although the risk in São Paulo is considered low for distant earthquake events, the authorities' guidance is to remain calm.

In cases where the resident identifies signs after a tremor, such as new and deep cracks or constant cracking, the recommended procedure is to call the Civil Defense or Fire Department for a technical assessment.

Source: CNN