What is the plate subduction that caused Colombia's strongest earthquake in a decade

The 7.4-magnitude earthquake that shook western Colombia on August 10 was caused by tectonic plate subduction, the same phenomenon behind the Pacific’s great quakes. The epicenter was located in San José del Palmar, Chocó, at a depth of about 107 km.

What subduction is

The Earth’s surface is divided into plates that move constantly. On Colombia’s Pacific coast, the Nazca plate sinks beneath the South American plate at a rate of several centimeters per year. When the plates jam from friction, they accumulate energy that is released all at once: that is an earthquake.

Why it was so strong

The August 10 quake is the strongest felt in Colombia in the last decade, according to the director of the Colombian Geological Service, Julio Fierro Morales. The energy released by the colliding plates traveled through the Coffee Region, Antioquia and Valle del Cauca, where the greatest damage was recorded.

Why it is not connected to Venezuela

Experts consulted by BBC Mundo clarify that the earthquakes in Venezuela respond to a different fault system, related to the interaction between the Caribbean plate and the South American plate, not to Pacific subduction. That both countries felt tremors on nearby dates is geological coincidence, not a shared origin.

The key figure

7.4 magnitude. The strongest earthquake in Colombia in a decade, and the deadliest since the 1999 Coffee Region earthquake, which left 1,185 dead.