8.8 earthquake in Peru: where will the powerful earthquake predicted by the IGP begin?

Sooner or later, a large earthquake will occur in Peru. The reason? A specific area along the convergence between the Nazca and South American tectonic plates, located on the Peruvian coast, has been accumulating energy that has not been released since 1746, when a great 8.8 magnitude earthquake occurred in that territory.

For this reason, the Institute of Geophysics of Peru (IGP) predicts that a telluric event of a similar magnitude will have to occur in the country anyway, since those that have happened in that territory have always been of a magnitude less than 8.

Although it is not known when this ‘mega-earthquake’ will be, with the help of GPS satellites and other monitoring technologies, the seismologists of this institution already know exactly which provinces of the country are most at risk of being the epicenter of the earthquake, how will be felt on the surface and what consequences the phenomenon could cause.

Where will the 8.8 earthquake occur?

Along the entire Peruvian coast, there are various seismic coupling zones that could unleash a large earthquake. These are areas where tectonic plates cannot move normally, and the friction between them has formed bulges that, over time, will release energy in the form of earthquakes.

However, of all of them, the most dangerous is located just in front of the provinces of Lima and Ica, in an area that goes from Huacho to Pisco, and is the one that would be associated with the imminent 8.8 earthquake.

Seismic coupling map along the Peruvian coast. Photo: PGI

Despite the fact that other powerful earthquakes have occurred in the last 277 years on the central coast, all the seismic energy has not been released, since the moment magnitude scale is logarithmic. That is, the amount of energy produced by a large earthquake is much higher than that of a smaller one.

As the Seismology Laboratory at the University of California at Berkeley points out, it would take about 32 magnitude 5, 1,000 magnitude 4, or 32,000 magnitude 3 quakes to equal the amount of energy produced by a magnitude 6 temblor.

Considering that 277 years have passed since the great central coast earthquake, its repetition is predicted to be as devastating as the one that happened in February 2023 in Turkey and Syria, in which the seismic silence was greater than 300 years.

What will the megaquake feel like?

The intensity with which a person experiences an earthquake, as well as the damage that buildings on the surface can suffer, depends on the type of soil on which one is.

Sand, clay or fill soils are the most dangerous, since in these territories the level of ground shaking is much higher because seismic waves are amplified.

According to the IGP, in the province of Lima, the 8.8 earthquake will produce a level of ground shaking above 500 cm/s² in Lima metropolitan, between 700 and 900 cm/s² in Callaoand up to 1,100 cm/s² in Ventanilla.

To get an idea of ​​these values, it is enough to know that, during the Pisco earthquake (2007), the soils of the city of Ica reached an average maximum value of 400 cm/s², while in Lima that value was 80 cm. /s².

A woman sits on the facade of her collapsed house during the 2007 Pisco earthquake. Photo: AFP

Meanwhile, during the Chile earthquakes (2010) and Japan (2011)the soils of some cities reached a maximum acceleration of 900 cm/s² and 1,200 cm/s², respectively.

According to the IGP, the 8.8 earthquake would cause at least 200 aftershocks in a span of 10 hours. These would happen 3 minutes apart and two of them would be of magnitude 7.5 and 8.8, the experts highlight.

The catastrophe in numbers: victims and collapsed houses in Lima and Callao

According to the latest report from the National Center for Disaster Risk Estimation, Prevention and Reduction (Cenepred), dated December 2020, in the face of an 8.8 earthquake, the 76% of the population of Lima and Callao would be at a very high risk levelwhich can translate into approximately seven million people affected and nearly two million homes at risk of collapsing.

In the following table, prepared by said institution after analyzing the types of soil, population density and economic levels of each district, the level of risk for homes and the population of both provinces can be observed.

Seismic risk in Lima and Callao. Red dots indicate very high risk; the orange ones, high risk, and the yellow ones, low risk. Photo: Cenepred (2020)

Regarding the damage that a potential tsunami derived from the earthquake could cause, Cenepred has determined that the number of homes and population at risk in all of Lima and Callao would be approximately 74,700 and 256,000, respectively.

In this scenario, the most affected districts would be Callao, Ancón, Chorrillos and Lurín.

It should be remembered that earthquakes do not kill people. They only lose their lives due to the total or partial collapse of their homes, which cannot withstand the level of shaking of the ground. For this reason, prevention is our best defense against nature.