Do the recent earthquakes in northern Chile herald a mega-earthquake?

It was 9:50 p.m. on July 18 when a strong movement shook a large part of northern Chile. It was about A earthquake of 7.3 on the Richter scale, whose epicenter was located 20 kilometers south of San Pedro de Atacama, in the Antofagasta region The depth was 166 kilometers, according to data from the National Seismological Center .

Residents of the regions of Arica and Parinacota, Antofagasta, Atacama, Coquimbo and Tarapacá were frightened by the intensity of the shock, and more after he began talking about the possibility that the earthquake was a “precursor” to a mega-earthquake in the region.

Is it true that this big earthquake in the north indicates that an earthquake is coming soon? This is an expert explanation.

The geologist of Development University Luis Donoso called for calm, because This would be a normal and expected movement because, like many other points in the country, it is a seismic zone.

“We live in an earthquake-prone country and this is part of our reality” start to say The third . “This is within the normal range of what should happen.”

However, Yes, there is something that worries the specialist, who is also a geophysicist. ENAP Sipetrol and advisor to the Fach : “I am afraid that it will be said that the seismic swarm is a predictor of something, when in reality an earthquake cannot be predicted.” . Furthermore, this is not a seismic swarm, but rather normal activity in the area. “It worries me because it is starting to generate panic.”

Donoso assures that In the north of the country there is “constant and permanent seismic activity, where there are good seismological stations that locate even the smallest movements.”

But if it is not a seismic swarm, What explains the series of (low intensity) movements that the north has been experiencing in recent weeks? And now, after the great earthquake of the night of July 18?

“A seismic swarm is something that begins, without any other expression. It does not arise of any relevant magnitude and they disappear,” explains the seismologist.

In exchange, proposes the interpretation that in the north of the country “we are facing a phenomenon called seismic nest, which are tectonic zones that cause a certain geographical region to shake constantly and frequently, sometimes more or less, but it does not deteriorate over time.”

On the other hand, in the data of the Seismology Center, after the big 7.3, more than 40 earthquakes of all types of magnitudes were recorded, however, For the expert, they should be interpreted as significant aftershocks when they are greater than at least 3.0. Much of the long list falls below this figure.

“Just because it’s shaking doesn’t necessarily mean there’s something bigger. I had the privilege of having Edgar Kausel (winner of the National Science Prize) as my teacher, and he always said that “We call an earthquake a precursor only after the earthquake, never before” said Donoso to LT.

For example, “if we had located earthquakes of magnitude 4 to 7, 10 to 20 kilometers from the epicenter of last night’s big earthquake, they would be considered precursors, but “It would not be possible to know until the high-magnitude earthquake occurs.”

Furthermore, the expert emphasizes that You can’t know when an earthquake will happen, but you can roughly detect where it might happen. . “When I have significant deformation, I can tell that this area is deformed beyond what I would expect, but I can’t date the dislocation of the rock, which generates an earthquake.”

“On the other hand“History can give me some rough indications of the average frequency with which large earthquakes are generated.” said Donoso. In other words, if the trend indicates that every 80 or 90 years there is a strong movement, it is likely that it can continue to repeat itself, but this cannot be known with certainty.