Seismologist warns Peru faces possible magnitude 8.5 to 8.8 earthquake

Venezuela and Colombia quakes stemmed from separate tectonic processes, experts say

Seismologist César Jiménez Tintaya, a professor at the National University of San Marcos, told Peruvian radio station RPP that only about 20 percent of the energy accumulated in Peru’s central region since the 1746 megathrust earthquake has been released.

“That means a magnitude 8.5 to 8.8 earthquake could occur in central Peru,” Jiménez said.

Peru’s National Center for Disaster Risk Estimation, Prevention and Reduction has classified the country as facing a very high level of seismic risk, particularly in the Lima area, according to UPI.

Fabiola Barrenechea, executive director of the Intergeographic Foundation and a disaster risk and climate change expert, said Peru’s concerns have a scientific basis. “Off the coasts of Peru and Chile, the Nazca Plate continues to move beneath the South American Plate, and there are areas where they are strongly coupled, causing deformation to accumulate over decades or even centuries,” Barrenechea told UPI.

She identified southern Peru and northern Chile, as well as Ecuador and southern Colombia, as the areas with the greatest potential for a major earthquake. “We can identify where seismic potential exists, but we still cannot determine the date of an earthquake,” Barrenechea said.

The succession of major earthquakes has raised questions about whether South America is experiencing a period of increased seismic activity. Barrenechea said several events occurring within a few weeks are not enough to demonstrate such a trend. “We have indeed observed several significant earthquakes over a relatively short period, but that does not necessarily mean that South America is experiencing extraordinary seismic activity,” Barrenechea told UPI.

She added that earthquakes are not evenly distributed over time, meaning relatively quiet periods can be followed by periods when several major events occur within weeks.

Reynaldo Charrier, a geology professor at Andrés Bello University in Chile, attributed the Venezuelan earthquakes to the interaction between the Caribbean and South American plates. The Caribbean Plate moves eastward relative to the continent’s northern edge, while the South American Plate moves westward, creating a zone of friction and major geological faults across northern Venezuela. Those include the Oca-Ancón, San Sebastián and El Pilar faults, which form a fracture system extending more than 620 miles. The faults move about 20 to 30 millimeters, or 0.8 to 1.2 inches, per year, but not continuously.

“Friction can keep the faults locked for decades until the resistance is overcome and the accumulated energy is abruptly released,” Charrier said. Charrier cited major earthquakes associated with those faults in 1812, 1900 and 2026, with an average interval of about 100 years.

The Colombian earthquake had a different origin. It occurred more than 66 miles deep within the Nazca Plate beneath the Pacific Ocean, where the plate sinks beneath the South American Plate as part of the Pacific Ring of Fire. The Venezuelan earthquakes, by comparison, occurred at a depth of about 12 miles.

“It was an intraplate earthquake, with the rupture occurring as the plate bends downward. It normally occurs very infrequently,” Charrier said.

Geologist Andrés Folguera, a professor at the University of Buenos Aires, told Argentine news outlet Infobae that both events will be studied to better understand the phenomenon.

Although the earthquakes are not directly related, Barrenechea said they can alter existing stresses in the Earth’s crust. “Earthquakes modify the stress field in the crust, and a major event can even produce small seismic disturbances hundreds or thousands of kilometers away. That has been demonstrated,” she said. There is no scientific evidence, however, that such disturbances could trigger a major earthquake in Peru or Chile. Although a distant earthquake can produce a disturbance, “today we cannot predict that another major earthquake will subsequently occur,” Barrenechea said.

South America has experienced some of the strongest and most destructive earthquakes recorded by the U.S. Geological Survey, including the magnitude 8.8 earthquake that struck Chile in 2010 and the magnitude 7.9 earthquake that struck Peru’s Pisco region in 2007.