Earthquakes in the Region: Does Risk Increase in Argentina?
Following the magnitude 7.4 earthquake in Colombia on August 10, 2026 and the seismic doublet in Venezuela with magnitudes 7.2 and 7.5 in late June 2026, concern about a similar event in Argentina has been revived among the population. However, specialists from CONICET and national universities agree that these events, while serving as a warning, do not modify Argentina's seismic scenario.
According to geologist Gustavo Ortiz, seismologist and director of the CONICET-UNSJ Seismological Observatory in San Juan, in an interview with Infobae: "Risk in Argentina does not increase due to what happened in Colombia". This is because, although all the mentioned countries are on the South American plate, contact with different plates (the Caribbean plate in Venezuela and the Nazca plate in Colombia) determines independent tectonic contexts.
For his part, José Luis Tapia, head of the analysts department at the Geoscientific Network of Chile, explained to CNN Chile that intraplate earthquakes "are rather deficient in transferring stresses to their surroundings", ruling out a direct impact on Chile or Argentina.
Hazard Map: The Five Risk Zones
The National Institute for Seismic Prevention (INPRES), which updated its national map in 2022 with data collected since 1471, divides Argentina into five hazard zones, numbered 0 to 4, based on the probability of registering intense ground movements.
| Zone | Hazard Level | Main Regions |
|---|---|---|
| Zone 4 | Very High | Southern San Juan and northern Mendoza |
| Zone 3 | High | Central Mendoza, northern and eastern San Juan, western La Rioja, northwestern San Luis |
| Zone 2 | Medium | Other areas of Cuyo and the Argentine Northwest (NOA) |
| Zones 1 and 0 | Low to Very Low | Center, east, and south of the country |
The area of highest hazard (Zone 4) covers southern San Juan and northern Mendoza, including densely populated urban sectors. There, building codes require stricter earthquake-resistant standards.
Additionally, active geological faults exist in the Sierras of La Rioja such as Famatina, Velasco, and Ambato, as well as in the Lerma Valley in Salta, the Quebrada de Humahuaca, and the Calchaquí Valleys.
Tectonic Dynamics: Why the West Trembles
The explanation for Argentina's risk lies in the dynamics of tectonic plates. Geologist Eduardo Malagnino explained to LN+ that "The oceanic Nazca Plate (west of South America) moves toward the continental area about 7 centimeters per year, and the continental plate moves 1.5 centimeters in the same period in the opposite direction". When they collide, the denser oceanic plate slides beneath the continental plate in a process called subduction, generating an accumulation of energy that is released suddenly in the form of an earthquake.
INPRES notes that 80% of the country's seismic events occur at depths greater than 100 kilometers, while the remaining 20% originate at less than 40 kilometers. The latter are the ones that have historically caused the greatest damage.
Historical Background
- 📅 1861: The Mendoza earthquake destroyed the city and caused thousands of deaths.
- 📅 1944: The San Juan earthquake, the most serious in Argentine history, with nearly 10,000 fatalities.
- 📅 1977: San Juan province recorded an unusual "seismic doublet," two main earthquakes separated by thirty seconds.
The Case of the NOA and Jujuy
Geologist Juan Pablo Villalba Ulberich, from the National University of Jujuy and CONICET, explained that in the NOA region, between 10 and 20 earthquakes occur daily, most imperceptible because they are very deep. In Susques, Jujuy, movements are frequent at depths exceeding 200 km, with magnitudes around 2.
Recently, a shallow movement was detected at 5 kilometers depth near Cafayate and San Antonio de los Cobres.
The Role of Soil in Amplifying Waves
Geologist Andrés Folguera, researcher at UBA and CONICET, explained to TN that depth is not the only factor determining the level of destruction. "Soft terrains amplify the seismic wave", he assured.
In the case of Colombia, many affected localities are located in valleys filled with sediments that favor the amplification of waves. Folguera compared the valleys to a kind of "bathtub" that can favor the focusing of seismic energy: "You can have a very deep earthquake, but if the vast majority of localities are settled in valleys, the sediments can amplify the seismic wave".
Regarding a possible connection between the Venezuela and Colombia earthquakes, Folguera stated that "it is a hypothesis, but it could be. It could be, and it could also not be", and mentioned precedents in Turkey and Japan where neighboring fault segments broke months or years apart.
Earthquake-Resistant Construction: The Main Protection Tool
Andrés Folguera was emphatic: "Today, the way to protect lives is with earthquake-resistant construction".
Both Folguera and Ortiz agree that science cannot anticipate when an earthquake will occur. "It is impossible to predict seismic events. The only certainty is that the alert level should always be maintained", Ortiz stated.
Folguera mentioned recent research published in the journal Geodesy and Geodynamics analyzing changes in gravity before earthquakes. Gravimeters, relatively inexpensive instruments, could be installed on known faults to monitor variations that appear days or weeks before a major movement.
In San Juan and Mendoza, colonial architecture was completely replaced after the great earthquakes. However, in northern Argentina, vulnerable areas with old constructions persist. The permanent updating of hazard maps, public education, and building regulation remain the central pillars of seismic risk management in Argentina.