A sequence of tectonic shakes shook western Colombia once again on Wednesday afternoon, September 16, 2026. Two of the movements registered magnitudes greater than 4.0 with a difference of barely one hundred and twenty seconds, according to measurements published by USGS. This sudden activity revived concern in vulnerable communities still facing the havoc left by the magnitude 7.4 earthquake that occurred last August 10.
Specialists from the official agency warned that the frequency of these events does not guarantee the total release of the energy accumulated in local geological faults, so the possibility of a higher-intensity event remains present.
Chain of movements in the Chocó territory
The first telluric event recorded during Wednesday's day happened at 3:12 p.m. with an epicenter located in the municipality of Medio San Juan, near the village of Andagoya, placing its origin at a depth of 40 kilometers. After a scarce ninety seconds elapsed, exactly at 3:14 p.m., a new earthquake of magnitude 4.4 originated in the jurisdiction of Sipí, with a focus located 37 kilometers beneath the Earth's surface, according to the New York Times' journalistic coverage.
Informative follow-ups broadcasted by Pulzo and El Colombiano ratified a third jolt at 3:18 p.m., reaching an intensity of 3.6 once again in the Medio San Juan area. Hours later, entering the night at 8:12 p.m., the official monitoring network notified a fourth event of magnitude 4.7 with an epicenter in the same geographic area.
Discrepancies in frequency reports
Certain international news agencies broadcasted reports where they counted up to five tremors occurring in a span of less than sixty minutes during Wednesday afternoon. However, the main Colombian media outlets that consulted the technical bulletins confirmed only four events distributed between afternoon and night. This variation in the count reflects the complexity of real-time data processing when underground activity abruptly intensifies.
New episodes during the early morning
The instability of the Earth's crust persisted upon the arrival of Thursday, September 17. During the hours prior to dawn, seismographs detected three additional shakes in an interval of less than fifty minutes: a 3.4 tremor in Sipí, another 3.1 in Medio San Juan, and a third 3.5 in the municipality of Istmina, according to data compiled by El Tiempo.
This morning activity prolonged a streak that had begun from the early hours of Wednesday, when between 1:18 a.m. and 3:45 a.m. five minor events occurred, highlighting one of magnitude 4.5 with an epicenter in Istmina. Days prior, the same region had already experienced similar behavior in its tectonic fault network.
Expert evaluation and plate interaction
The coordinator of the National Seismological Network, Freddy Tovar Vergara, explained in statements offered to Colombia.com that the consecutive manifestation of small or moderate tremors does not clear the possibility of a destructive event. The scientific authority emphasized that a larger earthquake can occur here at any moment
, disproving the popular belief that mild movements gradually discharge all accumulated tension.
Tectonic convergence in this part of the country responds to two concurrent factors: the accommodation of layers following the August earthquake and an autonomous seismic swarm fostered by the friction of the Nazca plate with the South American and Caribbean plates, in the contact zone known as the Pacific Ring of Fire. Technical estimates accumulated by the scientific agency indicate that the zone has withstood hundreds of aftershocks since the main earthquake.
Faced with constant risk, authorities recall the importance of keeping Android operating system seismic alerts active on mobile devices, tools aimed at providing valuable seconds of preventive evacuation upon the detection of initial seismic waves.
The footprint of the August 10 earthquake
The recent shakes reopen the emotional and material wounds left by the previous month's cataclysm. The main earthquake of August 10 reached a magnitude of 7.4, placing its epicenter in San José del Palmar with a focal depth of 103 kilometers.
The consolidated reports issued by the National Unit for Disaster Risk Management detail a tragic balance exceeding three hundred deceased people, thousands of injured, and dozens of missing persons. Human affectation encompasses hundreds of thousands of citizens distributed across nearly five hundred municipalities belonging to sixteen departments, affecting Chocó, Valle del Cauca, Caldas, and Risaralda with special severity. As long as the earth continues to move on the Pacific slope, relief organizations keep their vigilance protocols activated at the maximum level.
