Colombia Earthquake: What Are the Chances of Another Big Tremor or Aftershocks?
After a powerful earthquake strikes Colombia, one question immediately rises above all others: Could another major earthquake happen soon?
The answer from seismologists is nuanced. Aftershocks are expected following a major earthquake, but predicting their exact number, magnitude, and timing is impossible. At the same time, the possibility that a subsequent earthquake could be larger than Monday’s event cannot be completely ruled out.
The U.S. Geological Survey (USGS) says that, worldwide, the probability that an earthquake will be followed by a larger earthquake nearby within one week is approximately 5%. In other words, about 95% of the time, the initial earthquake is not followed by a larger nearby event during that period.
That statistic is particularly relevant following Monday’s powerful earthquake in western Colombia, which was revised to magnitude 7.4 by the USGS, according to Reuters. The earthquake struck near San Jose del Palmar in the department of Choco and caused significant damage and injuries, including in Quibdo and Pereira.
Earthquake in Colombia: Aftershocks are much more likely
While the possibility of a larger earthquake is relatively low, aftershocks are a normal part of the aftermath of a major earthquake.
The USGS explains that aftershock activity generally decreases with time. The strongest and most frequent aftershocks tend to occur shortly after the main earthquake, although the sequence can continue for days, weeks, or even longer.
The agency’s aftershock forecasting system estimates the expected number of smaller earthquakes and the probabilities of potentially damaging events. It also emphasizes that the rate of aftershocks usually declines over time, although a larger aftershock can temporarily increase seismic activity.
This means Colombians should not interpret every subsequent tremor as evidence that a larger earthquake is imminent. At the same time, residents in damaged buildings should take additional shaking seriously because structures weakened by the initial earthquake can become more vulnerable.
Could Colombia experience another magnitude 7 earthquake?
There is no scientifically reliable way to predict that a magnitude 7 or larger earthquake will occur in Colombia at a specific time.
The USGS stresses the difference between forecasting probabilities and predicting earthquakes. Scientists can estimate the likelihood of earthquakes occurring over particular periods and can calculate aftershock probabilities following a major event, but they cannot provide an exact date, location and magnitude for the next earthquake.
The 5% figure therefore should not be interpreted as a forecast that Colombia has a 5% chance of experiencing another magnitude 7.4 earthquake this week. It is a broad global statistic concerning whether an earthquake will be followed by a larger nearby earthquake within seven days.
The actual risk associated with Monday’s earthquake requires a sequence-specific analysis using the earthquake’s location, depth, magnitude and subsequent seismic activity.
Why the first days matter
The first hours and days following a major earthquake are particularly important for emergency authorities.
USGS aftershock forecasts are designed to provide situational awareness by estimating the probability of additional earthquakes at different magnitudes and time intervals. As new earthquakes occur, the statistical picture can change.
Scientists also distinguish between a mainshock, foreshock and aftershock retrospectively. If a larger earthquake occurs later in the same sequence, the original earthquake can be reclassified as a foreshock, while the larger event becomes the mainshock.
For Colombia, that distinction means officials cannot definitively declare Monday’s magnitude 7.4 earthquake the largest event in the sequence until enough time has passed and the seismic activity has been analyzed.
What Colombians should expect now
The most likely scenario after a major earthquake is more, generally smaller tremors rather than another earthquake larger than the original.
Residents should nevertheless follow instructions from Colombia’s disaster authorities, avoid entering visibly damaged structures and prepare for additional shaking. People who felt Monday’s earthquake in Choco, Risaralda, Valle del Cauca, Caldas, Quindio, Antioquia, Bogota and other parts of the country should remain alert for official updates.
The key message from earthquake science is therefore neither alarm nor complacency: aftershocks are likely, another very large earthquake is possible but much less likely, and no agency can predict precisely when the next major tremor will occur.
For now, the safest approach is to rely on official seismic monitoring rather than social-media predictions, while emergency teams continue assessing damage and monitoring Colombia’s earthquake sequence.