Why the earthquakes occurred in Venezuela and what we can expect now

At 6.04 pm local time, a 7.2 magnitude tremor shook the west of the capital, Caracas; This was followed by just 39 seconds lateranother of magnitude 7.5. The so-called “doubles” are rare, but not non-existent. In September 2025, just southwest of Wednesday’s doublet, a pair of earthquakes (magnitudes 6.2 and 6.3) caused widespread damage to buildings and left more than 110 people injured.

The extent of the devastation is still unclear, and scientists may update their estimates of earthquake intensity. In the coming weeks, researchers will collect reams of geological data and build a detailed picture of these two earthquakes.

But now you have an idea of ​​why these earthquakes occurred in such a short period of time and why they caused so much damage. Here’s what we know so far about these catastrophic earthquakes and what to expect in the coming days.

In a sequence of earthquakes, the most powerful of them—in this case, the magnitude 7.5—is considered the mainshock, which would make the magnitude 7.2 the “foreshock.”

These two earthquakes together are known as a “seismic doublet,” because of their consecutive nature in almost the same place and probably on the same fault, or on a group of closely related faults. But Wednesday’s pair was peculiar.

“Most doublets don’t occur that close together,” said Brandon Bishop, a seismologist at Saint Louis University. “It is much more common for there to be delays of hours or even a few days.”

The timing was almost certainly no coincidence. “It is very likely that the first triggered the second.”said Harold Tobin, director of the Pacific Northwest Seismic Network at the University of Washington.

The fierce seismic waves unleashed by the initial rupture could have shaken an adjacent, blocked stretch of the fault, what would have triggered the second earthquake. Although these two quakes could be considered separate events, “they could be seen as a single earthquake that lasted about 50 seconds,” said Stephen Hicks, a seismologist at University College London, in England.

Instead of a pause between the two events, it is perhaps better to think of this disaster as an almost continuous break that “became this even bigger beast”he added.

Although a magnitude 7.2 earthquake sounds slightly less severe than a magnitude 7.5, this scale is not linear. According to scientists, The second earthquake released almost three times as much energy as the first.

Other factors combined to make this double shock especially devastating.

“Both earthquakes are relatively shallow,” Bishop said. That means that the power of the seismic waves had not been reduced much by the time they crossed the Earth’s surface.

The earthquakes took place in the Yaracuy valley, which is full of loose sediments —just the kind of sediments that amplify tremors—. This caused landslides and even liquefaction, a temporary state in which soil behaves like a fluid.

And as the fault rupture moved east toward the capital, Caracas “took a direct hit,” Hicks said.

Venezuela lacks a technologically advanced earthquake early warning system and is in a state of economic and political chaos, a fact that only aggravated the potential for catastrophe.

This region is a complicated geological puzzle. The Caribbean tectonic plate is moving eastward with respect to the South American plate at a rate of less than 2.5 centimeters per year. In one area, the Caribbean plate has also been pushed beneath the South American plate, which has caused the fragmentation of parts of the latter.

In the last century there have been seven earthquakes of magnitude 6 or higher within 250 kilometers of Wednesday’s earthquakes. And around the epicenters of this week’s two earthquakes, there are three major known and mapped faults: the Boconó fault, the Guayabo fault, and the Morón fault.

The magnitude 7.5 earthquake appears to be closer to El Guayabo, while the magnitude 7.2 appears to be closer to Morón. But, given the uncertainties that exist, all three are suspect, and More than one could have been fractured.

This complexity makes unraveling the root cause of Wednesday’s earthquakes somewhat complicated. But the first indications are that the fault, or faults, that fractured They did it by means of a lateral slide, meaning that two blocks of crust slid relative to each other from side to side.

“Side-slip faults usually produce strong seismic shocks, especially near and along the fault that has moved,” Tobin said.

“It is similar to what happened with the Eastern Anatolian fault, which devastated Turkey a few years ago, with the Haiti earthquake in 2010 or with the San Andreas fault,” he added.

They are already happening. According to forecasts from the US Geological Survey, the region will be shaken by a host of smaller earthquakes (magnitude 3 to 5) over the next week.

In this period, there is a 24 percent chance of a magnitude 6 earthquake in the areaand 3 percent of another magnitude 7 occurring.

“Usually aftershocks are most frequent right after a large earthquake, and then decline exponentially over days, weeks, or even years,” Tobin said. That means the chaos and fear that has gripped the country right now will likely continue for quite some time.