Powerful Back-to-Back Earthquakes Killed at Least 188 People in Venezuela. Here’s the Science Behind the Rare ‘Doublet’

On June 24, two quakes above magnitude 7 struck the northern part of the country only 39 seconds apart. While doublet sequences aren’t unheard of in seismology, they are uncommon—especially in such short succession

Michele Debczak | Correspondent

June 25, 2026 3:10 p.m.

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Northern Venezuela is reeling from a pair of earthquakes that shook a densely populated region of the country on Wednesday. Shortly after 6 p.m., the initial 7.2-magnitude quake struck roughly 15 miles northeast of San Felipe. Less than a minute later, a 7.5-magnitude quake hit just a few miles away from the first.

The death toll stands at 188, with more than 1,500 people injured as of Thursday afternoon, said Jorge Rodríguez, the president of Venezuela’s National Assembly, in remarks streamed by the state-funded television station Telesur, reports the New York Times’ Pranav Baskar. The powerful quakes caused catastrophic damage to hundreds of structures in the area, including in the capital city of Caracas, around 100 miles east of the quakes’ epicenters, and experts fear the death toll could be much higher than the current number.

The earthquakes are some of the strongest to hit the South American nation over the past century, according to the U.S. Geological Survey (USGS). The agency said that the events were a back-to-back seismic sequence known as a “doublet.”

“Every once in a while, two earthquakes of almost the same magnitude will occur close together in space and time, so we know that they’re related,” Allison Bent, a seismologist with Earthquakes Canada, tells CTV News.

Doublets are different from aftershocks, which are smaller quakes that happen in the wake of a larger main quake, but are still part of the same event. If the two big earthquakes that hit Venezuela were, indeed, a doublet, that would make them related but distinct from each other. USGS data suggests that the two quakes occurred on separate faults, or fractures in the crust, and had different rupture patterns, which supports this categorization.

“It’s likely the first earthquake triggered the second one,” Mark Quigley, an earthquake scientist at the University of Melbourne in Australia, writes for the Conversation. “This could have happened because Earth’s crust displacement in the first earthquake fault increased stress on the second earthquake’s source fault. Additionally, the passage of seismic waves from the first earthquake could have rattled nearby faults already prone to a rupture, causing them to fail.”

While doublets are rare, they have been documented in Sumatra, Japan, Alaska and the Philippines, Apoorva Misra reports for News18.com. In 2023, a 7.8-magnitude earthquake coupled with a 7.6 quake led to more than 55,000 deaths in Turkey and Syria. The two related shocks occurred roughly nine hours apart.

This hours-long separation time is typical for these types of back-to-back seismic events, Bent tells CTV. “Less than a minute apart really is unusual.”

The strange nature of this most recent phenomenon has some seismologists questioning the USGS’s categorization.

“I don’t know for sure that I would call this two earthquakes. I think we’re going to need to see more science come out,” says Judith Hubbard, an earthquake scientist at Cornell University, to Michel Martin on NPR’s “Morning Edition.” “A magnitude 7.2 earthquake, like the first one, would take about 30 to 40 seconds to finish. So whether you define a break between that one and the next one is a little unclear to me.”

The USGS currently considers the first quake to be a “foreshock,” followed 39 seconds later by the larger “mainshock.” The agency might revise its report as seismologists continue to uncover more details about the devastating events.

Michele Debczak | Read More

Michele Debczak is a writer and editor based in Brooklyn, New York. She appears in seasons four through six of History Channel’s “The Food That Built America,” and her work has been featured in Mental Floss, IndieWire, Eater and Vice.