pair of – A magnitude 7.2 earthquake hit Caracas, then just 39 seconds later a magnitude 7.5 quake followed—an unusually catastrophic sequence likely involving separate faults near major population areas, raising new questions about how earthquake risk models handle mul
Caracas didn’t get a pause after the first jolt.
Instead, the ground kept moving—one major earthquake striking the Venezuelan capital, followed less than a minute later by another. The timing is what makes the deadly sequence stand out to earthquake specialists: William Barnhart. a geophysicist at the U.S. Geological Survey in Golden. Colo. said a magnitude 7.2 quake on its own in this region would be “devastating.” But Barnhart emphasized that it was “followed 39 seconds later by a magnitude 7.5 earthquake that’s about three times more powerful.”.
Those two bursts of shaking landed on land, close to major population centers, which Barnhart said made the outcome especially deadly. “It’s just an awful tragedy,” he said.
In the moments after a quake, scientists can’t yet say with certainty what happened under the earth. Barnhart said it appears the pair of earthquakes may have occurred on two separate faults in a tectonically complex region where several faults intersect. He pointed out that this is not how most risk conversations are framed. “There’s not just a single easily identifiable fault that you can point to and say. ‘The earthquake definitely happened on this fault. ’” he said.
Chris Goldfinger. a paleoseismologist at Oregon State University. described how that kind of multifault scenario has long been treated as the exception rather than the rule. Historically, he said, experts evaluating earthquake risk haven’t necessarily accounted for events that involve multiple faults. “We always tend to kind of assume that earthquakes will just be on one fault and only on one fault. ” Goldfinger said.
He compared the Venezuelan situation to a lesson learned elsewhere. In 2016. the Kaikōura earthquake in New Zealand surprised people by rupturing in a way that changed scientists’ understanding of interconnected faults triggering multiple ruptures. Goldfinger said that if the Venezuelan quakes turn out to be similar. it could provide important information for studying multifault risk. “The first one was completely out of the blue. We had no idea that could happen at all,” he said. “And here’s a second one 10 years later where two really big earthquakes happened on separate faults.”.
Other regions can also have complicated fault systems. Goldfinger noted that parts of California’s fault system— including the San Andreas Fault—have similarly complex tectonics. A recent study. he said. found that parts of the San Andreas and San Jacinto fault systems may now be at their highest modeled stress levels in at least 1. 000 years. Even so, Goldfinger said the difference on the ground is preparedness. “Experts say that area in California is far more prepared for such an event than Venezuela,” he said.
That preparedness gap is one of the most sobering parts of the story, Goldfinger added. He said engineering in many places hasn’t kept pace with rapidly evolving earthquake science. “Many of these buildings around the world were built before plate tectonics,” he said. He also stressed how hard it is to respond after the science moves ahead: retrofitting entire cities is “just an intimidatingly difficult thing to think about.”.
The sequence in Venezuela also came on the same day as two other earthquakes elsewhere: one in Japan and one in California. Barnhart said the earthquakes are unrelated. “As we understand things, these earthquakes are all completely unrelated,” he said.
Still, the coincidence of big quakes happening on the same day can make the event feel larger than it is. Barnhart said that’s because most people don’t see the constant background of earthquake activity. “Earthquakes happen all the time,” he said. “Most people don’t pay attention because most of the earthquakes are out to sea and nobody is impacted.”.
For Venezuela, the catastrophe wasn’t just the strength of shaking—it was the double hit. One earthquake, then another 39 seconds later, both near where people live, and possibly on separate faults in a region where the earth’s structure is anything but simple.
Venezuela earthquakes Caracas magnitude 7.2 magnitude 7.5 U.S. Geological Survey USGS Golden Colorado William Barnhart Chris Goldfinger Oregon State University multifault earthquakes Kaikōura earthquake 2016 San Andreas Fault San Jacinto Fault earthquake risk modeling seismic preparedness
39 seconds?? That’s insane.
So it hit Caracas twice like back to back? I feel like the news always says “rare sequence” but then it happens anyway. Wonder if buildings were supposed to be safer or if the models just missed it.
Wait isn’t 7.5 basically just like… a stronger 7.2? Like same thing different day? If it was “separate faults” then why does it still count as one event? Either way that’s bad for sure.
Earthquake risk models are probably junk tbh. They’re like “we can’t say what happened under the earth” so how are we supposed to plan anything? Also the article says it was close to population centers—so like we knew it was near cities, right? Makes me think they should’ve been predicting repeat strikes like that instead of acting shocked.