On June 24 and 25, three powerful earthquakes struck different parts of the world within a span of roughly seven hours, a California tremor that shook Mendocino County, a devastating doublet in northern Venezuela that killed at least 164 people, and a strong subduction-zone quake off the coast of northeastern Japan. The clustering naturally raised the question: were they connected?
The answer from seismologists is a clear no.
“If you look at the last 100 years of earthquakes, we’ve never seen earthquakes this far apart be related,” Martin Hudson, adjunct professor of civil and environmental engineering at UCLA, told the Guardian.
What happened, and where
The temporal clustering began at 15:10 UTC on June 24, when a magnitude 5.6 earthquake struck 11 kilometers north of Redwood Valley, California, on the Maacama fault, part of the San Andreas plate boundary system. The shallow crustal quake (8.8 km depth) was the strongest in the region since 1940, cutting power to about 8,000 PG&E customers and causing scattered structural damage, but no deaths.
Seven hours later, at 22:04 UTC, a pair of quakes struck just 39 seconds apart near San Felipe in northern Venezuela, a magnitude 7.2 foreshock followed by a magnitude 7.5 mainshock, both shallow (10-20 km). The doublet, occurring on the Boconó strike-slip fault system where the Caribbean Plate meets the South American Plate, caused catastrophic damage. At least 164 people were confirmed dead, with nearly 1,000 injured, and the Simón Bolívar International Airport near Caracas was damaged and closed.
Twenty-six minutes after the Venezuela doublet, at 22:30 UTC (7:30 a.m. JST on June 25), a magnitude 7.2 thrust earthquake struck off the coast of Iwate Prefecture in northeastern Japan, on the subduction zone where the Pacific Plate dives beneath the Okhotsk Plate. At a depth of 44-50 km, the quake produced shaking rated Upper 6 on the Japanese intensity scale in parts of Aomori, strong enough that standing was impossible. Ten people were injured, one seriously, and the Tohoku Shinkansen bullet train service was temporarily suspended. No tsunami was triggered.
Three different tectonic systems
The three events occurred on entirely separate tectonic systems:
| Earthquake | Plate boundary | Fault type |
|—|—|—|
| California M5.6 | Pacific & North American plates | Transform (Maacama Fault) |
| Venezuela M7.2/M7.5 | Caribbean & South American plates | Strike-slip (Boconó Fault) |
| Japan M7.2 | Pacific & Okhotsk plates | Subduction thrust (Japan Trench) |
“Earthquake sources across the globe are numerous, so when they occur close together in time, it is just a coincidence,” said Daryono of the Indonesian Disaster Experts Association. “There is no propagation or triggering effect between them.”
William Barnhart, assistant coordinator of the USGS Earthquake Hazards Program, put it simply: “Earthquakes happen every day all over the world. Most of them happen far from people. Yesterday was just a very peculiar day where you had a couple of fairly significant earthquakes happen in areas where people felt them.”
The exception within
The one caveat: the two Venezuelan quakes, 39 seconds apart on the same fault system, were likely causally related. This is a classic earthquake doublet, where the initial M7.2 rupture transferred stress to a neighboring segment of the Boconó Fault, triggering the M7.5 mainshock. But this is a local, not global, triggering effect.
“There is a difference between a doublet and global synchronization,” Barnhart noted. The Venezuela pair belongs in the first category. The California, Venezuela, and Japan quakes as a group belong to the second, or rather, to no category at all beyond random chance.
The psychological pull of temporal clustering
The perception that earthquakes cluster in time is a well-studied cognitive bias. The San Francisco earthquake of 1906 was followed 38 days later by a magnitude 8.2 in Valparaíso, Chile, and the 2004 Sumatra-Andaman earthquake was followed three months later by the Nias earthquake 160 kilometers to the southeast. In each case, journalists and the public asked whether one triggered the other, and in each case, seismologists said no, they were simply separate events in a world where, on average, the USGS records about 50 earthquakes per day of magnitude 2.5 or greater.
What made June 24-25 unusual was not the number of earthquakes, there were hundreds of smaller ones, but the fact that three large ones happened in populated areas within hours of each other, making the news simultaneously.
“Earthquakes are not like hurricanes,” Hudson said. “They don’t form a pattern that propagates around the world. They’re sudden, local, and fundamentally unpredictable. When three happen on the same day, it feels like a pattern. But the Earth’s crust doesn’t care about what feels like a pattern.”
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Source: Barnhart, W., Hudson, M. as quoted in Uwa Ede-Osifo (2026). Experts say three recent powerful earthquakes are not related. *The Guardian*, June 25 2026. https://www.theguardian.com/world/2026/jun/25/three-recent-powerful-earthquakes-not-related