A magnitude 5.6 earthquake struck a rural area of northern California on Wednesday. Hours later, a magnitude 7.2 quake hit the northern coast of Japan, and two powerful quakes struck Venezuela in a devastating mass‑casualty event.
The tremors occurred within an eight‑hour window, prompting widespread speculation about a possible connection.
Experts say there is no causal link.
“Earthquakes occur daily worldwide, most far from populated areas,” said William Barnhart, assistant coordinator for the US Geological Survey’s earthquake hazards program. “Yesterday was an unusually active day, with several relatively strong quakes felt in inhabited regions.”
A large quake can trigger tremors elsewhere, Barnhart added.
Nevertheless, a cascade of quakes thousands of miles apart is exceptionally rare, according to Martin Hudson, an adjunct professor of civil and environmental engineering at UCLA.
“In the past century we have never observed earthquakes this distant from one another being related,” he said.
The initial 7.1‑magnitude tremor in Venezuela likely triggered the subsequent 7.5‑magnitude event due to their proximity.
“A fault may be primed to rupture; a nearby quake can push it over the edge,” Hudson explained.
Each year, dozens of earthquakes exceed magnitude 7 globally, Hudson noted.
“It was a tragic coincidence that this sequence struck a populated area in Venezuela,” he added, noting at least 188 fatalities.