A 5.6-magnitude earthquake struck northern California on Wednesday, followed hours later by a 7.2-magnitude quake in Japan and two large tremors in Venezuela, raising online speculation about a possible link. However, seismic experts have said the events were unrelated.

Earthquakes Along Plate Boundaries

All three quakes occurred along known plate boundaries with high seismic hazard, according to William Barnhart, assistant coordinator for the USGS earthquake hazards program, as “Yesterday was just a very peculiar day where you had a couple of fairly significant earthquakes happen in areas where people felt them,” Barnhart said. Globally, dozens of quakes above magnitude 7 happen each year, he added.

While a large earthquake can sometimes trigger others nearby, experts say it is unusual for such an effect to occur across vast distances. Martin Hudson, an adjunct professor at UCLA, noted that in the past 100 years, no such cascade of earthquakes has been observed over thousands of miles. In contrast, the initial 7.1-magnitude quake in Venezuela likely triggered the 7.5-magnitude follow-up due to their close proximity. “A fault might be ready to go, and then if there’s a nearby earthquake, it causes it to tip over the edge,” Hudson said.

Local Impact and Response

In Mendocino County, the 5.6-magnitude earthquake caused items to fall from shelves and structural damage to two buildings, including a Grocery Outlet. No injuries were reported, and power was restored. Willits Mayor Tom Allman said the situation could have been worse. “Yesterday could have been worse. Today is a better day,” he said. City officials are now assessing damage and helping businesses reopen.

The Milo Foundation animal rescue sanctuary was also affected. “I think everyone felt it. We were shocked, surprised and, of course, afraid for the animals,” said founder Lynne Tingle. The organization is calling for more volunteers and pet adoptions to help support its ongoing operations.

Earthquake Risks in Istanbul

While the recent global quakes were unrelated, concerns about seismic risk remain high in Istanbul. Experts say the city is unprepared for the next major earthquake. According to the Chamber of City Planners, about half of Istanbul’s 1.6 million buildings were constructed illegally, without proper engineering oversight. AFAD estimates suggest an earthquake could kill nearly 30,000 people, injure 50,000, destroy 44,800 buildings, and leave 2.6 million people homeless. Other estimates are even higher, with potential fatalities ranging from 140,000 to 600,000.

Under President Recep Tayyip Erdogan, Istanbul has seen a construction boom fueled by credit and urban renewal projects. However, many high-risk areas have been neglected in favor of luxury developments. Residents have been displaced and relocated to state-supported housing on the city’s outskirts. “The question is not whether there will be an earthquake; it’s just a matter of when,” one expert told DW. “There will be an earthquake and every day the risk of a giant tremor shaking Istanbul increases.”