Dismissal of “Tokara Theory” Connecting Recent Earthquakes to Nankai Trough Megaquake

The so-called “Tokara Theory” has gained traction online, suggesting that a recent wave of earthquakes in Akusekijima and the surrounding Tokara islands could be indicative of an approaching megaquake along the Nankai Trough. However, Naoshi Hirata, a prominent seismologist and professor emeritus at the University of Tokyo, has dismissed these claims, stating that no scientific studies or data indicate a causal relationship between the Tokara chain earthquakes and other seismic regions.

In the wake of capturing over 1,600 tremors in the Tokara region since June 21, which varied from minor vibrations to significant shakes that caused physical disruptions, social media discussions have surged around this theory. The strongest tremor recorded amidst this swarm measured below magnitude 6, and Hirata reassured the public that such seismic activities are unlikely to impact Japan’s main islands, including Kyushu, Shikoku, and Honshu—areas expected to be affected by a future Nankai Trough event.

While Hirata downplayed the fear surrounding the connection to a larger quake, he highlighted the ongoing necessity for earthquake preparedness. He reminded the public that Japan is prone to earthquakes and urged individuals to take proactive measures to safeguard their lives and property.