Japan Hit by 470 Earthquakes

A swarm of earthquakes at least 474 in total has rattled the remote Tokara Islands in southern Japan since Saturday, according to the Japan Meteorological Agency (JMA), prompting warnings about the potential for stronger tremors.

The quakes, mostly mild, have registered a seismic intensity of one or more on Japan’s seven-level scale, a level typically felt only by people quietly indoors. However, the JMA has urged residents to remain alert, noting the region’s history of prolonged seismic activity.

“Seismic activity has increased. As this area has experienced similar patterns in the past, please stay vigilant against quakes that may produce strong shaking,” the agency said Thursday, June 26.

Two of the strongest tremors both magnitude 5.1 were recorded on Sunday and Tuesday, each registering an intensity of four. At that level, shaking is enough to rattle dishes, sway hanging objects, and startle most people.

This current uptick follows a similar episode in September 2023, when 346 quakes struck the same region over a 15-day period.

The Tokara Islands, a chain of 12 volcanic isles south of Kyushu, have only seven inhabited islands with a combined population of about 700. Access is limited to a ferry that runs twice weekly, weather permitting.

Marine volcanologist Hisayoshi Yokose of Kumamoto University warned of the potential for a larger event: “An earthquake of up to magnitude 6 could occur. Please remain vigilant,” he told NHK.

Japan, located along the seismically volatile Pacific “Ring of Fire,” sits atop four tectonic plates and experiences roughly 1,500 quakes annually nearly 18% of all global seismic activity.

While most quakes in Japan are minor, the impact can be devastating. On January 1, 2024, over 400 people died when a powerful quake hit the Noto Peninsula, causing fires, collapsed buildings, and widespread damage as New Year celebrations were underway.