The Japan Meteorological Agency (JMA) has recorded more than 900 earthquakes in the remote Tokara island chain in southern Japan over the past two weeks, underscoring a period of heightened seismic activity in the region.
Ayataka Ebita, director of the JMA’s Earthquake and Tsunami Observation Division, said the tremors have been ongoing in the waters surrounding the islands since June 21. A magnitude 5.5 quake struck the area on Wednesday, further alarming residents.
While no significant damage has been reported and no tsunami warning has been issued, authorities have urged local communities to remain vigilant and prepare for possible evacuation in the event of stronger quakes.
According to The Mainichi Shimbun, 740 of the earthquakes were recorded between June 21 and July 1, all registering at least 1 on Japan’s 7-point seismic intensity scale. An intensity level of lower 5 is typically strong enough to cause panic and force individuals to grab onto nearby supports.
Official data show that daily earthquake counts peaked at 183 on June 23, before dropping to 15 on June 26 and 16 on June 27. However, the activity surged again with 34 quakes on June 28 and 98 on June 29. Sixty-two tremors were recorded on June 30.
A similar swarm occurred in September 2023, when 346 earthquakes were detected in the same area, the JMA noted.
The Tokara Islands are located between Yakushima and Amami Ōshima, in the waters south of Kagoshima Prefecture on Kyushu’s mainland. Seven of the 12 islands are inhabited, with a combined population of approximately 700 residents.
Experts attribute the frequent seismic activity to the complex geological structure beneath the region. The area’s unusual seabed topography allows tectonic pressure to accumulate and release more readily in the form of earthquakes.
Japan sits at the convergence of four major tectonic plates and is one of the most earthquake-prone countries in the world. It lies along the Pacific “Ring of Fire,” a zone known for frequent volcanic eruptions and seismic activity.
