Hokkaido / Tokara Islands, Japan – June 2025.
Northern Japan has once again found itself at the center of seismic unrest. On June 23, a magnitude 6.1 earthquake was recorded near the city of Kushiro, located on the island of Hokkaido, according to the United States Geological Survey (USGS).
The epicenter was approximately 50 kilometers south of Kushiro, with the hypocenter located at a depth of about 20 kilometers. The tremor was strongly felt across northern Hokkaido, though no casualties or structural damage have been reported. Authorities have confirmed that no tsunami warning was issued.
🔍 Seismic Activity Escalates Beyond Hokkaido
While the tremor in Hokkaido drew immediate attention, a prolonged swarm of earthquakes has also been shaking the waters around the Tokara Islands, located further south in Kagoshima Prefecture. Between Saturday and Monday, the Japan Meteorological Agency (JMA) recorded over 200 earthquakes with an intensity of shindo 1 or higher on the Japanese seismic scale.
The most powerful of these occurred on Sunday at 5 p.m., registering a magnitude of 5.2 and shaking the island of Akuseki with an intensity of shindo 4. While no tsunami has followed any of the tremors, the frequency and distribution of quakes remain a concern.
📈 Tokara Islands Under Close Watch
According to JMA officials, seismic activity in the Tokara region is expected to persist for several weeks, possibly mirroring similar episodes that occurred in December 2021 and September 2023, during which over 300 tremors were recorded. One such event in 2021 included a magnitude 6.1 quake, which reached shindo 5 intensity on Akuseki Island.
Seismologist Masashi Kiyomoto stated that the quakes appear to be occurring within the continental plate at shallow depths. However, the precise cause remains unclear, as there are no known undersea volcanoes or active faults in the vicinity. The current swarm began as faint tremors but intensified rapidly between Akuseki and Kodakara Islands, with most epicenters located near Kodakara.
🛑 Warnings for Residents and Travelers
Authorities have urged residents and visitors, especially on Akuseki, Kodakara, and Takara Islands, to remain vigilant and prepared. As of May 2025, the combined population of the seven inhabited Tokara Islands was just 669 people, yet the risks posed by prolonged seismic unrest remain significant.
Local safety recommendations include:
- securing heavy furniture and household objects,
- preparing emergency supply kits,
- closely following official updates and evacuation instructions.
In light of Japan’s dynamic seismic landscape, many citizens are turning to advanced technological tools for early detection. One such solution is the Geoquake app — a modern platform that enables users to monitor real-time seismic data and receive early warnings of potentially destructive earthquakes. Leveraging cutting-edge algorithms based on the method of seismic entropy, Geoquake offers a proactive layer of personal safety in regions prone to tectonic activity.
While the current wave of quakes has not caused damage or loss of life, experts warn that stronger aftershocks may still occur, and the situation remains volatile. Ongoing monitoring and public preparedness are key to mitigating future risks.