Key Facts
• Since June 21, 2025, 1,725 earthquakes recorded near Tokara Islands.
• Tokara’s Takarajima moved 1.8 cm northeast by July 2, then 4.2 cm south on July 3.
• A magnitude 6 earthquake struck Akusekijima on July 3, 2025.
• Experts link crustal shifts to magma and water activity beneath the surface.
• Philippine Sea Plate subducts under Eurasian Plate, releasing high-temperature water.
• Released water may create magma chambers, causing seismic activity.
• Fault slippage due to water infiltration may explain directional crustal changes.
• No observation equipment is currently installed on Akusekijima.
• Japan’s Ministry of Education is considering temporary monitoring equipment for data collection.
Summary
The Tokara Islands near Kagoshima Prefecture have experienced 1,725 earthquakes since June 21, 2025, with significant crustal movements observed. Takarajima shifted 1.8 cm northeast by early July, then abruptly moved 4.2 cm south before a magnitude 6 earthquake struck Akusekijima on July 3. Experts suggest magma and water activity beneath the surface, influenced by the subduction of the Philippine Sea Plate under the Eurasian Plate, may be driving these phenomena. Released water from the subducted plate could create magma chambers or lubricate fault lines, causing seismic activity and directional crustal changes. However, the lack of observation equipment on Akusekijima limits data collection. Japan’s Ministry of Education is exploring the installation of temporary monitoring devices to better understand these mysterious crustal dynamics.
