Islands in Japan’s Tokara group shift by 10 cm in three days due to seismic activity
Two small islands in the southwestern part of Japan have moved apart by nearly 10 centimetres over the course of three days due to seismic activity, according to reports from international news outlets.
The Japan Meteorological Agency continues to report ongoing seismic activity in the Tokara Islands, Kagoshima Prefecture, particularly after a 4.5 magnitude earthquake struck Akuseki Island on July 9. This has brought the total number of earthquakes in the area to 1,688 since June 21.
According to reports, Japanese researchers have discovered that two small islands in the Tokara Islands group, Kodakara and Takara islands, have shifted apart by nearly 10 centimetres in just three days.
This is an unprecedented situation, raising concerns about the possibility of a major disaster.
Ota Yusaku, a professor at the Graduate School of the Higher School of Sciences at Tohoku University, used data from the Geospatial Information Authority of Japan’s observation points and mobile phone towers to analyse the movement of the Earth's crust.
The study revealed that since the 5.6 magnitude earthquake on July 2, Kodakara Island has shifted 6 centimetres to the north-northwest, while Takara Island has moved 3.5 centimetres to the south.
What is concerning is that, normally, the two islands move in the same direction—northeast. However, following the recent earthquake, Takara Island shifted southward, unlike its usual pattern. This suggests that the two islands are now moving apart, rather than in the same direction as before.
Yusaku explained that the abnormal movement of the islands may not be directly caused by the 5.6 magnitude earthquake when considering the quake's size and its distance from the islands.
One possible cause could be the infiltration of underground fluids, such as magma, into the Earth's crust, causing it to expand, along with the slow shifting of fault lines in shallow areas of the continental plate.
However, Yusaku acknowledged that it is still unclear whether this movement of the Earth's crust will lead to a major earthquake in the future. He plans to examine historical data in detail and investigate the true cause of this unprecedented phenomenon.
Scientists are urgently working to understand the situation to assess the potential risks that may arise in the future.
