A Japanese researcher discovered that two small islands in the southwestern Japan departed from each other by almost 10 cm in just three days, against the background of a seismic activity that continues in the region.
The seismic activity has intensified in the last weeks around the Tokara archipelago, in the Kagoshima Prefecture.
Professor Yusaku Ota, from the Superior School of Sciences of the University of Tohoku, analyzed the movements of the terrestrial bark using the data of the observation points of the Japanese service of geospatial information, as well as the basic stations of the mobile networks.
He discovered that the island of Kodakarajima moved 6 cm to north-north-west, and the island of Takarajima-3.5 cm to the south, during the three days after the earthquake with magnitude 5.6 produced on July 2.
Previously, both islands were traveling to the northeast.
According to Ota, such trips have never been observed so far.
He considers that, given the magnitude of the earthquake and the distance from the epicenter, these movements may not have been caused by the 5.6 degree earthquake.
OTA assumes that among the possible factors are the movement of flows, especially the infiltration and spread of the magma in the terrestrial bark, as well as the slow slip along a fault near a superficial area of the continental tectonic plate.
Ota said he does not know if these recent movements of the earth’s crust will lead to a strong earthquake.
He expressed his intention to study the past data to try to determine the causes of this current phenomenon.
