Contraction of northeastern Japan: evidence from horizontal displacement of a Japanese station in global very long baseline interferometry networks

Abstract

Kashima very long baseline interferometry (VLBI) station is situated on the outer arc of the northeast Honshu Arc and its position has been monitored in international geodetic VLBI networks since 1984. Kashima station is found to be moving with respect to the stations on the stable North American craton by about 1.4 cm y −1, which is inconsistent with the general concepts that the Japanese eastern half belongs to the North American plate and that plates are rigid. The direction of the movement (N60°W) is almost the same as the subducting Pacific plate which creates the compressional stress field in the island arc. This suggests that the east—west intraplate contraction of the arc under this stress field is responsible for the movement of Kashima.