1949 Volume 58 Issue 6-7 Pages 224-231
On Dec. 21th. 1946, one of the most destructive earthquakes since the Meiji Era outbroke in the Southwestern Japan. It is called Nankai Earthquake and its epicenter situated off the shore of Cape Muroto at the southeastern extremity of Shikoku.
Fig. I. show the amount of the upheaval and the subsidence of land along the coast of Shikoku. It was measured by comparing the relative height of land surface to the sea level, immediately before and after the earthquake. At the northern coast of Shikoku where the land is used intensively, this small change of level along the coast has caused the considerable damage in various ways, such as the decrease of salt production in salt bed, the dilapidation of rice field in considerable area, the degradation of sandy shore etc. In this paper the author treated in the first place various kinds of damage suffered from the subsidence of land in details, in the second place the progress of this phenomena during one and a half years since the catastrophe and finally the relationship between this earth movement and the movements on the several Nankai earthquakes during historical age, as well as the relationship between the earth movements in historical age and that in recent geological Past known from the studies of the coastal features of this region.