Abstract
By the morphometric analysis of the topographic maps of four Japanese main islands, the following results are inferred:
1. The geomorphic history of Japan Arc is divided into three stages by the intensive up-warping.
2. The continental shelf of Japan Arc is the former subaerial geomorphic surface. The age of this surface is far older than the Riss-Würm interglacial age.
3. Maximum glaciation in Japan Arc took place in the Würm glacial age.
4. The formation of the coastal plains and the lower alluvial plains in Japan Arc is the unique phenomenon during the later stage of the geomorphic history.
5. The continental age of Japan Arc is twice during the later stage of the geomorphic history; the first during the subaerial period of the shelf, and the next during the Würm glacial age.
