noun
convex side of a mountain arc; outer zone of an arc-shaped archipelago
Geological term referring to the outer, convex side of a curved mountain belt or island arc. Often contrasted with 内帯 (inner zone).
See also: 内帯
日本列島の外帯は太平洋側に位置する。
The outer zone of the Japanese archipelago is located on the Pacific side.
noun
southwestern Japan south of the Median Tectonic Line
Specifically refers to the region of southwestern Japan (southwest of the Itoigawa-Shizuoka Tectonic Line) that lies on the Pacific Ocean side of the Median Tectonic Line. This is a major geological division of Japan.
See also: 西南日本外帯
西南日本外帯には四国山地や紀伊山地が含まれる。
The outer zone of southwestern Japan includes the Shikoku Mountains and the Kii Mountains.