northeast Japan
Refers to the region northeast of the Itoigawa-Shizuoka Tectonic Line, a major geological boundary. Often contrasted with 西南日本 (southwest Japan).
See also: 西南日本
Northeast Japan is the region on the northeast side of the Itoigawa-Shizuoka Tectonic Line.
Refers to the region southwest of the same tectonic line; the complementary term to 東北日本.
Compound of 東北 (tōhoku, 'northeast') and 日本 (Nihon, 'Japan'). The term is used in geology and geography to divide the Japanese archipelago along the Itoigawa-Shizuoka Tectonic Line.