Ubagahara

...The eruption points of Mt. Asama have moved eastward in the order of Mt. Kurobanzayama, Mt. Maekakeyama, and Mt. Kamayama. The foot of the volcano stretches 35 km north to south and 20 km east to west, with the northern part called Ubagahara and Rokurigahara, and the southern part called Oiwakehara and Jizogahara. The northern end of the foot of the volcano reaches the Agatsuma River, and the southwestern end reaches the Chikuma River. ...

*Some of the terminology that refers to "Ubagahara" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…浅間山の中では黒斑山，前掛山，釜山の順に噴出点が東に移動してきた。裾野は南北35km，東西20kmの範囲に及び，北側を姥ヶ原，六里ヶ原，南側を追分原，地蔵ヶ原と呼ぶ。裾野の北端は吾妻川に，南西端は千曲川に達する。…

※「姥ヶ原」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報