Kamaana - Kamaana

...Records of Omiwatari have been kept since the Muromachi period, and are valuable sources for learning about climate change in Japan. There is a hot spring at the bottom of the lake near the eastern shore, and since this is the only place that does not freeze over even in winter, it is called Kamaana (Nanakkama). Lake Suwa is one of Japan's representative eutrophic lakes, and is known for its high catch per lake surface area, with fish such as smelt, carp, crucian carp, dace, tanago, moro, and oikawa caught there. ...

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

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…御神渡の記録は室町時代から残されており，日本の気候変動を知る貴重な資料になっている。湖の東岸近くの湖底には温泉湧出地があり，冬季にもここだけは結氷しないことから釜穴（かまあな）(七ッ釜)とよばれている。　諏訪湖は，日本の代表的な富栄養湖で，湖面の面積あたりの漁獲高が多いことで知られ，ワカサギをはじめ，コイ，フナ，ウグイ，タナゴ，モロ，オイカワなどがとれる。…

※「釜穴」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