Lake Suwa


Lake Suwa is a lake in the Kiso Mountains, in the central region of Nagano Prefecture, Japan.

Geography

The lake is the source of the Tenryū River. It ranks 24th in lake water surface area in Japan. The cities of Suwa and Okaya and the town of Shimosuwa are located on the shores of Lake Suwa.

Features

Lake Suwa is the site of a natural phenomenon known as the "God's Crossing". The lake has a natural hot spring under its surface. When the lake's surface freezes in the winter, its lower waters are still circulating. This results in ice pressure ridges forming in the surface ice, reaching heights of or more.
Local Shinto tradition holds that the ridges are formed by the gods crossing the lake, when travelling between the various buildings of the Suwa Grand Shrine. Folklore says it is the guardian god of Suwa, Takeminakata-no-kami, leaving his sanctuary to meet with his wife, the goddess Yasakatome, joining the opposite bank by walking on frozen water.

Natural history

Research on ice breakup on the lake and at the mouth of the Torne River in Finland suggested "global processes including climate change and variability are driving the long-term changes in ice seasonality."

In popular culture