Crackling Ice - Lake Kussharo
Lake Kussharo (屈斜路湖) is a caldera lake in Akan National Park, eastern Hokkaidō, Japan. It is the largest caldera lake in Japan in terms of surface area, and sixth largest lake in Japan. It is also the largest lake in Japan to freeze over completely in winter.
Along the lake shore are several outdoor hot springs and a sand beach with naturally heated sand and hot ground water. As a result, there are sections near the shore which do not freeze or lightly freeze.
I was there recently on a typical winter morning. The ice along the shore near a hot stream was thinly frozen. As the sun rose on this cloudy day, the slight increase in temperature caused stresses in the thin ice which began crackling. As each piece broke, it caused a chain reaction in the remaining ice nearby. Over the course of minutes, the sound of crackling ice could be heard all around. These sessions extended for a few minutes, then after some quiet would begin again.
This short movie clip was recorded in stereo audio: