Sounds of Skating on Thin Ice

Otherworldly sounds: This small lake outside Stockholm, Sweden, emits otherworldly sounds as Mårten Ajne skates over its precariously thin, black ice. “Wild ice skating,” or “Nordic skating,” is both an art and a science. A skater seeks out the thinnest, most pristine black ice possible - both for its smoothness, and for its high-pitched, laser-like sounds.

https://youtu.be/v3O9vNi-dkA