Please don’t try this without proper training and supervision. Thin ice brings with it many risks and dangers.

How Skating on Thin Ice Creates Laser-Like Sounds – Amy Rankin, National Geographic

The idiom “skate on thin ice” usually means: danger—stop what you’re doing, or else. However, skating on thin, black ice is exactly what Swedish ice skating enthusiasts Henrik Trygg and Mårten Ajne love to do.

To hit the ice when it has just begun to freeze, in its most pristine, dangerously thin state, is the ultimate thrill in “wild ice skating,” or “Nordic skating.” It’s the “holy grail,” says Trygg. (Learn about the similar sport of backcountry ice skating.)

A photographer and filmmaker based in Stockholm, Trygg has made an art of capturing both the clear, black appearance of the ice, and the laser-like symphony of sounds created when an ice skater’s bodyweight passes over it. Ajne is a mathematician who has written books on the art and science of Nordic skating, featuring Trygg’s photographs. Both men have been skating for decades.