Rare footage appears to show a Canadian forest 'breathing'.  

Scenes filmed in Quebec's Sacré-Cœur went viral, earlier this week, after the earth appeared to inhale and exhale at will - despite being populated with heavy, towering trees.

In reality, it was the flexible roots countering the force of gale-force winds, which momentarily raised the base's topsoil.

Nonetheless, viewers were still amazed at the optical illusion, which scientists say is a relatively common phenomenon.