Substrata is an ambient music album by Biosphere, released in 1997 by All Saints Records. It is considered to be a classic ambient album, consistently in the top 5 in surveys on the Hyperreal ambient mailing list.
Biosphere's first truly ambient album, it has a theme of cold, of mountains and glaciers and running water. Sounds of howling wind and creaking wood, although infrequently employed, create a chilling soundscape interrupted by sonorous but quietly suspenseful music. .