Substrata is the third studio album by Norwegian electronic musician Geir Jenssen under the stage name Biosphere, released in 1997 by All Saints Records. It is Biosphere's first truly ambient album, and has a theme of cold, of mountains and glaciers, and of running water. Sounds of howling wind and creaking wood, although infrequently employed, create a chilling soundscape interrupted by sonorous but quietly suspenseful music.