Series showing how new camera technology is revealing the inner workings of the Earth's most spectacular natural wonders. Dr Helen Czerski examines the extraordinary new images - from eyewitnesses, scientists and film-makers - that are transforming our understanding of how and why these phenomena form. In this episode she reveals the latest scientific insights into icebergs. From side-scanning sonar that scrutinises the edge of glaciers where icebergs are born, to satellite images that show how icebergs create hotspots for life and eyewitness pictures that give us a unique glimpse of how they transform over time, we can now capture on camera the mysteries of icebergs - and how their lifecycle is intricately linked to our changing planet.

• Helen Czerski