When you picture the North Pole, you probably imagine a vast, frozen expanse of floating sea ice. But hidden deep beneath the surface of the Arctic lies something incredible: a massive, churning reservoir of nearly fresh water, suspended right in the middle of a saltwater ocean. In this episode of The Rest Is Science, Professor Hannah Fry and Michael Stevens (VSauce) explore the hidden hydrodynamics of the Arctic. Fresh off a real-world scientific expedition to the sprawling ice sheets of Greenland, Hannah shares firsthand accounts of the colossal forces currently reshaping our polar regions. Together, they unpack the bizarre physics that allow a gigantic freshwater lake to form beneath the Arctic ice. Fancy some some of your own glacial water? https://svalbardi.com/pages/the-water Send questions of your own to therestofscience@goalhanger.com or find us at r/TheRestIsScience. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Video Editor: Jack Meek Animator: Sam Benson Video & Social: Bex Tyrrell Assistant Producer: Lucy Lipscombe Producer: Simona Rata Senior Producer: Lauren Armstrong-Carter Chief Digital Officer: Samuel Oakley Exec Producer: Neil Fearn