With 70% of the earth's surface covered in water, it is bound to play a massive part in the earth's history and future. This episode looks at the importance of water in shaping the earth's landscape, as well as its role in the survival of civilization. Formations like the Grand Canyon and Niagara Falls are the extreme examples of water's power to create landscapes. The powerful effects of ice are also observed in the erosion of rock as well as its effect on the sea levels. Floods and Tsunamis are documented using case studies from around the world. It is thought that water arrived on the surface of our planet thanks to two major processes. The early planet was almost constantly erupting; this process released water vapor from the molten material below the earth's outer crust. Vapor collected in the early atmosphere, gradually forming cloud. At the same time Earth was being bombarded by a series of asteroids, many of which contained stores of water. As they crashed into the earth yet more water vapor was released to join the cloud layer. Eventually the air became saturated and the earth's first and longest storm began. It is thought that the downpour of rain lasted for a million years, flooding much of the planet. Indeed when the rain eventually eased, 90% of the planet was covered by water. Today water remains concentrated in the oceans that still dominate our planet.
Episode #102 / Length: 57 minutes