Ends of the Earth: Journeys to the Polar Regions in Search of Life, the Cosmos, and Our Future

by Neil Shubin

Sixty million years ago, India sat below the equator as a separate island continent surrounded by water. By about 50 million years ago, it was moving north at the rate of 1 centimeter per year. Over millions of years, India crept ever northward until it slammed into Asia. Still pushing north, the crust at the border of India and Asia was the same density and had nowhere to go but up. Thus began the uplift that formed the Tibetan Plateau. Gradually, this slow uplift led to the origin of the highest mountain range, and the most extensive mountain plateau, on Earth. Today, the Tibetan Plateau continues to rise at about 1 centimeter per year. But erosion of the rocks happens so fast on the Himalayan mountains that their height rises somewhat less—as the mountains get pushed upward, their summits weather downward.