India drift
In the history of continental drift, India has been a mysterious record-holder. More than 140 million years ago, India was part of an immense supercontinent called Gondwana, which covered much of the Southern Hemisphere. Around 120 million years ago, what is now India broke off and started slowly migrating north, at about 5 centimeters per year. Then, about 80 million years ago, the continent suddenly sped up, racing north at about 15 centimeters per year — about twice as fast as the fastest modern tectonic drift. The continent collided with Eurasia about 50 million years ago, giving rise to the Himalayas. For years, scientists have struggled to explain how India could have drifted northward so quickly. Now geologists at MIT have offered up an answer: India was pulled northward by the combination of two subduction zones — regions in the Earth’s mantle where the edge of one tectonic plate sinks under...