BotEC: The Himalayas and Continental Drift

Peter Kresan



The story of the Himalayas can be traced back to the breakup of the supercontinent, called Pangaea, about 200 million years ago, when India began its rapid movement northward towards Asia. Asia was a much smaller continent then. Then, between 45 and 55 million years ago, India and Asia collided. Before collision, India moved northward at about 7-10 centimeters per year. Remarkably, India's northward movement was slowed only a little after the collision—it continues to plow into Asia at a rate of 5-6 centimeters per year. We can measure the present northward movement of India into Asia using GPS measurements over a period of time. So, there is little doubt of the continued movement of India. There is much debate about how the northward march of India into Asia is being accommodated. Of course, the high Himalayan Plateau is a manifestation of this collision between two continents.

Let's assume that India began to plow into the Asian continent 55 million years ago and that, since then, it has continued to uniformly move northward into the Asian continent at 6 centimeters per year (for 55 million years). Calculate the total distance (in kilometers) that India has plowed into Asia.


Answer: 3,300 km

References and Resources

This SERC page describes the use of Back of the Envelope Calculations

A View from the Back of the Envelope (more info) : This site has a good number of easy simulations and visualizations of back of the envelope calculations.

The Back of the Envelope : This page outlines one of the essays in the book "Programming Pearls" (ISBN 0-201-65788-0). The book is written for computer science faculty and students, but this portion speaks very well to back of the envelope calculations in general.