December 11 is International Mountain Day. It is a day to create awareness about the importance of mountains to life. The theme for this year's celebrations is food security in the mountains.
A globe is supposed to represent Earth. But does it? Hardly.
It doesn’t represent Earth’s shape—an ‘oblate spheroid’, slightly flat at the poles and bulging at the equator. The globe is also super-smooth. Earth is not! There are plains, valleys, plateaus, and, of course, mountains.
In Indian culture, mountains have long been revered. They have seen a lot of history—even though geologically speaking, they may not be that old.
Earth is made up of the outermost crust, under which are the mantle, outer core, and inner core. The mantle is ‘molten rock’ which is thick, gooey, and moving in all directions.
The crust is made up of plates which are slipping and sliding on this gooey hot stuff.
Mountains affect the climate of the regions they are situated in. For example, if the Himalaya were not where they are, many parts of India would be a lot colder due to the Northeast monsoon winds.
The climate changes as you go from the base to the top of the mountains. In the Andes of South America, several animals experience all four seasons in a single day by simply changing their altitude on the mountains.
Today, to visit some of the remains of the Inca civilisation, you will have to travel by train at dizzying altitudes.
Do you like chocolate? If yes, thank the ancient people of the Andes for pioneering the use of cocoa to make a drink that eventually led us to having chocolate.
The next time you enjoy “French” fries, say “Thank you” to the ancient Incas of the Andes. They were the earliest to cultivate potatoes. When you enjoy sweet apples from Himachal Pradesh, you must know that the Himalayas provide the right environment to cultivate them.
Magma (molten rock from the mantle) pushes up through the crust, and causes the crust to erupt,(e.g.: Mt. Pinatubo, Philippines) leading to the formation of volcanic mountains.
In some places, magma’s pressure pushes up the Earth’s crust but doesn’t erupt, leading to the formation of dome mountains . (e.g.: Half Dome in California’s Sierra Nevada).
Sometimes the plates of the crust (“tectonic plates”) collide and the crust crumples to form fold mountains (e.g. Himalaya).
When large areas of plateaus (high plains) are eroded by rivers, plateau mountains are formed (e.g.: Adirondack Mountains, the US).
Fault-block mountains emerge when boundaries between plates cause a block of land to rise high or fall low (e.g.: Harz Mountains, Germany).