Mountains are rocky habitats. They expose their habitants to all sorts of weather. Some of the big mountains are at bottom of sea. Most of the largest ones are actually below water. Temperature at the top of mountain is less than the temperature at sea level. Groups of mountains are called mountain ranges. Ranges normally cover 1000 or more miles. Mountain ranges together are called mountain system.
The mountain systems on our planet are believed to be the result of a collision of two of the drifting plates that make up the earth’s crust. Over the course of millions of years, the crustal plates underlying push one against another. Under intense pressure of collision, rock layers are rumpled up into great folds. Volcanic activity helps change the buried rocks into harder types of crystalline rocks. In course of time, once horizontal rock layers get upended or overturned completely. The end result is the arc of mountain extending many miles across.
Our planet has very impressive mountain ranges. There exist Rockies mountain range in North America, Andes in South America, the mighty Himalayas in Asia and Alps in Europe.
There are a wide variety of animals living here. Mountain lions, mountain goats and many others have got themselves adapted to life there. From rain to snow, when it comes to weather a mountain is a place of extremes.
For every foot we climb, it gets cooler and also harder to breathe. When one side of the mountain is sunny, other side may face rains. Mountains in a cool part of the world are temperate mountain zones. In such zones, mountains have a permanent coating of snow. Nothing grows at this height. A major portion of earth’s fresh water originates in ocean. Water remains permanently frozen in some mountainous area. Such a source of water is called glacier.