Mountain

A mountain is an elevated portion of the surface of a planet, generally with steep sides that show significant exposed bedrock. Although there are no universally accepted definitions, a mountain is usually considered higher than a hill. By definition, mountains are often thought of as being a landform which is higher than 2,000 feet (610 m). It may either have a limited summit area or be a smaller plateau with high elevation and steep sides. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction, such as mining...