Types of landforms

There are many different types of landforms on the Earth. Some of them were formed over millions of years and others were formed in a matter of hours. The formation of a mountain range, for example, would usually take a few million years. Events like earthquakes and volcanic eruptions can 'wipe off' landforms, or form new ones in a matter of hours. Examples of some natural landforms are mountains, oceans, rivers, hills, volcanoes, valleys, desserts, waterfalls, caves and cliffs. This chapter looks at the formation of some major types of landforms.

Mountains

A mountain is a raised part of the Earth's surface. Mountains can be formed in different ways that involve internal (inside) or external (outside) natural forces. The movement of tectonic plates is called plate tectonics. Plate tectonics is an internal natural force because it happens inside the Earth. When tectonic plates collide, they raise the Earth's crust. As mentioned before, tectonic plates move very slowly, so it takes many millions of years to build a mountain. Mountains can also be formed by external natural forces like rain, wind and frost in the process of erosion.

Mountains with shapes that are sharp and jagged are called young mountains. Mountains that have a smoother, more rounded look are called old mountains. The South American mountain range, the Andes, is a young mountain range. Old mountains look smoother because they have been shaped by natural weathering over a longer period of time. The Himalayan Mountains, which are an older type of mountain, are still 'growing' due to plate tectonics.

If they are given enough time, usually millions of years, all mountains crumble. High, jagged peaks become low, rounded hills. Eventually, mountains wear away, becoming soil and sand. Valleys

A flat area of land between hills or mountains is called a valley. Valleys