Why the relief of the Earth is very diverse: the main factors, examples
Every schoolchild knows that there exist on our planet mountains, plains, plateaus, canyons, caves, deserts, hills and valleys, which are collectively called the word "relief". The question of why the terrain of the Earth is very diverse, is considered in this article.
What is meant by the word "relief"?
Our planet has three important components: the lithosphere, the atmosphere and the hydrosphere. Before analyzing the question for schoolchildren of the 7th grade, why the relief of the Earth is very diverse, it is necessary to define this concept.
So, the word "relief" is understood as a set of forms of the upper part of the lithosphere of our planet (the earth's crust), which are both on land and form the bottom of oceans and seas. All of these forms are studied in the section of geology, which is called the science of geomorphology. The main object of its study becomes the surface of the continents and islands.However, it also explores the seabed with its underwater mountains, plains and valleys.
What types of relief are there?
Considering the question of why the terrain of the Earth is very diverse, a few words should be said about how it is.
First of all, it is a macro-relief, that is, huge areas on the surface of the planet that have a certain characteristic. Here are the following types:
- Plains. Vast surface spaces of the planet, which are characterized by small elevation differences (several tens of meters). Plains, as a rule, are located low above sea level (up to 200 m). An example is the East European Plain, which is also called the Russian.
- The mountains. When asked why the terrain of the Earth is so diverse, most people think about the mountains. They represent areas of land and the ocean floor, which raise to a great height (several kilometers) relative to the surrounding area. An example of this type of relief is the Caucasus Mountains or the Himalayas.
- Plateau. It is also a huge terrestrial space, which have a wavy relief. They are located at altitudes of about 1000 m above sea level and often share mountain ranges.The plateaus are formed by rocks, this fact distinguishes them from the plains, which, as a rule, are of sedimentary origin. A vivid example of this type of macrorelief is the Central Siberian Plateau.
There is also the concept of "relief of the area", which implies the presence in the area under consideration depressions, ravines, canyons, valleys, beaches, hills, elevations, and so on.
Why is the relief of the Earth very diverse?
So, the above were briefly listed the main types of relief observed on our planet. But why are there plains, mountain ranges and ridges, why is a certain area cut up by ravines, the other is smooth and there are no hills on it?
Answering briefly why the terrain of the Earth is very diverse, it should be said that this fact is associated with the result of the action of internal (endogenous) and external (exogenous) processes.
Endogenous processes are those that occur inside the Blue Planet, that is, these are movements of magma and displacement of lithospheric plates that appear on the surface in the form of volcanic eruptions and earthquakes. This is the most powerful source of relief formation, which largely determined the appearance of our planet.
Exogenous processes can be divided into three types:
The effect of the atmosphere on the relief includes the effect of wind and changes in daily temperatures. Both processes are destructive or erosive in nature. A striking example of the influence of wind on the terrain is the movement of sand dunes in deserts.
Hydrospheric, that is, due to the action of water. Many examples can be cited here: the appearance of ravines in the course of river flow, the formation of alluvial sediments, modification of the coastline due to the influence of seas and oceans, the formation and movement of glaciers on the land surface and others.
Biospheric processes of changing the relief of the planet are associated with the activity of living organisms. For example, the formation of coral islands. But the most powerful means of modifying local relief is human economic activity.
To clarify the above material, we give a short video.
How to depict the relief on the maps?
Geographic maps that reflect the characteristics of the terrain of a particular locality are called topographic. All over the world, it is customary to depict a relief in one of the two following ways or a combination of them:
- using closed lines - elevations;
- using color coloring (brown mountains, green plains).