Relief is a feature of the shape of the Earth’s surface, which is part of the terrain. Mountainous reliefs, hills, plateaus and plains are the four main types of relief. The movement of tectonic plates underground can change the terrain, forming mountains and hills. Erosion caused by water and wind can modify the appearance of the earth and create such reliefs as valleys and canyons. Both processes occur over a long period of time, namely several million years. This article talks about the mountain diversity of the Earth, as well as the economic importance of mountains for the inhabitants of the world.
Land surface
The topography of the Earth is many different types of terrain. Landforms can be formed under the influence of various natural forces, including erosion of water and wind, plate movement, folding and destruction, as well as volcanic activity. The main forms of mountainous terrain are: elevation, hollow, ridge, hollow, saddle.
Hills
Hills are natural areas of relief. This type of geological formation has special characteristics in terms of shape and height. Unlike mountains, hills usually do not exceed 100 meters in height. They are characterized by the presence of an extensive mountain topography, but slightly steep and rounded peaks.
Many experts call the hills ancient mountains deeply damaged by water erosion or wind.
The plains
This type of terrain is located at a low altitude relative to sea level. The plains rise to 200 meters and even more than 300 meters.
Plains are flat areas of land or territory with minor irregularities that in certain places are adjacent to mountainous areas.
A plain is the surface of the Earth, which has neither maxima (mountain peaks), nor minima (troughs), which means that it is flat over the entire area related to it.
Plateau
The plateau as a type of mountainous relief is represented by large elevated flat territories that were supplanted by the forces of the Earth or by layers of lava.
They are located above the plains and are usually located at an altitude of 200 to 5000 meters above sea level. This type of relief is born as a result of erosion of old mountain systems or under the influence of tectonic forces.
Depending on the location of the plateau, the following classification exists. The first group is a plateau between the mountains that are formed together with the mountains and are completely or partially surrounded by them. The second group is a plateau located near the mountains and the ocean. The third is continental plateaus, which rise sharply from coastal plains or the sea. A plateau of mountains can be found next to the folded mountains. Mountains in New Zealand are examples of plateaus.
Valleys
Valleys are areas between mountain slopes, next to which a river usually flows. In fact, valleys are formed precisely because of the erosive effects of the river channel.
Valleys can also be formed by tectonic movements or melting glaciers. This type of relief is mainly a territory that fits into the surrounding area, which can be occupied by mountains or mountain ranges.
The mountains
What is mountainous terrain briefly? This is a natural terrain, which is characterized by high altitude and slopes. It occupies almost a quarter of the planet’s surface.
Most of the existing mountains were formed as a result of movements and overlapping plates. This process is often called deformation.
Mountains are formed from several parts, one of them is the base, which is the lowest region. The top is the highest part, and the slope or ridge is the inclined part of the mountain, which is located between the foot and the peak. The main elements of the mountainous terrain: the sole (base), the slope (slope), the bottom (top), the depth (height), the steepness and direction of the slope, the watershed and watershed lines (thalweg).
Main meaning
Most of us can imagine mountains, but how are they really defined?
In general terms, a mountain is a topography that has a significant ledge (usually in the form of a peak) that distinguishes the mountain from the surrounding forms of the earth. The mountains are considered steeper, above the hills. The features of the mountainous terrain for each mountain are individual. Mountains can be located separately, but more often they form a sequence of mountains called a mountain range. But what makes a mountain a mountain? And what makes a hill a hill?
Unfortunately, there is no clear answer to this question, because there is no universally accepted definition providing for the identification of the difference between these concepts. Some geographers believe that everything above 300 meters is a mountain, while others indicate a border of 600 meters.
The most outstanding relief on Earth is Mount Everest in Nepal. It is located 8848 meters above sea level and passes through several countries in Asia.
Specifications
There is no minimum height for a plot of land from which the terrain can be called a mountain. However, there are several characteristics by which a mountain can be calculated.
Elevations of the terrain determine the types of mountainous terrain. A mountain or ridge usually has a peaked peak. On the mountain, the climate is different than at sea level or plain. The mountain climate has a colder and more humid climate, more rarefied air. At high altitudes, there is very little oxygen. In addition, in the mountains, as a rule, less favorable conditions for the life of plants and animals.
Orientation
In geography, mountains and ranges are usually the highest elevation areas, while valleys and other low-lying areas are the lowest.
Relief is important for understanding the topography of the area. Map makers display different heights using several methods. Contour lines show the change in height between the lines drawn on the map, they are often used on flat maps. The closer the lines to each other, the steeper the height of the mountain. Color is also used to characterize the height of mountain systems: brown is characteristic for higher elevations, and green or lighter for lower values.
Types
Sometimes the crust is folded and bent, sometimes it is divided into huge blocks under the influence of the movements of lithospheric plates. In both cases, large tracts of land rise up, forming mountains. Some mountain ranges are formed by the earth’s crust rising into the dome, or by volcanic activity. Denote the main types of mountainous terrain.
Stacked mountains
This is the most common type of mountains. The largest mountain ranges in the world are folded mountains. These chains have been formed over millions of years. Folded mountains form when two plates collide, and their edges deform in much the same way that sheets of paper fold when they are compressed. Bending upwards are known as anticlines, and bending downwards are known as synclines.
Examples of stacked mountains are: the Himalayan mountains in Asia, the Alps in Europe, the Andes in South America, the Rocky Mountains in North America, the Ural Mountains in Russia.
The Himalayan mountains were formed when the lithospheric plate of India collided with the plate of Asia, thereby the highest mountain range of the whole world began to rise.
In South America, the Andes formed as a result of the collision of the South American continental plate and the Pacific Ocean plate.
Block mountains
These mountains form when faults or cracks in the earth's crust move some materials or rocks up and others down.
When the crust collapses, it breaks into blocks. Sometimes these blocks of stone move up and down, and they eventually become stacked on top of each other.
Often block mountains have a steep front and a sloping back. Examples of blocky mountains are the Sierra Nevada Mountains in North America and the Harz Mountains in Germany.
Dome mountains
Dome mountainous reliefs are the result of a large amount of molten rock (magma) under the earth's crust moving up. In fact, without breaking to the surface, magma pushes up the upper layers of the rock. At some point, the magma cools down and forms hardened rock. The elevated area created by the rising magma is called a dome because it looks like the upper half of a sphere (ball). Layers of rock above hardened magma bend upward to form a dome. But the rock layers around remain flat.
Domes can form many separate peaks called Dome Mountains.
Volcanic mountains
As the name implies, volcanic mountainous reliefs are formed by volcanoes. Volcanic mountains appear when molten rock (magma), located deep in the ground, erupts and accumulates on the surface. Magma is called lava when it breaks through the earth's crust. When ash and lava cool, a stone cone forms. They accumulate, layer by layer. Examples of volcanic mountains are Mount St. Helens in North America, Mount Pinatubo in the Philippines, Mount Kea and Mount Loa in Hawaii.
Variety of relief by continent
America. The mountainous terrain of the American continent is diverse. The relief is formed by mountain ranges, plains, massifs and plateaus. The highest peak is in the Andes and is called Aconcagua. The most important islands here are Victoria, Greenland, Newfoundland, Baffin, Aleutian, Antilles and Tierra del Fuego.
Asia. The relief of the Asian continent is represented by mountains, plains, plateaus and depressions. In this part of the world, the mountains are young and elevated, and the plateau is very high.
Africa. The relief of Africa is formed by vast plateaus, massifs, tectonic pits, plains and two great mountain ranges.
Europe. The relief of Europe consists of three main parts. The first zone is a plateau and mountains in the north and in the center; the second is the Great European Plain in the center; the third is young high mountains in the south.
Australia. On this continent, the most prominent landforms are the McDonnell and Hamersley Mountains, as well as the Great Dividing Range. On some islands there are mountainous areas of volcanic origin.
Antarctica. It is the highest continent on the planet. Elements of mountainous terrain include mountains with volcanoes and plateaus.
Economic importance
- Resource storage. Mountains are a repository of natural resources. Large reserves of minerals, such as oil, coal, limestone, are in the mountains. They are the main source of wood, medicinal herbs.
- Hydroelectricity production. Hydroelectricity is mainly generated from the waters of perennial rivers in the mountains.
- A plentiful source of water. Perennial rivers arising in the snowy mountains are one of the important sources of water. They help in irrigation and provide residents with water for other purposes.
- The formation of fertile plains. Rivers originating in high mountain ranges bring sludge along with water to lower valleys. This helps in the formation of fertile plains and the further expansion of agriculture and related activities.
- Natural political boundaries. Large mountainous reliefs can act as natural boundaries between the two countries. They play a significant role in protecting the country from external threats.
- Climate Impact. Mountains serve as a climatic barrier between two neighboring regions.
- Tourist centers. The pleasant climate and beautiful landscapes of the mountains have led to the fact that they have become attractive holiday centers for tourists.
Facts
Mountainous reliefs make up about one fifth of the global landscape. At least one tenth of the world's population is located on them.
The height of the mountains is usually measured in altitude.
The highest land mountain in the world is Mount Everest (Jomolungma) in the Himalayas. Its height is 8850 m.
The highest mountain in the solar system is Mount Olympus Mons, located on Mars.
Mountains and mountain systems also exist beneath the surface of the sea.
Most often mountains are found in the oceans, rather than on land; some islands are peaks of mountains emerging from the water.
About 80 percent of our planet’s fresh water belongs to mountain snows and ice.
All mountain ecosystems have one common characteristic - rapid changes in altitude, climate, soil and vegetation at short distances from the foot of the mountain to the top.
In the mountains you can find many plants and trees: conifers, oak, chestnut, maple, juniper, stonecrops, mosses, ferns.
The 14 highest mountains in the world are in the Himalayas.
In some mountainous areas, rivers regularly freeze.