Relief is a feature of the shape of the Earth's surface, which is part of the terrain. Mountainous landforms, hills, plateaus and plains are the four main landform types. The movement of tectonic plates underground can change the terrain, forming mountains and hills. Erosion caused by water and wind can change the appearance of the land and create features such as valleys and canyons. Both processes take place over a long period of time, namely several million years. This article talks about the diversity of the Earth's mountains, as well as the economic importance of mountains for people around the world.
Surface of the Earth
The topography of the Earth is made up of many different types of relief. Landforms can be shaped by a variety of natural forces, including water and wind erosion, plate movement, folding and breaking, and volcanic activity. The main forms of mountain relief: upland,hollow, ridge, hollow, saddle.
Hills
Hills are natural landforms. This type of geological formation has special characteristics in terms of shape, height. Unlike mountains, hills usually do not exceed 100 meters in height. They are characterized by having an extensive form of mountainous relief, but slightly steep and rounded peaks.
Many experts refer to the hills as ancient mountains, deeply damaged by water or wind erosion.
Plains
This type of terrain is at 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 slight irregularities, which in certain places are adjacent to mountainous regions.
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
Plateaus as a type of mountainous landform are large raised flat areas that have been displaced by Earth forces or layers of lava.
They are located above the plains and are usually found at an altitude of 200 to 5000 meters above sea level. This type of relief is born as a result of the erosion of old mountain systems or under the influence of tectonic forces.
Depending on the location of the plateau, there is the following classification. The first group is a plateau between the mountains, whichformed along with mountains and completely or partially surrounded by them. The second group is the plateau, located near the mountains and the ocean. The third is the continental plateaus, which rise sharply from the coastal plains or the sea. Plateau mountains can be found next to 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 action of the riverbed.
Valleys can also be formed by tectonic movements or glacier melt. This type of terrain is basically an area that fits into the surrounding area, which may be occupied by mountains or mountain ranges.
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 movement and overlapping plates on top of each other. This process is often referred to as warping.
Mountains are formed from several parts, one of them is the base, which is the lowest area. The summit is the highest part, and the slope or ridge is the sloping part of the mountain that is located between the foot and the summit. The main elements of the mountain relief: sole (base), slope (slope), bottom (top), depth (height), steepness and direction of the slope, watershed and catchment lines (thalweg).
Basicvalue
Most of us can imagine mountains, but how are they actually defined?
In general terms, a mountain is a terrain that has a significant protrusion (usually in the form of a peak) that distinguishes the mountain from the surrounding landforms. Mountains are considered steeper, taller than hills. Features of the mountain relief for each mountain are individual. Mountains can be isolated, 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 generally accepted definition that provides for the identification of the difference between these concepts. Some geographers consider anything above 300 meters to be a mountain, while others mark a limit of 600 meters.
The most outstanding relief on Earth is Mount Everest in Nepal. It is located at 8848 meters above sea level and passes through several countries in Asia.
Features
There is no minimum height for a piece of land from which a relief can be called a mountain. However, there are several characteristics by which a mountain can be calculated.
The heights of the relief predetermine the types of mountainous relief. A mountain or ridge usually has a peak. On the mountain, the climate is different than at sea level or the plain. The mountain climate has a colder and more humid climate, more rarefied air. There is very little oxygen at high mountain altitudes. In addition, in the mountains, as a rule, less favorableconditions for the life of plants and animals.
Orientation
In geography, mountains and ranges tend to be the highest elevation areas, while valleys and other low-lying areas are the lowest.
Terrain is essential to understanding the topography of an area. Map makers display different heights using several methods. Contour lines show elevation changes between lines drawn on the map and are often used on flat maps. The closer the lines are to each other, the steeper the height of the mountain. Color is also used to characterize the height of mountain systems: brown is typical for higher elevations, and green or lighter for lower elevations.
Types
Sometimes the crust folds and bends, sometimes it breaks into huge blocks under the influence of lithospheric plate movements. In both cases, large tracts of land rise up to form mountains. Some mountain ranges are formed by the earth's crust rising into a dome, or by volcanic activity. Let's designate the main types of mountain relief.
Stacked Mountains
This is the most common type of mountains. The largest mountain ranges in the world are the 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 squeezed. The upward folds are known as anticlines and the downward folds are known as synclines.
Examples of folded mountains are: Himalayan Mountains in Asia, Alps in Europe, Andes in South America, Rocky Mountains inNorth America, Ural Mountains in Russia.
The Himalayan Mountains were formed when India's lithospheric plate collided with the Asian plate, causing the world's highest mountain range to rise.
In South America, the Andes were formed as a result of the collision of the South American continental plate and the oceanic Pacific plate.
Blocky Mountains
These mountains are formed when faults or cracks in the earth's crust push some materials or rocks up and others down.
When the earth's crust collapses, it breaks into blocks. Sometimes these boulders move up and down and over time they end up stacked on top of each other.
Often blocky mountains have a steep front side and a sloping back side. Examples of blocky mountains are the Sierra Nevada mountains in North America, the Harz mountains in Germany.
Dome Mountains
Domed mountainous reliefs are the result of a large amount of molten rock (magma) moving upwards under the earth's crust. In fact, without breaking through to the surface, magma pushes up the upper layers of the rock. At some point, the magma cools down and forms solidified rock. The uplifted area created by rising magma is called a dome due to the fact that it looks like the top half of a sphere (ball). Layers of rock above the solidified magma curve upward to form a dome. But the rock layers around remain flat.
Domes can form many individual peaks called the Dome Mountains.
Volcanic mountains
As the name suggests, volcanic mountainous landforms are formed by volcanoes. Volcanic mountains appear when molten rock (magma) deep in the earth erupts and accumulates on the surface. Magma is called lava when it erupts through the earth's crust. When the ash and lava cool down, a stone cone is formed. They build up, 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.
Relief diversity across continents
America. The nature of the mountainous relief 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 sublime, and the plateaus are 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 Greatwatershed ridge. Some islands have mountainous areas of volcanic origin.
Antarctica. It is the highest continent on the planet. Mountain relief features 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 located in the mountains. They are the main source of wood, medicinal herbs.
- Production of hydroelectric power. Hydroelectric power is mainly generated from perennial rivers in the mountains.
- Plentiful source of water. Perennial rivers arising in the snow-capped mountains are one of the important sources of water. They help with irrigation and provide residents with water for other uses.
- Formation of fertile plains. Rivers, originating in the high mountain ranges, bring silt along with water to the 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 borders between two countries. They play a prominent role in protecting the country from external threats.
- Climate impact. The mountains serve as a climatic barrier between the two neighboring regions.
- Tourist centers. The pleasant climate and beautiful scenery of the mountains have made them attractive holiday destinations for tourists.
Facts
Mountainous landforms make up about one-fifth of the world's landscape. They contain at least one tenth of the world's population.
Mountain heights are usually measured in altitude above sea level.
The world's highest mountain on land - Mount Everest (Chomolungma) 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 below the surface of the sea.
Mountains are more common in oceans than on land; some islands are mountain tops rising out of the water.
About 80 percent of our planet's fresh water comes from mountain snow and ice.
All mountain ecosystems have one thing in common - rapid changes in altitude, climate, soil and vegetation over 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, stonecrop, mosses, ferns.
The 14 highest mountains in the world are in the Himalayas.
In some mountainous areas, rivers regularly freeze over.
