The mountains are topographical eminences, which means that they are elevations of land of more than 700 meters from its base. They are grouped in mountain ranges and mountain ranges, with the exception of volcanoes that can be found alone.
Mountains make up 24% of the Earth's surface, where we find 53% of Asia's area covered by mountains, 58% in America, 25% in Europe, 17% in Australia and, lastly, the continent with Less mountains, Africa, with only 3% of its surface covered by mountain ranges.
Mountains form when two pieces of the Earth crust , The lithosphere, collide. This causes the slates of the lithosphere to be forced downwards and others to be piled upwards. The bark rises in this process and forms the mountain ranges.
Main features of the mountains
Training period
We can classify the mountains according to their period of formation. We can distinguish three periods. The Caledonian orogeny, where the mountainous reliefs were formed more than 400 million years ago. Some of the mountains that formed in this period are found in Scotland.
The Hercinian, where we find most of the mountain ranges of Europe, Asia and America, which occurred about 270 million years ago. We can emphasize in this period the mountain ranges of the Urals and the one of the Appalachians
The Alpine, which were the youngest mountain reliefs, produced 35 million years ago, where we find much steeper reliefs such as the Alps and the Himalayas.
Parts of the mountain
We can distinguish four parts in a mountain.
We start from the foot or base, which is the lowest part of the mountain. On the other hand, the top of the mountain, which is the highest part of the mountain and where it ends.
The slope or skirt of the mountain, which is the part that joins the foot and the top, and usually has an angle of inclination and slope.
And the valley, which is not really part of the mountain, but the land that links two mountains.
Altitude
The altitude of the mountains defines the Type of ecosystem That we find in them. It has higher altitude, there will be lower atmospheric pressure, which will imply lower concentration of oxygen and humidity, lower temperatures, higher wind speed and less sun protection.
Given these characteristics in the higher areas of the mountain, vegetation will be less scarce, there will be less food for animals and will be unpopulated areas .
In the upper parts of the mountains there is also a great temperature change between day and night.
Here we show the highest mountains divided by continents:
- Africa: Kilimanjaro (5895 meters)
- America: Aconcagua (6959 meters)
- Asia: Everest (8846 meters)
- Europe: Elbrus (5633 meters)
- Oceania: Jaya (5029 meters)
Everest is the highest mountain on the planet. It is a mountain that is constantly growing due to the collision of the plates that are underneath it.
It is located in the Himalayan mountain range where several of the highest mountains in the world are found.
Pending
The slope is the characteristic unevenness of the mountainous terrain. The shape of the slopes may vary depending on each mountain.
As we saw earlier, the younger mountains are steeper and steeper. This, in terms of slope, means that they have steep walls, rocky edges and high peaks.
In mountains with more seniority, the slopes are more rounded presenting rounded mounds.
Weather
As we indicate in the altitude, the higher the temperatures are descending. It is believed to descend about 5 degrees per 1000 meters in height. At higher altitude, although the humidity drops, rains increase due to the screen effect.
The screen effect, also known as Föhn effect, arises when a mass of warm air meets a mountain, and to get around the obstacle has to ascend along its slope.
By increasing the height at which warm air is located, the temperature decreases causing the water vapor to cool and condense. This condensation causes clouds and rainfall, which are known as orographic rains.
The slopes of the mountain affected by the screen effect are known as windward. It may happen that while in the windward there are rains, in the leeward there is a warmer and drier climate. Providing that there are large temperature variations between the sides of the mountain-
On the slopes of windward, having greater concentration of humidity, we will find more vegetation, and therefore, the possibility that they are more livable than leeward.
Vegetation
The vegetation of the mountains will vary depending on the height at which we are. As we discussed earlier, at higher altitudes we have less concentration of oxygen, which is essential for the development of life.
At the bottom of the mountain, we can find vegetation similar to the one we would find in the flat areas that surround it.
As we begin the ascent through the mountain, the vegetation varies and we find different types of plants. Usually we find hygrophilous plants, are plants that survive in humid and cold environments.
The vegetation that we find in the mountains, also depends on the area in which we are, since the vegetation in the subpolar mountains will not be similar to the mountains that we find in the tropics.
At the top of the mountain, especially in the higher mountains, vegetation gradually disappears, and at the peak or top, many of them are covered with snow all year round.
References
- GERRARD, John. Mountain environments: an examination of the physical geography of mountains . MIT Press, 1990.
- GETIS, Arthur Getis, et al. Introduction to geography . 2011.
- SMETHURST, David. Mountain geography. Geographical Review , 2000, vol. 90, no. 1, p. 35-56.
- FUNNELL, Don C.; PRICE, Martin F. Mountain geography: A review. The Geographical Journal , 2003, vol. 169, no. 3, p. 183-190.
- SOFFER, Arnon. Mountain geography: a new approach. Mountain Research and Development , 1982, p. 391-398.
- PRICE, Martin F. Mountain geography: Physical and human dimensions . Univ of California Press, 2013.
- HAEFNER, H.; SEIDEL, K.; EHRLER, H. Applications of snow cover mapping in high mountain regions. Physics and Chemistry of the Earth , 1997, vol. 22, no. 3, p. 275-278.