We explain what the continental relief is, its characteristics and what its shapes are like. Also, what is the oceanic relief?
What is continental relief?
In geography, we speak of continental relief or emerged relief to refer to the different forms that the Earth's lithosphere takes on its surface as long as it is not covered by the oceans. In this it is distinguished from the oceanic relief, and together they constitute the terrestrial relief, that is, the relief of our planet.
As its name suggests, the continental relief is typical of the platforms emerged from the earth's surface, that is, the continents. This type of relief also includes the surface of the islands, since they protrude from the water, and in total it is estimated that it covers 30% of the total surface of our planet.
Given that the earth's crust that is submerged and that which is exposed to the air are subject to different physical and erosive processes, it is logical that they present very different characteristics and that they be studied separately.
However, in both cases the terrestrial relief is subject to long-standing geological forces, which as the centuries pass modify the relief and transform the surface of the planet, throughout what is known as the geological cycle.
Features of the continental relief
In general, the continental relief is characterized by the following:
- As we have said, it is characteristic of the emerged portion of the lithosphere that is, it is distinguished from the oceanic or submerged relief.
- It has huge irregularities as a consequence of the erosive and sedimentary action of wind, rain and rivers, and also of tectonic movements over time.
- For the same reasons, it is always a changing relief although at such a slow pace that human beings can hardly perceive it.
Continental landforms
The continental relief is extremely varied, and its different forms are produced as a consequence of numerous geological and erosive forces over millions of years. These forms are the following:
- Mountains, mountain ranges and mountain ranges. These are natural elevations of the landscape, formed by the folding of the lithosphere due to the tension between two confronting tectonic plates. They reach heights of more than 600 meters and usually have pointed shapes, with many peaks, when they are young mountains; while ancient mountains have rounded tops due to the erosive action of the elements. When they occur in large numbers they can be called mountain ranges (groups of regular mountains), cordilleras (groups of high mountains) or mountain systems (groups of mountain ranges or mountain ranges). When it comes to smaller elevations, we can rather talk about hills or hills. Examples of mountains are the Urals, the Pyrenees and the famous Aconcagua.
- Valleys Valleys are depressions or low parts that are formed between mountains or mountain ranges that are close to each other, and consist of plains of different sizes, very often crossed by rivers that descend from the mountains. Valleys are usually “U” or “V” shaped, depending on whether they were formed by glacial erosion or river erosion, respectively. Examples of this relief are the Valley of Caracas, where the Venezuelan capital was built, or the Valley of the Moon, in the Atacama Desert, in Chile.
- Plateaus Also called altiplanos, they are elevations between 600 and 5000 meters high, at the top of which there is a plain or plateau. They originate as a result of the particular erosion of the mountains, and usually have deep hills on their sides. Examples of plateaus are the Andean Altiplano, where the Quebrada de Humahuaca is located in northern Argentina, or the Tibet Plateau, whose average altitude is around 4,500 meters and has a vast surface area of 2.5 million km.2.
- Plains or plains. As its name indicates, these are long extensions of flat or almost flat land, generally located at or a few meters above sea level. They can present gentle elevations – hills or hills – or consist of vast plains such as the North American Great Plains, located in the US states of New Mexico, Texas, Oklahoma, Wyoming, Montana, South Dakota and North Dakota.
- Absolute depressions. This is the name given to the falls of the land below sea level, that is, to the deep depressions in the surface that can occur as a result of erosive processes or in craters formed by the impact of meteors, for example.
Ocean relief
It is known as oceanic or submerged relief at the bottom of the oceans, that is, the shapes that the earth's surface acquires under the different layers of water that make up the seas and oceans. This relief is significantly different from the one that emerged, since it is subject to enormous underwater pressures and completely different forms of wear.
References
- “Earth relief” in Wikipedia.
- “Ocean relief” in Wikipedia.
- “The forms of the continental relief” in the ICT Platform of the Ministry of Education of Spain.
- “Land relief” in the Mexican Meteorological Service.
- “Types of relief” at the Bernardino Rivadavia Technical School (Argentina).
