Mountains, beaches, marshes, capes, valleys…the Earth, the world in which we were born and which shelters us, is a rich and varied planet in which we can observe a great number of environments, landscapes and impressive places.
Within this richness we can observe a great number of shapes and geographical features, caused by the movement of the tectonic plates and the movement of the elements that make up both the crust, the mantle and the core of the planet, as well as the interaction between land and water. That is why throughout this article we are going to see the different types of geographical relief and their main characteristics.
What do we call geographical relief?
Before considering the types of relief that exist, one must first consider what the idea or concept of relief implies at the geographical level. Relief is understood as the set of forms and levels, elevations and depressions existing in a given object or element .
Taking into account the above definition, we can consider that the concept of geographical relief refers to the set of elements that are part of the structure of the planet and that give shape to the surface of the planet. This relief, which is studied by the discipline known as orography , arises from the interaction of the terrain with different types of agents: among them is the friction of the tectonic plates, the erosion caused by wind, water or living beings or the emission of organic or inorganic material by, for example, elements such as volcanoes.
The different types of surface relief
There is a great variety of different types of accidents and geographical reliefs in the world, both on land and at sea. In this sense, below we are going to see some of the best known at surface level, in the part of the orography that is not covered by water.
Within the geographical reliefs, depressions are considered to be the set of geographical features in which the surface presents a sudden decrease in height or sinking in relation to the situation of the rest of the environment , sometimes even below sea level.
A type of geographic relief that is characterized by not having any type of elevation or undulation but is relatively homogeneous throughout its length is called a plain. They are found at a height similar to or slightly higher than sea level and usually originate from the accumulation of sediments after the water has withdrawn.
3. Plateaus or highlands
An area of land that, similarly to the plains, is relatively flat, but in this case is situated at a high altitude. These are often regions of eroded territory that are located or formed in mountain ranges or other similar terrain elevations. While a plain is no more than a few hundred meters above sea level, a plateau can be thousands or even thousands of meters away.
Valleys are the type of geographical relief that appears between two mountainous formations, and which means a descent or depression of the land between both mountains. Generally they are produced as a result of erosion generated by river or glacial courses. They can have very different forms depending on the type of erosion and the time it has been receiving it.
Although when we talk about geographical relief we usually imagine rocky elements, the truth is that we cannot ignore the existence of a type of relief mainly generated by erosion and shaped by sand. This is the case with dunes, which are elevations generated by accumulations of sand and which can disappear or change their shape or position thanks to the action of forces such as the wind.
6. Hills, hills or mounds
Any of the names mentioned above are given to the type of geographical relief formed by a slight elevation of the terrain that does not usually exceed one hundred metres in height and whose slope is usually gentler than that of a mountain. Even so, they may be steep.
7. Mountains or hills
The name “mountain” is given to those elevations in the terrain that generally arise from the accumulation of rocky material arising from the union of two tectonic plates (although they can also be formed by the accumulation of emissions from a volcano, for example). They are characterised by their high altitude and by the fact that they have a variable but high level of slope , with a foot or base and a peak or summit being distinguished.
Although at a popular level it may be thought that mountains are small mountains, the truth is that they actually refer to the same concept except for the fact that while mountains are used to talk about an isolated elevation, they usually refer to one that is located between a group of them.
A geographical feature is considered to be that in which the terrain is cut vertically, so that a sudden fall or descent appears in the form of an abrupt depression in which two clearly differentiated levels can be observed. It can be observed for example at mountain level, but also on the coast.
A mountain range is a set or group of mountainous elevations that appear very close to each other and generally have a very steep slope.
A mountain range is a type of geographical relief in which there are a large number of linked mountains or mountainous elevations, usually higher than in the case of the sierra. They usually arise in the places where there has been the greatest collision and friction between the tectonic plates , with the land rising under the pressure of one against the other.
Main types of coastal and marine relief
Below we indicate a series of the main types of relief that can be found at sea level or in direct contact with it.
The geographical relief is called beach and is characterized by the fact that it is the point where land and sea geography meet, which is at sea level. It is characterised by being a relatively flat or flattened area with a variable slope in which the terrain is sandy or rocky due to erosion caused by water and the friction of marine materials.
We know as island the type of geographical relief characterized by the presence of a fragment of emerged territory which is completely surrounded by water (not necessarily at sea level). Different geographical features may also appear on it, such as those mentioned above.
The name archipelago is given to the geographical formation consisting of a group of islands that are close together and often linked , although separated by bodies of water.
The term peninsula refers to an extension of land not submerged and part of the continental orography which is surrounded by water in all directions except for one part, which connects with the rest of the emerged land .
A land mass that goes into the sea beyond the rest of the surrounding land, which may be of varying size, is called a cape.
It is understood as such the type of relief in which the waters of the sea penetrate and occupy an area of the land , this water being surrounded by land except for the end through which the water penetrates. This would be the opposite case of the peninsula.
We understand as such a geographical accident similar to the bay, but with the difference that it usually refers to concave areas where the sea gains place to the land and which are generally surrounded by the land except for a portion where it is in contact with the sea or ocean. It is generally considered to be larger than the bay, although the concept is practically identical.
18. Cove or inlet
This type of geographical relief is conceptualized in the same way as the bay, except that is usually circular in shape and that the point where the water enters and penetrates the land is a relatively narrow mouth.
Narrows are geographical elements made up of water masses surrounded by land that act as a channel or bridge between two other water masses, allowing the passage of the liquid element from one to the other.
We define estuary as the geographical region located at the mouth of a particularly large and abundant river, forming a funnel-shaped area and which is formed because the entry of seawater slows down the exit of fresh water from the river and later, at low tide, allows it to exit normally.
Geographical area that usually appears at the end of a river$0027s course, at its mouth, and that is characterized by a softening of the orography due to the unfolding of the river$0027s sediments .
The different types of underwater relief
Below we will show some of the main examples of types of geographical relief that can be found below sea level, all of which are submerged.
1. Continental shelf
We know as continental platform that region of the earth$0027s crust that corresponds to the terrain of the continent that serves as a base for the emerged terrain above the water level. It is therefore the part of the continents that is submerged
2. Continental slope or battalion zone
Geographical relief characterized by the presence of a very pronounced slope of the sea bed, being the part of the land that descends sloping from the continental platform to the abyssal plain. It is located between 200 and 4000 metres under water.
3. Abyssal plains
We call abyssal plain the part of the earth$0027s orography that corresponds to the surface of the earth located between 4000 and 6000 meters deep , where the sunlight stops illuminating the land.
4. Abyssal trenches
The depressions that can be found in the abyssal plains, which are part of the so-called hadal zone of the ocean and where high levels of pressure make life difficult, are called abyssal pits.
5. Underwater ridges
We call underwater ridges the set of mountain ranges that, unlike those on land, are located below sea level . Although we do not usually see them in our daily lives, they are higher than those on the surface.
- Newell Strahler, A. (2008). Visualizing Physical Geography. New York: Wiley & Sons and The National Geographic Society.
- Bielza de Ory, V. (Editor) (1993). General Geography I. Madrid: Santillana.