When we talk about plate tectonics theory, we say that the earth's crust is divided into different tectonic plates. That is, on continental and oceanic platforms that are the basis of all the development of life. The Continental platform it is the limit of the continental crust. That is, it is said to the entire surface of the underwater bottom that extends from the coast until there is a jump of less than 200 meters. This area has a great abundance of animal and plant life, which is why it has great economic value for the territories.
In this article we are going to explain everything you need to know about the continental shelf and its importance.
Definition of continental shelf
One thing is that, geologically speaking, let's say that it is one more part of the tectonic plate in which we find ourselves. The difference is that it is underwater and these conditions they make it possible to house a large number of living beings. These living beings constitute what we call biodiversity. The development of fauna and flora under the sea increases the resources available to humans.
With all this, mineral and rock exploitations are also used. So that, economically, it can be known and defined what the continental shelf is, in 1958 the Geneva Convention made a definition in one of its articles. Under the law, a continental shelf is the underwater platform that surrounds the continental lands to an average depth of 200 meters, which given the low slope reaches an average width of around 90 kilometers.
The outer limit of said platform must have a sharp change in slope to signal the end. In the background from this change, we find the ocean floor that does not have the same economic value. What we must mention is that these events have given governments headaches. The line where the relief changes is called the continental slope.
The constitutional law modified the definition previously cited in 1982. Here it was said that the continental shelf of a state comprises from the bed and the subsoil of the submarine lands that are beyond its territorial sea and along the extension natural of its territory to the outer edge of the continental margin, or up to a distance of 200 nautical miles from the beginning of the territorial sea.
Parts of the continental shelf
These new definitions provided the necessary concepts so that there were no mistakes when exploiting the present natural resources. With all this, the continental shelf can be perfectly divided into two parts: the continental margin and the continental slope.
Continental margin
This first part is the one that is covered in all the extension that is submerged in the land of the continent. It is mainly composed of the bed and subsoil of the underwater zone, the slope and the continental rise zone. However, this entire part does not encompass the deepest ocean beyond where we are 200 meters deep. The platform is delimited in the most extreme and remote areas by a distance that it does not usually exceed 350 nautical miles from the sea line.
The entire area where the natural resources for exploitation and economy are found are submerged under water. The marine life here is wide and varied, so most of the fishing takes place here. Going out to sea to fish is more expensive, less efficient and more dangerous. Therefore, the economic rate of return is important when we talk about the profitability of products.
Not only do we find valuable resources such as flora and fauna, but we also have areas where a quarter of all the world's oil and gas reserves are found. Thus, It is not uncommon to see oil rigs doing their thing in areas of the continental shelf. The problem with this is the impacts that this oil extraction causes on marine life. There are many species that are threatened by the noise of the oil companies, the contamination of the water, fragmentation and deterioration of habitats, etc. Normally, what offers economy destroys nature.
Continental slope
This other part of the continental shelf It is the underwater region that is located between 200 meters deep and 4000 meters under the sea. On the slope we can find important changes in the entire morphology of the terrain and relief. The most normal thing is to observe valleys, seamounts and huge canyons within the ocean. Landslides can also be seen on the western slopes since they have originated thanks to the accumulation of numerous sediments that have been deposited by the rivers from the nearest lands.
The animal and plant life in this area are more difficult. The biomass decreases since the depth at which they are does not allow the sun to reach them and they can proliferate. In all this area of the continental slope is the ocean floor that extends up to 4000 meters deep. Here the average slope is usually between 5 and 7 degrees, although in some areas it can reach 25 degrees and even exceed 50 degrees.
In terms of surface, we can find surfaces between 8 and 10 km long and up to 270 km.
Economic importance
It is no wonder that governments have fought hard for who can exploit these areas and benefit economically from their resources. Among the abundance of marine vegetation used in cosmetics, pharmacy, medicine, etc. The fauna for the restoration, preparation of dishes, captive offspring, fish tanks, the world of fishing, etc. And energy resources such as oil or natural gas reserves, we find a very rich platform in resources of all kinds.
As you can see, the continental shelf is more important than it may seem from its name and I hope that with this information you can learn more about it.