A current is something that runs or flows. The marine, for its part, is linked to the sea: a mass of salt water. The idea of ocean current, in this way, refers to the surface movement of sea water.
According to DigoPaul, ocean currents have various causes. The action of the wind, the rotation movement carried out by the planet Earth and the characteristics of the coasts are some of the reasons that generate the existence of marine currents.
It is important to note that ocean currents involve not only horizontal movements of water, but also vertical ones. Several decades ago, researchers discovered that the planet’s ocean currents are structured in three dimensions:
* on the one hand, on the surface there are horizontal movements that mainly involve the inertia generated by the rotation of the Earth and the wind;
* the vertical movements, for their part, alter the effects of the terrestrial rotation due to the configuration of the coasts and the underwater relief, so that a centrifugal force is produced that tends to concentrate, so to speak, the oceanic level over the entire circumference of the equator.
We must clarify that it is known as centrifugal force, according to what is established by Newtonian and classical mechanics, to a fictitious force that occurs in the description of the movement that a body performs in a reference system that is rotating. It is also possible to define this concept as the apparent force noticed by an observer in which Newton’s laws of motion do not apply, which is also found in a rotating reference system.
On the other hand, different kinds of currents can be differentiated according to their characteristics. Cold sea currents, as their name suggests, involve the movement of waters that are at low temperatures. They are due to the rotational movement of the Earth and develop from east to west due to the rise of cold water that comes from very deep areas. The Humboldt Current, which is also known as the Peru Current, is an example of a cold current. The German Alexander von Humboldt was the one who described this marine current for the first time.
The warm sea currents, on the other hand, originate in the intertropical region, born on the eastern coast and moving in the opposite direction to the rotation of the planet. The Gulf Stream, originating in the Gulf of Mexico, is a warm current.
Oceanic currents, on the other hand, register a constant movement because they are due to the Earth’s rotation, unlike wave currents (related to the wind) and tidal currents (linked to the attraction exerted by the moon), among others. whose displacements vary.
One of the uses that human beings have found in marine currents is the extraction of energy, especially in the deepest areas, and for this they have been developing specific devices for a long time. It is necessary to clarify that this process supposes a very high economic investment, which includes the manufacture of the machinery, its installation and the inevitable maintenance tasks.
To offset these costs, the Polytechnic University of Madrid presented at the beginning of 2018 a series of designs and procedures that promise considerable savings. In addition to Spain, another country that is working on obtaining energy from ocean currents is Canada, where there are already several experimental parks with first-generation devices that are placed on the seabed.
Some experts point out that about 80% of this energy is found beyond 40 meters of depth, and that is why the production of extraction devices is so expensive.