10 julio, 2024

Divergent plate movement: what it is, theory, consequences, examples

What is divergent plate motion?

He divergent plate motion It is the movement that is generated between two tectonic plates when the separation between them occurs, generating the formation of volcanoes and the expulsion of lava from between them.

With the divergent movement, in the process of separation, faults are produced, which translate into holes in the earth or the appearance of an underwater mountain range.

The plates of the lithosphere are set in motion due to the energy and heat produced by the magma that emerges from the bottom of the sea.

In the areas where two plates meet, the force of the magma manages to produce a separation between them. When this phenomenon occurs at the bottom of the ocean, magma flows and solidifies, creating an underwater ridge.

Bases of the theories of tectonic plate movements

All these discoveries took place in 1960, when the studies of Alfred Wegener and his theory that explained the composition of the lithosphere were resumed.

With the discovery of tectonic plates and the study of their movements, it was possible to determine that when the forces that modify the lithosphere affect, volcanic and seismic activities occur that affect the earth’s surface.

the pacific plate

The Pacific plate is one of the largest. This plate borders the North American Plate to the north, Antarctica to the south, the San Andreas Fault to the east, and the Eurasian Plate to the west. At these boundaries, divergent boundaries form between the plates.

The main feature of the Pacific plate is the formation of hot spots. These points, during the divergent movement of the plates, have produced the growth of submarine ridges. These are created by the magma when it solidifies, originating islands and archipelagos when they emerge to the surface.

This plate is very active and its constant movements maintain frequent seismic and volcanic activity in the countries of South America, which are mostly located on it.

As evidence of the above, islands that have emerged in the region as a consequence of millions of years of activity can be indicated, which to date does not cease and continues to contribute to the formation of new surfaces that house all kinds of life forms within the new territories.

Consequences of divergent plate motion

With the divergent movement of plates, mountain ranges are formed at the bottom of the sea, since as the plates separate, new material rises through the volcanic chimneys that solidify. That is why it is also called a constructive edge. For example, the Mid-Atlantic Ridge. Islands or a line of volcanoes are also formed in a certain place, such as in Iceland.

Examples of volcanic islands born from divergent movements

Easter Island

This island originated from the eruption of the Poike, Rano Kau and Terevaka volcanoes. It has a triangular shape, which is due to the physical location of the volcanoes and the union of the lava that flowed from each one of them. This island is located in Chile.

Hawaii

It emerged from the eruption that occurred on the tectonic plates that meet in the Pacific Ocean. These eruptions formed an archipelago made up of 18 islands.

Juan Fernandez Archipelago

This archipelago is located in Chile. It is said that its age is 1 or 2 million years, product of constant volcanic eruptions.

It should be noted that not all archipelagos come from this type of movement. Some are the product of the separation of the continents; so island and archipelago are not necessarily synonymous with volcanic islands.

Examples of divergent plate motion

One of the most emblematic examples is the separation suffered by the North American and Eurasian plates in the Atlantic Ocean. From this separation, a crack is formed through which molten rocky material rises, which cools and forms ridges (oceanic ridges). From this separation arose the Mid-Atlantic Ridge. The South American plate is drifting westward, breaking away from the African plate. This produces that it overlaps the Nazca plate, and causes the border that separates them to gradually move. The Arabian plate is separating from the African plate. This created the Red Sea 20 million years ago.

References

Adam Hart-Davis. Science: The Definitive Visual Guide. London: Penguin.
Aguilar, HC Nature and society: an introduction to geography. Lima: PUCP Editorial Fund.

Deja una respuesta

Tu dirección de correo electrónico no será publicada. Los campos obligatorios están marcados con *