Movement of Earth’s Plates – Plate Tectonics

Plate Tectonics

Large pieces of plates known as tectonic plates make up the Earth’s thin outer shell.

Though they fit together like a puzzle, these plates are not fixed in any one position.

They are resting on the mantle of the planet, a large layer of heated, moving rock.

The plates fit tightly against one another and sit on the heated, molten rock of the Earth’s mantle like pieces of a broken shell.

Causes of Plates Movement

The plates occasionally move toward and occasionally away from one another due to the heat produced by radioactive processes occurring within the planet’s interior. This movement is called a tectonic shift or plate motion.

Scientists used to think that Earth’s plate just surfed on top of the massive convection cells in the mantle, but they now think that plates actively assist in their own motion..

Plates have warmer, thinner regions that are more likely to rise and colder, denser parts that are more likely to sink, similar to convection cells.

The rigid tectonic plates of Earth move in response to convection currents in the planet’s fluid, molten core. Seafloor spreading is the process of tectonic plates moving apart in regions where convection currents flow up towards the surface of the crust.

Ridge Pull

Due to the warmth and the thinness of the plate, new portions of the plate rise. A new crust is formed when hot magma rises to the surface at spreading ridges and pushes the rest of a plate aside. We refer to this as ridge push.

Slab Pull

At subduction zones, older portions of a plate are more likely to subduct because they are thicker and colder than the warm mantle material underneath them. This is known as a slab pull.

Movement of Earth’s Plates

Three different types of tectonic boundaries are produced by the movement of the plates on the Earth’s crust.

Depending on the types of movement of plates, different plate boundaries are formed: Convergent, divergent, and transform.

Convergent Boundaries

An area where two plates come together is referred to as a convergent boundary.

The boundaries of one or both colliding plates may bend up into mountain ranges as a result of the impact, or one plate may bend down into a deep undersea trench.

A chain of volcanoes and strong earthquakes are common across convergent plate boundaries. As an example of a convergent plate boundary, consider the Pacific Ring of Fire.

The oceanic crust is frequently pushed down into the mantle, where it starts to melt along convergent plate boundaries. The other plate is penetrated by magma as it rises, forming granite, the rock that forms the continents. This means that at convergent borders, continental crust is formed and oceanic crust is destroyed.

Divergent Boundaries

When two tectonic plates diverge and move away from each other, a divergent boundary is created. As magma (molten rock) rises from the Earth’s mantle to the surface and solidifies to form a new oceanic crust, earthquakes frequently occur along these borders.

Divergent plate boundaries can be seen, for example, in the Mid-Atlantic Ridge.

Transform Plate Boundaries

A transform plate boundary is created by two plates sliding past one another. The San Andreas fault zone, which spans under the ocean, is home to one of the most well-known transform plate borders.

Structures, whether created by nature or by humans, that cross a transform boundary are unbalanced; they are cut into pieces and moved in opposing directions.

As the plates move apart, the rocks that line the boundary are crushed, forming a fault valley or submarine canyon. These faults are prone to earthquakes. At transform margins, the crust is fractured and broken rather than formed or destroyed, in contrast to convergent and divergent boundaries.

Although these boundaries don’t result in visually appealing landscapes like mountains or oceans, the halting motion frequently leads to severe earthquakes.

Result of the Movement of Earth’s Plates

The folding and faulting of the Earth’s crust are the results of the tectonic movement of the Earth’s plates.

The Earth’s plates collide, diverge, or intersect, causing plate movement.

This results in the Earth’s crust buckling and straining, creating enormous pressures that accumulate over time and could eventually lead to the release of this energy.

Layers of materials that have been crushed together make up the crust.

These layers, which are referred to as strata, were formed by the denuding of previously existing rocks.

Tectonic activity leads to folding and faulting, while tension, compression, and shearing forces also actively contribute to plate motions.

Fold mountains, like the Himalayas, are an example of a landform produced by the effects of folding, whereas rift valleys, like the East African Rift Valley, are formed by faults.

Folding

When the Earth’s crust is folded, it is pulled and strained, creating a range of various features that are frequently visible when looking at a rock face.

A fold consists of three components: the anticline (high), the syncline (low), and the limbs, sometimes known as the “arms” of the folds.

Folds can be categorized into a number of different types, including monoclines, in which the layers move in the same direction, symmetrical folds, in which both arms have the same slope, and asymmetric folds, in which one arm has a steeper slope than the other, and overfolds, in which the arms have slightly turned over.

Faulting

Due to the high strain that the folding of layers places on plates, faulting is a process that takes place.

In the fold, which can form along a fault line, the pressure of compression or tension causes a fracture to occur.

This fault can move either horizontally or vertically.

The San Andreas Fault Line in America is an example of this type of fault line.

Normal faulting, reverse faulting, and tear faulting are the three main types of faulting. They are caused by the divergence, convergence, and transverse movement of the plates, respectively.

In conclusion, the folding and faulting of the Earth’s surface caused by compression, tension, and shearing caused by the movement of the Earth’s plates deform and reorganize the crust of the planet.