Lewis Robins 8E

The Earth has been around for billions of years, being here for so long, must only mean changes will have come with it.

Formation of the Earth

4.6 billion years ago, the earth was just a few rocks, asteroids and pieces of dust that collided. More rocks and asteroids crashed into this building up over time, and these impacts produced immense amounts of heat. The earth developed with more clumps of rock whilst cooling down but the heat stayed trapped inside the center of the earth, the modern day inner core.

4 Layers of the earth were formed, the inner core, the outer core, the mantle, which is made of rock as well as magma, and the part that we live on, the earths crust. The heat beneath the earths surface moves and flows, this must mean it affects the surface.

Pangaea & Continental Drift

When the earth was formed, there was a super continent which was later named Pangaea. Tectonic plates and continents move because they are floating on top of the liquid mantle. The mantle itself moves due to convection currents: hot rock rises, gives off some heat, then falls. This creates vast swirls of moving liquid rock under the crust of the earth, which slowly pushes the plates of crust on top in all different directions. The core and mantle changed the shape of the earths surface to what we see today, but how do we know this? Mostly because of countries that share very specific similarities like having the same plants, rocks and fossils, also if you look at different countries and continents some of them look like they would fit together, almost like a jigsaw.

Tectonic Plates

Tectonic plates move in different directions, this can only mean that sooner or later two plates will crash. There are four ways that this can happen.

A destructive plate boundary is sometimes called a convergent or tensional plate margin. This occurs when oceanic and continental plates move together. The oceanic plate is forced under the lighter continental plate. Friction causes melting of the oceanic plate and can cause earthquakes. Magma rises up through cracks and erupts onto the surface.

Collision zones form when two continental plates collide. Neither plate goes under the other, and so both are forced up and form mountains.

A constructive plate boundary occurs when plates move apart. Volcanoes are formed as magma wells up to fill the gap, and eventually new crust is formed.

A conservative plate boundary occurs where plates slide past each other in opposite directions, or in the same direction but at different speeds. Friction is eventually overcome and the plates slip past in a sudden movement. The shockwaves created produce an earthquake.

As the plates and continents are still moving, the earth will look different in the future. Judging by the direction of movement, some believe that a new supercontinent will be formed in the future, and it might look like this.

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