Terrain

Internal Structure

The Earth has an external, solid rock layer called the crust.

Under the crust there is a layer of thick, liquid rock called the mantle.

Under that there is a thin liquid layer called the outer core and then the solid iron inner core.

The inside of the Earth is very hot, the outer core may be 7000 degrees.

Surface

Over 70% of the Earth surface is covered by water.The underwater surface has also got volcanoes, mountains and trenches.

The 30% not covered by water is basically forests, deserts, plains,

mountains and plateaus.

Many things can change the surface of the Earth, for example erosion from wind and rain, erosion by the oceans or meteorite impacts, vegetation and the human being.

Tectonic Plates

The Earth's crust basically floats on the mantle.

The crust is split up into parts called tectonic plates.They can also change the surface but how?

These plates interact when they move causing earthquakes and creating volcanoes and mountain ranges.

Earthquakes

When the tectonic plates move, they don’t move carefully so an earthquake happens.

Earthquakes send surface waves through the earth and the ground moves.They usually last a few seconds.

Earthquakes

When the earth moves in an earthquake, it can cause waves in the ocean. A big wave in the ocean caused by an earthquake is called a tsunami.

We give the earthquake a number ( the Richter scale) to say if it is big or small.

The epicentre(epicenter) is the point on the Earth’s surface above the hypocentre (hypocenter) or focus, where an eathquake happens.

Earthquakes

Volcanoes

Volcanoes are usually made when two tectonic plates move towards each other. When these two plates meet, one of them goes under the other one. Then, it melts and forms magma (inside the magma chamber), and the pressure builds up until the magma bursts through the Earth's crust.

Volcanoes

The parts of a volcano are:

magma chamber pipe crater flank branch pipe lava flow

Landforms

The most important landforms are:

mountain and mountain range valley drainage basin plateau plain island/archipelago

peninsula ria/fjiord cape gulf/bay

Landforms

And now we are going to see some of the landforms