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THE LAYERS OF THE EARTH

Crust: It makes up only 1% of the Earth's volume. It consists of solid rock such as basalt and granite. There are two types of crust: continental crust and oceanic crust.

Mantle: It makes up 84% of the Earth's surface. It consists of silicate, iron and nickel. It's solid and fluid.

Core: It makes up 15% of the Earth's surface. It consists of iron and nickel. It has a solid inner core, and a fluid outer core.

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TECTONIC PLATES

The lithosphere is made up of large tectonic plates that float on the mantle.

The tectonic plates continue to move. The collision zones between plates produce volcanic and seismic activity (earthquakes).

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CONTINENTAL CRUST RELIEF

MOUNTAIN: Is a natural elevation of land. A mountain range is a continuos chain of mountains, and a system is a group of ranges.

PLAINS: They are at the foot of the mountains. A plain is an area of flat land. There are different types of plain:

plateau: is a large flat raised area.

depression: is a large area of land lower than te surrounding area.

moor: is an area of uncultivated hilly land.

VALLEY: is a long depression in the relief. There are different types of valleys:

canyon: is a deep narrow passage between two mountains.

basin: is a valley surrounded by high areas, wider than a canyon.

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EARTHQUAKES AND TSUNAMIS

Earthquakes are produced by:

The movement of the Earth's tectonic plates and the collision or friction between them.

The action of volcanoes.

Its intensity is measured on the Richter scale.

When this happens under the sea it is called a seaquake. It can cause a tsunami, a series of giant waves produced by the force of the quake.

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