The Earth

							The Earth: The Miracle Planet
The Earth in Space
          Facts about our Planet
The earth is one of nine planets in the Solar System.
The sun is at the centre of the solar system and all of
the planets orbit the sun.

   More than 6 billion people live on our planet.
   2/3 of the earth’s surface is covered by water.
   1/8 of the earth’s surface is covered by deserts
   1/10 of the earth’s surface is covered by mountains
   1/4 of the earth’s surface is covered by forests.
            Inside Planet Earth
If we could cut through the
earth like an apple we would
see that it is made up of
3 different layers.

These are called the,

1.   The Crust
2.   The Mantle
3.   The Core
Inside Planet Earth
The Structure of the Earth
                The Earth’s Crust
   The crust is the outer skin
    of the earth. It is like the
    skin on a piece of fruit or
    the crust on bread.

   However, the earth’s crust
    is made up of a layer of
    solid rock 10-60km thick.

   This hard shell is where
    we live.
                 The Mantle
   Beneath the hard crust is a layer of hot,
    soft rock called the mantle.

   The rocks in the mantle are molten or
    melted because it is so hot (4000 C).

   This molten rock is called magma.
                    The Core
   Beneath the mantle, in the centre of the earth,
    we find the earth’s core. It is made of hot metals
    such as iron and nickel.
   The core can be divided into an inner and an
    outer core.
   The Outer Core is made of molten metals
    because is so hot.
   The Inner Core is made of solid metal because
    the pressure is so great.
        The Earth’s Crust - Plates
   The earth’s crust is not an
    unbroken shell.
   It is made up of a number of
    different pieces, like the
    surface of a leather football.
   Each one of these pieces is
    called a Plate. The plates fit
    together like a jigsaw.
   Plates meet each other at plate
    boundaries.
   All of the plates have names,
    such as the Eurasian Plate
    and the American Plate.
The Earth’s Plates
The Earth’s Plates
The Earth’s Plates
                Plate Movement
   The plates which make up the earth’s crust are
    continually moving.
   This is because the plates are floating on top of the
    molten (melted) rock of the Mantle.
   Convection currents within the mantle cause the molten
    rock to move, thus moving the plates floating on top of
    them.
   This movement is very slow, but it means that the plates
    continually collide, pull apart, and push past one another.
Plate Movement
                   Continental Drift
   We now know that the plates
    move because they are
    floating on top of the mantle.
   The continents, such as
    America and Africa, are
    attached to the American Plate
    and the African Plate.
   Therefore, when the plates
    move, the continents move
    too. This movement of the
    continents is called Continental
    Drift.
   Continental Drift is still
    occurring today. For e.g.
    Europe is still slowly moving
    away from America.