Changes to the earth and atmosphere

The Earths StructureAll resources come from the Earth, its atmosphere and the oceans. The Earth is a sphere. It is made up of several layers. The main ones are:• The rocky crust, which is thin compared to

the other layers.• The mantle, which goes down almost half

way to the centre of the Earth. The mantle has solid properties, but can flow very fast.

• The core, which is made of iron and nickel. Surrounding the Earth is a mixture of gases. This is the atmosphere.

Alfred Wegner

Alfred Wegner theory was at one point all of the continents were joined. Evidence to support this:• The shapes of the continents look as if they

might once have fitted together.• Fossils of the same plants had been found on

continents once thought to be joined.• The two continents have the same type of rock at

the edges where they might have been joined.

Wegener was not believed at first

Wegener’s theory of crustal movement, or continental drift was not at first accepted. People could not see how the continents moved. They were reluctant to believe Wegner as he was not a geologist.

Why have CO2 levels changed?

Tectonic Plates

Earthquakes

• There are many earthquakes each year• Most do very little damage• Scientists do not know what is happening

below the crust• Scientists can not accurately predict when,

where and the strength of earth quakes.

Higher