C1 Our changing planet

OUR CHANGING PLANET

Structure of the Earth

• The Earth is made of layers called the core, mantle and crust with the atmosphere around the outside.
• The Earth's limited resources come from its crust, the oceans and the atmosphere.

The restless Earth

• The Earth's crust and upper mantle is cracked into tectonic plates which are constantly moving.
• The tectonic plates move because of convection currents in the mantle that are caused by radioactive decay.
• Earthquakes and volcanoes happen where tectonic plates meet, butit is difficult to predict accurately when and where earthquakes will happen.
• Wegner's theory of continental drift was not accepted for many years.

The Earth's atmosphere in the past

• The Earth's early atmosphere was formed by volcanic activity. 
• It probably consisted mainly…