THE EARTH'S RELIEF

Internal and external processes change the Earth's relief

INTERNAL PROCESSES

• They cause volcanic eruptions and earthquakes.
• A volcano is created when the magma reaches the surface of the Earth through a crack o fissure. The parts of a volcano are its crater, its main vent and its volcanic cone.
• Earthquakes are caused by the vibrations of the ground moving inside the Earth. This movement is transmitted from a point called the hypocentre.

EXTERNAL PROCESSES

• Geological agents change the Earth's relief. the most important geological agents are wind and water (rivers and streams, sea and ice).
• Geological agents produce erosion, transportation and sedimentation. they create V-shaped valleys and beaches.

ROCKS AND MINERALS

• Rocks are made up of minerals. depending on their origins, rocks can be:
• Sedimentary rocks, like clay. They are formed by compacting deposited material.
• Magmatic rocks. they are formed from magma. They can be volcanic like pumice or plutonic like granite.
• Metaphormic rocks, like slate. they are not melted rocks, but they have been under high pressure and temperatures

CLAY
 

PUMICE

 

GRANITE

 

SLATE

 

VOLCANO ERUPTION:

PLATE TECTONICS