The crust of the Earth is made up of many rigid plates, some of which form the continents and others form the rocks beneath the oceans. The edges of the plates are often areas where volcanoes and earthquakes occur. These plates are always moving slowly, caused by heat currents from the mantle below the crust. This process is called 'plate tectonics'.

Sometimes continents collide and produce mountains and larger continents while sometimes oceanic plates get pushed beneath plates and eventually melt. New oceanic crust is formed along the mid-oceanic ridges. Over time the positions and sizes of continents have changed, and in the last 500 million years Ireland has moved northwards from below the Equator to its present position.

 

2009. Site designed by Adam Stuart Smith and Patrick Wyse Jackson.