The Earth's crust is not one unbroken piece. It is made up of many pieces that fit together like a giant jigsaw puzzle. These pieces, called plates, ride on soft, partly melted rock moving underneath them. The pieces push against each other with spectacular effects. Earthquakes split the Earth's crust, volcanoes are formed, new land is made and huge mountain ranges are pushed skywards. The plates are never still, they are always moving. In one year alone they can move about 2.5 centimetres, about as much as your fingernails grow in the same amountof time.
Fact file
When water seeps into the ground and reaches hot rock, it boils violently. This produces steam which can shoot the water out of cracks, causing a geyser. Geysers can be very spectacular and some shoot water as high as 500 metres into the air.
resources: Tell me Why (Chancellor Press)
image 1: http://www.suanews.com/wp-content/uploads/2015/09/TectonicsAll.jpg
image 2: https://water.usgs.gov/edu/graphics/wcgwdischarge.jpg
