How do tectonic plates work? – Mendelevium Zone

Question: How do tectonic plates work?
- Keywords:
  earth,
  geology,
  tectonic plate
Asked by anon-193405 to Morwenna, Jamal, iainstaniland, Heidi, Emma, Carl on 11 Nov 2018.
- Emma Crawford answered on 11 Nov 2018:
  
  The Earth’s crust and upper part of the mantle are broken into large pieces called tectonic plates. These are constantly moving at a few centimetres each year. Although this doesn’t sound like very much, over millions of years the movement allows whole continents to shift thousands of kilometres apart. This process is called continental drift.
  See more here: http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/earth/earthscrustrev2.shtml
- Heidi Gardner answered on 13 Nov 2018:
  
  The surface of the Earth is a bit like a jigsaw with pieces that don’t quite fit together – these large puzzle pieces are called tectonic plates, and they are able to move slightly.
  
  When these plates move (the main force on them is gravity) they create mountain ranges, volcanoes, new areas of ocean floor, tsunamis, earthquakes and more.

Question: How do tectonic plates work?