How was Iceland created - Constructive (Divergent) Plate Boundaries | GCSE Geography Explained — Transcript

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1. 0:03Today we're diving into the fascinating  world of constructive plate boundaries,
2. 0:08(also known as divergent plate boundaries). We'll  break down this process into simple steps so you
3. 0:15can easily understand how new crust is formed  and how it shapes our planet. Step one, what are
4. 0:22constructive plate boundaries? Constructive plate  boundaries occur where two tectonic plates move
5. 0:28apart from each other due to convection currents.  This movement creates a gap between the plates.
6. 0:35Step two is the formation of mid ocean ridges. As  the plates separate, magma rises from the mantle
7. 0:42to fill the gap. When this magma reaches the ocean  floor, it cools and solidifies, forming new crust.
8. 0:50This process creates underwater mountain ranges  known as mid ocean ridges. The mid-Atlantic ridge
9. 0:57is a prime example. Step three is creation of rift  valleys on land. When tectonic plates diverge,
10. 1:06they create rift valleys. These are large  depressions formed by the sinking of the earth's
11. 1:11crust. The East African rift is a significant  example where continental plates are being
12. 1:17pulled apart. Step four is volcanic activity.  The rising magma at constructive boundaries not
13. 1:25only forms new crust but also creates volcanoes.  These volcanoes are usually less explosive than
14. 1:32those at destructive plate boundaries because  the magma at these boundaries are less viscous.
15. 1:38Iceland located on the mid-Atlantic ridge  has many volcanoes. Step five is sea floor
16. 1:45spreading. As new crust forms at mid ocean  ridges, it slowly moves away from the ridge,
17. 1:51causing the seafloor to spread. This process  continually adds new material to the ocean floor,
18. 1:57pushing older crust further away from the ridge  and contributing to the expansion of ocean basins.
19. 2:05Next time you think about the Earth's crust,  remember the dynamic process of the seafloor
20. 2:10spreading and volcanic activity  at constructive plate boundaries.
21. 2:14These boundaries are vital in continuously  shaping and reshaping the Earth's surface.