Plate Boundaries
Divergent Boundaries
Divergent boundaries are when two plate boundaries are slowly moving in the opposite directions. When the two plates are moving apart a large amount of magma rises between the two plates from the lower mantle. The separation of the plates sometines leads to the creation of a new sea/ocean. Transform Boundaries Transform boundaries occur when teo plates are sliding/grinding past each other, while no significant difference happens, faults are known to happen as of a side-affect of the boundary. Convergent Boundaries Convergent boundaries occur when the two plates are forced together, and collide; the thicker, denser plate will often sink underneath the other plate. This process is called subduction; subduction will often cause a volcano to form due to the sudden amount of extra magma being squeezed towards the surface. There are many types of convergent boundaries; these include:
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The Causes of the Christchurch Earthquake
On the 22nd of February 2011, 12:51 pm a catastrophic earthquake hit Christchurch, New Zealand. The Australian Plate and the Pacific Plate share a convergent plate boundary. The earthquake was caused by the two plates being forced together for a long time. The earthquake's epicentre was at 43.58 degrees S and 172.68 degrees E, the devastating earthquake was caused by a hidden fault (Port Hills Fault) that had shifted. The earthquake happened 5 km south-east of Christchurch; it had a focal depth of of 5 km.