The Student Room Group


how are earthquakes formed i cannot understand an eq and a tsunami.
Yippeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee, a question that I can certainly answer.

Earthquakes are the result of plate movement, our planet is divided up into about 12 huge plates which form the land on which we walk. As the plates move and jostle each other around, they create areas where tension builds up and creates faults, mountains and canyons.

The plates have several different locations where they either move apart, lock together or slide passed each other. A few examples are listed below.

1 ) Divergent Plate Boundaries : These are where the plates are moving apart such as at mid ocean ridges as they do in Iceland which straddles the Mid Atlantic Ridge where the Eurasian and American plates are being created as new magma rises from insie the planet.

2 ) Convergent Plate Bournemouth : These are where the plates lock together, a good example here is where the Indonesian & Australian plates meet each other and can also form Subduction Zones where 1 plate is forced down back into the planet.

3 ) Strike Slip Faults : These are where the plates get locked up and cannot push each other out of the way or down into the planet, consequently the only they can then do is slip passed each other. The San Andreas Fault is a perfect example of this kind of fault, 1 side of it is moving north and the other side does not move ( will have to check up on that ).

In reference to Tsunamis, the best example here is the boxing day tsunami of 2004. This happened because at the point where the Indonesian and Australian plates were locked together. The extreme forces building up underground eventually ruptured a fault just to the west of Indonesia and as a result sea floor was jolted upwards in 2 massive waves of tectonic force and this upward movement is what caused the tsunami wavs which slammed into the west of Indonesia only minutes after the huge magnitude 9.1 earthquake struck but the waves created by this massive quake also travelled westwards and also struck several locations around the pacific.

Hope this helps and any further questions, please don't hesitate to ask.

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