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Distribution of earthquakes and volcanoes 2.1
An earthquake is a sudden, violent period of ground-shaking which mostly occur at plate margins. Friction between plates creates enormous pressures which build to a breaking point.
-The Earth’s crust is split into seven major and several minor tectonic plates.
-There are two types of crust: The dense, thin oceanic plate and the less dense, thicker continental crust.
–Plates move by convection currents within the mantle.
–Plates separate at constructive margins forming new crust and causing volcanic eruptions.
-Plates collide at destructive plate margins which causes subduction, earthquakes, volcanic eruptions and fold mountains.
–Subduction is the sideways and downward movement at the edge of a plate of the earth’s crust into the mantle beneath another plate. Also known as the subduction zone.
–Fold mountains are mountains that form mainly by the effects of folding on layers at the upper part of the Earth’s crust.
-Plates slide by each other at conservative margins therefore causing earthquakes.
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