Ask a Teacher

Search



Why volcanic eruption occur
 The Earth is so hot interiorly, that some rocks slowly melt and become a thick flowing substance called magma. Because it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through vents and fissures in the Earth's surface.  which causes volcanic eruption occurs.  The Magma that is erupted is called lava.  Volcanic eruptions can happen at destructive and constructive boundaries, but not at conservative boundaries. 
    Magma rises through cracks or weaknesses in the Earth's crust. Pressure builds up inside the Earth.
    When this pressure is released, eg as a result of plate movement, magma explodes to the surface causing a volcanic eruption.
    The lava from the eruption cools to form new crust.
    Over time, after several eruptions, the rock builds up and a volcano forms.


comments powered by Disqus