Eruption of a Volcano

The gas-filled magma chamber is under tremendous pressure from the weight of the solid rock around it. The pressure forces the magma chamber to blast or melt a conduit (channel) in a fractured or weakened part of the rock, giving the magma a way to reach the surface. Gas is released when magma reaches the surface. The gas and magma blast out a central vent, allowing most of magma and volcanic materials to erupt. Some of the magma may break through the conduit and branch out into smaller channels, escaping through a vent at the sides of the volcano. The materials, which gradually pile up around the vent, form a volcanic mountain or volcano. A bowl-like crater forms at the top of the volcano. The vent lies at the bottom of the crater.

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