Question: What is a volcano explaind for a dumb person?

James Verdon answered on 25 Jun 2012:

Hi libbywyatt,
I’m pretty sure I haven’t seen any dumb people around here, just lots of good questions.

A volcano is anywhere where molten magma erupts to the surface. In certain places, the heat of the earth below ground is enough to melt the rock. This molten rock is what we call magma, or lava, and in some places there is a lot of it underground.

Initially, this molten rock will be trapped below the ground. But because it is less dense than the rock around it, it wants to rise up. So it will find cracks, faults and tubes through which it can move up towards the surface. Sometimes, it will accumulate for a while in magma chambers – which are basically caverns below volcanoes where the magma can accumulate. But eventually, it will reach the surface and erupt.

Sometimes the eruptions can be very gentle, and you’ll jut get a stream of lava running out. However, sometimes, if the magma rises quickly and is full of gas, the depressurisation as it comes up will cause an explosion. This is just like when you shake a coke bottle and then open it. Taking away the pressure causes all the bubbles to come out at once and you get an explosion of coke. Well, same thing with magma – if it rises quickly and the pressure is released, you get an explosion. Only instead of coke going everywhere, you have boiling magma, ash and scalding hot toxic gasses going everywhere.

I hope that makes sense for you libby. Please comment if you’d like more info.