What's Happening to the Earth?

A cross-section of the earth looks a bit like an onion, so if you take an onion apart, it has layers of different material. But in the middle is a ball of solid iron and outside it then is this ball of liquid iron which is about the size of Mars. Then we have all this green stuff which is green and it's called the mantle. And that is where it goes solid again. So it's perhaps not as well represented by the orange. I was hoping to get there the idea of the land shifting so that magma comes up through and creates a new land. It doesn't seem to have gone very well.