After this, magma is created by the frictional heat which is caused when the crust collides. It is a viscous liquid, like a jelly, which mixes the molten rock, gas, and other. When it is created, it gradually rises having the low density compared with other rock which has the high density within the mantle. By rising, it has lower pressure, and the amount of gas which is melted in the magma increases.
Lava that came out to the earth's surface has temperature as high as 1,200 degrees Celsius.