Why is lava called magma underground and it is called lava when it
is on the surface of the earth?
Jacob Alison
Dear Jacob
I think that another reason for two different names is that, although
its the same solid material in the ground and on top of it, there are
great differences in the physical properties. Magma has a high and
relatively uniform temperature, but lava immediately begins to cool as it
flows out of the ground. Perhaps more importantly, magma is under
pressure and has water and other gases inside and they can't easily
escape. But magma quickly loses much of its gas as it erupts. Without the
gases, and at lower temperatures, lava acts differently from magma. Lava
is more sluggish (slower - more like cold syrup) than magma. So there are
good reasons to use both the words magma and lava.
Charles A. Wood
Other Categories
Other Questions
To VolcanoWorld