the crust
Yes it is call a crust 😁
The crust is the outer or surface layer of the planet.
An intrusion.
There is no ladder if (of?) rocks under the earths surface, your question is meaningless.
Molten rock material on Earth's surface is called lava. When under Earth's surface it's called magma
A temperature inversion.
a boat
mantle
it is called temperater inversion
substratum
There are almost no extrusive rocks on the earths surface because they are all under the earths surface. They are mainly lower than the earths surface.
If there were such a thing it would not be soft, it would be liquid, and would be called magma. There really is no completely molten layer of Earth except for the outer core which is composed primarily of liquid iron along with some nickel and other trace elements.