Composition and mechanical behaviour provide related but different ways to describe Earth’s layers. The crust and uppermost rigid mantle form tectonic plates; most of the mantle remains solid while deforming over geological time. Pressure helps keep the inner core solid despite high temperatures. Our radial model omits small-scale variations and detailed transition zones.
Earth and geology · Discover & try
What is inside Earth?
Reading level 5 of 5 · AdvancedChange
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Mantle
The thick layer of mostly solid rock below the crust.
Outer core
Earth’s liquid, metal-rich layer surrounding the inner core.
Depth
Distance below the surface, distinct from distance from the centre.
Watch · Try · Explain
See how it works
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Approximate radial boundaries; crust thickness varies and its thin edge is highlighted for visibility.
What to look for
- Compare depth with radius.
- Look for the liquid layer.
- Notice how thin the crust is.
Explain what you noticed
A diagram colours the mantle red. Does that prove it is a global liquid magma ocean?
Keep this idea: Earth’s mantle is mostly solid rock; the outer core is liquid and the inner core solid.
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