Which layer of the Earth is situated directly beneath the crust?

The layer of the Earth situated directly beneath the crust is the mantle. The mantle is a thick layer of rock that lies between the Earth's crust and the outer core. It extends to a depth of about 2,900 kilometers and is primarily composed of silicate rocks that are rich in magnesium and iron. The mantle is critical in Earth's geology, as it convects heat and is responsible for the movement of tectonic plates, which leads to geological activities such as earthquakes and volcanic eruptions.

The outer core and inner core are deeper than the mantle. The outer core is a liquid layer composed mainly of iron and nickel, while the inner core is solid and made of similar materials. The upper crust, on the other hand, refers specifically to the outermost solid layer of the Earth, which includes the landforms we see on the surface, and does not extend beneath the crust itself.