what is mantle

The mantle is a layer inside a planetary body, such as the Earth, bounded below by a core and above by a crust. It is the mostly solid bulk of Earth's interior, lying between the dense, super-heated core and the thin outer layer, the crust. The Earth's mantle is about 2,900 kilometers thick, making up a significant portion of the Earth's total volume. It is mostly made up of silicate rock and is responsible for driving plate tectonics, contributing to phenomena such as volcanoes, seafloor spreading, earthquakes, and mountain- building. The mantle is also characterized by its high temperature, which varies greatly throughout its layers, and its viscous fluid-like behavior on geologic time scales. The mantle is a key component in understanding the structure and dynamics of the Earth's interior