1. Crust:
* Composition: Primarily composed of igneous, sedimentary, and metamorphic rocks. The oceanic crust is thinner and denser, made mostly of basalt, while the continental crust is thicker and less dense, containing granite and other lighter rocks.
* Thickness: Ranges from 5-70 km (3-44 miles).
* Features: The Earth's surface we live on, including continents, oceans, mountains, and valleys.
2. Mantle:
* Composition: Mostly solid rock composed of silicate minerals, mainly peridotite. However, the mantle behaves like a very viscous fluid over long periods due to extreme heat and pressure.
* Thickness: Approximately 2900 km (1800 miles).
* Features: Convection currents within the mantle drive plate tectonics.
3. Outer Core:
* Composition: Liquid iron and nickel, with trace amounts of other elements like sulfur and oxygen.
* Thickness: Approximately 2200 km (1367 miles).
* Features: The movement of the liquid outer core generates Earth's magnetic field.
4. Inner Core:
* Composition: Solid iron and nickel.
* Thickness: Approximately 1220 km (758 miles).
* Features: Extremely hot and dense, despite being solid due to immense pressure.
In summary:
* Crust: The outermost layer, thin and rocky.
* Mantle: Thick layer of mostly solid rock with convection currents.
* Outer Core: Liquid iron and nickel, generating Earth's magnetic field.
* Inner Core: Solid iron and nickel, extremely hot and dense.
It's worth noting that these layers are not distinct boundaries but rather zones of gradual change in composition and properties.
