Explain the three main layer of the Earth.
The Correct Answer and Explanation is :
The Earth is divided into three main layers: the crust, the mantle, and the core. Each layer has distinct properties and plays a vital role in the structure and dynamics of the planet.
- The Crust: The Earth’s outermost layer, the crust, is a thin, solid layer that forms the planet’s surface. It is composed mainly of rocks like basalt and granite, which vary in composition between the oceanic crust (thinner, denser, and primarily basaltic) and the continental crust (thicker and composed mostly of granite). The crust is broken into tectonic plates that float on the semi-fluid mantle beneath them, and their movement causes earthquakes, volcanic eruptions, and the creation of mountain ranges.
- The Mantle: Beneath the crust lies the mantle, which is much thicker and extends to a depth of about 2,900 kilometers. The mantle is made of silicate rocks that are rich in iron and magnesium. It is semi-solid, meaning it behaves like a solid over long periods but can flow very slowly over shorter timescales, especially near the base. This layer is divided into the upper mantle (which includes the asthenosphere, a partially molten layer that allows tectonic plates to move) and the lower mantle. Convection currents within the mantle drive the movement of the Earth’s tectonic plates.
- The Core: The Earth’s core is the innermost layer and is primarily composed of iron and nickel. It is divided into two parts: the outer core and the inner core. The outer core is liquid and extends about 2,200 kilometers beneath the mantle, generating the Earth’s magnetic field through the movement of molten iron. The inner core, on the other hand, is solid and extremely hot, with temperatures exceeding 5,000°C. It extends from around 5,150 kilometers to the center of the Earth, and while it is solid, it remains under immense pressure that prevents it from melting.
These layers work together, with the movement of tectonic plates on the crust and mantle affecting the planet’s surface, while the core influences Earth’s magnetic properties.