What’s happening down under?
- POSTED ON: 6 Mar, 2024
- TOTAL VIEWS: 284 Views
- POSTED BY: Madhuvanti S. Krishnan
- ARTICLE POINTS: 150 Points
We all know much about the Earth. But, how much do we know about its layers? Beginning at the centre, the Earth is made up of four layers: the inner core, the outer core, the mantle and the crust.
The crust: Thin, brittle, and cold, it is composed of light elements, especially oxygen, aluminium, and silica. However, its thickness varies. For instance, under the oceans, it may be as little as five kilometres while beneath the continents, it may be 30 to 70 kilometres thick.
Mantle: Around 3,000 kilometres thick, the mantle is Earth’s thickest layer. It starts about 30 kilometres beneath the surface and is composed mostly of iron, magnesium and silicon. It is dense, semi-solid, and hot.
The outer core: Made from iron and nickel in liquid form, it sits about 5,180 to 2,880 kilometres below the surface. Heated largely by the radioactive decay of uranium and thorium, this liquid churns in turbulent currents, which generates electrical currents that create the Earth’s magnetic field.
The inner core: This is solid metal and has a radius of 1,220 kilometres. It is very dense and is made mostly of iron and nickel. It is also extremely hot at 5,400°C; almost as hot as the sun’s surface.
Fun fact: Barring the crust, no one has ever explored these layers in person. In fact, the deepest humans have ever drilled is just over 12 kilometres.
Here’s a fun game to see how much you’ve understood. Drag and drop the labels to see if you are able to correctly identify the different layers of the earth.