The Earth is that planet that has life on it and for that over the years, educated people and researchers have tried to find out what makes up the Earth. Scientists have proved that the Earth has 3 layers namely the Crust, Mantle and Core.
Fact 1 The Crust Of The Earth
The layer that covers the uppermost surface of the earth is known as the Crust. It is made of mostly granite and basalt rocks. The crust is compared to the icing of a cake and humans live on top of that layer. It is made up of the familiar seabed, soil and rocks on which humans and animals live. Compared to the size of the crust humans are super small and appears to be just like tiny bits of confectioners’ sugar. Although the crust is a thin layer and is only 1% of the earth’s entire mass, it is about 70 km thick at the center and 25 km at the edges. The layer or crust under which the continents are found is known as Continental Crust and it is 10 to 70 km thick. On the other hand the Oceanic Crust that is under the oceans is just 5 to 7 km thick.
Fact 2 The Mantle
The Mantle is the largest layer that lies underneath the Crust. It is made up of silicates and rocky oxides under extreme pressure. This part covers 2/3 of the entire mass of the earth. It is 2900 km deep and is divided into two sections namely the upper mantle and the lower mantle. The upper part of the mantle also known as asthenosphere flows and moves although it is solid. This movement is very slow and is caused by convection currents which are the results of heat and pressure that makes it lighter than the other layer and so it acquires the ability to move. The currents in the mantle break the crust into blocks and these are known as plates. During their slow movements they collide with each other and thus form mountains and seafloor.
Fact 3 The Core
The Core is the center of the earth and lies just below the mantle. It occupies 1/3 of the entire mass of the earth. The Core is comprised of metals like iron. It also has two sections namely the inner core and the outer core. Information gathered by scientists from earthquakes and seismic waves tells us that the outer core is in liquid form and flows around the earth. The temperature is 4000 to 5000 degrees Celsius. The inner core is solid and is made up of iron and nickel. According to scientists, the inner core is solid due to the extreme pressure exerted by the other layers. They also say that the magnetic field that exists around the earth is due to the circulation of the outer core that is nearly 2300 km thick. It moves in counter-clockwise direction that points to the North Pole presently. It is believed to switch its direction every million years and the effects are felt on both the ocean and land crusts.
Fact 4 Interior Of The Earth
The interior of the earth is made up of four different layers among which 3 layers are solid and only one layer is in liquid form. The liquid is not magma but is molten metal. The innermost layer is a ball of solid iron that is nearly 2400 km in diameter and the temperature is between 9,000 and 13,000 degrees Fahrenheit.
Fact 5 Study Of The Earth’s Layers
Details of the earth can be studied only with the help of seismic waves because only the earth’s crust can be drilled to collect samples but not any other layers of the earth.