Our planet is unique, but not only that, she had a lot of liquid water. Of course, on other worlds, including several moons of the gas giants, also has an atmosphere, ice, and even oceans, but only Earth has all the necessary for the emergence and maintenance of life “ingredients”. So, the oceans cover about 70% of the planet’s surface and their average depth is 4 kilometers. Fresh water exists in liquid form in lakes and rivers, as well as in the form of water vapor in the Earth’s atmosphere. But what happens inside this ball with a diameter of 12 700 km, which we call home? As is known, the structure of our planet consists of different layers, and in the center of the Earth is the core, then the mantle and finally the crust. But why our planet has many layers and what happens in each of them?
Bark – the outer layer of the Earth
The earth has several layers. The ocean basins and the continents are the crust, the outermost layer of our cosmic home. The depth of the crust is from five to 75 km, and The thickest part under the continents and thinnest under the oceans. Is the earth’s crust, according to the basics of Geology, of several elements: oxygen is 46.6%; silicon, 27.7 per cent; aluminium and 8.1%; iron 5%; calcium – 3,6%; sodium and 2.8%, potassium 2.6% magnesium 2.1 per cent. The crust is divided into huge plates that float on the next layer – the mantle. Plates are constantly in motion; according to NASA, they move at about the same rate at which fingernails we have on hand. Earthquakes occur when these plates closely in contact with each other. Mountains formed by collision of tectonic plates, and deep trenches when sliding of one plate on another. It explains the movement of the plates tectonics.
Mantle – the middle layer of the Earth
The mantle under the earth’s crust has a depth of about 2890 km, It consists mostly of silicate rocks rich in magnesium and iron. High temperatures make the rocks rise, and when they cool down, then sink back to the core. It is believed that this is what makes moving tectonic plates. When the mantle breaks through the crust, begin eruption. By the way, recently in Italy woke up the largest volcano in Europe. Read more about how it was, read our material.
The kernel is the heart of the Earth
In the center of the globe is the kernel, which consists of two parts. Solid, inner iron core with a radius of about 1220 km. It is surrounded by a liquid outer core, which consists of an alloy of Nickel and iron. The thickness of the outer core is about 2180 km, While the inner core rotates at a different speed than the rest of the planet. It is believed that the cause is the Earth’s magnetic field.
Earth, Venus and Mars are rocky planets
To better understand the composition and history of the Earth, geologists sometimes compare our planet with other rocky planets in the Solar system. So, the size of Venus is similar to earth, but the planet itself is slightly closer to the Sun. The size of Mars is only half the space of our home.Venus and Mars were sent several spacecraft, we don’t know so much about their inner workings – at least not yet. Let me remind you that recently, thanks to the NASA mission InSight, became aware of the fact, that Mars is seismically active planet. Read more about this I told in my previous article.
As for Venus, it is extremely dense and toxic atmosphere which can’t be seen without special tools, meanwhile, testifies to the enormous volcanic activity on this planet is incredibly hot. While Venus probably has a crust, mantle and core, its magnetic field is very weak compared to earth. Researchers believe that this may be due to the fact that either the core of Venus slowly rotates to generate a magnetic field, or his this hellish planet at all.