The Mantle
The
layer above the core is the mantle. It begins about 6 miles(10 km)
below the oceanic crust and about 19 miles (30 km) below the
continental crust (see The Crust). The function of the mantle is to
separate the inner mantle and the outer mantle. It is about 1,800
miles(2,900 km) thick and makes up nearly 80 percent of the Earth's
total volume. Science deals with the structure of the mantle in two
different ways. One way is based on its chemical construction (the
material), the other on the way layers stream or move.
What does the mantle consist of?
Based on the chemical construction:
Inner Mantle: the inner mantle can be found between 190 miles (300 km) an 1,800 miles (2,890 km) below the earth’s surface. The average temperature is 5400 ºF (3000ºC), nevertheless the rock is solid because of the high pressures. The inner mantle for the biggest part probably consists of sulphides and oxides of silicon and magnesium. The density is between 4.3g/cm³ and 5.4g/cm³.
Outer Mantle: The outer mantle is a lot thinner than the inner mantle. It can be found between 7 miles (10 km) and 190 miles (300 km) below the surface of the earth. You can divide the outer mantle into two different layers. The bottom layer is tough liquid rock and probably consists of silicates of iron and magnesium. The temperature in this part is between 2520 ºF (1400ºC) and 5400 º F (3000ºC) and the density is between 3.4g/cm³ and 4.3g/cm³. The upper layer of the outer mantle consists of the same material but is stiffer because of its lower temperature.
What does the mantle consist of?
Based on the chemical construction:
Inner Mantle: the inner mantle can be found between 190 miles (300 km) an 1,800 miles (2,890 km) below the earth’s surface. The average temperature is 5400 ºF (3000ºC), nevertheless the rock is solid because of the high pressures. The inner mantle for the biggest part probably consists of sulphides and oxides of silicon and magnesium. The density is between 4.3g/cm³ and 5.4g/cm³.
Outer Mantle: The outer mantle is a lot thinner than the inner mantle. It can be found between 7 miles (10 km) and 190 miles (300 km) below the surface of the earth. You can divide the outer mantle into two different layers. The bottom layer is tough liquid rock and probably consists of silicates of iron and magnesium. The temperature in this part is between 2520 ºF (1400ºC) and 5400 º F (3000ºC) and the density is between 3.4g/cm³ and 4.3g/cm³. The upper layer of the outer mantle consists of the same material but is stiffer because of its lower temperature.
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