Sagot :
Upper Mantle
The special about the upper mantle is its ability to flow like fluid. The upper mantle has soft weak layer called the asthenosphere, which capable of flowing. This property facilitates the movement of lithospheric plates. The heat brought about the by the radioactive decay of uranium in the inner core increases the temperature of interior of the earth including the mantle which resulted to melting of rock material. Melting of the rock material in the upper mantle causes it to flow like fluid resulting to convection current in the mantle.
Convection current in the Mantle
Convection current can be apply in the mantle, and it can also be apply in the atmosphere which states that the less dense particles rise while denser particles sink. When the hot and less dense particles cool down, they sink, and the other less dense particles rise. This continuous process is called convection current. This is exactly what happens in the Earth’s mantle. The hot and less dense rising material spread apart increases space between each particle as it reaches the upper mantle causing upward and side-ward forces. These forces lift and split the lithosphere at divergent plate boundaries. Magma rise up out of the mantle and cools down to form the new ocean crust. The downward movement of the convection current occurs along a convergent boundary where the sinking force pulls the tectonic plate downward.
Layers of the Mantle
- Upper Mantle
- Lower Mantle
Upper mantle
Upper mantle is divided into two layers. The first layer in the upper mantle is Lithosphere and below the lithosphere is the layer known as Asthenosphere. Lithosphere is made up of solid rocks while asthenosphere are made up of melted rocks due to increasing temperature which has the ability to flow like fluid (plastic).
Lower Mantle
The layer we can find in the lower mantle is known as Mesosphere. Mesosphere is below asthenosphere and is above the outer core. Mesosphere is solid due to increasing pressure it may have the same chemical composition with asthenosphere except that it is solid and don't flow.
Here are the four layers of the Earth
- Crust
- Mantle
- Outer core
- Inner core
Crust
The crust is the thinnest and the outermost layer of the Earth that extends from the surface to about 32 kilometers below. This are layer where we live and volcanoes, earthquake, and mountain ranges are formed.
Type of crust
- Oceanic crust
- Continental crust
Oceanic crust
Are denser and thinner compared to continental crust.
Continental crust
Thicker and are less dense compared to oceanic crust.
Mantle
Beneath the crust is the mantle, which extends to about 2,900 kilometers from the Earth's surface. The mantle is the thickest layer of the earth and is more dense compared to the crust. It is way hotter than the crust and capable of melting it. The upper mantle are plastic, its made up of magma that because of too much heat it flows which causes changes on the surface of the Earth.
Outer Core
The outer core is 2900 kilometers below the surface of the Earth. It is mostly made up of iron and nickel but in liquid phase and its temperature reaches to about 2000°C. Even if the outer core has a high pressure, but due to its much higher temperature, nickel and iron are melted. The outer core is flowing outside the inner core which generate a magnetic field that protects the earth from the dangerous radioactive material coming from the heat of the sun.
Inner Core
The inner core is the deepest layer made up of solid iron and nickel and has a radius of approximately 1,300 kilometers. Its temperature reaches to about 5000°C. The inner have the highest density compared to the other. The heat in the interior of the Earth is caused by the radioactive decay of uranium in the inner core which releases tremendous amount of heat.
Visit the link below for more information:
brainly.ph/question/133488
brainly.ph/question/1494840
brainly.ph/question/660109