Question

What causes convection currents in the mantle?

Answer 1

Hint: Mantles are composed of ice or/and rocks, and they are the earth's biggest and the most expansive surface. Convection currents use the fluid’s mass motion like that of water, molten rocks, or the air to carry heat from one location to the other.

Complete answer:
- The earth has three primary layers: the crust, the mantle, and the core.
- We know that the heat in the mantle is originally derived from a few factors like the molten outer core of Earth, then from radioactive decay, and also due to the pressure from the tectonic plates that move downward in the upper part of the mantle.
- The outer core has heat that is produced by decaying radioactive elements and leftover energy from the Earth's formative events. This heat raises the temperature of the mantle's foundation to about seven thousand degrees Fahrenheit. The temperature of the mantle is estimated to be three hundred and ninety-two degrees Fahrenheit at the boundary of mantle-crust.
- We need to understand that the difference in temperatures between the boundaries of upper and lower mantles is the reason for causing this heat transfer to happen. Convection also happens in the mantle, beyond the fact that conduction seems to be the more apparent mode of heat transfer. Now the part that is warmer and rock material that is less dense close to the core steadily starts to move up.
- Rocks that are there at the higher parts of the mantle are cooler, steadily sinking into the mantle. Then what happens is that the warmer parts there rise and cool, finally being forced aside and falling down into the core by warmer growing material hence causing convection currents.
- Then the mantle material moves quite slowly. The heat and pressure cause convection currents to shift the mantle material while it still continues to be in solid form.

Note: Let us understand another similar topic called as conduction. Heat energy is transferred by collisions between adjacent atoms or molecules in the process of conduction. Solids and liquids, where the particles are closer together, conduct more readily than gases, where the particles are farther separated. These are the basic things that happen during a conduction process.