convection in the mantle is caused by

Answer 1

Convection in the mantle is primarily caused by the heat generated from the core of the Earth. The Earth's core is composed mainly of iron, which is a highly dense and hot material. The heat from the core rises and therefore heats the overlying layers of the mantle.

As the mantle is heated, the warm material expands and becomes less dense, causing it to rise towards the surface. Once it reaches the surface, it begins to cool and becomes more dense, causing it to sink back towards the core. This sinking material is then reheated and the cycle continues, creating a convection current within the mantle.

Additionally, the movement of tectonic plates at the Earth's surface also contributes to the convection within the mantle. As the plates move and interact with each other, they can create areas of compression and extension. The compression leads to the sinking of material in the mantle, while extension leads to the rising of material. This plate tectonic activity further enhances the convection currents within the mantle.