Question

what is the source of heat in mantle convection current​

Answer 1

The primary sources of thermal energy for mantle convection are three: (1) internal heating due to the decay of the radioactive isotopes of uranium, thorium, and potassium; (2) the long-term secular cooling of the earth; and (3) heat from the core.

Answer 2

The source of heat in mantle convection current is mentioned as follows:

• Internal heating caused by the decay of radioactive uranium isotopes is the principal source of thermal energy for mantle circulation.
• It can also be caused by the heat of the inner core.
• The heat energy from the core is transferred to the mantle, forcing it to rise towards the cooler Earth's surface.
• The heated mantle distributes its heat energy to the lithosphere.