Chahal's Gyan Ki Baat

CONVECTIONAL CURRENT THEORY

WHAT IS CONVECTIONAL CURRENT THEORY?

  • In 1930s, Arthur Holmes discussed this theory with the possibility of convection currents in the mantle.
  • He considered it as the soul of Seafloor Spreading Theory.


WHAT IS THE MECHANISM OF CONVECTIONAL CURRENT THEORY?

  • The extreme heat is generated by radioactive chemicals in the mantle (100-2900 km down the earth's surface).
  • The heat seeks a way to escape and causes convection currents in the mantle.
  • Divergent convective currents pull crustal blocks away from each other.
  • Convergent convective currents create subsidence in the crustal zones
  • The movement of lithospheric plates is caused by the movement of the magma in the mantle.
  • How much amount of heat needed for mechanism to occur?
  • Convective currents may not be formed if heat is insufficient.
  • This process may result in heat loss, which could cause currents to weaken.