<P> Mantle convection is the slow creeping motion of Earth 's solid silicate mantle caused by convection currents carrying heat from the interior of the Earth to the surface . The Earth 's surface lithosphere , which rides atop the asthenosphere ( the two components of the upper mantle ) , is divided into a number of plates that are continuously being created and consumed at their opposite plate boundaries . Accretion occurs as mantle is added to the growing edges of a plate , associated with seafloor spreading . This hot added material cools down by conduction and convection of heat . At the consumption edges of the plate , the material has thermally contracted to become dense , and it sinks under its own weight in the process of subduction usually at an ocean trench . </P>
<P> Mantle convection is the slow creeping motion of Earth 's solid silicate mantle caused by convection currents carrying heat from the interior of the Earth to the surface . The Earth 's surface lithosphere , which rides atop the asthenosphere ( the two components of the upper mantle ) , is divided into a number of plates that are continuously being created and consumed at their opposite plate boundaries . Accretion occurs as mantle is added to the growing edges of a plate , associated with seafloor spreading . This hot added material cools down by conduction and convection of heat . At the consumption edges of the plate , the material has thermally contracted to become dense , and it sinks under its own weight in the process of subduction usually at an ocean trench . </P>
what layer of earth do convection currents occur
what layer of earth do convection currents occur
asthenosphere
asthenosphere