Question

When mantle rocks near the radioactive core are heated, they become less dense than the cooler, upper mantle rocks. These warmer rocks rise, while the cooler rocks sink. This movement of warmer and cooler mantle rocks creates pockets of circulation within the mantle called _________, which are thought to be the force behind the movement of tectonic plates over the asthenosphere.

A) magma flows
B) density cells
C) convection cells (currents)
D) conduction points

Answer 1

the answer is convection cells (currents)

Step-by-step explanation:

Answer 2

C

Step-by-step explanation:

This is similar to the convection currents of all fluids. The mantle is semi-plastic – meaning the rocks are hot enough to melt but remain ‘solid’due to the enormous pressure in the region. The currents are slow and though frictional drag they cause movement of tectonic plates of the crust above as they churn.