Question

select the correct answer.
which of these conditions would likely cause the tectonic plates of earth to stop moving?
a. earths crust and mantle reach thermal equilibrium.
b. earth stops receiving energy from the sun.
c. the temperature of the surface of earth drops considerably.
d. the amount of radiogenic heat released by the mantle multiplies.

Explanation:

Tectonic plate movement is driven by convection currents in the mantle, which result from heat differences (thermal gradients) between the core - mantle boundary and the crust - mantle boundary. If the Earth's crust and mantle reach thermal equilibrium (no significant temperature difference), the convection currents in the mantle would stop. Without these convection currents, the driving force for tectonic plate movement would be lost.

• Option B: Earth's tectonic plate movement is not primarily driven by solar energy, so stopping solar energy reception wouldn't stop plate movement.
• Option C: A drop in Earth's surface temperature doesn't affect the mantle's convection currents (the main driver of plate movement) significantly enough to stop plate movement.
• Option D: If the radiogenic heat released by the mantle multiplies, it would likely increase convection currents and thus increase plate movement, not stop it.

Answer:

A. Earth's crust and mantle reach thermal equilibrium.