In order to maintain isostasy,what must occur after new igneous rock is added to the crust (either on top of or intruded into)?

Question

Quizplus · Accepted Answer

Isostasy is the state of gravitational equilibrium between Earth's lithosphere and asthenosphere. When new igneous rock is added to the crust, it increases the mass of the lithosphere. To maintain isostasy, the base of the lithosphere must sink, but not as much as the surface has risen. This is because the denser lithosphere sinks into the more fluid asthenosphere, until a new equilibrium is reached. Therefore, choice C - The base of the lithosphere must sink but not as much as the surface has risen - is the correct answer.

In Order to Maintain Isostasy,what Must Occur After New Igneous