Describe the asthenosphere. Why is it also known as the plastic layer? What are the consequences of its convection currents? What is a discontinuity? Describe the principal discontinuities within...

Describe the asthenosphere. Why is it also known as the plastic layer? What are the consequences of its convection currents?

What is a discontinuity? Describe the principal discontinuities within Earth. Define isostasy and isostatic rebound and explain the crustal equilibrium concept.