Question

In the interior of continents the earth's crust is typically about 40km thick and the elevation is near sea level.In an area where the crust is 20km thick, isostasy would suggest the elevation in this area would be ________ unless the density changes from one area to the other.A) below sea level

B) near sea levelC) high mountains
D) slightly above sea level

Answer 1

B) near sea level

Step-by-step explanation:

Firstly, Isostasy is an equilibrium of adjacent lithosphere floating on the asthenosphere . The continental crust been solid floats on the denser mantle and balance the equilibrium between the portion on the mantle and the elevated parts.

The higher it elevation on the lithosphere or continental crust the more portion of the crust that sinks into the aesthenospere to balance the equilibrium. Therefore to balance a 40km thickness of continental crust requires more portion sinking into the interior of the earth(mantle) .

Both continental crust(40km and 20km) will be near sea level to be in equilibrium.