The upper part of the mantle above which the crust floats is called

The upper part of the mantle above which the crust floats is called

پردے کا اوپری حصہ جس کے اوپر پرت تیرتی ہے اسے کہتے ہیں۔
Explanation

The upper part of the mantle upon which the crust of the Earth floats is known as the Asthenosphere.