What is main difference between lithosphere and asthenosphere?
Asthenosphere is is a low-viscosity shell that extends from 100 km down to 700 km, The solid crust inclusive of some upper part of mantle is lithosphere extends below up to 100 or 200 km.
Beneath land surface, lithosphere extends up to 100 km, nearly. Beneath sea it is thicker, up to 200 km, nearly. The thickness of lithosphere is determined from brittle and viscosity characteristics..