What is the difference between Pratt's and Airy's hypothesis of isostasy?

Answer 1

Pratt's hypothesis of isostacy proposed that topography is produced by

crustal blocks with varying density, that terminate at a uniform depth whereas Airy's hypothesis

of isotacy, the mountain range can be thought of as a block of lithosphere (crust) floating

in the asthenosphere (lava). Mountains have roots, while ocean basins have anti-roots. whereas