where does partial melting occur in the earth
Partial melting Partial melting is an important consideration in geology with respect to the chemical differentiation of crustal rocks. Virtually all rocks on Earth derive from material from the interior of the earth that has been partially melted. The main places where partial melting occurs are subduction zones, mid-ocean ridges and hotspots. In all these places partial melting is often associated with volcanism, although some melts do not make it to the surface. Partial melts are thought to play an important role in enriching old parts of the continental lithosphere in incompatible elements.[1] Partial melts produced at depth move upwards due to the compaction of the surrounding matrix.[2]
Glacier Large masses, such as ice sheets or glaciers, can depress the crust of the Earth into the mantle.[47] The depression usually totals a third of the ice sheet or glacier's thickness.  After the ice sheet or glacier melts, the mantle begins to flow back to its original position, pushing the crust back up. This post-glacial rebound, which proceeds very slowly after the melting of the ice sheet or glacier, is currently occurring in measurable amounts in Scandinavia and the Great Lakes region of North America.