Question

Convection currents in the plastic mantle are believed to cause divergence of lithospheric plates at the

Answer 1

They are believed to cause divergence of lithospheric plates at the mid atlantic ridge
The currents reallocate heat from a certain place to another through mass motion of fluid (such as molten rock or water), The difference in temperature between core and lithosphere material generate enough force for the divergence to happen.

Answer 2

A mantle tuft underlies Iceland, of which the hotspot is believed to be the surface articulation. This upgrades the volcanism as of now caused by plate partition, both at the focal point of the island and at the Reykjanes edge toward the southwest of Iceland's principle volcanic zone. The crest is accepted to be very tight, maybe 100 km over, and reaches out down to no less than 400– 650 km underneath the Earth's surface, and perhaps down deeply mantle limit.