  Radiative corrections to neutrino mixings in seesaw models depend on the
nature of new physics between the weak and the GUT-seesaw scales and can be
taken into account using the renormalization group equations. This new physics
effect becomes particularly important for models with quasi-degenerate neutrino
masses where small neutrino mixings at the seesaw scale can get magnified by
radiative renormalization effects alone to match observations. This mechanism
of radiative magnification which provides a simple understanding of why lepton
mixings are so different from quark mixings was demonstrated by us for the
standard supersymmetry scenario where the particle spectrum becomes
supersymmetric above the weak scale. In this paper, we examine this phenomenon
in split supersymmetry scenarios and find that the mechanism works also for
this scenario provided the SUSY scale is at least 2-3 orders below the
GUT-seesaw scale and one has larger values of ${\tan\beta}$.
