Geometry of bifurcation sets of generic unfoldings of corank two functions

We study the geometry of bifurcation sets generic unfoldings $$D_4^\pm $$ -functions. Taking blow-ups, we show each -functions admits a parametrization as surface in $${\varvec{R}}^3$$ . Using this parametrization, investigate behavior Gaussian curvature and principal curvatures. Furthermore, number ridge curves subparabolic near their singular point.