The GCR at t = 1 Myr for a 15 M_⊕ core as a function of distance from the star, assuming the core starts accreting at t₀ = 0.1 Myr. Here we vary the height z_ϵ from which gas is accreted by the planet. A GCR of 0.48 is marked with a dashed gray line, indicating the threshold for the onset of runaway gas accretion (Lee et al. 2014). The water-ice line is marked with blue triangles.