= Solution
After removing orbital, topographic and atmospheric contributions, an earthquake <InSAR> <radar interferogram> would show elongated displacement lobes and generally closed or nested fringes associated with uplift and horizontal shortening of the <hanging wall>. Each full phase cycle represents $\lambda_r/2$ of <line-of-sight displacement>, where $\lambda_r$ is radar <wavelength>; equivalently $\Delta\phi=\pm4\pi d_{\mathrm{LOS}}/\lambda_r$, with sign fixed by processing convention.<Interferometry by NASA>[Phase differencing, nuisance contributions and half-wavelength displacement per fringe]{ref}
If primary slip reaches the surface, expect a displacement discontinuity across the surface trace: fringes can terminate or change abruptly there, and large near-fault gradients or disturbed ground may decorrelate. For a <blind reverse fault>, the elastic displacement field is continuous at the ground surface and spread over a broader zone, giving smoother gradients and fringes over the uplifted <fold>. A blind rupture can still create sharp local gradients or secondary faulting.
\b[The exact colour order, number of fringes and sign of the displacement lobes cannot be fixed from this shaded relief alone.] They depend on slip, depth and radar look direction; uplift is only one contribution to <line-of-sight displacement>.
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