Isostasy with Love: II Airy compensation arising from viscoelastic relaxation

SUMMARY In modern geodynamics, isostasy can be viewed either as the static equilibrium of crust that minimizes deviatoric stresses, or a dynamic process resulting from viscous relaxation non-hydrostatic crustal shape. Paper I gave general formulation Airy an elastic loading problem solved with Love numbers, and applied it to case minimum stress isostasy. this sequel, same framework is used study long-time evolution viscoelastic shell submitted surface internal loads. Isostatic ratios are defined in terms time-dependent numbers. Dynamic depends on history, two examples which constant load far past shape maintained by addition removal material at compensation depth. The former model results decreasing exponentially time has no analogue, whereas latter (stationary) equivalent form Viscoelastic approaches completely equivalent. If both vary slowly time, isostatic look like those stationary model. models thus belong independent groups: elastic/stationary approaches. homogeneous, all predict similar large-scale gravity perturbations. rheology depth, more long wavelengths, result negligible compensation. Mathematica Fortran codes available for computing incompressible body three homogeneous layers.