Petascale computing and future breakthroughs in global seismology

Will the advent of “petascale” computers be relevant to research in global seismic tomography? We illustrate here in detail
two possible consequences of the expected leap in computing capability. First, being able to identify larger sets of differently
regularized/parameterized solutions in shorter times will allow to evaluate their relative quality by more accurate statistical criteria
than in the past. Second, it will become possible to compile large databases of sensitivity kernels, and update them efficiently
in a non-linear inversion while iterating towards an optimal solution. We quantify the expected computational cost of the above
endeavors, as a function of model resolution, and of the highest considered seismic-wave frequency.