On the tsunami model of the origin of multi-ring basins.

By use of the theory of shallow water waves generated by an impulsive pressure, the tsunami theory of the origin of multi-ring basins is rediscussed and an approximate formula used for calculating the ring location is derived. From the computed ring spacing of three multi-ring basins on the Moon (Orientale, Moscoviense and Serenitatis South), it is shown that the tsunami model can only be applied to the area within the IV ring which signifies the rim of the excavated basin and the end of the fluidized region. In the frame of the tsunami model, no explanation for ring spacing is plausible for exterior rings as well as interior ones.