Ice shelves play a crucial role in helping controlling the current rate of mass loss from the Antarctic ice sheet through their buttressing potential. This control is modulated by variations in ice shelf mass balance, which cause changes in the thickness of the ice shelf, and therefore in its ability to restrain flow from the grounded ice sheet. We present results showing temporal variability in sub-shelf melting using autonomous phase-sensitive radio-echo sounders (ApRES) near the grounding line of the Roi Baudouin Ice Shelf, Dronning Maud Land, East Antarctica. When combined with additional oceanographic evidence of seasonal variation in stratification and the amplification of the diurnal tides around the Gunnerus Bank, the results suggest an intricate mechanism in which topographic waves control the seasonal melt rate variability near the grounding line of the Roi Baudouin Ice Shelf.