Fig. 8: Schematic representation of channelized ice shelf—ocean boundary currents.

The upper panel shows a comparison of critical physical processes underneath deep (left) and shallow (right) basal channels. Shallow channels have little influence on the properties of the across-channel glacially modified water (GMW) flow, with little GMW recirculated along the western flank of the channel. In contrast, the stratification and hydrodynamics are significantly changed in deep channels by four critical processes, as illustrated, leading to the enhancement of basal melt and meltwater channeling. The colored arrows transitioning from blue to pink denote the transformation of GMW to warmer and saltier intermediate GMW and vice versa. The lower panel illustrates the surfacing of warm channelized GMW, leading to the formation of coastal sensible-heat polynyas by melting fast ice adjacent to an ice shelf with a wealth of implications for the multidisciplinary Antarctic oceanography. Not to scale.