Marine Ice Modification of Fringing Ice Shelf Flow

Abstract

Locally derived ice is often observed to fill through-cutting rifts and uneven fronts in ice shelves. That ice may nucleate as fast ice at the shelf front, by growth at the sea surface within rifts, or by basal accretion. Here, we investigate the role of such ice in the flow of the Brunt Ice Shelf and adjacent Stancomb-Wills ice tongue, along the Caird Coast of Antarctica. Much of the shelf system is severely rifted, with locally derived ice filling the space between rift walls and around ice rafts. A series of numerical experiments that account for thermal properties of the different ices is used to investigate the influence of that mixture of sea and marine ice on the kinematics and dynamics of the shelf system. The simulations are constrained by a variety of satellite remote-sensing data. We find that the locally derived ice forms a dynamic connection between the ice tongue and the Caird Coast, effectively creating an embayment where no coastal embayment exists. This may have implications for the expansion of ice shelves along arctic coasts during past glaciations.