Ice Shelf Water-Influenced Fast Ice and Sub-Ice Platelet Layer Near the Campbell Ice Tongue, Terra Nova Bay

Abstract

Here, we present the first dedicated in situ measurements of the thickness distributions of fast ice and the sub-ice platelet layer, formed by supercooled Ice Shelf Water in north Terra Nova Bay, Antarctica. With the objective of inferring source regions and circulation of Ice Shelf Water, we measured fast ice and sub-ice platelet layer thickness distributions near the Campbell Ice Tongue in late spring of 2021, using drill hole surveys and high-resolution ground-based electromagnetic induction soundings. We observed thicker fast ice and sub-ice platelet layer near the ice tongue with very thick and narrow sub-ice platelet layer maxima indicating highly channeled outflow of supercooled Ice Shelf Water from beneath the ice tongue directed by ice mélange, subglacial formations, and grounded regions. We conclude that a significant volume of supercooled Ice Shelf Water is locally sourced from the Campbell Ice Tongue through basal melting and affirm that the icescape in north Terra Nova Bay results from a complex interplay of glacial morphology, polynya forcing, and ocean circulation.