Actively evolving subglacial conduits and eskers initiate ice shelf channels at an Antarctic grounding line

• DOI: 10.1038/ncomms15228
• Publication Date: 2017-05-09T09:21:41Z
• Authors: R. Drews; F. Pattyn; I. J. Hewitt; F. S. L. Ng; S. Berger; K. Matsuoka; V. Helm; N. Bergeot; L. Favier; N. Neckel
• Keywords: Ice divide; Lead (geology); Iceberg; Fast ice; Antarctic ice sheet

Abstract Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic shelves. Many them originate near the grounding line, but their formation mechanisms remain poorly understood. Here we use ice-penetrating radar data from Roi Baudouin Ice Shelf, East Antarctica, to infer that morphology several ice-shelf is seeded upstream line by large basal obstacles indenting below. We interpret each obstacle as an esker ridge formed sediments deposited subglacial water conduits, and calculate eskers’ size grows towards where deposition rates maximum. Relict features shelf indicate these linked systems conduits have been changing over past few centuries. Because loci intense melting occurs shelf, findings expose a novel link between drainage, sedimentation stability.