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

ABSTRACT: Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic ice shelves. Many of 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 the morphology of several ice-shelf channels is seeded upstream of the grounding line by large basal obstacles indenting the ice from below. We interpret each obstacle as an esker ridge formed from sediments deposited by subglacial water conduits, and calculate that the eskers' size grows towards the grounding line where deposition rates are maximum. Relict features on the shelf indicate that these linked systems of subglacial conduits and ice-shelf channels have been changing over the past few centu

SUBMITTER: Drews R 

PROVIDER: S-EPMC5482720 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature