Oliver Marsh
Ice dynamics and mass-balance near the grounding zone of outlet glaciers in the Transantarctic Mountain
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Oliver Marsh, Gateway Antarctica
Supervisors:
Wolfgang Rack, Gateway Antarctica, University of Canterbury
Wendy Lawson, Department of Geography, University of Canterbury
Andrew Mackintosh, School of Geography, Victoria University Wellington
Grounding zones of ice sheets are key locations for studying ice dynamics and glacier mass-balance due to their position at the junction of relatively stable grounded-ice and unstable, easily disturbed floating ice. Understanding grounding zone structure and spatial and temporal variation in position is vital to understanding how changes in the cryosphere are linked to changes in global ocean circulation.
The aim of this PhD research is to combine a range of remote sensing techniques with finite-element modelling to characterize the grounding zone of the outlet glaciers in the Ross Sea section of the Transantarctic Mountains. The presence of a series of floating ice tongues of different lengths and shapes, as well as marine terminating glaciers without ice tongues and outlet glaciers terminating in the Ross Ice Shelf makes this region particularly interesting for an in depth analysis of the relationship between floating and grounded ice, especially concerning how location and configuration of the glaciers play a part in their dynamic variability.
Satellite data which has previously been interpreted in other areas independently will be synthesized and combined with ground-based measurements of ice movement to produce a finite-element model of ice dynamics. This data will provide accurate information on grounding line position, ice thickness, surface velocity and ice flux for glaciers in the Transantarctic Mountains, allowing current rates of basal melting and vulnerability of the grounding zone to perturbations in boundary conditions (i.e. ocean temperature, ice flux from upstream) to be estimated.