Investigations of the mass balance of the southeastern Ronne Ice Shelf, Antarctica

Author： Lambrecht A. Mayer C. Oerter H. Nixdorf U.

Publisher： International Glaciological Society

ISSN： 1727-5644

Source： Annals of Glaciology, Vol.29, Iss.1, 1999-06, pp. : 250-254

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Abstract

Data from the Filchner V campaign were used to investigate the mass-balance conditions in the southeastern Ronne Ice Shelf (RIS), Antarctica. Radio-echo sounding and seismic measurements over this area show a maximum ice thickness of >2000 m close to the grounding line of Foundation Ice Stream. The measurements also revealed that the position of this grounding line is 40 km further south than previously thought. New mass-flux calculations result in an estimate of 51 km³ a⁻¹ for the ice-stream transport from the ice sheet into the eastern ice shelf. The Möllereisstrom (MES), west of Foundation Ice Stream, shows a maximum ice thickness of 1100–1200 m in the grounding-line area and a mass flux of 23 km³ a⁻¹.Assuming steady-state conditions, mass-balance calculations based on the new data result in a mean melt rate of about 1 m a⁻¹ at the ice-shelf base for the entire southeastern part of the RIS. The melt rate in the grounding-line area of Foundation Ice Stream exceeds 9 m a⁻¹. In contrast, other ice streams draining into the Filchner–Ronne Ice Shelf show maximum melt rates from 1–2 m a⁻¹ (MES) to 4 m a⁻¹ (Rutford Ice Stream). Our calculations indicate that nearly all of the ice deposited in the drainage area of the eastern RIS on the ice sheet does not reach the ice-shelf front as original meteoric ice, but is melted at the ice-shelf base.