The Drainage Systems of Antarctica: Accumulation
- Malcolm Mellor
Published Online: 14 MAR 2013
Copyright © 1971 by the American Geophysical Union.
Antarctic Snow and Ice Studies
How to Cite
Giovinetto, M. B. (1971) The Drainage Systems of Antarctica: Accumulation, in Antarctic Snow and Ice Studies (ed M. Mellor), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR002p0127
- Published Online: 14 MAR 2013
- Published Print: 1 JAN 1971
Print ISBN: 9780875901169
Online ISBN: 9781118669808
- Accumulation surface;
- Drainage systems;
- Mass budget;
- Temporal and areal variability
Antarctica, excluding the region of the Antarctic Peninsula but including the ice shelves, has been divided into ten drainage systems to facilitate studies of the mass budget. The main part of the study pertains to accumulation terms; ablation terms will be studied in future reports. Using data from 336 locations, the mean net accumulation at the surface is estimated at 15±3 g cm−2 yr−1; the estimates for particular systems vary between 8±2 g cm−2 yr−1 and 52±11 g cm−2 yr−1. Mass input for Antarctica as a whole is estimated at (2100±400)×1015 g yr−1. The emphasis here is on errors in these estimates. The error in the estimate of net accumulation is examined as a composite error, including the error in the determination of the rate of accumulation at single locations, the error due to different interpretations of given sets of data used in compiling accumulation charts (data interpolation arid extrapolation), and the error in computation of data that are not simultaneous for all locations. Data from stratigraphic sections and stake networks at 24 locations are used to estimate that the local areal variability of net accumulation is approximately 3 g cm−2 yr−1 and that the local temporal variability is approximately 25 per cent. The error in the estimation of mass input indicates that studies of the mass budget in six systems, or 70 per cent of the area of Antarctica, would be promising at present, because in these systems the rate of mass input can be estimated with errors smaller than 30 per cent. The relationship between mass input and the mass of the ice body in each system indicates that in four systems and in part of a fifth the flow behavior can be considered as a model for the whole ice sheet; one system is relatively sluggish and the remaining are relatively active. Incidental conclusions are drawn concerning the area (65,000 km2) and distribution of the zones of net ablation (four segments extending along the coast between 40° and 135°E), the mean ice thickness (1700±300 m), the ice mass [(21±4)×1021 g], and the accretion history of the ice sheet. It is suggested that a former ice cap, centered at 76°S, 125°W, was the last important accretion to the ice sheet.