Sir, On the regime of the western part of the Ross Ice Shelf drainage system
Reference BauerBauer (1967) does not understand our paper (Reference GiovinettoGiovinetto and others, 1966). The only assumption that we make in delineating the ice-drainage divide is that ice flows in the direction of the ice-surface slope.
Bauer is wrong in implying that our estimated error is a claim of “precision” in the estimate of the net mass budget. An estimated error is simply an attempt to quantify the word “approximately”, which now and for years to come must precede net-budget estimates of large features such as ice sheets. If no error is stated and there is a conclusion about the net budget, the reader is led to believe that the error in the estimate is not greater than one-third of the net budget. For example, a statement such as “the nett balance of the [Greenland] ice cap is negative and about 100 km3 of water per year” (Reference BauerBauer, 1955) implies that the error in the estimate is not greater than ±33 km3 year−1. We doubt if Bauer could substantiate such “precision”. We certainly do not claim it for our own figures.
M. B. Giovinetto
Department of Geography, University of California, Berkeley, California 94720, U.S.A.
E. S. Robinson
Department of Geology, Virginia Polytechnic Institute, Blacksburg, Virginia 24061, U.S.A.
C. W. M. Swithinbank
Scott Polar Research Institute, Lensfield Road, Cambridge, England 27 May 1968
