The weak underbelly of the West Antarctic ice sheet

Does the permanent creep-rate of poly crystalline ice increase with crystal size?Journal rifGlaciology, Vo!. 25, No. 91, p. 151-57. SIR,The weak underbelly of the West Antarctic ice sheet Possible collapse of the West Antarctic ice sheet by surges of Thwaites and Pine Island Glaciers into the Pine I sland Bay polynya of the Amundsen Sea was a subject ad dressed in papers by Lingle and Clark (1979) and Thomas (1979), and in abstracts by Denton and others (1979) and Hughes (1979), that were published in Vo!. 24, No. 90 of the Journal of Glaciology.This concept was first developed in 1975 by George H. Denton and me as part of our CLIMAP responsibilities to reconstruct the maximum Antarctic ice sheet and then to disintegrate the marine West Antarctic portion.Lingle and Clark (1979) have acknowledged us and CLIMAP in this regard, and we are grateful to them.A brief history of the development of the concept that Pine Island Bay may be the weak underb elly of the West Antarctic ice sheet is in order, because the American Society for the Advancement of Science (AAAS) and the United States Department of Energy (DOE) sponsored a workshop at the University of Maine on B-IO April 19Bo to formulate a science plan that would "elucidate the research that might establish once and for all the likelihood and time frame of collapse of the grounded ice" in West Antarctica (David M. Burns, Director of the AAAS/DOE Climate Project, letter of I I October 1979) .CLIMAP (Climate: Long-range Investigations, Mapping, and Pred iction) cond ucted two experiments, reconstructing the maximum ice-age climate IB 000 years ago and the maximum interglaciation climate 125 000 years ago.George H. Denton was the Principal Investigator responsible for provid ing the areas, elevations, and volumes of ice sheets as input boundary cond itions for these two CLIMAP experiments.This work was done at the University of Maine, where I was the Task Group Lead er responsible for numerically reconstructing and disintegrating ice sheets having areal extents specified by Denton.Results of this work are presented in chapter 6 (Hugh es and others, I9BI) and chapter 7 (Stuiver and others, 19B1) of The last great ice sheets.