Giant fjords beneath Antarctica

Thiss story can be seen at www.sciencedaily.com/releases/2011/06/110601134253.htm and is based on a paper in Nature just out. It is also featured, with comments, at http://wattsupwiththat.com/2011/06/01/radar-mapping-reveals-ancient-anta… which indicates the manner of the research, radar mapping that is able to penetrate thick ice to look at what lies underneath. What they have been looking at is a subglacial basin buried under eastern Antarctica amd this basin, larger than Texas (and therefore larger than Yorkshire) is cut by fjords. One interesting thing to emerge – the Antarctic ice sheet was significantly smaller in the past. In fact, it has grown and it has shrunk on a number of occasions. This is assumed to have caused rises in  global sea levels so it is unclear if the modelling involved assumed a melting of Antarctica  was necessary to achieve higher sea levels elsewhere or the other way round. It is difficult to see how they might have observed shrinkage prior to this study – or even coincidental with this study. Modelling appears to be what is involved in the conclusions so assumptions have been made – basically that higher sea levels equals less ice near the Poles. The mapping reveals large channels cut through  mountain ranges by ancient glaciers that mark the edge of the ice sheet at different times in prehistory – sometimes hundreds of miles from the current edge of the ice. To account for shrinkage it is assumed, in addition, the world at times was much warmer than it is now – and it is here the obligatory mention of AGW makes an entry. What it fails to mention is that a change in the axis of rotation could equally account for higher sea levels, and a smaller ice cap. Only the consensus opinion is given an airing – anything different from the 'we know best' attitude is ignored. That is not to say the world was not warmer in the past – just that such an interpretation is just too orthodox for the palate of everyone.