Ice Age Anomalies

17 Feb 2010

Science News February 11th ... coastal caves on the Ballearic Islands just off the coast of Spain (including Majorca) have produced some very surprising evidence of sea level rise and fall during the last Ice Age, a finding that might cast some doubt on just how long such cold spells may actually last, develop, and remain. The theory is that during the Ice Ages immense volumes of water are locked up in land based ice sheets. In that situation sea levels would fall, revealing large areas of what is now the submerged coastal shelf system. It is thought they might be as much as 130m below present sea level which scientists suggest is what they have found on the ground. However, if the last Ice Age, for example, was simply a rearrangement of the northern polar ice cap, sea levels should not have fallen quite so dramatically. However, genuine research of Pleistocene sea levels is hampered by the fact that for the polar ice cap to move the geoid itself would be forced to rearrange itself - which would have included the oceans finding a new equilibrium that would be manifested by large swings in sea level. Anyway, returning to the research, some surprising results emerged (published in the journal Science on February 12th 2010) as evidence was found that sea levels rose and fell, the water sloshing into the caves on the Ballearics or leaving them high and stranded above the tide, within the last 100,000 years. In the Milankovitch Theory as favoured by science consensus at the moment, Ice Age cycles last a full 100,000 years - during which time the ice sheets grow and extend over a very large area, sometimes shrinking back from their extremities but in general the period is simply very cold and inhospitable. It is envisaged that there was a whole series of these 100,000 year cycles, a feature that gells remarkably well with uniformitarian ideas. Therefore, received wisdom is that 110,000-10,000 years ago = the last cold glacial phase, which ties in with evidence that between 121,000-116,000 years ago the global temperature was warm and sea levels were 2.6m higher than today. That level is thought to be consistent with sea level data obtained from elsewhere at other sites around the world. However, what brought the present study up with a jolt was the discovery that around 81,000 years ago sea levels in southern Europe were higher than they are today - well into the cold glacial cycle. Other palaeo-climatologists are currently sceptical of the results and accuse the researchers of bad practise. They refute this as they expected such a response and this made them check their facts thoroughly. However, the fact is that at the moment this information is indigestible to a lot of geologists - it does not conform to the uniformitarian and Milankovitch model. The findings are likely to be 'politely ignored' but obviously if further research confirms the finding we may see a more pronounced study of Pleistocene sea levels that may turn up a bad smell as far as uniformitarianism is concerned. The figures appear to be this - 85,000 years ago sea level was 20m below present, between 82 and 80,000 years ago it rose to 1.25 - 1.6m above present levels, but by 79,000 years ago it had fallen somewhat once again. The question is why?