Ice Age ice

20 Feb 2016

At ... although the paper is presented as part of the global warming discussion, presumably as a requisite to garner funds for further research, the conclusions may also have a catastrophist angle - but only if you think movements at the Poles are a possibility. The jury is out on that one. Mainstream is adamant that it can't be done - but being a trifle irreverent we should always keep an open mind (shouldn't we?)

At the end of the last Ice Age the West Antarctic peninsular was covered in ice and extended much further in the direction of the tip of South America. They have confirmed this as a reality by looking at the isotope beryllium 10 (which forms in the atmosphere) in sea floor sediments. This seems to show that the isotope was absent during the Late Glacial Maximum - which implies it could not fall to the bottom of the sea as it was restricted, in this instance, by an ice sheet. It confirms the reality of ice sheets in spite of some people with a contrary view. Not only that the ice sheet extended much further than it does now, covering the entirety of the Ross Sea (have a look at an atlas to get a proper angle). The Ross Sea a big bay in the Antarctic and this must mean either that mainstream is right and the Ice Age amounted to a bigger by far ice sheet than we have today or that the Poles have moved and the ice sheet covered a slightly different area than it does now. It would also explain temperature differences in Patagonia and in SE Australia.

The paper, published in PNAS (February 2016) dates the changes quite perfectly (in respect to ice core evidence from Greenland). The ice sheet was at its maximum extent prior to 18,000 years ago (the Late Glacial Maximum) but they go on to say that around 10,000 BC an armada of ice bergs was set loose into the Southern Ocean - presumably in order to account for the sudden warming at the end of the Younger Dryas event (9500BC). The news flash actually reads 10,000 years ago but I am assuming this is a mistake for 10,000BC as the ice should have receded long before 8000BC (but may be it didn't)*. 

The research is said to show (analysis of the sea sediment cores) the ice sheet contracted rapidly and fell back hundreds of miles in a step like fashion - what we might expect if the Poles had moved position, coming to a temporary halt near some shallow banks (where the ice remained anchored to the bottom for some time) but elsewhere an ice shelf developed (water under the ice). This situation existed for around 5000 years which if the 10,000 years ago figure is correct means from 8000 to 13,000 years ago (and the latter date is associated with the Younger Dryas event when ice sheets may have reformed to some extent).

* However, if the 5000 years is from 10,000 to 15,000BC we have a coincidence worth mentioning. At 15,000BC the Oldest Dryas event came to an end followed by a warming (the Bolling period). At the end of this there was a shorter cooling known as the Older Dryas event and this was followed by another warming, the Alleroed (which in Europe is the warm phase prior to the onset of the Younger Dryas cooling event). So, a rather up and down period that might well suit the 5000 years as witnessed in the sea floor sediments.

Another break up of ice is dated to around 3000BC, which again is another interesting date as it follows a cooling episode (possibly lasting a couple of hundred years) where we know that glaciers in the Andes and the Alps grew rapidly over a short period of time (encasing the body of Oetzi in the process). So, what might have caused the ice to break up at that time - the warming, or the event that caused the cooling? Intriguing.