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The Millennia After Tomorrow?
frankthechicken writes "Analysis of a three-kilometer-long ice core drilled from the Antarctic, has revealed our planet has had eight ice ages during that period, punctuated by rather brief warm spells - one of which we enjoy today. And fortunately, the end of the world is not the day after tomorrow, instead it may be expected on Sunday, 17000."
It's interesting that the last 100m of ice should be so difficult. I wonder if there are any additional complications from waiting until November to finish the drilling... At that depth, they say the ice is just above the melting point from geothermal heat, so I'm assuming that it is somewhat plastic and under huge pressure from the 3km of ice above it. I wonder if they had to take precautions against pressure closing the hole before they finish drilling?
Very impressive, anyway. I hope they manage to complete the ice core this time. It's amazing to think of how long that ice has been there, untouched.
Not as far as I know. The ice is sitting on bedrock, and that's not going anywhere. I don't think that the hole moves significantly in the course of a year anyway.
Even if it did move, as long as you have the correct depth you should still get the same general results. Although, we have seen some slight differences in heavy metal levels from site to site (there are things like mountains which obstruct air flow). This is one of the reasons that there are a number of sites being analysed - so that we can compare the results.
You probably want to keep in mind that the ice sheet has been there for roughly a million years (maybe a bit less). Over the bedrock, the only significant event affecting the ice is the depositing of snow every year, which becomes compacted, becomes firn (really dense snow) and then ice. From year to year this is insignicant, but over hundreds of thousands of year you build up an ice sheet with a climatic record preserved in it.