“Something happened about 900,000 years ago,” says Dr Catherine Ritz from the Institute of Environmental Geosciences in Grenoble, France. “The ice age cycles changed from every 40,000 years or so, to every 100,000 years; and we don’t know why,” A European consortium plans to extract the oldest Antarctic ice core ever starting soon to find out.
The Oldest Antarctic Ice Core will be 1.8 Miles Long
“And it’s rather important,” Dr Ritz continued, speaking at the European Geosciences Union General Assembly. “That’s because we want to forecast what will happen to the climate in future with the increase in greenhouse gases.” We will have to use models, and we will calibrate them based on what happened in the past.”
Fourteen nations from ten countries will join forces for the project to drill the oldest Antarctic ice core. They estimate five years to extract the 1.8 mile (3.0 kilometer) core and another year to complete their analysis of their 1.5 million year snapshot of time. They hope to learn what caused the ice age cycles to flip in frequency in ages past.
What Information Will the Scientists Glean from Their Sample?
Antarctic ice comprises innumerable snowfalls over countless years. As these compress they capture bubbles of air. They are therefore samples of the atmosphere at those existential moments in time. The European scientists know how to read the levels of carbon dioxide and other greenhouse gases in them.
The molecules in the ice holding these bubbles will also reveal the prevailing temperatures. The scientists will then be able to draw a time map of this information across 1.5 million years. This data will include the period when the ice ages flipped 900,000 years ago.
An earlier, 800,000-year core drilled between 1996 and 2004 at the same spot revealed a ‘lock-step’ climate relationship. During past ice ages the greenhouse gases declined. When earth warmed the concentrations increased again. What will the oldest Antarctic ice core ever reveal as we go back further into time?
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