By drilling through that ice, and recovering cylinders of it, it is possible to reconstruct records of temperature and of atmospheric gases for periods of hundreds of thousands of years.
Technologically the recovery of ice cores and their analysis is an amazing feat.
From top to bottom: * Levels of carbon dioxide (CO2). High rates of snow accumulation provide excellent time resolution, and bubbles in the ice core preserve actual samples of the world’s ancient atmosphere.
By looking at past concentrations of greenhouse gasses in layers in ice cores, scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past, and, essentially, compare past concentrations of greenhouse gasses to temperature. Ice cores have been drilled in ice sheets worldwide, but notably in Greenland and Antarctica[4, 5].
Indeed, dating information is sometimes given for the “ice age” and “gas age”.
Secondly, to analyse the content of the air bubbles, and determine not only the proportion of different gases but also the proportion of specific isotopes of those gases is also technologically challenging.Climatic instability observed in the core part believed to date from the Eemian interglacial has not been confirmed by other climate records.In the first drilling season in 1990, the drill reached a depth of 770m where the ice is 3840 years old.To restore access and understand how to better interact with our site to avoid this in the future, please have your system administrator contact [email protected] cores are one of the most effective, though not the only, methods of recreating long term records of temperature and atmospheric gases.Whilst ice cores allow direct measurement of atmospheric gases, like CO2 and Methane, some care is needed in interpreting the results.