Figure 1 Scientists measure ice cores from deep drilling sites on the ice sheet near Casey station Photo by M. Antarctica is the coldest, windiest, highest and driest continent on Earth. That's right - the driest! Antarctica is a desert. The annual precipitation of snow, averaged across the continent, is about 30 centimetres, which is equivalent to about 10 centimetres of water. In some locations as little as 2 centimetres water equivalent is recorded.
UCAR E&O - Randy Russell - Ice Core Climate Proxies
Detailed information on air temperature and CO2 levels is trapped in these specimens. Current polar records show an intimate connection between atmospheric carbon dioxide and temperature in the natural world. In essence, when one goes up, the other one follows. There is, however, still a degree of uncertainty about which came first—a spike in temperature or CO2. The data, covering the end of the last ice age, between 20, and 10, years ago, show that CO2 levels could have lagged behind rising global temperatures by as much as 1, years.
How do ice cores allow researchers to see climate change?
Snow that is compressed into ice forms distinct layers. Ice that is old, such as glaciers and polar ice caps, contain thousands of layers. These layers in ice sheets can be read like the pages of a book — if you know the language. In this video, we see how scientists are deciphering the history of Earth's climate by analysing ice cores taken from western Antarctica.
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers for shallow holes or powered drills; they can reach depths of over two miles 3. The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core.