11 December, 2000

Ice Cores

What could you possibly learn from a piece of ice taken from deep within an Antarctic ice sheet? Actually, these samples of glacial ice, called ice cores, provide scientists with the best information available about the Earth’s past climate.

The continent’s interior receives only a few centimeters of snow each year. Because it doesn’t melt, the snow accumulates year after year, eventually turning into glacial ice. The current ice sheets, which are thousands of meters thick, consist of ice that has built up over hundreds of thousands of years.

The ice retains chemicals, dust, and tiny air bubbles from the atmosphere long ago. By analyzing these clues we gain information about past climates, climate changes, and the causes of those changes. This will allow us to better understand the impact that human activities may have on climate

The ice core obtained at Siple Dome between 1997 and 1999 is just one of many from Antarctica, Greenland, and other locations that are contributing to our understanding of the Earth’s climate system.

The ice core drill rig at Siple Dome. (image credit: G. Lamorey)

Preparing ice cores for transport. (image credit: USGS)

Unpacking a core from Siple Dome at the National Ice Core Laboratory in Denver. (image credit: NICL)

The storage facility at the National Ice Core Laboratory holds 85 cores from Antarctica, Greenland, as well as other locations.