Ice cores have provided climate and ice dynamics information over many hundred thousand years in very high, sometimes seasonal, resolution.Ice core records provide the most direct and detailed way to investigate past climate and atmospheric conditions.
While there I had the opportunity to talk to a team of scientists who were loading supplies in order to head back out onto the cap. They said that they were working in an area where the ice was about 9,000 ft. I mentioned that I was amazed that the ice went up that far.
He said that it didn't but that the weight of the ice actually depressed the land. At any rate, he talked about the seasonal layers in the ice.
Scientists are learning much about Earth's past by drilling deep into its surface-both ice and rock-with specialized instruments to remove long cylinders, or "core" samples.
Six deep ice cores and one sediment core now provide a clear and continuous record of Earth's history.
Layers in ice cores correspond to years and seasons, with the youngest ice at the top and the oldest ice at the bottom of the core.