When flying from the Dry Valleys across the Transantarctic Mountains towards the Polar Ice Plateau, the thickness of the ice cover constantly increases until - like on this picture - only the mountain peaks stick out of the ice shield. This peak still has a height of several hundred metres above the ice. In the background of the picture, less and less peaks stick out of the ice, followed by the Polar Plateau, which covers the whole continent with ice like a gigantic dome. At its highest part it is more than 4 km thick. Because the annual ice build-up is only about 2 cm in average, the ice of the Polar Plateau is sometimes several 100,000 years old. This is one of the reasons why this block of ice is so precious for mankind: information about the former climate of earth is frozen in it, like the rings in a tree trunk. If we know how the climate used to be in former times, we can possibly answer the question whether today's climate is changed by man, or whether such climate changes happened before - as a random event of nature.