ABSTRACT

Ice sheets are vast ice bodies reaching several kilometers in thickness and stretching over areas thousands of kilometers wide. Although they appear stable and static, ice sheets like living creatures are in a perpetual motion and respond strongly to changes in their immediate environment. These rapidly growing and disintegrating icy mountains not only act as important controls over atmospheric mass transport, global sea level and ocean circulation, but also cause significant undulations of the Earth's surface and tilts in its rotation axis. Ice sheets are therefore often perceived as the connecting elements between atmosphere, ocean and solid Earth.

It has long been recognized that internal layers of the Greenland and Antarctic ice sheets contain highquality uninterrupted records of past climate conditions spanning entire glacial-interglacial cycles. Not until recently however were measurements from ice cores used to look even further back into the history and to recover events that predated the onset of large-scale glaciations by tens of millions of years. Also the imprints of now extinct ice sheets transmit numerous messages from the past, bringing to a close long-standing debates about the strength of the Atlantic meridional overturning circulation and ice-free conditions in Beringia at the culmination of the last glacial period. Each ice sheet tells its own story, and in this talk I will combine observations, geological evidence, paleoclimate proxy data and numerical models to reveal some of the secrets that ice sheets conceal.