Аннотация:Scientific interest in glaciers and glaciation dates back at least 200 years, but the knowledge explosion of the past 20 years has been truly breathtaking. Milutin Milankovitch's once unpopular belief that periodic variations of Earth's orbit regulate the timing of the glacial cycle is now embraced as mainstream orthodoxy. The detailed record of Ice Age climate preserved within the Greenland and Antarctic ice sheets is slowly being decoded and completely upsets the comfortable assumption that extreme climate change necessarily proceeds at a slow pace. Hoary discussion of the processes of glacial erosion and sedimentation has been replaced by serious attempts to observe the mechanical and hydrological processes active beneath mountain glaciers and polar ice streams.