How glaciers shape the Earth's surface?
Presently, 10 percent of land area on Earth is covered with glacial ice, including glaciers, ice caps, and the ice sheets of Greenland and Antarctica. Glacierized areas cover over 15 million square kilometers. As the glaciers move, friction causes the bottom of the glacier to melt. This this water freezes into joints in the rock. When the glacier moves again the rock is pulled away or ‘plucked’ from the base of the valley. Rock pieces that have been plucked away and carried by the glacier act like sandpaper scraping away at the valley bottom and sides. Glacial processes create different lanforms that will be presented during this lecture.