Glacial rill, Greenland

Root glaciers can be simple trickles of water or real rivers on all types of glaciers. The largest can be found on ice sheets and ice caps. While the ice floe floats on the sea, the ice sheet is a continental ice cap that rests on a land base. In Greenland, the almost 2 200 000 km2 ice cap can be over 3 000 m thick. The ice sheets are relics of the main ice ages that took place on our planet and shaped it. They contain part of the Earth's memory trapped beneath billions of tons of ice : the deepest layers are indeed over 250 000 years old. None of the 57 000 of the island's inhabitants live on the ice cap. Towns and villages are on the rocky coast covered by a little vegetation, tundra, which grows as soon as the ice melts. Greenlanders were under Danish hegemony for almost 300 years but in November 2008, 75.5% of them voted for their territory's autonomy. According to American scientific estimations, the region contains significant oil reserves and global warming could make prospecting and exploiting mineral wealth easier. The subsoil, future economic pillar of an independent Greenland, will inevitably be coveted by great powers in years to come.