The geology of the Himalaya is a record of the most dramatic and visible creations of modern plate tectonic forces. The Himalayas, which stretch over 2400 km between the Namcha Barwa syntaxis in Tibet and the Nanga Parbat syntaxis in Pakistan, are the result of an ongoing orogeny — the result of a collision of the continental crust of two tectonic plates. This immense mountain range was formed by tectonic forces and sculpted by weathering and erosion. The Himalaya-Tibet region supplies fresh water for more than one-fifth of the world population, and accounts for a quarter of the global sedimentary budget. Topographically, the belt has many superlatives: the highest rate of uplift (nearly 10 mm/year at Nanga Parbat), the highest relief (8848 m at Mt. Everest Chomolangma), among the highest erosion rates at 2-12 mm/yr, the source of some of the greatest rivers and the highest concentration of glaciers outside of the polar regions. This last feature earned the Himalaya its name, originating from the Sanskrit for the abode of the snow.