Tibetan Plateau

The Tibetan Plateau, also known as the Qinghai–Tibet or Qingzang Plateau, is a vast elevated region at the intersection of Central, South, and East Asia. It is the world’s largest and highest plateau above sea level, stretching roughly north to south and east to west, with an area of approximately 2,500,000 square kilometers and an average elevation exceeding 5,000 meters. Surrounded by imposing mountain ranges that include the world’s two highest summits, Mount Everest and K2, it is often called the "Roof of the World." The plateau is bordered to the south by the inner Himalayan range, to the north by the Kunlun Mountains (which separate it from the Tarim Basin), and to the northeast by the Qilian Mountains. To the west, the rugged Karakoram range curves around its edge. The plateau contains the headwaters of most major streams in surrounding regions, including the three longest rivers in Asia: the Yellow, Yangtze, and Mekong. Its tens of thousands of glaciers and other features serve as a natural "water tower," storing water and regulating river flow, earning it the nickname "Third Pole" because its ice fields hold the largest reserve of fresh water outside the polar regions. Geologically, the plateau’s formation is tied to the collision of the Indo-Australian and Eurasian plates, which began around 55–50 million years ago. This collision closed the Tethys Ocean, crumpling its light sediments into mountain ranges. The plateau’s mean elevation has varied since its initial uplift; isotopic records indicate it was around 3,000 meters above sea level near the Oligocene–Miocene boundary, then fell by 900 meters between 25.5 and 21.6 million years ago before rising again by 500 to 1,000 meters between 21.6 and 20.4 million years ago. Today, the plateau is a high-altitude arid steppe interspersed with mountain ranges and large brackish lakes. Its southern and eastern edges have grasslands supporting nomadic herdsmen, though frost occurs for six months yearly. To the north and northwest, the plateau becomes higher, colder, and drier, with annual precipitation comparable to a polar desert and extensive permafrost. The remote Changtang region in the northwest averages over 5,000 meters in altitude, with winter temperatures frequently below -30°C, making it unsuitable for permanent settlement except for a few nomadic herders in its southern part.