In northwest China, the Taklimakan Desert fills the Tarim Basin—a bowl of land ringed by the Kunlun Mountains to the southwest, the Tibet Plateau to the southeast, and the Tien Shan Mountains to the north. The basin is located almost as far from the ocean as any point on Earth, and the mountains block nearly all of the two principal sources of moisture to the region: the Asian Monsoon and Arctic storms. The heart of the desert gets less than 10 millimeters of rain a year.
At the margins, streams run out of the mountains and are augmented by freshwater springs in the foothills. These rivers fan out as they flow toward the center of the basin. In this image, those oases appear deep greenish-brown in the west and southwest of the desert, while a river of rippling dust blows across the northern part of the desert and out of sight at image right. Frequent dust storms in April and May can blanket the whole region for days at a time, sometimes blocking out the sun. The dust storms can spread for hundreds, even thousands, of kilometers, and are a health and safety problem for people in their path.
The sea of sand and salt stretches over roughly 259,000 square kilometers (about 100,000 square miles), and as much as 85 percent of it consists of enormous, shifting, crescent-shaped sand dunes that often reach heights of 100-300 meters and widths of more than a kilometer. Some of these dunes make light-colored ripples against the deeper color of the desert to the east of the small river in the bottom center of the basin (see high-resolution image).