Click on image for larger annotated version
This image captures the beauty of a major alluvial fan in Tsinghai, a
province of China. Tsinghai is located in Northwestern China and its lands
are characterized by the high elevation of the Tibetan Plateau. The
average elevation is 13,000 ft (4,000 m), but the region visible in the
picture is in the Tsaidam Basin, a low-lying area whose lowest point is at
an elevation of 8,700 ft. When a highland river flows into an area with a
lower elevation, the river's flow causes erosion of sediments from the
higher area to the lower area. As this process continues, sediments of
earth are deposited in the lower area and a fan-shaped deposit of
sediments is formed, with the smallest part of the fan at the
high-elevation river inlet. The resulting geographical feature is called
an alluvial fan. Here, the inlet river Xi Taijnar He has formed an
alluvial fan as its waters flow north into a lower elevation. The build-up
of sediment deposits has caused the river to split into several segments
that fan out to the northwest and northeast. This splitting up of the
river has led to the formation of two major lakes at the edges of the
alluvial fan: Xi Taijnar Hu, and Dong Taijnar Hu. Up until the 1940's, the
Tsaidam basin was home only to a small assemblage of farmers living in
rural areas. Since World War II, however, mines have been founded
throughout the region to take advantage of its rich mineral deposits of
salt, potash and boron.
Photojournal note:
EarthKam was formerly known as KidSat. To see images of KidSat, see
http://photojournal.jpl.nasa.gov/mission/KidSat .
