While many of the small glacier- and snowmelt-fed streams on the Plateau give rise to major Southeast Asian rivers (including the Mekong and Yangtze), some empty into saline lakes such as Lake Ayakum. This astronaut photograph highlights two river deltas formed along its southwestern shoreline. Gray to tan surfaces indicate prior positions of the river channels; the uniform coloration and smooth texture suggest that they are relatively old and now inactive. By contrast, the younger and currently active delta surfaces have reddish-brown sediment and visible river channels. (via River Deltas, Lake Ayakum, Tibet : Image of the Day)