In late May 2008, a large lake continued to occupy a stretch of landslide-dammed river upstream of the small city of Beichuan, Shichuan Province. Landslides caused by the May 12 earthquake dammed a section of river with rocks and mud, and behind the barrier, the waters continued to rise.
This pair of natural-color images from Taiwan’s Formosat-2 satellite shows the lake on May 22 (top) and May 26 (bottom). The differences in color (especially the color of the lake) are probably due to the viewing conditions (viewing angle and time of day) during the satellite overpass, and not to actual changes in water clarity. Compared to a previous series of images that documented the filling of the lake, these images show much less change over the four-day period. The lack of obvious change may be an indication that the diversion channels being dug by Chinese engineers and soldiers had begun to drain the dangerous lake, or that the water had found natural outlets. It is also possible that the lake simply seems to be filling more slowly because of its increasingly large surface area.
On May 12, 2008, an earthquake with an estimated magnitude of 7.9 struck China's Sichuan Province. Aftershocks, some of them larger than magnitude 6.0, continued in the weeks after the quake. Large lakes formed behind landslide-created dams.
Meltwater from glaciers to the east and west drains into Lake Morari, a large lake that lies at an altitude of 4,521 meters (14,830 feet) on the Tibetan Plateau. A stream on the west side provides the lake’s main inflow. Mud from this river gives the light blue hues to the lake water. The well-formed alluvial fan (image center), built by sediment from the main inflow river, is the reason the lake has formed at this point in the valley.