The two largest lakes– Chibzhang Co and Dorsoidong Co– have actually grown bigger over time as the mountain glaciers have actually thinned and shrunk. The color distinction between the 2 lakes in the 1987 image was caused by the two lakes being separated by a thin strip of land. The 2 lakes combined into one in the mid-2000s when increasing water levels submerged the strip of land.
Multiple processes affect the size and depth of lakes in this area: the quantity of yearly precipitation, the rate of evaporation, and the amount of overflow from melting glaciers and permafrost throughout summer months. In another project, scientists used Landsat data to compare the number of lakes on the Tibetan Plateau and the area covered by lakes in 1977 versus 2014.
October 12, 1987
October 9, 2021
As temperatures increase on the Tibetan Plateau, lakes are growing larger and deeper.
Glaciologists frequently call the Tibetan Plateau and its numerous range of mountains the ” Third Pole” because the rugged, high-elevation landscapes include the largest reserve of freshwater outside the polar regions. Much of that water is stored in the meantime within tens of thousands of glaciers scattered across the area. However, rising temperature levels, speeding up ice loss, and meltwater runoff are beginning to change that.
These pictures of lakes west of the Tanggula Mountains– a small range in the central part of the Tibetan Plateau– use a view of modifications triggered, in part, by retreating glaciers. The first image was acquired in October 1987; the 2nd image reveals the very same area in October 2021. The 2 largest lakes– Chibzhang Co and Dorsoidong Co– have grown larger in time as the mountain glaciers have thinned and diminished. (Note that a few of the differences in between the images are due to differences in snow cover, however notice in the big downloadable images here and here that the front edge of the glaciers have actually retreated substantially.).
By Adam Voiland. NASA Earth Observatory
October 19, 2021
The color difference in between the two lakes in the 1987 image was triggered by the two lakes being separated by a thin strip of land. Dorsoidong Cos meltwater came from glaciers in mountains to the west; Chibzhang Cos originated from glaciers to the east. Dorsoidong Cos water likely had more suspended sediment on October 12, 1987, making the water appear lighter blue. The 2 lakes merged into one in the mid-2000s when rising water levels submerged the strip of land.
According to one team of scientists who examined decades of Landsat imagery, the location of the lakes grew by 23 percent in between 1976 and 2017. Satellite radar altimetry observations suggest the lakes have actually ended up being much deeper over time. Information from NASAs Global Water Monitor show that the depth of the channel that links the 2 primary lobes of the lake increased by about 8 meters (26 feet) in between the early 1990s and 2021.
Several procedures impact the size and depth of lakes in this area: the amount of yearly precipitation, the rate of evaporation, and the quantity of overflow from melting glaciers and permafrost throughout summertime. Chibzhang Co and Dorsoidong Co are filled by water from both precipitation and melting glaciers, however a group of smaller sized lakes to the southwest (consisting of Khongnam Tso) receive the majority of their water from precipitation. By evaluating years of satellite data for both types of lakes, scientists discovered that water levels were much steadier in the lakes that received water from glacial melting. In truth, about half of the overall increase in the size of Chibzhang Co and Dorsoidong Co seemed driven by glacial melting.
In another task, scientists utilized Landsat information to compare the number of lakes on the Tibetan Plateau and the location covered by lakes in 1977 versus 2014.
NASA Earth Observatory images by Joshua Stevens, utilizing Landsat information from the U.S. Geological Survey.