Lake Puma Yumco, located on the Tibetan Plateau, is one of the most remote lakes in the world. The lake is 32 km long and 13 km wide and is situated at an altitude of 5,030 meters above sea level. The lake is fed by melting water from the snow-capped surrounding mountains, but it has no outlet. Despite this, the nutrient concentrations in both the water column and lake sediments are extremely low, a condition known as UltraOligotrophy. Water in such lakes tends to be blue to blue-green and to have high clarity due to low levels of photosynthesizing organisms such as phytoplankton. The lake appears bright blue when viewed from above the earth. Indeed, the name Puma Yumco literally means “The Blue Jewel which is floating in the sky”.
Photograph of Lake Puma Yumco in winter taken on January 6, 2006 from the ISS. Photo credit: NASA
The most striking feature of the lake is the intricate ice block pattern the develop on the lake surface during winter. The ice pattern is caused by repeated cycles of freezing, fracturing, and refreezing of the ice due to variations in temperature and wind-induced ice motion. Usually, when lakes freeze over, they tend to develop a thick crust of uniform ice, which only breaks apart when the warmer season comes. But, in order for that to happen, environmental conditions must remain steady for at least a short while, allowing the ice to establish itself. When this does not happen, only superficial layers of water freeze over, while the others do not. Slight variations in ambient temperatures can then break some of the ice apart, rearranging it into new patterns. When temperatures drop by a few degrees, the ice solidifies again.
Photo credit: NASA
Photo credit: NASA
Sources: NASA / Wikipedia / Softpedia News
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