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St. Petersburg scientists explain why water retreats from lake on Severnaya Zemlya

The pushed glacier eventually opened an under-ice channel and many tunnels, through which the lake water rushed out into the sea fjord

ST. PETERSBURG, March 23. /TASS/. Experts of the Arctic and Antarctic Research Institute (AARI) in St. Petersburg found how to explain the phenomenon of Lake Spartakovskoye, which is located on the Severnaya Zemlya Archipelago's second largest island - the Bolshevik. Every decade the lake may lose up to 250 million cubic meters of water to return gradually afterwards to the initial condition, the institute's press service told reporters on Wednesday.

"AARI scientists have found the reason why the by-glacier Spartakovskoye Lake on the Bolshevik Island of the Novaya Zemlya Archipelago regularly releases water," the press service said. "Every eight - ten years, within a few days the lake may lose up to 250 million cubic meters of water."

The lake, located on an Arctic archipelago, depends absolutely on ice processes and climate change. The lake is 5 km long. To the west from it lies an effluent glacier, which separates the lake from the Spartak fjord of the Bolshevik Island.

Scientists have noted earlier the changing water levels in the lake. However, in 2021, they registered almost a complete retreat of water from it, which has never happened earlier. Prior to this discovery, AARI's scientists have installed cameras, which recorded the water retreat process. The big late released water within just 117 hours. The water speed at times reached 2,000 cubic meters per second, which is comparable to the Neva River's effluence.

Water retreat reasons

The scientists say the lake accumulates water in summer when the Semenov-Tyan-Shansky and Wojciechowski glaciers are melting. The water accumulation in the lake bath is not a uniform process, since it depends greatly on summer temperatures.

After several warm seasons, water in the lake reaches its maximum level, and thus the glacier, separating Spartak from the fjord, being pushed by the water force, begins to float. While being pushed out, the glacier collapses into many fragments, comparable in size with a city house, and those icebergs float across the lake.

The pushed glacier eventually opened an under-ice channel and many tunnels, through which the lake water rushed out into the sea fjord. As the water level drops, many channels get closed again, in winter the water in those channels freezes up, and for a few years the lake remains waiting for the next critical water level in the dammed reservoir.

Threat of extinction

Scientists of the Arctic and Antarctic Research Institute fear that due to such high fluctuations in the water level, and taking into account the full descent of the lake in 2021, it is highly probable that soon Lake Spartak may disappear due to climate warming.

This process affects many by-glacier lakes since effluence glaciers tend to disappear, opening the way for lake waters towards the sea fjords where they get mixed with sea water.

However, the scientists say that based on the ancient climate studies on Novaya Zemlya, even if Lake Spartak eventually disappears, after many millenniums it may reappear due to new climate changes and new glaciation processes in the Arctic in the distant future.