From: Editor, ENN
Published October 30, 2013 12:24 PM

Rising Summer Temperatures Threaten Eastern Siberia

The high cliffs of Eastern Siberia, have been eroding at a relatively fast pace which researchers are attributing to rising summer temperatures in the Russian permafrost regions as well as the retreat of the Arctic sea ice.

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In an effort to understand permafrost erosion, researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research have evaluated data and aerial photographs of Eastern Siberia coastal regions for the last 40 years.

The warmer the east Siberian permafrost regions become, the quicker the coast erodes. For example, "if the average temperature rises by 1 degree Celsius in the summer, erosion accelerates by 1.2 metres annually," says AWI geographer Frank Günther.

As erosion occurs and coastal land recedes, waves undermine these shores and cause the land surface to sink. As a result, scientists fear that Muostakh Island, an island east of the Lena Delta may disappear altogether.

For the little island of Muostakh east of the harbour town of Tiksi, this may well mean extinction. "In fewer than one hundred years, the island will break up into several sections, and then it will disappear quickly," predicts Frank Günther. On its northern tip, the island shows fluctuating annual erosion rates between 10 and 20 meters per year, and it has already lost 24 per cent of its area in the past 60 years. Because the subsurface here consists of more than 80 per cent of ice that has formed within the soil, and since the ice is gradually melting, the island’s surface collapses as well. The scientists speak of a 34 per cent loss in volume. "If one bears in mind that it took tens of thousands of years for the island to form through sedimentary deposition, then its disintegration is proceeding at a very rapid pace," says Paul Overduin, AWI permafrost researcher.

In addition, long-term studies conducted by AWI scientists show the impact of coastal erosion for the sea as well. Depending on the kind of erosion and the particular structure of the coast, between 88 and 800 tons of plants, animal, and microorganism-based carbon are currently washed into the sea per year. This has further implications as once in the water, carbon may turn into carbon dioxide and, as a result, contribute to the acidification of the oceans.

Read more about the thawing permafrost at the Alfred Wegener Institute.

Permafrost image via Shutterstock.

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