The thawing and erosion of Arctic permafrost coasts has dramatically increased in the past years and the sea is now consuming more than 20 meters of land per year at some locations. The earth masses removed in this process increasingly blur the shallow water areas and release nutrients and pollutants. Yet, the consequences of these processes on life in the coastal zone and on traditional fishing grounds are virtually unknown. Scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, urge to focus our attention on the ecological consequences of coastal erosion in the January issue of the journal Nature Climate Change. According to the scientists, an interdisciplinary research program is required, and must involve policy-makers as well as inhabitants of the Arctic coasts right from the onset.
The difference could hardly be greater. In the winter, when the Beaufort Sea is frozen around the Canadian permafrost island of Herschel Island (Qikiqtaruk), the sea water in the sample bottles of the AWI researcher Dr. Michael Fritz looks crystal clear. In summer, however, when the ice floes are melted and the sun and waves start to wear the cliff away, the water sample of the Potsdam geoscientist contains a cloudy broth.
“Herschel Island loses up to 22 meters of coast each year. The thawed permafrost slides down into the sea in the form of mud slides and blurs the surrounding shallow water areas so much that the brownish-grey sediment plumes reach many kilometres into the sea”, reports the polar researcher.
His observations of Herschel Island can now be transferred to large parts of the Arctic. 34 percent of the coasts around the world are permafrost coasts. This means, especially in the Arctic, that its soil contains a large amount of frozen water, which keeps the sediments together like cement. If the permafrost thaws, the binding effect fails. The sediments as well as animal and plant remains, which are frozen in the permafrost, are suddenly released in the water and are washed away by the waves.
Read more at Alfred-Wegener-Institut
Photo credit: Ansgar Walk via Wikimedia Commons
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