Washing Away The Arctic Coastline

April 19, 2011

Andrew Prince

Michael Fritz
A scientist stands in front of an ice-rich permafrost exposure in the coastal zone of Herschel Island, Yukon Territory, Canada. Ice in the permafrost is melting, contributing to rapid erosion.
Hugues Lantuit
Large slumps of coastal land are caused by the thawing and erosion of ice-rich permafrost. As a result, large quantities of sediment are introduced into the coastal ecosystem, which alters the food web.

Two-thirds of the Arctic coastline is made of permafrost — an environment that is very sensitive to warming temperatures. A new report says erosion is causing these coastline regions to recede by an average of 1.5 feet per year.

Unlike rock shoreline, permafrost loses its structure when it warms above freezing. "Surface air temperatures have reached record levels over the past decade," the report from an international consortium found. Combine this with weakened permafrost and there's a recipe for erosion.

Heightened temperatures have also melted sea ice; with this gone, wind can whip up stronger waves that are able to erode the softened Arctic coastline.

Researchers studied more than 62,000 miles of Arctic coast and analyzed climate data. Northwestern Canada and Northeastern Russia showed the largest changes: Coastlines there have receded by as much as 25 feet per year. Researchers say these changes will have a major impact on arctic ecosystems.

There's a map of the affected areas here.