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Glacial melting creates important food stations

Glacial fronts like this one in Kongsfjorden are important feeding stations for the Arctic ecosystem. FOTO: Ole Magnus Rapp

Glacial melting creates important food stations

For bears, seabirds, fish and seals.

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Increasingly deep meltwater rivers are flowing under glaciers and into the sea. The burrowing currents stir up bottom feeders, drawing large quantities of nutritious food to the surface.

The increase is occurring at the same time as a large amount of research into the melting of Svalbard's glaciers that uses new methods to measure the reduction. Scientists now believe four to eight cubic kilometers of glacier disappeared last year.

More food

Previously, ice extended to glacier fronts during winter. Now the fronts are ice-free in many places, and have become important feeding places for birds, fish and animals.

The Norwegian Polar Institute has for many years researched the phenomenon that occurs when the melting rivers are flowing into the sea.

"Within a few years the entire pattern changed," said Harald Steen, head of the institute's Ice, Climate and Ecosystems (ICE) center. "The vortexes in front of the ice-free glacier fronts create increased access to food. Since, among others, Kongsfjorden has become warmer, the glaciers and glacier rivers gained importance since calving and melting creates what scientists call 'local Arctic conditions.'"

Researchers have studied several of the major glaciers in Svalbard, including Kronebreen in Ny-Alesund. A slightly milder climate has resulted in more melting, and increased amounts of meltwater coming under the glaciers and into the sea.

"We see that seabirds adhere largely to the front of glaciers," Steen said. "Seals also have a fixed abode there, and they have a hierarchy where older seals have entrenched feeding territory and fend off the younger animals. All the animals and birds we find there are in good shape."

He said polar bears have discovered this feeding place, with some specializing in taking seals resting on small ice floes.

The researchers are also looking at what happens when glaciers shrink. Glaciers have mostly calved into the bay until now, but over time several glacier fronts will be on dry land. Then the nourishing power vortex in front of the glaciers will be absent.

Polish-Norwegian research

An enormous amount of resources and technology is used to keep track of the total mass of Svalbard glaciers.

Researchers use different methods to see the changes. The polar institute, University of Oslo, The University Centre in Svalbard and Polish scientists at Hornsund participate in a cooperative effort..

"Kronebreen, for example, has since 1869 retreated almost ten kilometers back," said Jack Kohler, a researcher at the polar institute, which has been following the evolution of Svalbard's glaciers for decades. "The reduction has really accelerated since 2010 and the glacier is approaching dry land."

"Everything here utilizes satellite data, via fixed 3D photography measuring points calibrated from helicopters," he said.

Lasers and radar

Among the new measuring techniques are lasers from aircraft. They can with great accuracy estimate changes by comparing the old and new measurements. Also being developed are radar methods to determine the glaciers' thickness.

"Using various methods are we mapping the terrain under glaciers," Kohler said. "Here we see several glaciers that over the years have been in the fjord will soon retreat to shore."

Seas rising slightly

"The glaciers are reducing between four and eight cubic kilometers a year – and the pace is increasing," Kohler said. "Our monitoring shows that melting increases with increasing air and ocean temperatures."

The increased melting of Svalbard also affects sea levels globally. While melting of ice in the Greenland ice has resulted in a one millimeter increase, Svalbard's contribution is estimated at 0.026 millimeters.

Changes in Svalbard are visible in numerous locations. Blomstrandhalvøya in Kongsfjorden is no longer a peninsula, but an island, after the the glaciers receded. The emerging new landscape also features others islands and islets.

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