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Images: A Mooring in Iceberg Alley

A satellite image shows Helheim Glacier, one of many glaciers that drain ice from the Greenland Ice Sheet into coastal fjords that connect to the open ocean. Rebecca Jackson, a graduate student in the MIT-WHOI Joint Program, was part of a team that deployed a mooring, named SF1, near the terminus of the glacier in Sermilik Fjord. The researchers are investigating fjords as links between glaciers and the open ocean, and in particular, the role of warming ocean waters and underwater glacial melting in accelerating the flow of glacial ice into the ocean. If more ice melts into the ocean than accumulates on the ice sheet via snowfall, global sea levels rise.

Helheim Glacier is a river of ice flowing in this photo from left to right, from the ice sheet dominating the interior of Greenland to the coast.

The ridge of ice is the terminus of Helheim Glacier, where it flows into the ocean. To the right of the ridge, the fjord is covered by a thick melange of floating icebergs and sea ice. That makes the region near the glacier's terminus inaccessible by boat. On the mountains in the background, you can see a "bathtub ring" indicating the previous extent of the glacier before it had thinned and retreated in recent years.

Icebergs calving from Helheim Glacier drift into Sermilik Fjord, posing a danger to instruments deployed in the fjord.

The research team used the M/V Viking Madsalex to deploy the SF1 mooring in Sermilik Fjord in 2011 and to retrieve it two years later. (William Ostrom, Woods Hole Oceanographic Institution)

The aft deck of the M/V Viking Madsalex was the staging area to deploy the SF1 mooring in 2011 and for dragging operations to recover it in 2013. Clockwise from left, WHOI scientist Magdalena Andres, MIT-WHOI graduate student Rebecca Jackson, WHOI oceanographer Fiamma Straneo, and WHOI mooring technician Will Ostrom. (Nick Beaird, Woods Hole Oceanographic Institution)

WHOI graduate student Rebecca Jackson, right, and Dave Sutherland of the University of Oregon conduct operations from a small boat on Sermilik Fjord.

During deployment of the SF1 mooring in 2011, the buoyant yellow sphere at the top of the mooring line floated atop the surface. Then an anchor was attached to the bottom end of the line to pull the mooring under water. (Fiamma Straneo, Woods Hole Oceanographic Institution)

A huge iceberg looms over the 82-foot-long M/V Viking Madsalex in Sermilik Fjord.

(Alexander Korablev)

The research team returned to Sermilik Fjord in 2012 aboard the M/V Fox to recover their moorings, but the water in the upper fjord was too clogged with ice and they could not reach the site where they deployed the SF1 mooring.