Where Icebergs are Born

22 Jul 2013

Students on Ice Arctic Expedition 2013, Disko Bay, Greenland

All icebergs in the North Atlantic start in this place. Disko Bay is littered with ice. Huge bergs sit somnolent in the morning sun, their surfaces lined with dark blue veins of frozen fresh water. A sudden clap of thunder announces the birth of a new crack that presages the collapse of an eroded flank.

Humpback whales ride the surface nearby leisurely feeding, untroubled by the ship that cautiously approaches. The ship’s bow is lined with students, cameras in hand. Their excited cries carrying across the water as the whale surfaces and blows, then slowly slides under to the task at hand. 

Once such a sighting would have had dire consequences for this massive sea mammal, which lives in all the world’s oceans. Nearby Disko Island bears the remains of a whaling station. Overhunting drove the whales to the brink of extinction, just as it did in many other parts of the Arctic. Today the sound of digital cameras has replaced the cries of whalers closing in on their quarry.

As we head into the bay, the approach to the community of Ilulissat is choked with ice -- from massive icebergs smaller “bergie bits” scattered across the ice surface. The ship slows and its experienced Russian captain brings it through the icy maze with the skill that comes from a lifetime in Arctic and Antarctic waters.
Next to Ilulissat is the Jacobshavn Ice Fjord, the nursery of all the ice we have been seeing. Human activity, which is warming the planet (and the Arctic at twice the global rate), is actually pushing more ice into the waters of the fjord. Since the ice began retreating from this part of western Greenland about 13,000 years ago, the glacier has flowed down from the three-kilometre deep Greenland Ice Cap. In the last 150 years, the glacier has retreated more than 50 kilometres. Two-fifths of the melting has happened since 2000. Last year, for the first time, melting occurred over the entire surface of the ice cap. The changes are dramatic and beyond what climate models were able to predict just a few years ago.
Jacobshavn is an “ice stream,” one of the three biggest in Greenland. Immense pressure on the ice cap forces ice through the narrow fjord. The ice behind it moves more slowly but is eventually sucked into the stream, like water in a bathtub. As the temperature increases and more ice melts, water flows below the glacier and lubricates the rock it is moving over, increasing its velocity. 
Jacobshavn is an UNESCO World Heritage Site and is the reason thousands of people come to Ilulissat. Tourism is important to the Greenland economy and the icebergs in Disko Bay are a major draw. But at the rate the ice is flowing out, in 20 years the glacier will no longer calve into the water, but will melt unspectacularly on the land. What will happen to the UNESCO designation? Will tourists still come? What will happen to the local economy?
These questions seem out of place when you look at the massive almost incomprehensible amount of ice in the fjord. But if we’ve learned anything about Arctic climate change in the last few years, it’s that the models are out of date and the future is about to arrive.
Jacobshavn Ice Fjord, Disko Bay, Greenland © John Crump.
Iceberg in Disko Bay, near Ilulissat, Greenland © John Crump.


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