Nature
Monitoring Greenland’s melting glaciers from a 15-metre long sailboat.
In early August, a 260-kilometre-square chunk of ice broke off the Petermann Glacier — the largest iceberg to calve in the Arctic Ocean since 1962.
The collapse didn’t surprise Richard Bates, a geophysicist from the University of St Andrews, UK. During a visit to Petermann last summer, with glaciologists Jason Box of the Byrd Polar Research Center at Ohio State University in Columbus and Alun Hubbard of Aberystwyth University, UK, the three noted rifts and meltwater — a sign of pending collapse. They installed time-lapse cameras atop the 900-metre-high cliffs and placed eight Global Positioning System (GPS) units along the glacier’s centre line to monitor the event.
The researchers returned to Greenland late last month to retrieve the equipment and make other oceanographic and geophysical measurements, but were thwarted in their attempts to reach Petermann by ice. Nature caught up with Bates soon after he stepped off the Gambo, the sailboat that voyaged to the north end of Humboldt Glacier, which the team is also studying.
What did you see while sailing up the Greenland coast?
We saw a lot of calving glaciers. One 400-metre-long section of the glacier broke off just after we surveyed it. On our way to the Humboldt Glacier we got close to some major calving. It can seem very dangerous to have such a small boat in front of these glaciers, but you can be a lot more reactive and nimble than in large research vessels. But once you’re stuck in the ice, you’re stuck. We were pushing it a bit last week.
What work did you have planned for this trip?
We worked our way up from central Greenland — the Lille, Store and Rink glaciers. We took time-lapse measurements and looked at the submerged portion of the glacier to see how fast the front is changing. We’ve been finding out that the submarine melt rates can be 20–100 times faster than the above-surface melt rates. We’re using a laser scanner to measure the changes above the water and using a sonar to look at the melt rates below the water.
→ Read the entire Q&A with Richard Bates at Nature.
Richard Bates photo courtesy of Richard Bates, Petermann Ice Island photo courtesy of NASA.
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