Kangerdlugssuaq melting

by Guest Blogger

July 21, 2005

You ever commute to work, and find your office building missing when you

get there? That’s probably what it felt like this Monday morning for

University of Maine glaciologist Dr. Gordon Hamilton.

He was commuting

to his place of work (a glacier of course) with Hughie, flying the

helicopter, and Melanie, one of our campaigners in the back seat.

Gordon, along with his PhD student Leigh Stearns, had already plotted

exactly where they wanted to place their precision GPS receivers, a

kilometer from the front of the glacier. But arriving at the research

coordinates, Gordon discovered something was missing. “Yeah, it was

quite a surprise when we came up here this morning,” he explained later,

“and found that as we flew over the way points marked for the survey

grid, we were still over water and the calving front of the glacier was

quite a bit further up the fjord.”

Here’s a satellite image of the Kangerdlugssuaq glacier. The older

colored lines represent where the glacier ended based on aerial and

satellite surveys. The dotted orange line is an estimate of where the

glacier ends today, based what we’ve seen. As you can see the change is

pretty dramatic. (Image courtesy of ASTER Science Team / University of Maine)

The Kangerdlugssuaq glacier has been surveyed using aerial and satellite

images since 1962. In all that time (and very likely for quite some

time before) its front has remained remarkably stable.

Now, over just a

few years, it’s retreated roughly three miles (5km). Previous research,

done by NASA, had shown the glacier thinning at a rapid rate – about 33

feet (10m) per year. It had been a little puzzling to Gordon how the

glacier could thin so fast without retreating. As he says, “Of course,

when we flew over Monday morning, once we saw the quite large retreat,

it started to make sense.”

A fast flowing ice river

Plotting a new research grid, Gordon and Leigh went about the work of

measuring how fast the ice that makes up this glacier is flowing

downhill.

Work that was complicated by 20 knot winds, and a more

chaotic glacial surface than any they’d ever been on before.

Towering pinnacles ready to collapse, tiny landing zones, and crevasses

hidden under the weathered surface by ice debris all hampered their

efforts. Nonetheless, the science team spent far longer out on this

glacier than any other on this trip – taking additional measurements to

try and figure out what’s going on here.

Their extra work paid off, though, and brought them another surprise.

When this glacier was last measured, in 1995, it was flowing at a fairly

speedy (for a glacier) 3.72 miles (6km) per year. Yet, preliminary

results from Gordon and Leigh’s survey suggest that since then it’s

speed has more than doubled, to almost nine miles (14km) per year –

making it one of the word’s fastest. As Gordon put it, “that’s pretty

staggering.”

All this ice has to come from somewhere. In this case, as with many

other Greenland glaciers, it’s flowing from the Greenland ice sheet.

Not that the ice sheet itself will disappear completely anytime soon.

That would take hundreds and hundreds of years.

But if the

Kangerdlugssuaq glacier is an example of what’s to come, then it could

go much faster than current models predict. In fact, we could be

looking at several feet of sea level rise over the next hundred years –

enough to wreck massive damage. More than 70 percent of the world’s

population lives on coastal plains, and 11 of the world’s 15 largest

cities are on the coast or estuaries. Weather patterns would also

change as the ice sheet shrinks. And the millions of gallons of melted

ice water would alter regional seawater salinity and global ocean

currents. In short, if the Greenland ice sheet is in fact draining

rapidly it will be a disaster of global proportions.

We’ll keep doing our part by bringing you news from the frontlines of

climate change, but we need you to join us in action. Everyone needs to

pitch in, but if you’re in the U.S. (the world’s biggest global warming

polluter per capita) your help is especially needed.

Find out more from Greenpeace and view video footage.

Find out more about the work of Gordon Hamilton and Leigh Stearns from the Climate Change Institute.

– Andrew

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