Kayaking Greenland's melting glaciers
On a remote Arctic glacier, scientists and an Aussie adventurer team up to study the melting ice.
An ice penetrating radar is deployed from a string of kayaks to survey a section of the Petermann glacier. (Nick Cobbing)
Kayaking Greenland's melting glaciers
BETWEEN INTIMIDATING CLIFFS, I paddle over freezing water towards a whirlpool of ice, threatening to suck me into the depths of the glacier. Attached by cables, three other kayaks are following me on this dangerous mission, a bobbing train of scientists 100m long.
Why am I here? Because Greenland is melting. Every summer the Arctic sun warms the ice and snow and decorates the great icecap's surface with ponds, lakes, brooks and rivers. Viewed from the air, it's a veritable ice-water flood so intensely blue it leaves you gasping.
But it's not the annual thaw that worries scientists. It's the growing discrepancy between the yearly accumulation and loss of ice - known as the mass balance - that's causing concern. There isn't enough snow falling on Greenland's icecap to replace the recent increase in icebergs calving into the sea.
Greenland's contribution to sea-level rise has doubled during this century alone. Some glaciers in Greenland's south-east have doubled, even tripled, their flow speed to 38m a day in the past six years. In comparison, most alpine glaciers move, on average, about 50m a year.
Greenpeace ship views the brunt of climate change
From 24 June to 10 September 2009, Greenpeace icebreaker MY Arctic Sunrise carried a team of independent scientists from the USA and the UK to conduct studies in locations rarely visited by humans and which are beginning to feel the brunt of rapid climate change. This research expedition all but circumnavigated Greenland, from the narrow channels this 2.17 million sq. km polar-island nation shares with Canada's Ellesmere Island, to its remote north-east coastlines.
I was retained as the polar guide to oversee the safety of operations beyond the ship. Greenland has no shortage of hazards - polar bears, crevasses and shifting sea ice among them - and the job would prove to be a unique marriage of adventure and science that tested my resourcefulness, and that of the ship and its crew, to the full.
The Petermann Glacier, among the largest in the northern hemisphere, lies above the 80th parallel in Greenland's northwest. It's an outlet glacier and it flows NNW from the inland ice of Knud Rasmussen Land to the coast. There, hemmed in by 1km high cliffs, it continues its journey afloat for more than 80 km down the fjord. The glacier then terminates in the Kennedy Channel. The Petermann is attracting international attention because a 120 sq. km chunk of its floating ice tongue - a colossal 10 per cent of the total - is set to break off.
One of the expedition scientists' main goals was to use the Sunrise helicopter to pepper the Petermann ice tongue and its surrounding cliffs with a mix of cameras and sensors. "Summer 2008 temperatures set records across the eastern Arctic, the warmest since record keeping began at Upernavik, north-west Greenland, in 1873," explained team leader Dr Jason Box, associate professor at Ohio State University's Byrd Polar Research Center. "Petermann's floating ice tongue has been disintegrating during this recent period of warming, losing 250 sq. km since 2000." Temperatures during our voyage were again above normal, and while there was no major collapse during the 2009 summer, Jason and his team expect data from sensors to reveal flow acceleration upstream, which will eventually sever the tongue's tenuous link to the glacier.
Ocean warming a new threat
Posing a far greater threat to polar ice, however, is another global trend - ocean warming. To better understand the effect of temperate currents on the underside of floating glaciers and ice sheets, glaciologist Dr Alun Hubbard, from Aberystwyth University, Wales, planned a foot traverse of the Petermann, towing an ice-penetrating radar to reveal its underlying topography. But with the surface awash with melt-water, he instead proposed we dance with the devil and paddle the glacier's main waterway in a convoy of kayaks interconnected by radar sensor cables.
I was appalled by the idea. In 1995 I traversed Greenland using skis and kites, jumping many melt channels that drained pitilessly into the ice via melt holes, or moulins. I'd also paddled an iceberg-laden whitewater river that spilled from the Greenland icecap down to sea level and knew the numbing cold of ice-borne water. The Petermann's melt-water was just short of freezing and its galloping flow could fill an Olympic swimming pool every 60 seconds. I agreed to Alun's proposal, with one condition: I see the route first.
From the air, we scouted a 25 km section that ended just upstream of a tumultuous vortex we dubbed 'the whirlpool'. Churning with ice, the whirlpool spiralled into the bowels of the glacier, a place I had no intention of visiting. Add to this the fact that we would be lashed together with cables and it all began to sound a bit messy. But this cocktail of adventure and science was too good to pass up and I spent the next three days planning a world-first descent of a melt-water river entirely embedded in a glacier.
Under a sky as blue as the tributary creek into which my paddle blades dipped, I mentally rehearsed the journey at lightning speed - known hazards, capsize drill, signals and exit strategy raced through my mind. In the wake of my single whitewater kayak, an incongruous train of boats and buoyed radar sensor cables trailed in a lazy arc.
Taking to new glacier streams via kayak
Perched in a red double kayak 20m behind sat Alun, tending his radar receiver, GPS and laptop. With him was Scottish Oceans Institute geophysicist Dr Richard Bates. Both men are experienced adventurers in their own right. Sixty metres behind their red boat tracked an unmanned green kayak carrying the radar transmitter and battery. And taking up the rear another 20m along, solo in a double kayak, was Sunrise radio operator and Greenpeace campaigner Texas Constantine. Texas had fitted each boat with a submersible two-way radio and each paddler was similarly waterproofed in a dry suit.
With teething issues resolved, we entered the 6 km/h flow of the Petermann melt-water river. Immediately, I felt a sense of relief: the water behaved just like any other I'd paddled. But the surroundings were otherworldly. The icescape changed with each bend - babbling creeks, idyllic eddies, ice canyons, distant cliffs - and the hours swept by like the crystal water below. The smooth riverbed was a kaleidoscope of patterns and shades, remnant snapshots of the glacier's history. Occasionally, we'd glide over giant ice chasms that left me gaping in awe, thankful they'd not yet turned into moulin maelstroms.
After a leisurely lunch on the icy bank, Jason was dropped in by helicopter to join Texas's double kayak for the final 10 km paddle. The melt had reached its peak daily flow rate of 9 km/h and we were sucked into a canyon-land of tight chicanes before reaching our pre-flagged exit point on the inside of a tight bend. I talked the team through the exit procedure via radio - slack in the lines, nose into the upstream margin of the eddy, paddle hard, break out. With visions of the whirlpool 1 km downstream, we nailed our exit.
As we waited for the helicopter to return us to Sunrise, Alun checked his laptop and rejoiced at the crisp radar signature; our audacious scientific adventure would add a piece to his glaciological puzzle. "There's been a complete shift in thinking of the crucial role that warming ocean currents play in destabilising floating glacial tongues and ice sheets," he said. "When compared with previous data, our longitudinal snapshot [from the kayak journey] indicates that the base of Petermann's floating ice tongue is melting away at a rate 25 times that at which its surface is melting."
With tropical water finding its way into the fjords of south-east Greenland via the Gulf Stream, innovative research, such as our kayak adventure, is going to be critical in helping scientists discover new information about the great melt.
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