Navigating by touch through the sea ice

Ships are meant to glide effortlessly through calm waters, but our Greenland expedition vessel Ortelius is shuddering and wiggling as it navigates through the calm yet frozen waters between Svalbard and the islands. We’re on the North Atlantic Odyssey, a journey that starts in continental Europe and concludes near the North Pole in Svalbard. Onboard are 115 enthusiastic passengers. Most of them are currently on the outer decks, cameras in hand, captivated by the sea ice.

Spell-bound by the frozen ocean

“I looked out at the ice this morning and I felt so at home,” says Mick Brown, a veteran guide and naturalist, who remains spell-bound by the frozen ocean. “It’s wonderful to be back – such a great feeling.” There was no need for an alarm clock this morning; the change in the ship's movement was enough to get us out of bed. The bow lifts as it contacts a floe of ice, and one can feel the deck rise underfoot. As Ortelius pushes the floe aside, she lists almost imperceptibly before settling down again to an even keel. Heavier floes result in a little shuddering followed by a gentle vibration that ripples along the decks. Occasionally, there is a sharp jolt if the ship hits a solid floe square on.

Careful, skilful navigation

“Speed?” questions the Officer of the Watch, not taking his eyes off the random pattern of floes and leads ahead. “3.6 knots,” replies the helmsman. Ice navigation is not to be rushed. “Ok, Rudder Port 10 degrees,” he orders. Taking advantage of the open patches of water – known as leads – the vessel zig-zags towards the north. The log book entry for this hour says it all: ‘various courses’.

Sound, as well as movement, indicates to anyone still below decks that we’re in the ice. The floes scrape along the side of the hull, grinding, juddering, and crackling as they go. Harder, glacial lumps of ice make the most noise. Sailors of old gave them the name growlers, which is still used today.

The Ice Lung

The Arctic Ocean freezes in the winter, and currents move that ice southwards along the east coast of Greenland. Our Arctic trip has taken us right up to the fringe of that ice. It’s relatively soft, one-year-old ice, around one meter thick. Oceanic swells meeting the ice cause a rise and fall among the floes. Pytheas the Greek, the first man to record his impressions of sea ice around 350 BCE, referred to this as the “ice lung.” The floes hiss and breathe as they rub against one another. The frozen sea has a mysterious quality. Pytheas wrote of those places where land properly speaking no longer exists, nor sea nor air, but a mixture of these things, a link between all these elements, on which one can neither walk nor sail. It is a shame that Pytheas’s original texts have been lost; we only have descriptions of his words and findings.

Home to phytoplankton, essential for all arctic animals

Although it might seem lifeless, the ice lung provides life. It is an active habitat, home to pagophilic – ice-loving – wildlife. So far today, we’ve spotted a hooded seal and a pomarine skua. We are keeping our eyes open for harp seals, which can gather in their thousands on this margin. Where floes are upturned, they expose a dirty brown underside: this is the growth of phytoplankton, the nucleus of the arctic food web, food-fuel for the rest of the fauna, beginning with zooplankton. In turn, this feeds the fish that sustain the seals, which are hunted by the king of the sea ice – the polar bear. Now, where are my binoculars?