Underland

by Robert Macfarlane

  Ice remembers forest fires and rising seas. Ice remembers the chemical composition of the air around the start of the last Ice Age, 110,000 years ago. It remembers how many days of sunshine fell upon it in a summer 50,000 years ago. It remembers the temperature in the clouds at a moment of snowfall early in the Holocene. It remembers the explosions of Tambora in 1815, Laki in 1783, Mount St Helens in 1482 and Kumae in 1454. It remembers the smelting boom of the Romans, and it remembers the lethal quantities of lead that were present in petrol in the decades after the Second World War. It remembers and it tells – tells us that we live on a fickle planet, capable of swift shifts and rapid reversals.

  Ice has a memory and the colour of this memory is blue.

  High on the ice cap, snow falls and settles in soft layers known as firn. As the firn forms, air is trapped between snowflakes, and so too are dust and other particles. More snow falls, settling upon the existing layers of firn, starting to seal the air within them. More snow falls, and still more. The weight of snow begins to build up above the original layer, compressing it, changing the structure of the snow. The intricate geometries of the flakes begin to collapse. Under pressure, snow starts to sinter into ice. As ice crystals form, the trapped air gets squeezed together into tiny bubbles. This burial is a form of preservation. Each of those air bubbles is a museum, a silver reliquary in which is kept a record of the atmosphere at the time the snow first fell. Initially, the bubbles form as spheres. As the ice moves deeper down, and the pressure builds on it, those bubbles are squeezed into long rods or flattened discs or cursive loops.

  The colour of deep ice is blue, a blue unlike any other in the world – the blue of time.

  The blue of time is glimpsed in the depths of crevasses.

  The blue of time is glimpsed at the calving faces of glaciers, where bergs of 100,000-year-old ice surge to the surface of fjords from far below the water level.

  The blue of time is so beautiful that it pulls body and mind towards it.

  Ice is a recording medium and a storage medium. It collects and keeps data for millennia. Unlike our hard disks and terrabyte blocks, which are quickly updated or become outdated, ice has been consistent in its technology over millions of years. Once you know how to read its archive, it is legible almost as far back – as far down – as the ice goes. Trapped air bubbles preserve details of atmospheric composition. The isotopic content of water molecules in the snow records temperature. Impurities in the snow – sulphuric acid, hydrogen peroxide – indicate past volcanic eruptions, pollution levels, biomass burning, or the extent of sea ice and its proximity. Hydrogen peroxide levels show how much sunlight fell upon the snow. To imagine ice as a ‘medium’ in this sense might also be to imagine it as a ‘medium’ in the supernatural sense: a presence permitting communication with the dead and the buried, across gulfs of deep time, through which one might hear distant messages from the Pleistocene.

  Ice has an exceptional memory – but it also suffers from memory loss.

  The weight on 2,000-year-old ice can reach half-a-ton per square inch. The air in this ice has been so compressed that cores brought up by deep drilling will fracture and snap as the air expands. This is why glaciers sound like shooting ranges. This is why if you were to drop a piece of very old blue ice in a glass of water or whisky, it might shatter the glass.

  Deeper still – in ice aged between 8,000 and 12,000 years – the pressure becomes so great that air bubbles can no longer survive as vacancies within the structure of the ice. They vanish as visible forms, instead combining with the ice to form an ice-air mixture called clathrate. Clathrate is harder to read as a medium, and the messages it holds are fainter, more encrypted.

  In mile-deep ice, individual layers can only just be made out as ‘greyish ghostly bands . . . visible in the focused beam of a fibre-optic lamp’. And because ice flows – because it continues to flow even when under immense pressures – it distorts its record, its layers folding and sliding, such that sequence can be almost impossible to discern.

  At the deepest points of the Greenland and Antarctic ice cap, where the ice is miles deep and hundreds of thousands of years old, the weight is so great that it depresses the rock beneath it into the Earth’s crust. At that depth, the compressed ice acts like a blanket, trapping the geothermal heat emanating from the bedrock. That deepest ice absorbs some of that heat, and melts slowly into water. This is why there are freshwater lakes sunk miles below the Antarctic ice cap – 500 or more of these subglacial reservoirs, showing up as spectral dashed outlines on maps of the region, unexposed for millions of years, as alien as the ice-covered oceans thought to exist on Saturn’s moon, Enceladus.

  As a human mind might, late in life, struggle to remember its earliest moments – buried as they are beneath an accumulation of subsequent memories – so the oldest memory of ice is harder to retrieve, and more vulnerable to loss.

  ~

  We load the boat chain-style on a rising tide, slipping on the kelpy rocks as we heave blue bear-proof barrels, weapons and packs along the line.

  ‘Watch where you put things down,’ says Helen. ‘There’s seal guts and cod heads and all sorts smeared on the rocks here.’

  It takes half an hour to load and check. Then Geo guns the Yamaha 1200, spins the boat around from the dock, and we roar out across the channel, aiming for where the glacier called Apusiajik – ‘the Little Ice’ – meets the sea.

  There is a high cry – haunting, falling away and then repeating, silver-gold in colour – that sets my neck tingling.

  A red-throated diver, no, three red-throated divers, flying in formation northwards over the channel, the same direction as us. Big birds, heavy-set in the body but graceful in their lines, smooth in silhouette as if poured from water rather than made of feathers. I haven’t heard the cry of a diver for a decade, since seeing one hunt on a loch in the shadow of Suilven in the far north-west of Scotland, and before that another decade earlier, on a forested lake in British Columbia.

  ‘Truly a bird of the north,’ says Matt.

  We can hear the divers calling long after they are lost to sight.

  Buck of the boat off the wave-chop. Salt spray, air cold and fast on the face. Sharp peaks rising in all directions. Fjords cutting away. A sense beginning to build in me of the scale of this landscape, beyond anything I have ever experienced or imagined: the vastness of the coastline, and always somewhere behind it to the west the ice cap itself, so huge it annihilates all features other than itself, all colours other than white and blue. I can feel a buzzing in my stomach, the surging excitement of a big journey starting. We will not see Kulusuk again for weeks.

  The lower mountains are scabbed with snow. The exposed rock is golden, brown, red, white: warm marbled colours. It is some of the oldest surface rock in the world, and I know that it makes a torn-page match with the gneiss of the Outer Hebrides. Hundreds of millions of years ago, these two coastlines were united. A deep time kinship existed between this wildly unfamiliar region, and those Scottish islands in which I felt at home.

  It is six miles across the channel from Kulusuk to Apusiajik, but it looks as if we could swim it. The glacier itself is five miles long, but it looks as if we could wander up it in a couple of hours with hands in pockets. We would die if we tried either.

  The foreshortening illusion is powerful, born of the air’s pristine clarity, and it is the first of countless misprisions of scale I will experience in Greenland. This is, I will learn, a landscape that plays tricks on the eye, dupes perception, induces forms of clarity that are in fact forms of delusion. Rock and ice walls reflect and redirect sound misleadingly: events occurring ahead of us seem to issue from behind. There are no usual units to which the eye has become accustomed: no buildings, no cars, no distant people. The terrain is built out of a few elements – rock, ice, water – that echo their own forms up and down the orders of magnitude.

  Geo steers expertly, using one hand, past a group of black rock islands near the middle of t
he channel.

  ‘There were orca around here a few days ago,’ says Matt. ‘And sei whales. We heard them before we saw them: the hooing of their blowholes.’

  As we near Apusiajik, the water thickens with blue-white pebbles and boulders of ice that thunk on the hull. Geo steers an elegant course, but eventually the ice is too thick to avoid, and so he lowers speed and noses through it, thud, thunk, thump, thud, closing in on the snout of the glacier.

  Apusiajik tumbles into the water. The tideline calving face is perhaps 2,500 feet in length, and pale blue at the points of freshest calving. Above the face the ice rolls over a drop, and a central bulge of rock is visible, splitting the roll-over, streaked black with lines of meltwater.

  ‘That’s new,’ says Matt. ‘A couple of years ago that wasn’t there – it was pure ice.’

  I will remember that island of fresh rock much later, when we take as our sleeping place another such ice-island, also recently revealed by the melt, far up a much bigger glacier.

  Geo slows the boat, then pulls the engine back to an idle. We float along parallel to the face, keeping 1,500 feet or so distant, to give us time to get clear if a big calving happens. Geo points at the glacier, then turns back towards Kulusuk and a peninsula of bare rock that pushes out from the margin of the glacier, into the channel.

  ‘Fifty years ago, when I was a boy,’ he says, indicating the peninsula in the channel, ‘ice was there.’

  Then he points to an island yet further out in the channel.

  ‘My father’s time, ice was there.’

  He points back to Kulusuk, then holds his hands to his ears, bunches his fingertips and flicks them open, miming an explosion.

  ‘Before, in Kulusuk, we hear glacier boom! Now, no sound.’

  In the course of Geo’s life, the face of the Apusiajik glacier has retreated so far back and around that the noises of its calvings are no longer audible in the village. Melt has changed the soundscape of everyday life. The glacier is experienced as a silence.

  ~

  We unload the boat chain-style on a falling tide, heaving the gear onto a rock-sand beach of white quartz and black mica. The tide has left little bergs stranded on the sand, along the line of the bay. They shine blue-silver in the late light. There is something exhausted about them. Other small bergs lap slowly towards land, or mill around in the offshore currents.

  We hump the gear for about 900 feet, making four return trips, through a shallow boulder valley and onto a flattened plain of mossy topsoil and boulders, along which a stream runs on a gradual incline to the sea.

  The plain is the path of a vanished glacier: moraines to seaward indicate the former extent of the glaciation. We are making camp in ghost ice.

  I think of the accounts I have read of how small craft hugging the Greenland coastline will sometimes find their GPS navigation devices screaming alarm, warning of collision. The coordinates of the former extent of glaciers have been inputted into the mapping, but the retreat rate has been so fast that they are sailing into and through the digital phantom left behind by the ice.

  The air around our tents is filled with white specks I cannot identify, which are not snow and are not dust, so that the atmosphere seems electrified, scintillating.

  Two grey gulls fly overhead, cranking their wings against the rising easterly. A raven circles, croaking, then glides down to land on the erratic against which we have piled our gear. It folds its glossy wings, shakes itself down, and watches us with a cocked head, curiously.

  We pitch the tents in a line, side to side, six feet separating each of them. Then we set to work on establishing a bear perimeter. Polar bears can smell a food source from up to twenty miles away. If you see a bear, you can be sure the bear has known of you for far longer, and has come to investigate. None of us wants to see a bear, for our sake and its sake. We have two weapons with us: massive-bore rifles that fire adapted shotgun shells containing single slugs rather than pellets. Each person carries flares at all times.

  Around the camp we start to set a rectangular boundary of tripwires which, if triggered, fire blank cartridges downwards into the earth, scaring away an inquisitive bear. We string the wires at a height of about two feet, so that they won’t be snagged by any white foxes coming to scavenge.

  It takes two hours to set camp to Matt’s satisfaction. We sing as we work. Bill is a professional singer, blessed with a resonant bass voice. I warble happily. The sun lowers to the west. Two bergs move from left to right across the bay.

  In a landscape as vast as the Arctic, the eye is surprised by details. Though the topsoil around the camp is only a few inches deep, it supports a diversity of mosses and plants. Club moss flourishes in the lee of boulders, and the rocks are painted with lichens: blotches of orange Xanthoria parietina, the intricate cartography of map lichens, and a crisp lettuce-like lichen I cannot name – acid green in colour, hard to the touch.

  Everywhere are the emerald leaves of the tiny dwarf willow. I pick a leaf, half the size of my little fingernail, and hold it to the sun. It shines green, and I can see the delicate red vein-work that marks it. I know this Salix only from the Cairngorms, Britain’s equivalent of the Arctic, where it grows sparsely on the highest parts of the plateau. Here it covers the ground, creeping sideways, its pitch-black branches a few millimetres thick at most.

  We have pitched our tents on top of a forest, I realize. We are canopy dwellers.

  I recall a joke I heard in Reykjavik. Question: ‘How do you find your way out of a forest in Iceland?’ Answer: ‘Stand up.’

  Now and then a muffled boom moves through the landscape, arriving softly but forcefully as a push on the eardrums, a vibration in the flesh. It is the sound of calving ice, made by a slab of glacier crashing into the water from the Apusiajik face, round the mountain from us. Sound is a blow delivered by air, through the ear, on the brain and the blood, and transmitted to the soul . . .

  Big bergs make slow journeys across the bay: a stricken U-boat, a cruise liner, the Scottie dog from a Monopoly set, white and clean, nodding its way over the course of the evening.

  ‘Sun dogs!’ calls Helen, pointing upwards with a smile. Glittering rainbow arcs stand at a convex to the curve of the sun itself.

  Ice in the inlet, ice in the sky. Ice in the bay. Ice in the air above us. Sounds of ice from the glacier. We are sleeping where ice had once been.

  That night the Northern Lights appear for the first time. A scarf of radar-green flutters in the sky. The mountains shoot jade searchlights into space.

  We lie on our backs in the cold black air and watch the show, amazed into silence.

  ~

  A week before leaving for Greenland, I go to the British Antarctic Survey on the outskirts of Cambridge to see a man called Robert Mulvaney. Mulvaney is an ice-core scientist, a palaeoclimatologist and glaciologist. He has spent his career studying the underland of ice: reading its memory for what it tells him about past climate and environment – and what it might foreknow about climate changes to come.

  Mulvaney has worked for twenty drilling seasons in Antarctica and five in Greenland. In the field he grows a big beard and moustache; in the office he is clean-shaven. He shakes my hand hard, leads me briskly through the corridors of BAS, speaks quickly.

  ‘I may seem like a relaxed person,’ he says. ‘I’m not. Not at all.’

  He doesn’t seem like a relaxed person. He seems like an impressive person who has spent most of a lifetime performing challenging tasks under conditions in which efficiency of effort is essential.

  As a young man Mulvaney was a hard climber, and a hard caver too. I tell him about the Timavo, and about descending the Abyss of Trebiciano with Sergio puffing on his briarwood pipe.

  ‘Ah, you were in the karst, then. I did some fairly far-out caving near there. Exploratory stuff in Yugoslavia, floating into wet systems on rafts, that kind of thing. I always preferred Yorkshire limestone, though. Drier.’ He looks briefly nostalgic for life under the earth.

>   He takes me to his study, points me to a seat. ‘I gave up serious caving and climbing when I’d lost too many friends to death and injury,’ he says. ‘So I became a sailor instead.’

  Pinned on the noticeboard above his desk is a tattered pennant in Jamaican black, gold and green.

  ‘I sewed that myself,’ he says with unguarded pride, ‘as we approached land at the end of my first Atlantic crossing.’

  Next to it is a yellowed photograph of his wife and two daughters, waving at the camera out of the cockpit of a drastically tilted yacht, beached on wet mud. It’s unclear if they are waving in greeting or distress.

  ‘We’d run aground on a mud pinnacle somewhere off Essex,’ Mulvaney says. ‘If you haven’t grounded when sailing the east coast, then you haven’t sailed the east coast.’

  Propped behind his computer is a handwritten postcard-sized sign in faded felt-tip, written in block capitals by a childish hand. It reads:

  ROB MULVANEY GONE TO THE ANTARCTIC

  Whereas Merlin and his fellow mycologists look down into the ‘black box’ of soil, Mulvaney and his fellow palaeoclimatologists look down into the ‘white box’ of ice. They use ice-penetrating phase-sensitive radar, which bounces off reflective horizons, to build up detailed images showing the internal layering and folding of deep ice. They use sonar: detonating explosions and mapping the echo returns. And they use core-drilling – the technique pioneered up in Camp Century by American scientists, while their military peers covertly tunnelled out the ice missile base.

  Mulvaney has worked with core from its early days as a technology, and he has personally designed and engineered several of the standard drill types used in British climate science.

  ‘For shallow drilling, down to twenty metres or so – that’s about 200 years back in time – it’s done by hand,’ he says. ‘Quick work. You stop off, set up, twist the drill down by hand. Any deeper than that and you have to move to electro-mechanical drilling: an engine-driven drill that’s dropped down and then pulled up again by winch.’