South: The Race to the Pole

1 WHITE DESERT

by Pieter van der Merwe

Looking up the Gateway to the Beardmore Glacier with Mount Hope on the left; taken by Captain R. F. Scott, 9 December 1911.

Most people know the Moon better than Antarctica. The ice-bound continent at the far end of the world is the fifth largest, Europe and Australasia being smaller, but until the early 1800s it was as far beyond human imagination as it is beyond sight.

Antarctica’s 14.2 million km² (5.5 million square miles) would cover the United States and Central America, while France and Britain together would fit easily into either of its two great bays, the Ross and Weddell Seas. Apart from small areas of the coastline and the peaks of its mountain ranges, it is permanently covered by some 29 million km³ (7 million cubic miles) of ice, lying on average between just under 2 and just over 3.6km thick (1.25–2.25 miles). The ice sheet has been there for at least 25 million years. Its weight is so vast that, in places, it has pressed the underlying land mass hundreds of metres below sea level.

Great God, this is an awful place

Scott at the South Pole, 17 January 1912

Over 90 per cent of the world’s fresh water is locked up in the Antarctic ice. Were it to melt, the planet would become uninhabitable and its land would shrink unrecognisably as the oceans rose by between 45 and 60 metres (150–200 feet), drowning most of the islands and coastal nations that we know. Of New York, London and other great maritime cities, only the abandoned shells of tall buildings would rise above the surface. Seen from these decaying grave markers, the view would often be of many new islands but with extensive land only on distant horizons, if visible at all.

Antarctica would also look very different but would still be the size of Australia and Indonesia. The peaks of the great Transantarctic Mountains would rise to between 2,000 and 4,000 metres (6,500–13,000 feet) over the rocky plateau of Eastern or Greater Antarctica. This is the older part of the continent, lying to the ‘right’ of the Greenwich and 180° meridians of longitude. Even below the ice this is still high ground, averaging about 460 metres (1,500 feet) above the sea. Western or Lesser Antarctica, the geologically younger area to the ‘left’ of longitudes 0/180°, which includes the 1,290km (800-mile) finger of the Antarctic Peninsula reaching towards South America, would by contrast have largely fragmented into an archipelago of islands between the enlarged Ross and Weddell Seas.

While the fossil record shows that prehistoric Antarctica was once a warm and life-rich zone, the prospect of a thaw making it one again is equally remote – man-made global warming aside. The ice and the rock beneath are inseparable and the continent is not only by far the coldest place on Earth but also the highest, the mean height of its frozen surface above the sea being between 2,130 and 2,440 metres (7,000–8,000 feet). This is more than twice as high as Asia, its nearest rival at 915 metres (3,000 feet) on average. The South Pole itself is at 2,900 metres (9,500 feet), so the European race to it was in no sense one between competitors and climate on a level playing field: it was a climb to, and endurance at, an altitude that is usually the province of mountaineers.

The spectacular grandeur of the West Antarctic Ice Sheet and mountains; taken from a window of a NASA ‘Operation IceBridge’ aircraft, 31 October 2016.

How the polar ice sheet originally formed is the subject of at least five theories. That it endures is partly due to its massive thermal inertia and altitude, and to the fact that the direct solar heat it receives during the brief Antarctic summer is reflected by its own whiteness into space rather than absorbed. Much also has to do with its being surrounded by the cold but biologically teeming waters of the Southern Ocean – the resource, in terms of whaling and sealing, that led to man’s first commercial interest in the region in the 19th century.

Most remarkable, perhaps, is how little appears to sustain the mainland ice coverage. Antarctic cloud, drawn in from the warmer ocean to the north, is high and thin – another factor preventing heat retention. Rain is practically unknown save for occasionally on the coast, and snowfall is surprisingly light. On average, snow equivalent to only about 16.5cm (6.5 inches) of water falls in a year. Perhaps less than 5cm (2 inches) falls near the Pole, as the high-altitude cold air inland is about ten times drier than in temperate areas of the world. Very little melts, however, since most of the continent stays well below freezing. It is a vast, dry and intensely cold desert, built up layer on minute layer over unimaginable time. Nothing decays: mummified seals several thousand years old have been found well inland. One of Scott’s dogs still guards his base camp nearly a century after its death, teeth bared in a desiccated snarl. Dead human bodies are preserved, freeze-dried, as is all normally biodegradable waste. The only indigenous plants are a scattering of highly adapted lichens and mosses clinging to exposed rock, mostly near the coast. All other life is sustained in or from the sea, with seals and penguins the only large animals that breed on the mainland.

In the deep Antarctic winter months of August and September, mean temperatures range from -20 to -30°C on the coast and from -40 to -70°C inland. In summer the interior remains between -20 and -35°C with the coast hovering around freezing point, although the Antarctic Peninsula can see brief rises to 15°C (59°F). By contrast, 0°C and -20 to -35°C are the normal summer and winter mean temperatures of the much warmer Arctic, which is a frozen ocean surrounded by continental land masses – it is Antarctica’s complete physical as much as polar opposite. The lowest temperatures on Earth, -89.2°C (1983) on the high interior and -60°C near sea level, are Antarctic records. At such temperatures fuel oil congeals into jelly.

By far the worst aspect of the cold in human terms is the additional effect of ‘wind chill’, for every knot of wind speed is the physiological equivalent to a drop of one degree. Frostbite in such conditions is a routine danger and rapid hypothermic death a penalty for accidents or failures of planning. These are the hazards that Scott and Shackleton’s generation were neither the first nor the last to face with no more than wool, silk and other natural types of clothing – none with the thermal efficiency of modern synthetics.

Wind is ever-present in Antarctica. The surrounding Southern Ocean is the stormiest in the world, with a 4.5-metre (15-foot) swell normal in calm conditions. Gales and cyclonic storms are perpetually being generated around the ‘Antarctic Convergence’ of cold polar air and seas with warmer ones at about latitude 50° south. These storms chase each other endlessly west to east around the world, creating huge seas that sweep on, unimpeded by intervening land save the few sub-Antarctic islands. The ‘roaring forties’ latitudes in which clippers like Cutty Sark drove eastwards on the Australian wool-run and home round Cape Horn merge with the ‘filthy fifties’, where the average wind speed is 37.7 knots – a force 8 gale. South from here, notwithstanding the wind, endemic Convergence fogs and the increased risks of ice add to hazards that only modern ships are fully equipped to handle.

If you drop a steel bar it is likely to shatter like glass, tin disintegrates into loose granules, mercury freezes into solid metal, and if you haul up a fish through a hole in the ice within five seconds it is frozen so solid that it has to be cut with a saw.’

John Bechervaise, The Far South, 1962

In the high mainland interior, winds are relatively light. However, heavy cold air pours down from the interior to the coast, creating fierce local storms. At worst, these ‘katabatic’ (descending) winds can average more than 160km/h (100 miles an hour) and have been measured in gusts of more than 240km/h (150 miles an hour). These storms easily become turbulent and, while no new snow is involved, they whip up the granular surface crystals formed by recent falls into lethal sub-zero blizzards. It was in such conditions on the low-lying Ross Ice Shelf that Scott’s party died in 1912.

It is not only wind that pours off the highlands. So too, on a longer timescale, does the ice itself in the spectacular coastal glaciers that formed early explorers’ gateways to the interior. Of these, the 161km (100-mile) Beardmore and the nearby Axel Heiberg Glaciers are (though not the largest) forever linked as Scott’s and Amundsen’s routes up to the Pole. They and five others flow down at a rate of about 335 metres (1,100 feet) a year to feed the Ross Ice Shelf, which fills the landward end of the Ross Sea. This – also called the Great Ice Barrier – is the largest of a dozen that make up about a third of the Antarctic coastline. At 803,000km² (310,000 square miles) it is larger than France, and ranges from 610 metres (2,000 feet) thick on the landward side to 185 metres (600 feet) thick at seaward.

The combined Filchner-Ronne Ice Shelf in the Weddell Sea – named after its German and American discoverers, Wilhelm Filchner (1911) and Finn Ronne (1947) – is next largest at about 451,000km² (174,000 square miles), of which the Ronne makes up just under 333,460km² (128,750 square miles). From the ‘ice front’ or outer edge of the shelves, which can present cliffs of more than 30 metres (100 feet) to approaching ships, tabletop icebergs more than a mile (over 1.5km) long routinely calve off and float more than 3,200km (2,000 miles) north before breaking up, which can take five years. They can be of even vaster size, 145km (90 miles) in one measured instance, and sometimes make spectacular appearances off the South African coast. This is an entirely normal process fuelled by pressure and stresses as mainland glaciers slowly push the shelves out from the coast, but it is also one that provides dramatic demonstrations of how global warming may be speeding up such mechanisms. Scientific opinion now agrees that the build-up of greenhouse gases, especially carbon dioxide, due to an ever-expanding human population’s attrition on such carbon-sinks as rainforests and a still overwhelming reliance on fossil fuels, is warming the Earth’s atmosphere and oceans at a debated but inexorable rate. Warming seas undoubtedly displace or destroy species and food chains that depend on cold waters and cannot rapidly adapt. They also change weather, usually for the worse in the short term and – should existing ocean currents also shift as a result – may produce radical and irreversible alterations of climate. Since 2000, there has been a dramatic and apparently permanent shrinkage of the Arctic ice cap, and while the Antarctic has far greater climatic inertia and stability from its greater area and (under the ice) an enormous land mass, it is also affected, albeit so far only at its outer edges. Whereas Arctic sea-ice depletion is largely from direct melting and that of the Greenland ice sheet is a 50/50 split between melting and icebergs, 99 per cent of Antarctic ice-sheet loss is from icebergs ‘calving’ from it. Even allowing that this is a peripheral process, a 2012 study predicted that the vast Filchner-Ronne Ice Shelf may largely disappear by the end of the 21st century, raising the world sea level by about 43cm (17 inches). In 1998 and 2010 two sections of it – nearly ten times the size of Greater London – broke off before disintegrating into smaller bergs, some of which were sighted 4,830km (3,000 miles) away off New Zealand. In 2000 the largest ever recorded, measuring just over 17, 600km² (6,800 square miles), detached from the Ross Sea Barrier, while in 2002 the 10,000-year-old Larsen-B ice-shelf in the Weddell area partially collapsed and is predicted to disappear entirely by about 2020. Most recently, in July 2017, and after creeping northwards for over ten years, a vast split in the Larsen-C shelf calved an iceberg – prosaically coded A68 – of about 5,800km² (2,240 square miles) – over three times the size of Greater London – with cliffs along the split over 457 metres (1,500 feet) high and an estimated mass of a trillion tons (i.e. 10¹² or a million-million). Even this, however, comprises only 12 per cent of just the Larsen-C shelf. In January 2017, another crack developing in the Brunt Ice Shelf further east also forced the British Antarctic Survey to tow the 200-ton module comprising the current version of its Halley base, established in the 1950s, 23km (14 miles) further ‘inland’, to avoid the risk of being set adrift.

Scientific opinion now agrees that the build-up of greenhouse gases is warming the Earth’s atmosphere and oceans at a debated but inexorable rate.

The degree to which these and other phenomena are either ‘natural’ or symptoms of climatic stress on a global scale due to human activity is much argued. But since neither air nor ocean respect human boundaries, the critical question is what the outcomes will be if they continue at an increasing rate. Apart from the huge costs of coastal protection, where practical, it will take little more than a metre of permanent global sea-level rise to drown some small, low-lying island states in the Pacific. This raises the question of where their people will go, or whether a nation can still exist if its land does not. Although likely to occur over long timescales and not as the result of the sort of sudden apocalypse envisioned by Hollywood disaster movies, the consequences of greater forced population shifts from large continental coastal areas, such as the Ganges delta, are even more incalculable. Other climate-change effects, like ‘desertification’ in parts of Africa, already contribute to more short-term causes of ‘uncontrolled migration’, but should rising seas drive coastal-plain populations in the millions to compete for space and resources on already crowded higher ground and across political borders, currently familiar migration problems may look quite minor. While there are climatic risks associated with Antarctica, it is a reassuring measure of its vast thermal inertia that – dramatic but peripheral symptoms like those mentioned aside – the last half-century of scientific readings across the continental interior has shown no significant longterm variation in its state of immemorial deep-freeze.

James Weddell with his ships reached a ‘furthest south’ in 1823 while seal-hunting and exploring in what became known as the Weddell Sea. Aquatint after WJ Huggins, October 1826.

The main Antarctic Barrier ice and bergs are of fresh water, being formed originally from compacted snow. The seasonal pack ice, which is far more dynamic in its movement and covers the greatest area, forms by a complex process from seawater into sheets of up to about 15cm thick (6 inches), rising to about 1.8 metres (6 feet) or more if it survives for more than two years. By the time it has lasted three years it is ‘old ice’ and has lost its surface salinity, providing good drinking water. The mainland lies almost entirely within the Antarctic Circle (66° 33’ south, the outer limit of 24-hour polar daylight in summer and darkness in winter) but the winter pack – at maximum extent in August and September – reaches north to latitude 54° in the Atlantic, 56–59° in the Indian Ocean sector and 60–63° in the Pacific, the Antarctic Convergence in both the last two being further south. At 60 nautical miles (112km) to each degree and expanding in all directions northwards, these are vast areas and can be greater in a severe season. Seen from space, the winter area of the Antarctic ice can practically double. However, there are astonishing variations, famously exemplified by the Scottish sealer James Weddell’s penetration of the sea that bears his name in 1823, when he reached just over 74° south without encountering significant ice at all.

A 1754 chart of the southern Pacific, including an inset speculating about the size and shape of Antarctica, by Philippe Buache.

Linear distances are also daunting. The tip of the Peninsula is 965km (600 miles) south of Cape Horn across the stormy Drake Passage but, isolated islands apart, New Zealand is the next closest land at 3,380km (2,100 miles) away. South Africa is some 4,020km (2,500 miles) away and the south coast of Australia around 3,700km (2,300 miles). Lesser and Greater Antarctica together, measured west to east through the Transantarctic range, are about 4,500km (2,800 miles) across at their widest. The narrow