I know more about continental breakfast than continental drift, but apparently the latter accounts for the fact that the south pole doesn't stay still. It drifts at a rate of about 10 metres a year, and because of the Earth's axial tilt (a complicated scenario of rotational obliquity  pass me another croissant), it also wobbles. Every New Year's Day, the pole's marker is moved to indicate its new position, though in the time it takes to drive the marker into the ice-pack the pole has already shifted slightly.

There are other poles on Antarctica, and they too move around, pursued by scientists with their markers. There's the pole of inaccessibility, for the greatest distance from a coast; the cold pole, for the most frigid place; the pole of variability, for the spot with the greatest range in atmospheric pressure. The most (upwardly) mobile is the south magnetic pole, which has moved over 500 miles north-west since its discovery by members of Shackleton's Nimrod expedition more than a century ago.

In Antarctica, "X" never really marks the spot. It's as if the continent were conspiring to mock that human nervousness, the urge to get an accurate fix on a place and, in so doing, claim it. Placing a marker anywhere in the Antarctic is a highly symbolic act. Although no country owns the geographic south pole, it is the American flag that stands next to it. Nearby, at the ceremonial pole, there is a semi-circle of 12 flags, representing the nations that, in a treaty of 1961, agreed to put the question of ownership on hold (which makes the presence of the American flag at the "real" pole rather mystifying). Today, as in the "heroic" age of discovery that is the subject of Chris Turney's book, 1912, the flag  in extremis, often just a rag on a flimsy tent pole  is an expression of entitlement: to immortality, or national interest, or scientific pre-eminence, or a combination of all these.

So strong is the need to lay a frozen glove on Antarctica's secrets, that men, and more recently women, have volunteered themselves for trials worthy of Beowulf, The Odyssey, Dante's Inferno. Every story of Antarctic exploration is hitched to this quest genre (Shackleton famously enlarged it, mid-storm, by reciting gusts of Browning's valorous monologue "Prospice"), and Turney's account of the five expeditions of 1912 is no exception.

The explorers  Robert Scott, Roald Amundsen, Nobu Shirase, Wilhelm Filchner, Douglas Mawson, and their teams  encounter the beasts of "katabatic" winds (cold, bearing down), crevasses that gobble them up, temperatures that shatter their teeth, and the coreless vortex, or "kernlos", of the Antarctic winter. They suffer starvation, frostbite, snow blindness, madness (one man's last act before dying is to bite one of his fingers off), yet still they are pulled deeper and deeper into terra incognita by "the lure of little voices". And all this with a stiff upper lip, though in minus 70C how could it be otherwise?

Back home, the public feasted on reports of these extreme adventures, framing both success and defeat (Shackleton's failure to set foot on continental Antarctica, the death of Scott and his party) as a kind of moral aggrandisement. The key was not survival so much as persistence (Shackleton sailed in the Endurance), and death in this context was always virtuous. "The toll of human life was still demanded, and was still cheerfully paid," as Lord Curzon, president of the Royal Geographical Society, put it. Amundsen, a great technician who reached the south pole first and, thanks to his clever management of supply depots, got his men back with increased body weight, was held to be something of a cheat. (Curzon privately dismissed him as a sneaky "self-seeker", though Amundsen's death in 1928 during a rescue mission for a beleaguered party near the north pole suggests otherwise.)

Curzon himself was an arch manipulator who worked to discard or even suppress elements of the British polar story that did not sit well with the sanctifying myths of Antarctica. The strong likelihood that Lawrence Oates took a powerful opiate before disappearing into the blizzard was not advertised to the public. Nor was the suggestion that Oates, along with Scott and the other three men, might have survived had the returning party ahead of them left sufficient fuel and rations in the last supply depot. One of Scott's final journal entries referred to the "lack of thoughtfulness and even of generosity" of Teddy Evans, his second-in-command, whose party had all but exhausted the supplies weeks earlier. Another member of the expedition, Edward Wilson, referred in his diary to the "inexplicable" shortage. The widows of both men, with Curzon's agreement, decided to withhold this allegation and "to keep [it] secret".

When Turney examined Wilson's diary (written in pencil), he found "gaps in the text", as if some entries had been rubbed out. He also discovered seven pages of previously unpublished notes alluding to the cover-up in Curzon's papers at the British Library. This is something of a scoop in what is otherwise a rehash of well-known material (except for the long-neglected story of the Japanese attempt on the pole). But the affair is tacked on to the end of the book and Turney hesitates to pursue its implications  that the morally redemptive story of Scott's death was stage-managed to obscure a competing narrative of sauve qui peut.

The instinct to self-preservation was not put on ice by Antarctic explorers. These men may have "sallied forth", "soldiered on", "blazed a trail" (Turney leaves no cliché unturned), but as they pioneered a continent their conduct often fell short of the altruistic ideal. When Evans reached the supply depot ahead of Scott, he was in a dreadful condition, suffering from scurvy and the bitter disappointment of being ordered back short of the pole by Scott. He may have consumed more than his share of supplies. And he may have lived as a result.

When the weather closed in, men were pushed into cramped proximity that could degenerate into a version of Bedlam. The crew of Filchner's German expedition were drunk for much of the time, waving revolvers around and threatening to kill one another (one later claimed he was actually shot at). They behaved, said one team member, like "a bunch of pigs". One went insane and on returning home was interned in a lunatic asylum, where he spent the rest of his life.

When the American admiral Richard Byrd sailed for Antarctica in 1928 his supplies are said to have included "only two coffins, but a dozen straitjackets". Eighty years later, in the medical room at Halley, the British Antarctic base on the Caird Coast, Gavin Francis finds ample stock of the modern substitutes  body bags and intramuscular injections of antipsychotics (Empire Antarctica: Ice, Silence & Emperor Penguins, Chatto & Windus, £16.99). But during his one-year residency as camp doctor, he has no use for either. In fact, beyond a bit of improvised dentistry, his skills as a physician are rarely tested. He has time on his hands  "a Mahabharata and Ramayana of time'  and this is the treasure he has come to the remotest place on Earth to find.

It is the "blankness" of Antarctica that appeals to Francis's imagination, "the absence of worn paths or cultural memories", "a whitewashed primordial backdrop against which ideas, memories, ambitions, regrets, could be examined without distraction". His freshman experience of this campus for the study of the self  Universitas Antarctica  is something of a disappointment. Arriving at Halley (formerly Ice Station Zebra), he finds skidoos, mobile cranes and snowcats spewing diesel fumes across the ice, carving an "avenue of noise" as they unload a huge tonnage of supplies from the ship on which he has sailed.

Although modest compared with the American super-station at McMurdo (a mere 1,000 miles away), with its bowling alley and decommissioned nuclear reactor, Halley bristles with fuel drums, radio masts and scientific machines for measuring this and that. Years after being abandoned, the twisted metal carcasses of earlier Halley bases have been carried away by the ice, their staircases and radio antennae jutting out. The accommodation block at Halley IV offers very little private space, an extensive collection of porn films, and the challenge of living cheek-by-jowl with 14 other people. Of the first evening together, Francis writes: "We shared ourselves in careful and calculated ways, like members at an Alcoholics Anonymous meeting." It is several months before he has a proper conversation with one of them.

Beyond Halley's perimeter stretches the vast "empty canvas" on which Francis hopes to "unravel" his thoughts, but he cannot go there unaccompanied. Unlike one fellow resident, who doesn't step outside once in three months, Francis will not be a recusant. He records his excursions, even if they only take him on to the steps of the accommodation block, with gentle excitement: a cupful of boiling water thrown into the air will freeze at once "with a soft and percussive 'whoosh'"; exhaling softly he hears "an unfamiliar sound: the vapour in my breath was freezing immediately it left my mouth. It rustled and tinkled like the very distant breaking of glass." He hears "the cochlear hum of a polar silence", notices the "polished sheen" of snowdrifts, "as if rubbed smooth by centuries of pilgrims' fingers", and the Dog Star "flaring like a welding spark".

There are occasional field trips, though constant radio communication with base must be maintained (on one occasion the chosen bandwidth is "taken over by the yammering din of a Latin American taxi company"). Francis relishes these expeditions because they bring him closer to the "murmur" of Antarctica and to the emperor penguin, the "wondrous beast" of his personal quest narrative. Yet when he muses on whether he might learn something from the penguins  about "the purity of living in the physical senses, of a life without tangles of motives", of "forgiveness"  I start to drift, hopefully in the direction of Werner Herzog's film Encounters at the End of the World, in which he sends up this ecumenical fantasy by asking if penguins can be gay.

 Frances Stonor Saunders's The Woman Who Shot Mussolini is published by Faber.