Laurasia had exploded too, fragmenting into wandering lumps that had the vague appearance of North America, Greenland, Europe and that part of Asia that today lies north of the Himalayan Mountains. Wegener was able also to suggest the paths of their various intercontinental excursions, and nudge them into their present shapes and dispositions.
The more that this modest, tweedy weatherman thought and theorized, the more it seemed probable to him that the two early continents of Laurasia and Gondwanaland had themselves in fact been one. This single Ur-continent came to be called Pangaea (though Wegener, who was credited with its invention, never actually used the word: the very Nordic term Pangaa appears in a later edition of his book, though it is not at all clear that he coined this either. The first use of the word comes in a 1924 translation of Wegener's book, by a man named Skerl). Pangaea had then broken apart in some giant mitosis, the Tethyan Ocean had swept in between the superfragments that resulted – and then many tens of millions of years later these two smaller bodies had broken up as well, eventually giving us the world we know and recognize today.
‘One day a man visited me whose fine features and penetrating blue-grey eyes I was unable to forget,’ the great German geologist Hans Cloos later recalled of his first meeting with Wegener. ‘He spun out an extremely strange train of thought about the structure of the Earth and asked me whether I would be willing to help him with geological facts and concepts.’ Such was the beginning of Wegener's attempts to get his idea accepted. It was a battle he fought long, and ultimately in vain. The world was simply not ready to accept that its surface moved with such immense drama.
Hans Cloos, who was himself to become a grandee of fundamental geology, with papers on the physics of faulting and the deep-seated deformations of granites, was kindly and sympathetic – though never entirely convinced. Wegener's theory, he wrote, ‘placed an easily comprehensible, tremendously exciting structure of ideas upon a solid foundation. It released the continents from the Earth's core and transformed them into icebergs of gneiss on a sea of basalt. It let them float and drift, break apart and converge. Where they broke away, cracks, rifts, trenches remain; where they collided, ranges of folded mountains appear. It was tempting to believe it – but it was not a temptation to which Cloos, thus far inhabiting a comprehensively proofless world, was quite prepared to yield.
The rest of the academic community was implacably hostile, almost to a man. ‘Utter, damned rot!’ said the president of the American Philosophical Society. ‘If we are to believe this hypothesis we must forget everything we learned in the last seventy years and start all over again,’ remarked Thomas Chamberlin, a towering figure in American geology, on hearing Wegener speak in New York in 1923. ‘Anyone who valued his reputation for scientific sanity,’ said a British geologist, at the same time, when Wegener's ideas were being given wide airing, ‘would never dare support such a theory.’
Harold Jeffreys, a giant among early geophysicists, denounced Wegener with indignation and scorn: however powerful the forces that might be brought to bear beneath the earth's crust, none could be sufficiently strong to move it. And what of all the suggestive evidence of the Permo-Carboniferous Ice Age cluster, neatly arranged around Gondwanaland's South Pole – perhaps the strongest piece of evidence that Alfred Wegener had? Mere ‘geopoetry’, they said, the stuff of little more than idle fantasy.
And so Wegener was pushed out into the cold, like a querulous customer in a bar-room of rowdies. Not a single German university would give him the professorship that his otherwise impeccable pedigree deserved; it was left to the University of Graz, in Austria, to offer him only the chair in meteorology. He was obliged to stand away from the geology that was the business of others.
Alfred Wegener died young, quite convinced that he was right, but with the world beyond equally convinced that he was wrong. His ideas, it was almost universally agreed, were the results of bad science at best, wishful thinking at worst.
He died in his beloved Greenland, contentedly engaged with the problems of what the weather was doing above the earth, rather than worrying over the complex strangulations of what might have happened below. He had helped set up an observation camp 250 miles inland, high up on the ice-cap, to study yet again the Byzantine wonder of the polar climate. He was said by his companions at the time to be deeply happy, blissfully unworried by the firestorm he had ignited among the academic community back to the south.
It was shortly after his fiftieth birthday, on 1 November 1930, that he and his faithful Greenlander companion, Rasmus Villumsen, set off to return to the west coast. It was very cold – recorded temperatures of – 58 °F – and dark; the only blessing was that the howling gales were, at least when they left the ice-camp, at their backs.
But neither man was ever seen alive again. The following May an expedition was sent out, and found Wegener's body, fully dressed, lying on a reindeer skin in a sleeping bag. His blue eyes were still open, and he seemed, the expedition report noted, to be smiling. It appeared that he had died of a heart attack; his companion had seemingly pressed on for the sea, but perished in the attempt. His body was never found.
The men who found him erected a 20-foot iron cross above the nameless spot on the glacier where he died. Sometime in the fifties, when another dog-team passed by, the cross had vanished. The glacier ice had moved on and torn itself to pieces, taking Wegener's body with it.
It would be stretching a point to suggest that the ice moved in quite the way the earth did. Indeed, the mechanism for the earth's postulated crustal movement was one of the factors that Wegener did not understand, and could not fully imagine; his inability to do so was one reason why his sceptical foes were so active and effective. But in Greenland the ice moved, and yes, whether it was provable now or sometime in the future, the earth's crust surely moved too. One can almost hear Wegener, calm and pipe-smoking to the end, insisting to those around him who would not believe, and using the very words that Galileo Galilei had used to the Churchmen who had made him recant nearly three centuries before: ‘Eppur si muove.’ (‘You may force me to say what you wish; you may revile me for saying what I do. But it moves’.)
And as with Galileo, so with Alfred Wegener. Aside from the barest murmurs of dissent from groups of present-day fundamentalists, creation scientists and Flat Earthers, the entire scientific world now happily acknowledges that Wegener, whom all once thought a crank, was in essence, and in fact, quite right.
Moreover, in the particular context of this story, it turns out that the very processes that Wegener first and so bravely suggested do indeed happen to underlie, both literally and figuratively, the making and unmaking of all volcanoes – the formidably spectacular eruption of Krakatoa among them.
3. Divination
Yet it was not anywhere near a volcano – and certainly not in the steamy heat of Java or Sumatra – where Wegener's theories first came to be confirmed properly. In the 1960s hard scientific evidence decisively proving the occurrence of continental drift flooded in from a great many sources – some of the most compelling being found fully 10,000 miles and two hemispheres away from Krakatoa, and eighty years after the catastrophe that happened there. Wegener would have savoured this particular irony of geography, since it was early exploration work in the high Arctic snowfields of east Greenland where some of his ideas were first fully tested and shown to be sound.
As it happened (and by a series of strange coincidences that I was not to appreciate fully until the day many years later when I stood watching the sound and light show from Anak Krakatoa), I played a part – a very lowly part but an unforgettable one – in one of the Greenland expeditions where some of those first confirmations of continental drift were gathered in. I was lucky: I happened to be in just the right place at what science has now shown to be just the right time.
It was the summer of 1965, and I was a 21-year-old geology student at Oxford. And though I did not attach any special significance to it then, much of the unravelling of the
most profound enigma of the world's volcanoes – why do some parts of the world erupt, while the rest do not? – started at the very same moment that I happened to win a place on a small expedition to a wild and unknown part of the east Greenland coast. While I was packing my steel crampons, shark-skinned skis and moleskin salopettes for the journey north, I had not the vaguest thought in my head that this trip might have anything to do with a tropical mountain of which I knew very little, and that lay half a world away.
From the moment I first spotted the Greenland announcement, thumbtacked on to a department noticeboard among offers of second-hand mineralogy textbooks and a former student's barely used Estwing hammer and Brunton compass, I was entranced by the thought of a summer in the cold of the far, far North. I positively yearned to go.
I had long felt a strange compulsion towards high latitudes. As a child I had been raised, quite conventionally for a Briton of my generation, on the heroic imperial stories of Scott and Shackleton, and, less conventionally, on the tall tales of even more heroic foreign figures like Fridtjof Nansen and Peter Freuchen. Much later, and thanks to the peculiar Arctic interests of my Everest-climbing Oxford professor, a tiny but physically and intellectually powerful man named Lawrence Wager, two of the most renowned of Greenland wanderers, Knud Rasmussen and Gino Watkins, became the greatest of my heroes too. Suddenly the chance of being able to take off to spend some time in their Arctic, in the wastes where they had made their names, seemed to me the most noble and romantic of ideas.
Since I had no obvious qualifications for making the team, I decided to teach myself a vaguely appropriate skill that might make me of some potential use. Morse code seemed as good a choice as any, and so I spent a fortnight learning it, and became in short order reasonably competent and fast. I then put the word around Oxford that I might in consequence have something valuable to offer. The ploy evidently worked. Shortly before the expedition was due to set off, and just as I had hoped and schemed, the leader called me for an interview, and, on hearing of my self-professed ability to tell a dot from a dash (he had me tap out the highly rhythmic code for the word ‘essences’ on his desktop), he signed me up. I was to go along as sled-hauler, because I was reasonably fit and strong; and I was required to add to my duties that of radio operator. Only out on the ice-cap did I discover that the team's radio was in fact set up for voice transmissions alone: there was no Morse key, nothing that would allow me to show off.
What happened that glorious high Arctic summer still remains paramount as the purest of adventures, the dream of every schoolboy everywhere. Despite my having subsequently lived a life of fairly unremitting world-wandering, that two-month expedition to the Blosseville Coast, south of the great high Arctic fjord-system (the world's biggest) known as Scoresby Sund, has never once been matched. The memories of those fifty days stay with me yet.
It started with embarkation in Copenhagen, the piles of expedition boxes among the coils of rope and crates of fish, the cold smell of the northern sea and the sweet-sharp aroma of Stockholm tar. It got properly under way a few days later, at the moment when, from the ice-breaker's chilly bridge-wing, we first picked out the luminous glow of the isblink on the north horizon of the Denmark Strait, and our little red ship began bucking and cracking her hull through the thick and wind-scoured pack-ice.
Greenland. The vast fjord-system of Scoresby Sund begins halfway up the east coast.
From then on, as we went higher and higher above the Arctic Circle, every subsequent moment, every experience, became vivid, intense, unforgettable. We landed on a remote beach on the iron-bound coast of the immense, mysterious island. We climbed, in brilliant sunshine, the ice-wall and then the crevassed length of a fast-moving, mile-wide glacier. We spent weeks camping high on the ice-cap. We rappelled down sheer walls of black basalt. We skied for scores of miles over snow where none had ever been before.
We learned to speak the Danish–Inuit linguistic blend called Greenlandic, in which the country is called Kalaallit Nunaat, ‘our land’, in which a snowflake is qanik, snow flurries nittaalaq nalliuttiqattaartuq, and a good forty-seven other words besides speak of snow or ice and their many varieties. We grew beards, we grew strong, we became bronzed by the perpetual midnight sun. And when the season was ending, and the dark and the cold crept in, so we would thaw our boots out each morning over the Primus stove and watch as our hot washing-water, when we tossed it into the air, fell back as a mist of perfect snowflakes.
There were problems, naturally. We ran out of supplies (except for low-temperature margarine, of which we had a good quarter of a ton), and so I – no great shot at the best of times, but the caretaker of the expedition's only rifle – had to shoot a polar bear for food. It was an aged bear, not at all tasty, and its limbs were riddled with Planaria, flatworm parasites that we had to tease from between its thigh muscles. The following day, entirely by chance, I followed the shooting of the bear by bringing down a goose, in flight, with another single shot. From today's perspective, all horribly incorrect things to do – except that we were keenly hungry, and there was nothing else to eat.
We then found ourselves socked in by bad weather, were delayed by two weeks, and our Danish ice-breaker had perforce to leave for Copenhagen without us. We had to risk walking for an endless day, sixty-pound boxes of precious rock samples on our backs, over a crazed sea-carpet of thin and fast-shifting ice-floes in order to reach an Eskimo settlement, and relative safety. We still needed food: we hunted musk-ox with the local men, and then dined with them on young seals, the seals' bellies opened up and filled with roasted sea-birds (to which we added from our near-depleted stores, as the most unfamiliar of condiments, bay leaves).
And we barely got home. The season was changing; the sun was setting earlier and earlier each afternoon; storms were blowing in from the north. The brave Icelandic pilot who came to collect us in a blizzard, in the near-dark, was killed the very next day, flying his Cessna into a cliff in that mythically ghastly part of north Iceland called the Claw. When we heard the news, we had been celebrating, eating cream cakes in the Savoy in London: we slunk away to our various homes in an awful, sombre silence.
But however memorable Greenland was as an experience, it was as science that our little expedition had its greatest value.
Ours was not the only expedition of its kind. At around the same time Oxford was sending people to Spitzbergen, Arctic Canada, Finnmark and elsewhere in the Arctic, with much the same scientific aims; and other universities and institutions did likewise. There was a great curiosity, particularly among geologists, about what could be discovered in what they called The Great White.
What we found out – or, more precisely, what was found out by others in distant laboratories once they had examined the rock samples we brought back – helped to prove a theory that, then still young enough to need the sturdiness of proof, turns out today in its maturity and certainty to have the most profound relevance to Krakatoa and to the key story of this book.
The frigid black-and-white coast of east Greenland may be a very long way from the lushly tropical green islands west of Java. But the two places in fact have a good deal in common, geologically. They are not formed from sandstone, or from shale, or from soft layers of fossil-filled chalk. They owe their origins instead to fire and brimstone. Both Greenland and Java are volcanic places, seared and branded into place by the earth's most elemental processes. And more than that: each was made, and stands where it does on the planet's surface, thanks to the workings of a once mysterious, much derided mechanism that was initially uncovered (or, at least, more than partly confirmed) by those who examined the collections, results and observations that our trifling little expedition and others like it brought back home.
Our collecting boxes (and many that we were obliged by the foul weather to leave behind and collect the following summer season) were filled with scores upon scores of carefully drilled and numbered samples of the country-rock of east Greenland. And that means volcanic rock.
At the latitude where we had been on the island's east coast, Greenland is more or less entirely underlain by basalt – a dark-grey, fine-grained variety of volcanic rock that was laid down in layer upon layer during Tertiary times, thirty million years ago.
Basalt is outwardly an unremarkable rock, generally scenically unpromising (except in its columnar variety, when it forms beguiling spectacles like the Giant's Causeway in County Antrim, or Fingal's Cave on Staffa). On close examination it is not at all pretty: it does not hold a candle to decorative igneous rocks like granite or gabbro or varieties of the more exotic porphyries; nor does it often compete as building stone with Jurassic limestones or Italian marble. But for the six of us trudging across the snows that summer, charged with this very particular task, the basalts did have one uniquely interesting feature, one that may not have been readily apparent to the casual glance, but that was crucial for what was then a fledgling programme of geophysical detective work.
Cooling basalts, it turns out, contain small crystals of iron-oxide compounds – principally of the cubic spinel mineral magnetite, Fe3O4 – that are highly magnetic. During the molten, plastic phase of their cooling process these crystals tend to act as miniature compasses, swinging hither and yon in the still viscous mix, in an elegant harmony that is extremely susceptible to the lines of magnetic force that radiate between the earth's North and South Poles.
Once the cooling has concluded, and the magma has passed what is known as the Curie point and become solid (technically frozen, though the word used here has nothing to do with the freezing of water and snow, which takes place at a much lower temperature), the alignment of the swarms of magnetite compasses becomes fixed, and is set for all time. And each, crucially, is then aligned to where the North and South Poles were at the time the rocks froze – in this east Greenland case, thirty million years ago. The compasses are thus powerfulforensic tools: they tell us where the poles were in relation to the rocks, or the rocks in relation to the poles, a long, long while ago.