Krakatoa: The Day the World Exploded: August 27, 1883 - Simon Winchester (2003)



And then,

the most humble of plants,

a moss.

And then,

one morning,

the first sound of an insect,

so dry

you would think it

still mineral.

And then,


– Max Gérard, 1968

It would be a bold local fisherman indeed who, any time after the summer of 1883, would dare steer his craft between the cliffs and islets and shallows that form the outer shell of old Krakatoa, and drop nets into the waters directly above where the volcano had once stood.

The sea in these parts by now had a fearsome reputation. For a long while after the cataclysm the Sunda Strait was a place that terrified mariners, and those who had to pass through it did so as quickly as they might. The idea of lingering to catch fish was quite out of the question: merely to peer down into the seas and wonder what might be going on deep below would give most passers-by the shudders.

The danger of a further catastrophe remained for a long while uppermost in the minds of everyone who had survived the first. For months no one would venture near the charred ruins of the remaining islands; only those who went out on the scientific expeditions dared, and they were reckoned to be foolhardy in the extreme.

But economic necessity is a hard taskmaster; and by the time six months had passed, the fear and the apprehension dissipated, as they always do. The various Javanese gods had been placated (with flowers and sweetmeats and offerings) and their anger assuaged (in part by the attacks on the Dutch soldiery). Slowly, one by one at first, and later in companionable little fleets, the prahus and the smacks were out bobbing among the Krakatoa reefs again, looking for fish. This time they may have been dodging the occasional clumps of pumice and stranding on the odd unanticipated shoals, but their doughty and long-experienced captains soon took to behaving as though nothing much had ever really happened.

And such remained the case, the fishing improving, the waters placid and unremarkable and comfortingly deep, the volcanic dangers steadily receding in the public memory – until one day, after almost exactly forty-four years had passed. Then, on the evening of 29 June 1927, a group of fishermen who were hauling up their nets after a day spent innocently trawling for wrasse and sweetlips, and trolling by line for grouper and skipjack, witnessed something entirely unexpected and wholly extraordinary.

With a great roiling and rumbling sound, a clump of enormous gas bubbles suddenly broke the surface of the sea. The bubbles seemed to be all around, to be rising in strange and random combinations to port, to starboard, ahead, abaft. * It was very confusing, and very frightening. Exactly where under the sea these bubbles – which exploded in clouds of spray and ash and foul-smelling sulphurous gas – were coming from, and whether they were coming from one point or from many, was difficult to say. The panicky sailors, caught in the midst of them, seemed to think they were concentrated a point more or less above where Danan, the middle of the three former Krakatoa peaks, had once been.

As a sea-mark, a point of reference, there had long been near the centre of the caldera a curious clump of needles of light-coloured rock that mariners (and the hastily printed new navigation charts) named Bootsmans Rots – Bo'sun's Rock. These guano-stained pillars, nearly vertical sheets of andesite that are, with the peak of Rakata, the only real relics of the old Krakatoa, rise fifteen feet out of the ocean directly above the old central peak of Danan – like ‘a gigantic club which Krakatoa lifts defiantly out of the sea', as one early visitor had it. Around the islets the waters, alive with scores of sharks, are 600 feet deep at least: the pillars rise from some unfathomable depths, and most fishermen still regard them today as they did back in the twenties, as a warning to keep back, a reminder that the volcano, if not all fully there in person, was still there in spirit, at the very least. *

And as if to underline the warning on this evening in June, the eruption of bubbles appeared to be coming almost from directly beneath the pillars, perhaps just a little to the north-west of them, and thus a little to the west of the old crater. Moving through the bubbles the fishermen felt the water quickly grow warm† – and there came a point where steam could be seen rising from where the bubbling had become most fierce. As the men paddled and sailed away as fast as they could, and as night began to fall, so they saw a diffuse red glow settle on the water, as if the bubbles were somehow mingled with fire.

Dr Verbeek, who had been the first to step on to the remains of the ruined mountain back in October 1883, and who had compiled his masterly study of the eruption two years later, would have known well what was happening. He died in 1926, but in 1885 he had written, with astonishing foresight:

… in any renewed activity of the volcano it is to be expected that islands will arise in the middle of the sea basin that is surrounded by Rakata Peak, Sertung and Panjang, just as the Kaimeni arose in the Santorini Group, and just as formerly the craters Danan and Perboewatan themselves formed in the sea within the ancient crater walls.

The bubbles were the first indication at the surface that a new volcano, lurking somewhere deep on the bed of this bathymetrically uncharted corner of the sea, was trying to build itself up. It came as something of a surprise, despite Verbeek's prognosis: when a survey was made in 1919 a shoe-shaped ridge was found to have developed to the north-west of Bo'sun's Rock, but there was no evidence that it was part of a developing volcano. But swiftly, in the aftermath of the random eruptions of bubbles and clouds of steam of June 1927, a distinct line of froth and bubbles and plumes of steam started to develop in the water – such that by the end of the year scientists were able to map a quarter-mile course through the water that appeared to mirror a rent in the seabed's surface, a thousand feet below.

The tenor of the activity then changed. The bubbles became more fierce, large fountains began to play from the surface of the sea, black froth, steam, spurts of ash and bombs of pumice began to surge from between the waves. Cones of water sixty feet high shot into the air, with rays of black magmatic material, like needles of jet, rising fifty feet further above the water-cones. As the eruptions became ever stronger, so domes of water, half a mile across, rose out of the sea, and the mixture of volcanic material within them gave a curious flecked appearance, with mottled layers of black and white and grey, so very different from the vivid blue seas all around.

And then, most bizarre of all, flames started guttering on the surface of the water, and then shooting out in huge yellow jets and sheets of fire: observers had the impression that the water itself was now ablaze, or had been covered with flaming oil, as if the scene were the aftermath of some terrible maritime tragedy.

Finally, on 26 January 1928, the volume of bubbles and flame transmuted into ash and solid rock, and broke surface: a thin curve of brand-new land appeared for the first time above the sea. This new land grew, black and sickle-like, for several days, until it formed a humped and scimitar-shaped island. It looked like a


A current official depiction of what the Hydrographer of the Royal Navy styles Anakrakata – the island of Anak Krakatoa, growing steadily at a rate of five inches every week.

sand dune 500 feet long and ten feet high, with a concave steeper side on its south-western edge and a rage of smoke and explosions discharging from its base. A Russian geophysicist named W. A. Petroeschevsky was on hand to see * the birth of this new piece of the world's real estate, and he gave it the name its successor still has today: Anak Krakatoa – the ‘son of Krakatoa’.

The mortality rate for new marine volcanoes is very high, and this one son did not survive for long: after a week the relentless power of the surf wore it away, and all that was visible in mid February was a patch of muddy-coloured water, occasionally pierced by a funnel cloud of smoke, steam, ash and, every so often, small ragged pellets of hot and plastic lava. Then, some months later, a new island appeared once again. This time eruptions from two separate points created a pair of cones that rose 700 feet above the sea and were joined to one another by a slender spit of land: but then the volcanic activity died away, the waves attacked and chewed away, and this new confection, after all too brief a life, slipped back beneath the surface.

Corrosive encounters between this matched pair of seemingly equally relentless and powerful forces – the volcano and the ocean – went on for the better part of the next three years. On some occasions the process of volcanic creation won the day, and land was produced that survived for a while. Sometimes the equally awesome power of the rainy-season seas and tides and currents made maritime mincemeat of it all, and reduced it to a pile of submarine grit.

The number of explosions was prodigious: during the twenty-four hours from noon on 3 February 1928, no fewer than 11,791 separate detonations were counted; on 25 June, an even more remarkable 14,269 – ten eruptions every minute of the day and night. The second of the islands stayed where it was long enough for scientists who were in Batavia attending the Fourth Pacific Science Congress in May 1928 to arrange an excursion there and do some real-time fieldwork: they were vexed when it slid back


Anak Krakatoa – the highly eruptive ‘child of Krakatoa’ – shown in 1979, nearly half a century after its explosive birth from below the sea.

beneath the sea again, destroyed by the relentless power of the waves.

Sometimes it was not just the waves that did the destroying: the newly appearing volcanoes occasionally self-destructed, blowing themselves to pieces, as happened with the third of the Anak Krakatoas in early August 1930. But gradually, and as a tacit reminder of the gigantic and unopposable forces of the subduction zone that was working away beneath it, the volcanic forces began to gain ground, and the island they were trying to create began to achieve a certain permanence.

On 11 August 1930 the submarine vents made their fourth concerted attempt to sculpt a lasting memorial on the surface. They put up a ring-shaped island that had the appearance of a large black doughnut – and it stayed put for two days. On its second day of existence a monumentally large phreatomagmatic eruption – the kind that results from the mixing of hot lava and hot gas with cold sea-water – tore upwards into the sky, reaching a height of almost a mile, and then dumped an enormous quantity of volcanic detritus back on top of the fragile wisps of island below.

Those that witnessed the explosions noticed a feature that would soon be regarded as typical of this kind of eruption – the so-called ‘cock's tail’ jets. The upward jets of the explosions are black with the material they carry, but they have outer edges that are rich with condensing steam, and so are starkly white. The whole phenomenon looks much like the tail of the more dramatic kind of male chicken.

And the dumping of an enormous volume of new material, all at once, seems to have done the trick. It allowed the island a degree of permanence that enabled it to stabilize and consolidate itself. Ever since then, the rate at which fresh ash and rock accumulate on the surface of the new island has managed to exceed the rate at which the island's edges are eroded away by the ceaselessly ruinous action of the sea.

The moment that Krakatoa's son was fully born it could be assured of the continued existence that it enjoys today. On the charts of the region the hydrographers of the various navies, recognizing the new status, steadily changed the colour of the island's outline from stippled blue, signifying new, temporary and uncertain, to the unbroken black that means established, permanent and fixed. It has been designated so ever since: Anak Krakatoa (or Anakrakata, as the Royal Navy's latest chart of the region now calls it) has been from August 1930 onwards as permanent a feature of the East Indies as Java and Sumatra have long been or, to be more realistic, has been as permanent as the islands of the Krakatoa complex that came before it.

It has, however, been an extraordinarily active volcano, growing rapidly and unstoppably ever since its birth. The observatory set up on Panjang Island by Petroeschevsky proved invaluable for the steady monitoring of its progress – as it grew from the twenty-foot-high weakling, half a mile long, that started life in 1930, to the 500-feet-tall peak, a mile long and half a mile wide, that it had become in 1950, to the 1,500-foot-high double-cratered monster of an island that it is today.

Its growth in size – from nothing – has been matched precisely by the growth – also from nothing – of its population of plants and animals.

For when Anak Krakatoa rose from the sea it was in all probability totally empty, * devoid of life and, in essence, quite sterile. Both its surface and its interior were, it was thought, far too hot to permit the existence of almost any kind of living thing; and the island was far too new to have any history, to possess any former biology or botany that might have the potential to generate a resurgence of life. The mountain was, to the fascination of biologists from around the world, a tabula rasa, ready to have the polychrome marvels of life painted upon it, layer upon layer, year upon year. It was a Garden of Eden, yet a Garden without plants, without animals and without mankind – and with a whole world of scientists waiting to see what might grow there, and what -might not.

But of course what remained of old Krakatoa was a clean slate too, the island remnants most probably all burned and sterilized by the flames of 1883. These two locations – the ruined remnant of old Krakatoa, and the newborn innocent of Anak Krakatoa – have thus become sites of huge international interest, where answers are still being sought to two fascinating questions. On the ruins of old Krakatoa – how did and how does life recover? And on the virgin-island that was later created in the midst of those same ruins – how did and how does life start? What were the differences, if any, between life returning and life beginning?

Of course these two questions could not at first be either asked or answered at the same time: biologists had forty-four years with only one site in front of them that they were able to study. In those early days there could thus be no kind of comparison. Ever since 1930 the three-island remnants of greater Krakatoa (if the scorched masses of Verlaten and Lang islands – Sertung and Panjang respectively – are to be counted, in ecological terms, as relics of the old volcano) and the brand-new single island of Anak Krakatoa have been standing there, beside one another, inviting inspection and comparison. Biologists from then onwards have been able to examine each, and try to work out if the mechanics of life-recovering-from-ruin (on the old islands) and life-starting-from-scratch (on their new neighbour) operated in the same way, in similar ways, or in altogether different fashions.

It is a study that continues today. More than a century after the creation in the Sunda Strait of what has turned out to be the extraordinarily useful biological laboratory of the new Krakatoa community, not all the answers are in, by a long chalk.

In considering the recovery of Krakatoa itself – which was all that could initially be considered – nineteenth-century scientists had one significant problem: because they could not be entirely certain what kinds of life had existed on the island before the eruption, they could not say – in what direction the island was likely to attempt to recover – what state it might be under pressure to return to.

Clearly it had once been richly endowed: John Webber's famous sketch, * drawn when Captain Cook's expedition made its melancholy  pause there in 1780, shows palms and ferns in gloriously feral abundance. Present-day botanists have pored over the picture to try to ascertain the various species Webber depicted: there is a type of grass that returned to the island in 1920, a palm-tree called Licuala spinosa that came back in 1982, and a fern that was first seen again in 1987.

Following the Resolution's sojourn, there had been some cultivation on the northern flank of the island, with a scattering of people (once even a small prison), and with goats, a vegetable garden and trees grown for firewood. The very few scientists who had landed on Krakatoa during the seventeenth, eighteenth and early nineteenth centuries had collected specimens of grasses, pepper plants, orchids and mahogany trees, as well as an unusual kind of parasitic mistletoe. One Dutch biologist went there looking for snails and found five types.

But no one had ever tried to produce a definitive systematic list of the entire populations that existed before the eruption: all that could be said with certainty was that Krakatoa had been covered with a snail-rich, orchid-rich, pepper-infested and grass-floored tropical rain forest, more or less similar to that found in today's Sumatra.

Despite this irksome lack of knowledge about what had gone before, the biologists from around the world who headed off in the direction of Sunda Strait knew that what awaited them in the aftermath of the eruption could well be fascinating. It would, one of those heading to the island wrote, ‘be very interesting to follow step-by-step the progress of the development of new life on this land now dead but which, in a few years, thanks to the intense heat of the sun and the abundance of equatorial rains, will surely have been recovered in its green mantle’.

The scientists fanned out with dispatch – and with care. Just like investigators who take elaborate precautions not to contaminate the scene of a disaster or a crime, so most of the biologists who came to Krakatoa did their best not to sully, with such usual contaminants as bacteria or seeds or rats or measles, the rare post-eruptive purity of the islands. It was a purity that remained untouched for some considerable while.

Rogier Verbeek was the first on to the island, in October, a scant six weeks after the eruption. And he was too early: when he first clambered on to the dusty shore, at a time when the islands' floors were still almost too hot to touch and mud flows were still pouring from the lava cliffs, he could see no living thing, nor any evidence that anything alive might be lurking near by. From a personal point of view it was a shame: given his heroic dedication to the story of the eruption, it might have seemed appropriate for him to be the first to find clear evidence of new life.

In fact it was a Belgian biologist named Edmond Cotteau who spotted the first stirrings, when he visited with a French government-sponsored expedition six months later, in May 1884. The leader of the expedition had reported finding much the same lifeless devastation as seen by Verbeek: ‘the magnificent vegetation which had been so often admired there remains nothing but a chaos of enormous trunks, whitened and desiccated, among the surrounding desolation’. It was dangerous too: Rakata's main cliff was eroding fast, and rocks were rolling down its sides in a ceaseless tumble, making an unending noise ‘like the rattling of distant musketry’.

It took the men a frustratingly long time to find a sheltered beach out of range of the fusillades of bouncing boulders. But then Cotteau, who had walked southward from the eventual first landing site on the north-west corner of Rakata, and who had managed to get all the way around the point to what is now called Handl's Bay, suddenly spotted something.

It was nestled between two rocks, on an otherwise arid and seemingly death-filled spit of grey and dusty land. This was the very first living thing that could with certainty be said to have appeared after the catastrophe: and it was, Cotteau wrote with measured excitement, a microscopic spider. He looked hard for


Nephila maculata, a ballooning spider.

another, but could find only this single specimen. Yet significantly, and with a nice symbolism, ‘This strange pioneer of the renovation was busy spinning its web!’ The lonely little spider was hoping, in other words, that it would eventually be lucky enough to catch a fly.

The arachnid's optimism was admirable, considering the trauma that must have otherwise unsettled him. Yet as it happened (though whether it happened for this one animal we cannot say), it was an optimism that was not at all misplaced. For within months an abundance of life – and that almost certainly included at least the modest sufficiency of flies required to satisfy a small army of spiders – began to return to the islands, in earnest.

This first spider's appearance on the island – and then the appearance of many of the life forms that subsequently resettled Rakata – in time triggered a question that has continued to vex the biological community for the many years since. Was there a chance that some of the animals and plants that first appeared did already in fact still exist on Krakatoa, as survivors? Or had life on what remained of Krakatoa been utterly extirpated – had it really been blasted and bombed and withered by the searing heat, and then buried under a hundred feet of ash?


Life returns to the Krakatoa beaches: a coconut husk, a morsel of random flotsam, sprouts a shoot, ready to become island vegetation.

If this last was the more likely explanation, then all of the new life that went into the repopulating of the islands must have arrived on their shores and crags from across the intervening stretches of sea. And if this was the case – if all the newly established forms of life were newcomers, in other words – how, exactly, had they come?

Had this one spider been lurking in a crevice and, though perhaps badly singed, been sufficiently compos mentis to spin his web for M. Cotteau? Or had a passing seabird, the spider lodged in one of his claws, landed on the otherwise uninhabited island, and left the insect behind when it flapped off into the air again? Had the spider floated in on a coconut husk, clinging grimly to the mesh of hairs until all the bobbing stopped? Or had it been borne in on the air, wafted on the breezes?

Today it seems most likely that wafting was the means by which this one baby spider reached the sea-red shoreline of Rakata. It is well known now that some spiders and other wingless creatures have a propensity for ‘ballooning’ – extending a strand of thread of silk from their bodies and allowing the wind currents to catch it and bear it and each of the creatures off to an unknown destination. Ballooning spiders can travel effortlessly for scores of miles: the sea crossing to Rakata from either Java or Sumatra would take no more than a trivial few hours. And in drifting and wafting on the breezes, this creature becomes a member of what has recently – and delightfully – been named the aeolian plankton, windborne kin to the microscopic drifters of the sea. *

Once properly under way the rush of life returning to the islands was impressive in both its speed and abundance. Crews of passing ships first thought they saw patches of green about a year after the eruption. In June 1886 an expedition spent four days on Rakata, and found they were right: they counted no fewer than fifteen flowering plants and shrubs – mostly beach plants, suggesting that these at least had arrived by sea – two mosses and eleven ferns. The visitors also found a gelatinous layer of blue-green algae in a moist film on top of the volcanic ash: this layer – wherever it might have come from – probably helped spores to germinate, it was later thought, and provided some kind of support for young and feeble rootlets.

Clearly something had helped – because by the time a new set of visitors arrived the following year there had been a positive orgy of rampant growth. There were now dense fields of grasses, so tall that a man could hide himself. The variety of grasses included Java's well-known alang-alang, which is always the first to grow (conveniently) after a forest fire and (rather less so) after a farmer has cleared a field for planting. There were tufts of wild sugar-cane poking out of the ash piles, many more ferns than the eleven that had been counted the previous year, scores of types of sand-binding creepers, hibiscus plants, self-fertilizing orchids, a very recognizable red-leaved coastal tree known as the Indian Almond, three varieties of fig trees and a pine-like tree that the Australians named (for its resemblance to the lush plumage of their native cassowary bird) the casuarina.

By 1906 the forests were thickening, the trees maturing, the climb to the 2,000-foot summit becoming ever more difficult as proper forests began to cloak the mountainside. Parties of visitors now had to hack their way in, getting attacked en route by red and black ants and carpenter bees, being surrounded by swarms of colourful butterflies, slipping on large earthworms, taking pleasure in seeing kingfishers, nightjars, green pigeons, wood swallows, bulbuls and orioles. Some visitors had reported seeing a large monitor lizard, and said that coconut palms had returned and were lining Rakata's southern shore.

Ever since then the island has become entirely overgrown. Casuarina trees on the coast stand well over a hundred feet tall. The mixed forests inland are alive with birds (among which are, prettily, the Zebra Dove, the Pied Imperial Pigeon, the Greater Coucal, the White-bellied Fish-eagle, the Brahminy Kite, the Orange-bellied Flower-pecker, the Pied Triller, the Mangrove Whistler and the Magpie Robin), together with beetles and centipedes, geckos, dragonflies, grasshoppers and tree-dwelling snails, a pompilid wasp that is designed solely to hunt and kill spiders (to the consternation of the descendants of M. Cotteau's first find) and a large snake that was initially identified as a boa-constrictor but that later turned out to be the species of the somewhat more congenial reticulated python. *

And civilian mankind's arrival, which was not always as carefully choreographed as the visits of those early biologists, resulted in the introduction of less comely animals. In 1917 a German named Johann Handl, to take one of the stranger examples, arrived on the southern end of Rakata with his family and servants, and announced that he was settling on the old volcano as a pumice collector. He built himself a small house on Rakata during (and presumably to get away from) the Great War; he planted a garden and lived comfortably in this somewhat unusual hideaway for the following four years. But it turned out that he had, presumably inadvertently, brought along with him in his boat a breeding pair of most unwelcome guests. A substantial population of Rattus rattus, the black rat, is now happily established on the island, and makes mayhem among the nests of most of Rakata's coastal birds.

And as the years wore on, so the numbers and types of plants and animals on the Krakatoan remnants waxed and waned, and in time created for themselves (by the way of what outsiders call the law of the jungle) some kind of biological equilibrium – a state that is never perfectly reached, a kind of biological nirvana, endlessly sought in every kind of complex community, yet rarely entirely attained.

Herr Handl's garden, once abandoned, filled quickly with ten kinds of weed. In the early 1920s a number of newly discovered large bees, velvet ants, * fungus gnats, scoliid wasps, mosquitoes, crane flies, swallowtail butterflies, fruit bats and woodpeckers were found. In fact Rakata was shown, forty years after the eruption, to be home to fully 621 species of animal. And by 1931 there were fully one hundred species of spider, according to a British spider expert called Mr Bristowe – the number and variety of everything having swelled almost exponentially.

Assuming for the moment that most of what exists today on the three islands of Rakata, Panjang and Sertung was brought in from across the sea (and was not born out of hidden survivors of the islands' original population) – how did it all arrive?

That first spider, as mentioned, very probably was of the ballooning variety. Other creatures and plants invaded by quite different means – all of them, when taken together, offering a powerful demonstration of the insistence of life to burst forth wherever it can, all showing the unquenchable nature of the fire in what the more romantic of today's biologists like to call ‘the crucible of life’.

The first samples of colonizing greenery, for instance, the creeping beach plants and shrubs and the small coastal forests, came by sea, rafted across on driftwood and pumice and other debris, * or hitch-hiking in with birds that feed on fruit and then excrete the seeds. The pioneering plants found in the inland areas were almost certainly created from wind-borne or bird-borne spores or seeds – and they had to be tough enough to survive with very little water and in the full glare of the sun. (Both they and their sea-borne coastal cousins would have an additional advantage if they were hermaphroditic, and could get along in an environment somewhat wanting for sexual partners.) The presence of the thin veneer of blue-green algae helped and it may well have been the key to getting the inland plant populations properly under way. The figs, especially, were typical of what could be brought in by this method – their presence in abundance being evidence of the way the fig tree, once settled, then manages to propagate itself.

As the spread of those first plants increased, and as new ones were introduced and started to compete and then struggle for existence and room – as the botanical ecology of the island began to change, in other words – so the zoological ecology changed too. As the coastal grassland began to give way to casuarina forests, as the woods on the mountain's upper slopes began to get darker and wetter and danker, so the populations of animals altered. The butterflies and beetles and open-country birds and reptiles that were the first to colonize the island, and that positively liked its dryness, started to be replaced by forest animals, geckos and skinks, bats and birds – the hobby, the barn owl and the hawk-eagle – that favour shade and like to live in a warm world dripping with moisture.

The overall result, a century and more after the eruption, is the existence today of a group of islands that have a markedly different biological and botanical make-up from the two great landmasses that lie fifteen miles to the north (Sumatra) and the east (Java).

One example will suffice: on the Javanese and Sumatran mainland there are twenty-four species of termite. Six of these live in hardwood trees, seven live in the dead trunks of living trees, six in wet softwood and five make their nests in the soil. On Rakata Island, though, there are a total of only eight types of termite. Not one of them lives in the soil; only one likes to inhabit the dead parts of living trees, just two like softwood and by far the greatest number – five species – prefer to live out their days in hardwood trees alone. Just why this marked difference might be is still a topic for much reflection. Perhaps Rakata's soil is still too newly volcanic, or the dead wood is perhaps just not dead enough. Perhaps the environment is fresher, more raw – there must be some good reason why termites do not much care for the island that once blew itself to pieces, and why they like the islands that have gone untouched for thousands of years.

Because of unanswered questions just like these, Krakatoa has remained for many decades the focus of intense studies worldwide, a fascination for a score or more of the world's leading botanists, and the target of expeditions and field-trips by the dozen. And yet, though the mechanics of the repopulation of the islands are now reasonably well established, the principal question that we set aside earlier remains sturdily only half answered: was the first population entirely fresh and new? Did it arrive on the devastated islands by sea and by air, coming from the volcanically wounded but far from biologically sterile outside? Or was it not really new at all? Did it start off with seeds or with living animals that somehow managed to survive the original inferno?

The controversy became so established a part of botanical lore that it long had a name: the Krakatoa Problem. Its central question – survivors or outsiders? – dogged entire generations of scientists, and was the trigger over the years for some bitter, angry, recriminatory and downright invective. Most of the ugly words swirled around the person of a forthright and feisty Dutchman named Cornelis Andries Backer, who held the delightfully titled post of ‘Botanist with Special Responsibility for the Flora of Java’ at the Buitenzorg Botanical Gardens; he first visited the islands in 1906.

Backer looked sceptically at the notion that all Krakatoan life had been destroyed, a theory agreed by almost the entire botanical establishment of the day, and proclaimed it to be near-total nonsense. He looked in particular, for example, at sweeping statements like that written by his superior, the Botanical Gardens' director, Melchior Treub, who had led the major post-eruption expeditions to Krakatoa and had written:

… at the time of the eruption the trees felled or smashed by violent outbursts must have been half-carbonized, in view of the extremely high temperatures that certainly prevailed over the whole island. After that, Krakatoa had been covered, from the summit right down to sea-level, in a layer of burning ash and pumice. This layer had a thickness varying between one and sixty meters. In those conditions it is clear that no vestige of the flora would have been able to exist after the cataclysm. The most persistent seed and the most protected rhizome must have perished…

Backer weighed into them with the kind of rhetoric hitherto unheard of in the genteel world of Edwardian botany. In 1929 he wrote and self-published a 300-page monograph that denounced the ‘hasty’ and ‘careless’ botanical work that had gone before, which, he insisted, resulted in the lazy, easy conclusions that all Krakatoan life had been wiped out. *

He had a venomous disregard for those who had carried out the early studies. Treub, he declared, was a prime example, a man who ‘was no florist, and whose knowledge of tropical plants was very limited’. Treub's expedition to Krakatoa had been ‘much too short’, the data acquired ‘very incomplete’, and his trip so shoddy an exercise that it was not worth calling it a scientific exploration at all but rather ‘a mere excursion of persons interested in the problem but not seriously devoted to trying to solve it’.

Other botanists went later to catalogue the growth of new plants. Backer accused them of ‘misspending their money’, acting under ‘childish delusions’, indulging in ‘vague speculations’ and making a series of expeditions that was ‘a complete failure’.

The tone of his remarks set off a firestorm of criticism from scientists around the world. But the underlying points he made were all seen to be valid: the principal one being that no one, he said, had ever spent enough time or carried out a systematic enough survey to be totally sure that nothing had survived the original cataclysm. It was easy to take a look at the island and surmise that nothing could have lived through the fire; but it had since become well known that some kinds of seed not only survive fire but actually need high temperatures of this magnitude to germinate properly. Was it not in fact highly likely that such seeds had existed, and survived, on Krakatoa?

The ash layers on the upper slopes of Rakata were thin, and would have been washed away by heavy rains. What if some roots and rhizomes that had been lurking beneath the earth's surface had lived – surely they would begin to sprout once tropic warmth and moisture and sunshine flooded their now ash-free setting?

Then again – the first expeditions had all noted (but had never properly investigated) the presence of greenery in the deeply scored valleys that lay between Rakata's summit ridges. Why had this greenery, whatever it was, never colonized the two lower islands, Sertung and Panjang? Why had these islands been given their vegetative resurrection much later than the upper slopes of Rakata? If airborne and seaborne immigrants were the source of this life, then all three islands should be gifted with new life at the same time. But they weren't. The upper slopes of Rakata got it first.

The answer to this and a number of similar unconsidered conundrums, Backer suggested, was that Rakata's colonization probably came from within – that surviving plants on the island's upper slopes had created the new life there; this was an upper-slope phenomenon that was entirely lacking on the islands Sertung and Panjang, which were lower in altitude.

It all made excellent sense – but it was a theory that was now, thanks to the sloppy field work and hastily written conclusions of the first years after the eruption, quite impossible to prove. And that was the shame of it: no one could henceforth ever be sure what had happened on Krakatoa's relic islets. Bad science, in short, had left mankind puzzled, a raft of questions unanswered, and the Krakatoa Problem essentially unsolved and, very likely, for ever insoluble. *


The same was not the case, however, over on Anak Krakatoa. For this was an island that was wholly new, and one whose newness precluded any possibility of there being survivors at all. Survivors of what, one might well ask. *And science was not about to make the same mistake that Backer accused it of making with Krakatoa. A later director of the Botanical Gardens, Karel Dammerman,  whose 1948 study of the islands became revered as the biological equal to Verbeek's famous geological study, said that in Anak Krakatoa

… we have an island originally entirely devoid of animal and vegetable life, with even a completely sterile soil. It is therefore of the utmost importance that the flora and fauna of this island should be constantly examined, and at regular intervals, and it is greatly to be hoped that this unique opportunity will not be neglected, as it was in the case of Krakatoa itself. [My italics.]

The first creatures to appear and to be noted on any of the four Anak Krakatoas (the first three islands were eroded to nothing by the waves: it was the second of these that was visited by scientists) were insects – first a very desiccated black cricket and next a female brown ant, both of which were already known to exist on Rakata, two miles distant. But their existence was cut short by the vanishing of their home; and the third Krakatoa did not survive long enough or peacefully enough for anyone to venture out to survey it.

But once the fourth edition of the island appeared in August 1930, and once it seemed to be enjoying some permanency, the scientists came out in their droves. One of the first was William Syer Bristowe, the English arachnologist who had enumerated the wild profusion of spider species on Rakata. * He was sailed over to the ashy shores of Anak, and in short order discovered a beetle, a mosquito, some ants – and three species of spider.

Plants came next: fifteen months after the emergence of the fourth Anak Krakatoa the northern coast of the island was littered with floating tree stumps, bamboo stems, roots and decaying fruit – eighteen seeds were discovered, and of these ten had already taken root. Another visit added four more plant species to the list, all of them already well bedded-in, together with moths, fungus and a number of migratory birds, mainly sand-plovers. All seemed set fair for an explosion of new life – when the volcano at the edge of the new island unexpectedly and catastrophically erupted once more, and all life appeared to have been snuffed out.

This was to happen three more times. Not until after a spasm of truly devastating eruptions in 1953 did some kind of volcanic stability return to the troubled young island – and yet then, and very unfortunately, it turned out to be a quarter of a century more before scientists returned in any significant numbers to the region.

For some curious reason, scientists stayed away from the new island. Perhaps biologists were just too fearful of the region's unpredictable vulcanicity; or perhaps they were afraid of the political troubles of the Indonesia of the time; or perhaps there were more mundane reasons, such as cuts in departmental budgets or the reordering of academic priorities. Dammerman's plea of 1948, that the world keep a very close watch on the island, was widely ignored – with the result that considerably less is known today about the resettlement of the island than should be known.

Krakatoa had itself suffered from bad and lazy science at the beginning of its post-eruptive phase. Now Anak Krakatoa was suffering from twenty-five further years of insouciance and benign neglect. It was left until the 1980s for research work on both mountains to begin again in earnest. It continues to this day – with every botanist and zoologist suddenly realizing that in order to learn as much as possible about these uniquely interesting and remarkably contrasting biological situations, there is much catching up to do.

The geological make-up of the island has changed in recent years, and in the 1960s lava flows – which were hitherto unknown in the Krakatoa region – began to cascade from the crater and flow down to the sea. More than half of today's island is currently covered by congealed black lava – meaning that large areas of Anak Krakatoa previously vegetated are now barren once again. Students of island biology find this irksome, to say the least.

Ian Thornton, an Australian biologist with a long-standing fascination for Anak Krakatoa, devised a simple experiment to see how rapidly insect life flooded into one of these seemingly barren lava flows. He placed plastic containers filled with sea-water on top of the flows – and waited to see how many airborne arthropods * they might catch. In ten days he found seventy-two species, including wasps, earwigs, moths and beetles: the aeolian tide of life appears to be quite as unstoppable as King Canute once found the sea to be.


A thick coastal casuarina forest on Sertung island, with Anak Krakatoa and Rakata in the background.

About 150 species of plant now inhabit the island: there are casuarina forests on the low and soft-soiled north-eastern shore; so-called wild sugar-cane, the aptly named Sàccharum spontaneum, bursts out of the hot and ashy slopes; delicate ferns are growing in the shaded parts of some of the jagged lava cliffs.

Once the plants were there, providing seeds and fruit and shade and moisture, and once the insect colonies that were first to be established had grown more varied and abundant, so the birds arrived and settled. The first to do so had to be ground-nesters (there being in the early years an inconvenient absence of trees) – birds like the savannah nightjar, the collared kingfisher (which can build its nest in the sides of gullies) and the white-breasted waterhen, which can settle in the mesh of salt-grasses at the margin of the sea.

Then, when the casuarinas were tall enough to allow nesting, in came the fruit-eating and insectivorous birds like the bulbul and the crow. And as the forests thickened, some amphibians that had somehow found their way across the sea began to slink in and make their nests – monitor lizards, paradise tree snakes. And, inevitably, rats.

Next a generation of fig trees started to flourish – and fruit-eating and fig-eating pigeons and doves arrived to feed on them. They began to jostle for space and, in doing so, began to drive out some of the lesser first arrivals, among which were the ground-nesting birds whom the jungle law dictated had now probably outstayed their welcome. Raptors then took over from the doves. In time the peregrine falcon arrived, established himself as Anak Krakatoa's avian monarch and, together with the barn owls, began to feed sturdily on the rats.

Thus, steadily and slowly, the population strengthened, evolving in appearance and flavour from being just the result of casual happenstance, becoming the ever more determined and rugged collection of island species that it remains today. And yet: nature proposes, but fate disposes. All of this happy development has been interrupted again and again – in the seventies and the nineties – by the mountain blowing its top.

Today the population that has consolidated itself is distinctly different from that on the relics of old Krakatoa, as well as from that on Java or Sumatra. But the degree to which the animals and plants are actually going to be permitted to sustain themselves is far from clear: the ash and the lava that falls nearly continuously now is wreaking havoc with what could otherwise be a vastly theatrical biological experiment, laid on for the world to see. What could be grand theatre turns out, all too often, to be just a tease.

The Great Chain of Being, an idea that has been in existence since the time of Aristotle, connects every living thing into one vast and seamless hierarchy – a system in which the Almighty, with Man just below, stands at the apex. If one wishes to look at illustrations of the processes that lie at the lower end of this grand and somewhat fanciful scale, one need only look at the creation of life that can be seen on Anak Krakatoa and at the re-creation of past life that can be seen on the relics of old Krakatoa. In both places the processes are in fact remarkably similar, though varied in detail.

Both processes seem to have begun with the making of films of bacteria, which clung to the beds of volcanic ash and coated the ragged, burned ruins of once-hot rock. Matters got properly under way with, on the one hand, the arrival of fungi and simple grasses, and with, on the other, the addition of spiders and crickets and beetles. Things continued with the establishment of ferns and orchids and more general plants, a mix of botanies into which were eased the herbivorous birds and a scattering of small animals; then came the fruit and fruit-eating insects and the perching, nesting birds – and finally the larger animals with teeth and snapping jaws that would, in time, prey on all of these.

The list is seamless, the Great Chain set down for all to see. Bacteria. Plant. Insect. Fruit. Herbivore. Carnivore. It is the classic development of life – a development a little more complicated on old Krakatoa perhaps, because of what lived there before and may have survived – but in all other senses, and assuredly so on Anak Krakatoa, entirely classic.

To the outside world the eruption of 1883 may have spelled death and devastation. To the world of biology and botany, however, the subsequent energetic happenings on islands in the Sunda Strait represent nothing more or less than a freeze-frame picture of the future of life itself – a demonstration of the utterly confident way that the world, however badly it has been wounded, picks itself up, continues to unfold its magic and its marvels, and sets itself back on its endless trail of evolutionary progress yet again. The crucible of life turns out to be the most difficult of vessels to break: not even the world's most dangerous volcano could do it truly irreparable damage.