The technology is simple enough. Some years ago a group of geologists from the Geological Survey of Indonesia and the US Geological Survey installed an array of seismic sensors on Anak Krakatoa, scattering some into clefts in the lava surface and settling others into holes drilled some few feet into the slopes of the mountain. The sensors were connected to a coder and to a radio transmitter built into a tough aluminium box. This box was then buried in a trench dug on the eastward-facing, Java-facing slope of the island, a couple of hundred feet above the sea and in line-of-sight with the Observatory that was at the same time being built north of Carita.
A solar panel on a mast above the buried box assured an uninterrupted source of power, and therefore a seamless flow of signals – such that night or day, every day of every year, what was happening seismically on this most potentially violent centre of the Krakatoa complex would be sent instantly across the Strait, to be picked up by the cluster of radio aerials that rises above the yellow-painted, rarely noticed and insignificant little Observatory.
The rules laid down by the Volcanological Survey of Indonesia require that there will always be at least one observer on duty inside the building. When I stopped by, the point-man was a thin, tired-looking and rather nervous forty-year-old named mas Sikin,* who lived in a nearby village. When we met he was halfway through his week-long shift, keeping the world's most notorious volcano under close invigilation – a duty for which he was paid the equivalent of fifty dollars a month, together with a substantial ration of rice.
He occupied two of the Observatory's rooms – the others were assigned to the Survey's chief, whose office was eighty miles away in Bandung and who stopped by only in the event of an emergency. In one of Sikin's pair of rooms there was just a cot and a hand-basin. In the other, under a formal portrait of the current Indonesian president, Megawati Sukarnoputri, on a trestle table beneath which were four large twelve-volt car batteries, was the monitoring machine itself, a black-and-silver chrome box with a metal plate identifying it as a radio-seismograph, made by a venerable American earthquake-measuring company known as Kinematics, Inc.
There is a needle, a large revolving drum and a sheet of paper. On this paper, which is changed every twelve hours, is a series of traces done in purple ink, recording second by second the activity across, upon and deep beneath the island. Today's trace indicated only the merest of trembles; the night before the needle had waved unsteadily for a few hours in the middle of the night; and the week before – Sikin took the trace down from a cardboard folder on a shelf above the recorder – the lines were crazed, as though someone had shaken the inked needle in a sudden fit of anger. The lines were blurred and entwined together, because the needle had been vibrating and waving back and forth both at a great frequency and with considerable amplitude: that week Anak Krakatoa had clearly undergone a spasm of some sort.
Not enough of one, however, for Sikin to have called out his superiors in Survey headquarters in Bandung. A routine eruption, of which last week's had been a classic of the kind, was nothing to get excited about: Anak Krakatoa is like a great safety-valve, blowing off steam and a good deal else besides on a regular basis, never holding itself back and distorting itself dangerously, with an enormous relieving eruption as the culminating climax. Generally speaking it is the active volcanoes that do not erupt that are the dangerous ones: inside them, energy is being stored up, little by little, until the stresses become too great and there is a catastrophe. On Anak Krakatoa there is continual release – which may look dramatic and may on occasion make for trouble and cause casualties, but which suggests that, in the short term at least, the danger is predictable and any crisis manageable. So long as the volcano is watched, current belief has it, the neighbourhood is safe.
A routine eruption is invariably visible from shore some minutes before it is detected by the seismometers and is then written on to the seismograph drum. That recent bad day's eruption – it was a Sunday afternoon, Sikin remembered, and he was standing at the Observatory door puffing on his clove-flavoured kretek cigarette – began with a sudden whoosh of dust and smoke that could be seen pouring from a vent just behind the obvious main summit of Anak.
He said that he watched for a moment only, counting the seconds by snapping his fingers. He walked back to the Kinematics machine and, sure enough, ten seconds after the first sight of the smoke, after ten snaps of his fingers, the needle began to move.
There was at first a great swing, several inches to one side, after which it slammed back to the other side so fiercely it might look to a stranger as though the needle would break. Then it moved back again, and again and again, the trace writing on top of itself, but with movements that were now diminishing somewhat as the drum unrolled, so that the record began to look like an arrowhead, tapering towards a point. It was a familiar pattern, remembered distantly from old newspaper pictures or images on museum walls at places that had suffered badly from seismic shocks, places like Skopje and Anchorage and Istanbul, or the volcanoes of Mount St Helens or Unzen.
Sikin was still clicking his fingers while he watched the machine's passionless unrolling – until another five seconds had passed, when he went over to the open doorway and cocked his ear. Sure enough, right on cue, there came from across the Strait a rumble, like distant thunder, or the shaking of a theatrical thunder-sheet. And then silence.
Below him, behind the tapioca plants, he could see that the masts of the prahus in the river had begun to swing back and forth as the craft shook at their moorings. The sea surface had the sudden look of hammered pewter – until the swell took over, the breeze ruffled away any pattern that might have been briefly imposed upon it, and everything returned to normal. Across on the mountain the smoke had lifted away from the summit, which was now quite clear; the billow of black had risen well into the sky and was being borne away southwards in the streaming winds. Otherwise the sky was cloudless.
Soon there was just a single ragged blot floating in the air, together with the traces written on the paper drum, to stand as a record of how Anak Krakatoa had once again reminded the surrounding world that it was still very much alive. And only the paper would survive. In six months' time a car would arrive to take it and all the rest away, to be stored in a damp basement in Bandung.
It is not entirely clear whether one is formally allowed to visit Krakatoa. The archipelago is a part of a national park,* is a protected treasure, can be dangerous on occasion and in theory is officially off-limits to those without government sanction. The bureaucrats safely in their offices in Jakarta fret over the scrapes that visitors might get into. People have been killed or injured on the island, hit by flying lava bombs. The Sunda Strait suffers from notoriously fickle winds and seas, is crowded with fast-moving cargo ships and has deep waters that are alive with hungry sharks. The local vessels commonly used for the crossing break down with depressing regularity: few Americans will forget the fate of the 27-year-old Californian women Rickey Berkowitz and Judy Schwartz, who, trying to cross to Krakatoa in 1985, found themselves drifting in a leaky open boat for three weeks, surviving on a diet of peanuts, rainwater and Crest toothpaste.
In Bandung I had been handed a piece of paper dripping with official permit-stamps and signatures, and told that just this once, an exception to the rule, I might be allowed to go to Krakatoa on my own. But in Carita it was perfectly evident that no one gave a thought about ever getting permission, and that whether it was allowed or not, going across to Krakatoa was simply, like so much in the East, a matter of nothing more than supply and demand. If you wanted to go, then, for a price, go you most assuredly could and would.
And so, early one morning on a Carita beach that was already swarming with boys selling shells, sarongs, fried squid, coconuts and kites, and with cheerful young women offering very un-Islamic-sounding full-body massages and broad winks that promised even more delights, I found myself among groups of young men who pestered me slyly, as though in a Saharan souk, hissing theatrically You like g
o Krakatau? Consequently, within an hour or so, after I had looked critically at the small armada of boats on offer, I had selected a sleek yellow wooden pinisi, a fishing craft with a reliable-looking 70-horsepower Evinrude engine, had found a guide with the improbable name of Boing, and had waded out into the surf and clambered aboard.
The skipper first made a drama of unfurling his national flag and tying it with twine to the jackstaff. It turned out that just by chance, we were sailing on 17 August, which was the anniversary of Sukarno's famous proclamation of independence in 1945.* With a mischievous grin, the captain then pulled up a case of Bintang beer from the cool waters down in the bilges, tossed a couple of cans each to his two shipmates and to Boing and to me, waved a salute to something that sounded like the glories of Indonesian freedom and the likely continuation of good post-colonial living, burped, hiccuped, gunned his engine noisily, bounced his boat through the green heaps of surf and finally sped off unsteadily into the open waters of the Strait and towards the hazy western horizon.
Early on this hazy morning, it wasn't possible to see the archipelago from sea-level – until we had been cruising steadily for about half an hour. I spent those first minutes gazing up at a frigate bird high above us, flicking its scissor-like tails to change direction. There were dolphins too, playing under the bow; and flying fish launching themselves like small missiles, darting across the troughs between adjacent swells.
And then the skipper nudged me out of my reverie. ‘Rakata!’ he cried – and sure enough, rising through the haze directly ahead of us, was the perfect pyramid-shape of the last relic piece of old Krakatoa. To its right, as I squinted into the distance, I could soon make out the smaller cone of Anak Krakatoa, a puff of white smoke rising above it, and a slash of white running across the face of the mountain, a lava flow that had so far escaped weathering by the elements. The skipper indicated that it was as well that the smoke rising above the volcano was white. If it turned grey –if it were filled with debris, in other words – then it would be time to think about leaving. Fast.
Between our position now and the islands ahead were the main north- and southbound shipping lanes of the Sunda Strait, and for a half hour negotiating them seemed to occupy the skipper's mind more keenly than the colour of Krakatoa's smoke. For the lanes were very busy, and when you are in a small craft, down at sea-level, the immense speed of the onrushing cargo ships is almost impossible to calculate.
There was, for example, the northbound container vessel that, when we first saw her, was a mere speck on the port horizon. Within five minutes, however, this speck had become a massive ship whose hullside proclaimed that she belonged to COSCO, the China Overseas Shipping Company. She was bearing down on us with an awful speed. We cut our engine and let her pass us, and when she did so she must have been no more than 500 yards ahead. The nub of her bulbous bow elbowed the waves aside, setting us rocking alarmingly as we sat, hove to, and watched her immense bulk slide cinematically in front of us.
And then she was past, safely. Her enormous screw thrashed wildly in front of the huge rudder; and as she drew away to our starboard we could see her name written in Chinese, and her port of registry: Shanghai. She was on her way home, probably back from a voyage to ports in Africa and the east coast of South America. There was no indication that she ever saw us; such crew as were on the bridge were most likely standing on her own port side, gazing from their vantage point across at the volcanoes.
Once she was safely gone, we sliced and bumped across her mile-wide wake, dodged another couple of smaller southbound ships and edged in towards the lumpy, confused-looking waters of the volcanic caldera itself. The boat began to lurch alarmingly again, as though we were passing through a line of rapids. The skipper grinned. He knew how strange a phenomenon this was. The submerged lip of the old caldera, it seemed, was somehow playing havoc with the tides and currents, tripping up the streams, creating a ring of intersecting overfalls that broke all around us in ragged rings of white and green.
We edged closer, coming to within half a mile of Rakata's huge vertical cliff, which was blindingly lit by the midday sun. Seen from this distance and angle, it displayed a textbook cross-section of a wrecked volcano: before us was the dark central vertical spire of the old core, and its sheared-off surface pierced by dozens of veins of long-frozen pipes of lava, the whole cone capped high up in the sky by a ragged crown of trees.
And then we were through the broken waters and into the belly of the thing, the omphalos of the Oriental world, a place where the waters were unimaginably deep once more; and down in their depths, unimaginable things were happening. Within the caldera, Rakata was large enough to shut out some of the northbound swells and to divert the currents, and so once we were inside the submerged walls and in Rakata's lee the sea suddenly became calmer, more congenial. The boat stopped its corkscrewing and resumed a more steadily upright putter to shore.
We set a course first towards the strange tilted aggregation of guano-covered pillars called Bo'sun's Rock, around which the waves gnawed hungrily. We turned slightly to port just as we seemed ready to touch it, and left it to our starboard; then we headed to the south side of Anak Krakatoa itself. The plan was to circumnavigate the island before landing on the beach on the east side. The skipper was showing off now, and liked to hug the shore for my benefit: the island, the child of Krakatoa, now an enormous black bulk a few feet off to our right, smoked contentedly and calmly; and the smoke, we all noted, remained steadily white.
Most of the western and northern shores of the island consisted of dark-grey lava flows – and the one paler flow, newer than the rest, that I had seen from afar. They were all horrible gnarly things, mostly quite unweathered, with rocky tentacles that probed into the sea, where the waves washed around and sucked hungrily underneath them. The land above the flows was spiky and crammed with razor-sharp cliffs of frozen basalt. Once in a while I could see a single red flower, sunning itself from within a cleft; and seabirds would perch on the highest points, surveying the world around them. But otherwise the flows were lifeless and harsh, the raw front edge of the volcanic process, all solidified into hundreds of yards of dead, unyielding and ugly black rock. The crater itself was invisible from here; the smoke column, though, wafted ever upwards.
Once we were around the eastern side, however, the island took on a completely different aspect. The slope down from the now-visible summit became much less pronounced, and instead of lava there was ash and, in places closer to the beach, ashy soil. It had been transmuted into soil because, fringing the eastern and northern flanks of the island, there was now a long copse of trees – and over time (though not very much time, since the island had only been born in 1930) they had died and fallen over and decayed, their corpses mingling with the ash to produce, to judge from the gorgeous fecundity of the growth all around, a wonderfully humus-rich substrate.
From this vantage point, indeed, Anak Krakatoa looked like a perfectly normal tropical island, with no suggestion that it was one of the youngest islands in the world.* And it was towards its fringing woodlands that the skipper directed his boat. We dropped anchor fifty feet from shore and splashed through the shallows, then up on to the scalding beach. There was a path through the casuarina trees: we walked in as quickly as we could – the sand was far too hot (whether from the pitiless sun or the volcanic origins of the sand, I could not be sure) to allow any dawdling – and set up camp in a grove, where we would build a fire and take our lunch.
It looked for all the world as though we were in a tropical forest. The vegetation was thick and dripping with moisture. Butterflies swirled in the thermals. Birds called from high up in the canopy; and one of the boat's crew showed me the nest of what he said was an owl. There were the footprints of rats and geckos; the fine pumice sand was alive with ghost crabs, which skittered delicately along on tiptoe, as if keeping away from the heat; and along one patch of sand close to where we were eating
Aerial photographs show the uncanny simil
arity between Anak Krakatoa, below, and its sub-Arctic cousin Surtsey, off Iceland. Geologically and tectonically, however, the islands and the volcanoes that created them could not be more different.
there were the tracks of some much larger animal, about which the crewmen only grinned, ominously.
After eating grilled fish and rice and drinking the remains of the Bintang, Boing and I set off uphill. The crewmen had in any case fallen asleep in the shade – making us promise beforehand that we would return two hours before nightfall, or risk being run down by a freighter if we tried to cross the Sunda Strait after dark. It should in any case take no more than an hour to get to the summit: Anak Krakatoa was only 1,500 feet high.
But of course climbing a third of a mile up a high hill made only of newly fallen ash is a far from easy occupation. First, there was the simple matter of getting out of the coastal forest – a hundred feet of thick, lush vegetation through which we had to hack our way until it ended abruptly, with a patch of low grasses and a sudden blaze of brilliant sunlight as we emerged right on to the naked flank of the volcano. Not only was it unbelievably hot here – and this was the kind of heat that drills painfully up through the soles of even the best insulated shoes – but the ash that rose up steadily ahead slipped and slid, and opened up into scores of small chasms and runnels and rills, such that for every five steps upwards, I fell backwards four.
We passed the aluminium box with its radio aerial, pointing directly at the faraway and, at this time, invisible coast of Java: Sikin would be there, I fancied, watching the paper roll steadily out from the Kinematics drum with nary a vibration coming from his charge. The island was quiet this day and, judging from the column of pure white smoke that coiled up from the summit ahead, was likely to remain so for a while.