Island on Fire Page 3
Priests at the time were expected to be farmers, and Jón’s boyhood training served him in good stead in that respect. He also developed another skill that garnered even more admiration from his parishioners: medicine. Being the autodidact that he was, Jón had studied the medical arts on his own and began practicing at Fell. He also trained for a while with a physician, natural scientist and former schoolmate named Bjarni Pálsson, who went on to become Iceland’s first surgeon general. Jón treated many people for free and was seldom without a resident patient in his home, sometimes accommodating two or three at a time. He later estimated that he successfully treated up to 2,000 people during his seventeen years of active practice.
Chalices, church bells and other sacred ornaments constituted the few fine possessions of Jón’s spiritual flock.
In 1778, the position of priest for the Sída district, to the east, fell vacant. Jón applied for and won the appointment. Now fifty years old, he had enjoyed being a priest in Fell, but he was ready to move on. The most painful experience was a lawsuit brought against him and Thórunn by Jón Scheving, the son of Thórunn and her detested late husband. Scheving had squandered his inheritance and was living a deadbeat lifestyle in Copenhagen. For some time, he had apparently harboured an intense hatred for his stepfather and mother, and he devised a plan to ruin them and appropriate their money. He bribed a hired hand to claim that his mother and Jón Steingrímsson had conspired to have his father murdered so that they could live together unimpeded. News of this scandalous accusation spread rapidly through Copenhagen and across to Iceland. Jón’s utterance that ‘it would be better if the master were dead’ came back to haunt him, because many people believed the stepson’s story. The lawsuit unravelled, however, when the hired hand retracted his testimony under investigative pressure and admitted that Scheving had paid him to make the charge. Upon learning that his scheme had been thwarted, Scheving signed up with a regiment of soldiers and transferred out of Copenhagen. Jón never heard from him again.
Although Jón and Thórunn were exonerated, the experience continued to weigh heavily upon them, and when the position became available in the Sída district they jumped at the chance of moving. The job was in the town of Kirkjubæjarklaustur, commonly known as Klaustur, a tranquil place with a rich religious history. Well before the Víkings arrived to settle Iceland permanently, Irish monks occasionally visited the broad, richly forested slopes beneath the steep cliffs of volcanic rock. By the twelfth century nuns had established a famous convent here (the ‘kirk’ in the town’s name), and many of the natural features in and around Klaustur are still named for the sisters. It was a place Jón could feel comfortable in and thrive, and he would serve it for the rest of his life.
Klaustur, it turned out, would also be an ideal location for witnessing the end of the world.
In the days following the first appearance of the black cloud, Jón recorded new and more inauspicious manifestations coming from the direction of Mount Laki. On 9 June, the day after Whitsun, the weather started out clear and sunny, but ominously the dark cloud returned and was rising ever higher in the north. Earthquakes were drumming faster and faster, accompanied by thuds and loud cracking sounds. The Skaftá River, which normally flowed at a volume so great that horses at the ferry crossing had to swim some 120 metres through the current to ford it, suddenly began to drop. An acid rain fell the next day, eating through pigweed leaves and scorching the hides of newly shorn sheep. By the afternoon, the Skaftá had dried up completely. Snow fell from the black cloud on 11 June, creating a hard, shellac-like surface over the grass. The sun, when it could be seen, was red as an ember, and the moon blood-coloured.
Then, on 12 June, lava gushed forth ‘with frightening speed’ from the Skaftá canyon southwest of Klaustur. As it encountered wetlands and other streams feeding into the river, the combination of water and molten rock created concussive explosions. At first, the lava followed along the course of the riverbed, but soon it breached the banks and began spreading over old lava flows, meadows and farmlands. This was to be the first of five such surges of lava from the gorge.
Cinders fell from the sky on the 14th. They were, Jón wrote, ‘blue-black and shiny, as long and thick around as a seal’s hair’. This was the first description of what volcanologists today refer to as Pele’s hair – thin strands of volcanic glass formed by molten particles ejected in a lava fountain and stretched into fibres as they are carried through the air. Just half a millimetre across, they may be as long as two metres. The unusual fallout covered the ground across the region, and the winds worked some of the hairs into long hollow coils.
Friction among ash particles generates ominous-looking lightning in volcanic plumes, as in the 2010 eruption of Eyjafjallajökull.
The following day, a party of farmers decided to climb Mount Kaldbakur, eight kilometres northeast of Klaustur, to see if they could get a good view of the eruption site. They reported seeing lava coursing through the river gorge, and, off in the distance, twenty fountains of fire exploding high into the sky. The news terrified everyone, including Jón, for it seemed certain now that the lava would breach the mountains and ravage the settlements.
Throughout the waning days of June, the forefront of the lava flow turned southeast, engulfing meadows and woodlands and laying waste to farms and churches. Birds fell dead from the sky and fish floated lifeless to the surface of streams and ponds. Earthquakes convulsed the ground and acrid odours filled the air, along with smoke and ash so thick that no one dared inhale deeply. The water tasted of sulphur and freshwater pools were fouled with ash. Thunderous eruptions could be heard coming from the glaciers up in the mountains. At night great showers of sparks shot into the sky. Lightning produced in the ash clouds was violent and at times continuous, so that ‘scarcely a moment passed between bolts for days on end.’ By early July, new lava was seen flowing under older lava, creating convulsions of subterranean fire and steam that caused the earth to heave upward and crack open.
Some people desperately tried to relocate their livestock, but their efforts usually came to naught. The proprietor of one of the region’s most prosperous farms collected ‘a great number’ of his sheep and placed them on a small island in a river, intending to herd them to safety as soon as he had an opportunity. Before he had returned to his house, however, the lava came rushing on more quickly than he expected. It rapidly engulfed the island and consumed the sheep.
Many owners abandoned their homes and land, vowing never to return. Others made preparations to leave and then decided to wait and see if the lava flow would reach the sea, in which case they and their families would flee eastward. ‘All the schemes, projects, and remedies that people undertook,’ Jón wrote, ‘led to confusion, frustration, exhaustion and expense, and in most cases were totally unavailing.’
Between July 13th and 19th, the lava edged further down the Skaftá riverbed toward the east, making its way – seemingly inexorably – toward Klaustur and Jón’s church. In some places the lava piled up so high that it blocked the noonday sun. In other places floodwaters inundated farmlands, reducing them to muddy sloughs. For more than a week, suffocating clouds of smoke blanketed the area, forcing people into their homes. Because of the encroaching lava, the estate overseer at Klaustur decided to remove as many valuables and ornaments from the church and cloister as possible. For Jón, relocating church accessories such as the altar, chalice, paten and other sacred vessels must have been a sorrowful turning point.
By 17 July, residents fleeing the lava’s advance west of Klaustur were streaming into the area, herding their cows before them. (Most of the terrorized sheep had fled in all directions.) Two nights later, the tumult subsided somewhat, though the relative calm was occasionally broken by thunder and distant cracking sounds. The approaching lava now lay less than three kilometres from the church.
In his home nearby, Jón lay in sleepless dread, praying and fretting over a terrible, dawning truth: that tomorrow would most likely be the la
st day he would ever hold service in his beloved chapel. Its destruction seemed certain.
CHAPTER TWO
Land of Ice and Fire
The volcanoes of Iceland
ICELAND IS AN ISLAND OF DESTRUCTIVE FIRE. Jules Verne sensed this when, never having visited the place, he conceived his novel A Journey to the Centre of the Earth. In many ways Verne got the basics of Victorian-era geology wrong: his protagonists encounter the most unlikely wonders, including a cave filled with giant mushrooms and a battle between prehistoric sea beasts. But in at least one aspect Verne was both accurate and far ahead of his time. To reach the centre of the Earth, he sent his characters down the throat of Sneffels (Snæfellsjökull) volcano, 120 kilometres northwest of Reykjavík. This mountain, Verne correctly suspected, was a direct conduit to the planet’s internal fire.
Almost since the day Iceland was settled in the ninth century, explorers, naturalists and writers have viewed the island as a geological wonderland. Here were full-throated volcanoes spewing fire and ash, with bubbling hot springs and geysers spouting wildly into the air. Here, too, were great ice-mountains, or glaciers, which ground their way down from lava-capped peaks. Iceland combined the dramatic flames of Italy’s volcanoes, such as Sicily’s mighty Mount Etna, with the snowy grandeur of the Swiss Alps. It’s little wonder, then, that the island quickly garnered a reputation as a marvellous land of fire and ice. Iceland is like nowhere else on the planet.
To understand why this should be, we have to take our own virtual journey to the centre of the Earth. By listening to how seismic waves bounce through the planet’s interior, geophysicists have worked out that the Earth is made of three main layers, each with its own characteristics. At the surface is a thin outer crust, like the skin of an apple; everything people see and do in their everyday lives happens on this crust. Beneath that, stretching from a depth of around 40 kilometres to 2,900 kilometres, lies the mantle, which makes up most of the planet, like the flesh of the apple. Finally, beneath the mantle beats the planetary heart: a spinning core made partly of liquid iron, whose sloshing generates the Earth’s magnetic field.
Volcanoes, in Iceland and elsewhere, are born hundreds of kilometres deep in the mantle. Most of the time, the crushing pressure at these great depths ensures that rock remains solid. The question is: what causes some of that rock to melt, rise toward the surface, and occasionally erupt as a volcano? People have been puzzling over this since at least the fifth century BCE, when the Greek philosopher Anaxagoras suggested that winds were forced among cracks deep in the Earth, heating up because of friction and melting the rocks around them. Five centuries later, the Roman philosopher Seneca proposed that burning fossil fuels, such as coal, fed the fire of volcanoes. Today, after 2,000 years of study and experiments, scientists appear to have a more precise answer: heat, chemistry and pressure all play crucial roles in causing mantle rocks to melt, rise and erupt.
Heat has been lurking in the planet’s interior ever since it formed 4.5 billion years ago, when Earth coalesced from a disc of gas and dust swirling around the newborn sun. Much of the planet’s internal heat comes from radioactive elements left over from its fiery birth. Such elements include thorium, uranium and potassium, which can take billions of years to decay into less radioactive substances. The nuclear breakdown releases heat that percolates up toward the surface.
Chemistry comes into play in determining which particular rocks are destined to melt. Most rocks are made of minerals in which atoms of elements such as silicon and oxygen are arranged in regularly repeating, or crystalline, patterns. Other elements, such as iron or magnesium, tuck themselves into this arrangement. Depending on what atoms are in the structure and how tightly they bond to one another, the atoms can be snuggled close together or strung out more loosely, like pearls on a string. When temperatures rise, the first chemical bonds to break are those between atoms that are less tightly linked; thus different minerals have different melting points, depending on how their chemistry is arranged. A rock made up of different minerals will melt its mineral types one by one rather than all at once. Over time, the chemistry of the rock changes as part of it melts out while the rest remains solid.
Finally, pressure is the key that links heat and chemistry together to produce molten rock. If you take a chunk of surface rock and raise its temperature to the melting point, it melts, naturally. But put that same chunk hundreds of kilometres deep in the mantle, and the high pressures will keep it solid. That’s why most of the Earth’s mantle is solid. It’s hot, to be sure, but the pressure is high enough in most places to keep the rocks from melting completely.
As a liquid, magma is less dense than the surrounding rock, and so it starts to rise. Magma will take any path it can: it might worm its way through pre-existing fractures in the rock, or shoulder its own path upward. Often flows will pool together in a shallow reservoir in the crust. Such holding chambers lie beneath most of the world’s volcanoes, and are the reason why a mountain considered dormant can come to life again at any time.
Once magma reaches the surface, the eruption can take any number of forms. It might shred the magma explosively into a plume of tiny ash fragments jetted kilometres into the air – as Iceland’s Eyjafjallajökull did in 2010, shutting down airspace across Europe. Or the volcano might ooze lava, so that glowing currents of rock course down the sides of the mountain – like Hawaii’s Kilauea, which frequently and picturesquely sends rivers of lava into the sea. Alternatively the eruption might be some combination of the two, belching out both ash clouds and lava flows at different times. But no matter what the volcano looks like at the surface, its magma always comes from melting deep within the Earth.
Which is why volcanoes don’t just appear willy-nilly across the planet, but instead crop up where geological forces trigger and concentrate melting – most famously along the Pacific Ocean’s Ring of Fire, linking Indonesia to Japan to Alaska to the Andes. And for that we can thank the phenomenon of plate tectonics.
The science of plate tectonics has a deep history, but it crystallized in the work of a German explorer and meteorologist named Alfred Wegener. In 1915, while recovering from war injuries, Wegener wrote a book laying out his ideas. Like many before him, including almost every child playing with a globe, he noted that the east coast of South America could nestle neatly against the west coast of Africa like jigsaw puzzle pieces fitting together. He traced the span of the Appalachian Mountains along a map and thought they linked up with other ranges across Ireland, Scotland and Scandinavia. He also noted that fossils of many species in Europe and North America looked fairly alike until around 180 million years ago, when they diverged dramatically. To Wegener, this suggested that something must have pushed the landmasses around over time.
But how could the Earth’s seemingly solid crust move like that? Wegener thought the answer lay in the difference between the land and the oceans. He noted that most of the continents lay between sea level and an altitude of 1,000 metres, whereas the oceans were mostly between 4,000 and 5,000 metres deep. For this arrangement to work, Wegener argued, the continents must be made of lighter material that floats on the denser ocean crust below. That would keep mountains at relatively modest heights compared to the oceans’ abyssal depths. More importantly, it suggested that continents and oceans were separate things, and that each behaved in its own way. Continents could drift around on this ocean base, like icebergs sailing through the sea.
Alfred Wegener (left) and his guide Rasmus Villumsen on their ill-fated final expedition to Greenland’s ice sheet. Both men died on the 1930 trip.
Wegener didn’t have much luck convincing other scientists of this ‘continental drift’ theory, mainly because he couldn’t explain what might start continents moving in the first place. And when he died on an expedition to Greenland’s ice sheet in 1930, still seeking to prove his idea, much of the impetus to understand the concept died with him.
Mid-ocean ridges run down the centres of oceans like seams on a basebal
l.
Until 1962, that is. That year, geologist Harry Hess of Princeton revived Wegener’s ideas. As a young researcher Hess had sailed on oceanographic expeditions to map gravity anomalies in several ocean trenches; from these he began formulating ideas about the rates at which oceanic plates might be moving. In 1962 he published what he called an ‘essay in geopoetry’, written two years earlier. It proposed that heat churning through the Earth’s mantle might be responsible for the movement of the plates. And the essay reopened the question of Wegener’s continental drift.
Iceland sits astride the Mid-Atlantic Ridge, east of Greenland.
Hess proposed that it all starts in the middle of the oceans, where lava spills out along great gashes in the sea floor. The lava cools as it hits the frigid seawater, and piles up as underwater mountain ranges. Picture a globe with the water drained away, and these ‘mid-ocean ridges’ snake down the centres of the oceans like seams on a baseball. If laid end to end, they would stretch for 50,000 kilometres or more. They are the biggest single volcanic feature on the planet.
Hess argued that fresh ocean crust is made at mid-ocean ridges every day. Heat churning within the mantle, rising up like the blobs within a lava lamp, carries the newborn seafloor away from either side of the fiery seam. More magma then wells up from the deep, bubbling up and hardening into new rock to fill the gap. The new crust rides away from each side of the mid-ocean ridge, as on a conveyor belt. The belt’s journey ends, Hess proposed, when the rocks reach the far side of the ocean basin, where they jam up against and dive beneath the higher-floating continental crust.