The Science of Middle-earth: The Great Wave
At the climactic moment of the Lord of the Rings, Faramir says to Éowyn that he is reminded of a "great dark wave climbing over the green lands and above the hills, and coming on, darkness unescapable. I often dream of it." The couple are as yet unaware of the passing of Sauron, but the symbolism is apt. Tolkien puts into Faramir's words a recurring dream that had troubled him since childhood (1): a "dreadful dream of the ineluctable Wave, either coming up out of a quiet sea, or coming in towering over the green inlands" (2).
Tolkien felt that this 'Atlantis haunting' was symptomatic of a tale of universal mythic applicability, a theme "so fundamental to 'mythical history'--whether it has any kind of basis in real history
that some version of it would have to come in [to his legendarium]"(3). Tolkien's version of the Atlantis legend was the tale of the downfall of Númenor, explicitly identified with Atlantis in many of the versions of the story that Tolkien wrote. The first was in the sketch for the novel The Lost Road, drafted around 1936 but soon abandoned (4).
I'm sure that many Tolkien fans will have been reminded of all this by the dramatic and terrible events of 26 December 2004, when the great Indian Ocean tsunami wrought its implacable and widespread destruction in Indonesia, Sri Lanka and other countries as far away as Somalia. Tolkien's image of the Great Wave seems to have been a very true-to-life account, for all that it was totally imagined. The geological events associated with the destruction of Númenor, by contrast, were completely unrealistic. In this essay I shall summarize the facts of the tsunami, of earthquakes more generally, discuss how and why Tolkien's image of the wave is so much more accurate than his geology, and speculate on the imagery that might have influenced Tolkien's mythological calamity.
More than 150,000 people are believed to have died as a direct consequence of the events of 26 December 2004. Whole cities now lie in ruins. Some may never be rebuilt. Islands and areas of coastline are permanently higher or lower than they were hours before--some islands actually moved by as much as 20 meters. Some areas have disappeared beneath the wave. The map of the Earth has changed (see ref. 5 for a brief and readable scientific account of the earthquake).
Earthquakes and tsunamis happen because of the way the Earth is made. The rocks that make up the Earth's crust--the continents and the ocean floors--seem thick and solid enough to us, but compared with the size of the whole planet they are less than eggshell-thin. The crust rests on the heavier, molten mantle, which comprises the vast bulk of the Earth's mass.
Driven by the radioactively-generated heat of the liquid metal core, the viscous rock of the mantle rises and falls in a series of convection currents, each convection cell taking hundreds of millions of years to circulate. The crust, resting on top rather like the froth on your morning latte, is prey to these vast forces.
Because of the interior dynamics of the planet, the crust is broken up into a crazy patchwork of separate plates that forever jostle and bump into one another.
As the convection currents rise to the surface and spread out sideways, they drag these plates apart, allowing new crust to form in the gaps. New oceanic crust is continually coming to the surface in huge chains of undersea volcanoes. A ridge of submerged mountains--the mid-Atlantic ridge -- runs north to south along the mid-line of the Atlantic Ocean. This, the largest range of mountains on Earth, for all that it is submerged, looks a lot like Hithaeglir, the Misty Mountains (a theme I might return to in a later column). As the lava wells up along the mid-Atlantic ridge, it forces the plates apart at a rate of millimetres a year. The Atlantic has been widening for more than 100 million years, but the process of ocean formation goes on all the time: the Great Rift Valley that stretches from southern Africa northwards, through the Red Sea to the Jordan Valley, is an ocean caught at the moment of birth, as eastern Africa is slowly being pulled apart from the rest of the continent, with new oceanic crust welling upwards to fill the gap. In 30 million years time, a person standing on the shores of one of the African Great Lakes would see not a lake, but a widening ocean.
Because the Earth isn't actually getting larger, the farther edges of the plates are driven beneath the edges of their neighbours. As the convection currents cool and fall, they drag continental margins together in continental pile-ups that create mountain ranges, and in which the margin of one plate slides beneath the lip of the other, getting dragged down into the Earth's interior, where the material is recycled (a process called 'subduction'). Each plate consists of combinations of thin oceanic crust and thicker continental crust, the latter formed from earlier episodes of crustal collision.
Subduction is responsible for some of the most dramatic features of our planet. The western margin of the Pacific Ocean is one great subduction zone, in which the crust of the Pacific is disappearing under eastern Asia. This leads to immense ocean trenches, and associated with them, volcanoes, which act as release valves for the titanic forces generated by subduction. Japan is an arc of islands created by volcanoes--and the deepest ocean trenches lie off its eastern coasts. The Himalayas and the Tibetan Plateau is a gigantic crumple zone caused by the northward march of the Indian Plate into the belly of the Eurasian plate, a process that started more than 55 million years ago. India is still driving, though, subducting its way beneath Asia. As it turns out, the tsunami was a direct consequence of the onward march of India.
This entire scheme, known as 'plate tectonics', was--amazingly--not accepted until the 1960s. Before that, scientists assumed that the continents had remained more or less in the same places for all time, and geological oddities--such as the discovery of fossil seashells on mountain-tops in the Alps, and of fossils of the same kinds of animals or plants in rocks separated by oceans--were explained away by proposing the existence of land-bridges (now sunken), or that the Earth was more or less completely flooded at various points in the Earth's past. The discovery of plate tectonics showed, in contrast, that the continents themselves had moved. In cycles each lasting more than half a billion years, the continents tend to coalesce into a giant supercontinent, before splitting up into fragments. The last great supercontinent, Pangea, started to break up during the early days of the dinosaurs approximately 225 million years ago. Pangea comprised the vast northern subcontinent Laurasia, and the even more leviathantine landmass of Gondwanaland (of which the Indian plate is but a fragment)--a fact not lost on Tolkien, who cited the name 'Gondwanaland' as the closest approach made by geology to poetry (6).
Sometimes columns of hot lava from the mantle don't wait for the sedate convection currents to bring them to the surface, but punch directly through the crust. These 'hot spots', which can persist for millions of years, remain static relative to the tectonic plate moving above them, and puncture a line of holes in the crust, in the same way that a static needle punctures a series of holes in a moving seam in a sewing machine. The Hawaiian Islands are a classic case of a chain of islands, far from the edges of any plate, created by a static hotspot beneath a tectonic plate moving north-westwards above it. Iceland is a complicated case of the volcanic upwelling of the mid-Atlantic Ridge being additionally fuelled by a hotspot, bringing these normally submerged mountains above the surface to create an appreciable landmass.
The jostling of continental plates is not a smooth and continuous affair. The edges of plates tend to snag against one another, and only move when the accumulated tension gets too great for them to manage. When the edges suddenly fail, earthquakes happen. When earthquakes occur on the ocean floor, tsunamis can be the result.
This is what happened on 26 December 2004. As part of its relentless northward march, the Indian plate has been burrowing under the Burma microplate (a fragment of the Eurasian plate, and which carries northern Sumatra) at an average rate of 6 cm per year. But this movement is not smooth. When it sticks, tension builds up until the rocks literally cannot hold the pressure any more and fail catastrophically. The tension in the region has been building since the last major quake in 1833--tension that was released suddenly last December, in the world's most powerful earthquake for more than 40 years.
The immediate result was that the India plate was suddenly thrust 15 metres beneath the Burma microplate, forcing the lip of the latter sharply upwards along 1200 kilometers of its length, and against the pressure of ocean above it. The energy required to do this is scarcely credible. If you think that a 10-liter bucket of water is no mean lift--and that my 80-liter fish tank is immovably heavy when filled--the force required to suddenly lift an ocean is almost beyond imagination, if not calculation.
The water lifted by this sudden upward thrust met the surface, and started to spread laterally as a single wave, dissipating the force--but in a curiously focussed way. After all, the earthquake wasn't dissipated by heat (the ocean didn't boil), or by a rash of turbulent waves, but by a single, coherent wave. Because all the power of the 'quake was concentrated in this one wave, it travelled at great speed, wasting relatively little energy as it went.
The wave, despite its power, rose hardly at all above the surface until it got close to the coast, when the ocean shallowed. In shallow water lies danger. A tsunami in shallow water sucks up water before it to fuel its progress, explaining why the sea recedes for great distances along coastlines that are about to be struck by a tsunami. And because the ocean is shallower close to the shore, the wave can build up to a towering height, twenty or thirty feet or more, before crashing onto land. This is where the energy of the earthquake is finally released, in an unstoppable shoreward surge, breaking towns as if they were miniature matchstick villages under the tracks of a tank. So far, Tolkien's image of the towering tsunami is startling in its realism.
The geological account of the destruction of Númenor, however, is rather more fantastical. Tolkien wrote and re-wrote this account many times, but the facts remain more or less constant from version to version. The central image is of a 'great rift' that opens up (7), dragging the Great Armament into a chasm, uprooting Númenor, and dragging that down, too.
Most readers will be familiar with the account published in The Silmarillion as Akallabêth, in which Ilúvatar opens a great chasm between Númenor, and the Deathless Lands, "and the waters flowed down into it". The Deathless Lands are then removed, the final calamity being laid on Númenor, itself "nigh to the east of the great rift", which also topples into the void. This scheme goes back more or less unchanged to the earliest sketches of the legend at the time of The Lost Road (4):
"The Gods therefore sundered Valinor from the earth, and an awful rift appeared down which the water poured and the armament of Atalantë were drowned."
In the same manuscript Tolkien writes of the Earth being made round, so that water flowed all around it "and there was a time of flood" (perhaps an account of a global tsunami), "but Atalantë being near the rift was utter[ly] thrown down and submerged."
Tolkien returned to the legend in 1944 in the context of that endlessly fascinating unfinished burlesque, The Notion Club Papers (8) where one of the characters visits the wrack of Númenor in a trance and declaims melodramatically "See! The abyss openeth. The sea falls. The mountains lean over", and much else of a similarly overwrought nature. The two texts of the related The Fall of Númenor as well as The Drowning of Anadûnê(8) are closely similar to that of Akallabêth inasmuch as they concern the geological facts of the Downfall.
Leaving aside the mythically necessary but geologically quite unfeasible notion of a flat Earth being made round, the geological details of the wrack of Númenor describe exactly the opposite of what really happens. Plate tectonics shows that chasms in the ground of sufficient size to swallow entire continents open to allow new material to come to the surface, not to swallow existing material. And if this is subduction, it is abnormally rapid.
The accounts are also somewhat ambiguous about the fate of Númenor, itself. One is given the impression that it is swallowed up by the chasm and completely obliterated, whereas other references speak only to its submergence--I think particularly of notes that the summit of the Meneltarma, the highest point on the island, might still appear above the surface of the sea.
However, there may be cases in which the sudden collapse of islands might provoke a tsunami. The tsunami of 1883, associated with the volcanic eruption of Krakatoa, was caused by the sudden slumping of a large amount of rock into the ocean. Some geologists suspect that Mt Tiede, a volcano on the island of Tenerife, could collapse, setting off a tsunami that could soak the eastern seaboard of the United States. This raises the question of the location of the Great Wave of Tolkien's nightmare. Nowhere does he give a precise location, but the context--the wave washing ashore on otherwise undisturbed green lands--suggests that it would have occurred not in Númenor, but on the shores of Middle-earth, preceding the arrival of the Faithful (carried there on the wings of a westerly gale.)
The entire episode--the tsunami, the destruction of Númenor--is, for Tolkien, uncharacteristically visual in inspiration, born out of images rather than languages. We know that the image of the Great Wave came from a dream. But where, if not in geology, did Tolkien get the image of the very un-geological void that swallowed Númenor?
One possible answer might be from art, and particularly from the apocalyptic paintings of the early Victorian landscape painter John Martin (1789-1854). Here is a description, by Brown University art historian George P. Landow, of Martin's painting The Great Day of His Wrath (1852):
Using his characteristic elongated horizontal format, Martin follows his usual pictorial strategy of juxtaposing many diminutive human beings to a world whose scale, depth, and energy is about to destroy them. A black chasm opens before the spectator in the immediate foreground, and into this emptiness pour the terror-stricken inhabitants of this doomed world, while down upon them cascade from the left enormous boulders. Lightning flashes across the sky and down on the ground, and this fire from the sky is matched in the right portion of the background by a sea of lava and fire (9)
This seems like as good a description of the destruction of Númenor as any, particularly as the context demands direct Divine intervention. It is notable that the destruction of Númenor was precipitated by one of the very few (if not the only) direct interventions of Ilúvatar in global affairs.
Apocalypse was something of a Martin family business. Although John Martin's paintings won him a reputation as 'Mad Martin', the soubriquet was better applied to his brothers. One, Jonathan, tried to burn down York Minster: another, his brother William, poet and inventor, took to composing doggerel and walking around with a turtle shell as a hat. As for John himself, although his art fell out of fashion (Ruskin, for example, hated it) "his influence can still be seen in the architecture and special effects of Hollywood biblical extravaganzas."(10) And, perhaps, in the most influential author of twentieth-century fantasy literature.
- Humphrey Carpenter, J. R. R. Tolkien: A Biography, Part 2, chapter II: and Letters of J. R. R Tolkien #163, to W. H. Auden.
- Humphrey Carpenter, J. R. R. Tolkien: A Biography, Part 4, chapter VI.
- Letters of J. R. R. Tolkien #154, to Naomi Mitchison.
- Christopher Tolkien (ed.) The History of Middle-earth Vol. V.
- Letters of J. R. R. Tolkien #324.
- Letters of J. R. R. Tolkien #156.
- Christopher Tolkien (ed.) The History of Middle-earth, Vol. IX.
- Myers Literary Guide to North-East England