Japan Sinks

by Sakyo Komatsu

  Surrounding it, like the white of the egg, is the mantle. Finally, the thinnest and outermost layer, the crust. Judging from the way that earthquake waves are transmitted from deep within the earth, we believe that the mantle is solid, the outer core liquid, and the inner core solid. The mantle is some two thousand miles thick, approximately half the radius of the earth. The crust, on the other hand, is a mere twenty miles thick beneath the continents and still thinner beneath the ocean floor—apparently no more than three miles. We like to think of the ground beneath our feet as solid, but the truth is that the thickness of the crust upon which we and all our history and civilization rest is, relative to the size of the earth, like the stretched rubber of an inflated balloon. And within the mantle itself, solid though it seems, the evidence indicates that, over vast stretches of time, convections take form here just as they do in liquids. The mantle, in fact, flows beneath the crust at the rather rapid rate of two inches per year in its deep portion and at the rate of six inches per year in the portion near the crust, which, in turn, provokes great movement on the surface of the crust, especially beneath the ocean. This seems to be the motive force that moves the continents. . . . Kataoka, let’s have a topographical map of the world.”

  Kataoka pressed a switch, and a brilliantly colored map appeared on the projection screen on the desk. Tadokoro took up his explanation, tapping the map with his pen.

  “Note the respective concave and convex portions of the European and African coasts and the North and South American coasts, so aligned that it seems as though they would fit neatly together. It is this configuration that gave Wegener the hint that they had in fact once been joined and so led him to his famous theory of Continental Drift.”

  Tadokoro next ran his pen down the middle of the Atlantic Ocean, indicating the massive Mid-Atlantic Ridge, which reached a height of 9,000 feet and was 600 miles wide, stretching in an S shape from the Arctic Circle all the way down to the southern polar region.

  “In the midst of this ridge, the source of almost all the quakes in the Atlantic,” Tadokoro continued, “there runs a deep crevice containing an extraordinary amount of heat. This heat is being conveyed upward from deep within the mantle by means of convection, and this Mid-Atlantic Ridge itself is nothing else but the upward thrust of this mantle convection. Here we have the motive force that long ago, in accordance with Wegener’s theory, opened up a great chasm in the continental mass and set what is now the American continents moving in a westward direction. Furthermore, this same kind of protuberance, resulting from the upward thrust of the mantle convection and constituting the same kind of break in the crust, runs along the sea floor of all the oceans of the world.” Professor Tadokoro stopped for a moment. He looked around at everyone before going on, his voice somewhat lower. “Now with regard to these mantle convections, using a method that I’ve developed myself, I have not only been able to make a detailed diagram of them and formulate a comprehensive explanation, but I am certain that I can predict the emergence of phenomena that will be completely new.”

  Yukinaga felt his pulse quicken. What a sensation Tadokoro’s theory would provoke if he could make it known! But that, of course, was out of the question. And then, too, even granting that the history of man’s scientific scrutiny of the earth was a short one, the thrust of Tadokoro’s argument seemed fantastic. . . .

  “All right,” said Tadokoro as he turned a dial and brought a relief map of the Pacific into focus, “now let’s take a look at the Pacific.” He picked up a pointer and indicated the undersea ridge off the coast of Chile. “You see how the ridge line of the Atlantic continues into the Southeast Pacific. Now look here.” He now pointed to an undersea mountain range that extended up through the Indian Ocean. “If one credits Wilson’s theory, it was the upward thrust of the mantle, represented by this range, that pushed the Indian subcontinent, formerly separate from Asia, to the north, thrusting it finally against the continent. And in the process the coastal impact area was pushed upward to form the great Himalayan fold. And even now this seems to be the explanation for the continual increase in the height of the Himalayas.” The pointer moved back to the Southeast Pacific. “It seems evident that the general flow of the Eastern Pacific mantle is from southeast to northwest, something corroborated by the fact that the Christmas, Hawaii, and Tuamotu groups run in that direction. Furthermore, this flow collides eventually, we believe, with the mantle flow coming from the Asian continent, as a result of which a part of it takes a down ward turn, something that would account for the long trenches that characterize the eastern side of the island arcs of the Western Pacific. But now let’s consider how all this pertains to our immediate concern.”

  There was dead silence in the room as Tadokoro flipped a switch to change the picture. The area now spread across the screen was the Northwest Pacific, taking in Japan and a portion of the mainland. “The Japan Archipelago was once joined to the continent, and some time in the distant past the continental mantle current I referred to thrust it out into the Pacific in a southeast direction. According to my theory, it is still doing so to this day at a speed of from one to three inches a year. In the first stages of this process, say twenty-five million years ago, the Archipelago lay much farther to the north and it lay straight rather than curving away from the continent. The constant pressure, however, bent it into its present arc shape and opened the fossa magna that divides Central Honshu. Furthermore, at this break line we have the Fuji volcanic zone. But now let’s consider the mantle current coming from the opposite direction, from the Southeast Pacific. What happens when these come together?” Tadokoro paused for a moment and then suddenly looked at Yukinaga, a gleam in his eye. “Yukinaga, what discipline concerns itself with the behavior of masses of fluids of varying temperatures on the earth’s surface?” he asked.

  “Meteorology, Professor,” answered Yukinaga, his voice hoarse.

  “Good. But you want perhaps to protest that vapors, liquids, and solids are quite different things, isn’t that right? But would it be too absurd to think that, given a sufficiently long period to overreach the difference in nature, meteorological analogies might be used to explain the behavior of the mantle? For it not only forms convections, but in the upper mantle there is a distribution of masses of varying temperatures. Would it be out of the question to think of these as behaving like vapor masses, given enough time?”

  They stared at Tadokoro’s unshaven face in amazement. Could there really be any similarity between atmospheric cur rents, ever moving and never knowing rest, and those heavy, solid masses of rock moving deep with the earth at high temperatures?

  “To put it in simple terms,” said Tadokoro, “let’s take a look at the kind of pattern that occurs when a cold front meets a mass of warm air.”

  Tadokoro drew a horizontal line on the blackboard. Above this he drew a line cutting down into it which formed half an oval, its long axis parallel. Within the curved line he drew an arrow pointing from right to left. “This is a vertical section diagram of a cold front. The straight line below is the earth’s surface. On the right is a mass of cold air. The cold air mass plunges beneath the warm atmosphere on the left. The warm air is pushed upward and is chilled. And along the line of discontinuity, clouds take form and rain begins to fall. In the case of a warm front, the reverse happens. The warm front climbs over the cold mass.” Tadokoro turned away from the blackboard and singled out Onodera this time. “Onodera, do you see where I’m going?”

  “I think so, Professor,” answered Onodera. “In terms of your analogy, the cold front moving from right to left is the mantle flow coming up from the Southeast Pacific, and the warm atmosphere on the left is the mantle flow coming from beneath the continent.”

  “Exactly. The continental mantle flow is much warmer be cause of the radioactive elements it contains, because the crust of the continent is some six times thicker than the crust of the ocean floor, and for other reasons I needn’t go into now. Thus, it climbs up the advancing mant
le. And this is the force that moved the Japan Archipelago away from the mainland, forming the Japan Sea in the process, and eventually bent the Archipelago into its present arc shape. Now bear this in mind: the Archipelago is still bending and moving, and the Japan Trench, formed by the descent of the Pacific mantle, is still growing deeper.”

  His intent listeners swallowed hard as they heard Tadokoro’s explanation. The Archipelago on which they lived was like a line of clouds that had taken form along the leading edge of a moving mass of warm air. Outside, the wind seemed to have risen and the sea grown rougher. The Yoshino began to pitch and roll, though gently at first. Since Tadokoro had paused once more, they could clearly hear the echo of creaking throughout the ship, the moaning of the wind, and the breaking of the waves. A gloomy mood took hold of them.

  Kataoka broke the silence: “But, Professor, hasn’t all this been going on for millions of years?”

  “Yes, it has. And you’re thinking that it will go on for still more millions in just this way?”

  “Well, yes.”

  “If so, we of course have nothing to worry about. But my research, my intuition also, if you will, leads me to think that we are on the verge of a sudden, a violent alteration of that pattern. I readily grant that a change of this nature would be something unheard of, but please remember this: since man as we know him now appeared on the earth, some hundreds of thousands of years have passed—no more. What incredible events may have happened before he appeared we have no idea. And even after he appeared, even in historical times, much has occurred that we know next to nothing about simply because our scientific scrutiny of the earth has barely gotten under way. For example, the fact that the earth’s axis has moved, the fact that terrestrial magnetism is lessening and will be gone in another two thousand years, the fact that creatures upon the earth will be subject to cosmic rays—these and many other things we’ve learned in just this past decade, and we’ve no more than scratched the surface. So we must be very slow to say that such-and-such a thing cannot happen.”

  The cabin lurched to one side. There came the noise of doors crashing shut.

  “There’s always a reason, though. There has to be a reason.” Tadokoro turned to Yukinaga. “Yukinaga, do you remember how, when Runcorn resurrected Wegener’s Continental Drift theory, he explained how the process began—the break-up of the single land mass and the westward movement of the Americas?”

  “I remember,” answered Yukinaga, feeling his throat dry. “He proposed Chandrasekhar’s calculations, the great Indian astrophysicist working in America.”

  Tadokoro nodded and then pointed to the diagram of the earth that he had drawn earlier.

  “Take another look at this cross-section, gentlemen. At present the diameter of the core is more than half that of the earth, having a diameter of about four thousand miles. It seems, how ever, that in the beginning the core was smaller. The earth as a whole has been contracting, by force of its own gravity, while the core, its heat and pressure growing more intense, has been expanding. And this has had its effect upon the mantle sur rounding it. In the beginning the mantle convection pattern was like a single whirlpool, but as the core expanded, it altered. Nor was this alteration a gradual process. Rather, once the core reached a certain size, the whirlpool suddenly was torn asunder and a multitude of small whirlpools took form, a theory verified by Chandrasekhar’s calculations. And so, after having remained a single mass for so many millions of years, the continents suddenly began the movement that would give them their present form. But you see what I’m driving at, Yukinaga?”

  “I think so. The still-expanding core has brought about an other sudden alteration of the mantle convection pattern,” Yukinaga answered. “Still smaller whirlpools are taking form. And somewhere near the Japan Archipelago, the mantle mass has developed a fine split or is on the verge of so doing.”

  “Basically, that’s it. Why things should be moving so fast, I don’t know. But, in any case, the mantle mass on the Pacific side of the Japan Archipelago is rapidly shrinking.” He tapped the block screen on which was projected a three-dimensional map of Japan. “This may be the harbinger of a crust change of un precedented kind extending over the whole earth. Or perhaps it will affect only this area.”

  Tadokoro’s tone was much softer than it had been, his voice lower. The room was hushed. There was not a murmur. Holding their breath, the group sat with their eyes fixed upon Tadokoro. Behind his back the computer lights flashed on and off incessantly. Outside, the whine of the wind and the crash of the waves seemed to be growing louder.

  Onodera noticed that his hands, clenched into fists, had become sweaty. He wiped his brow instinctively, to find it, too, slippery with sweat.

  “And what would its effect be, Professor?” Onodera found himself asking.

  “If the present speed and direction are maintained, there’s reason enough to believe that once the shift in matter reaches a certain point, the present dynamic balance existing between the mantle and the crust structure will collapse at a stroke. Up to now, you see, the pressure from the Pacific side has held the Archipelago relatively firm against the pressure coming from the continental side. And so, should the convection pattern on the Pacific side suddenly change, the result would be a crushing blow to Japan.”

  A single image took hold of Onodera’s mind: the bar holding the Japan Archipelago in place suddenly falling away. . . .

  “If the worst were to happen,” Tadokoro went on, swallowing noisily, “the usual way of thinking of greater or lesser quake damage would have no place. For if the worst were to happen, the greater part of the Japan Archipelago would sink beneath the sea. We have to think in terms of annihilation.”

  A chill silence fell over the room. No one dared release his breath. The whine of the wind, the creaking of the ship, the sound of waves beginning to break over the decks—all these seemed but to intensify the silence that held them in its grip.

  Out of the corner of his eye, Onodera noticed that the red lights of the computers and the communication gear had begun to flash steadily. Because no one was taking the messages, the equipment was starting to do its own recording. The telex was chattering. The facsimile machine began to crackle. But still no one moved.

  All at once there was the sound of hurrying feet in the corridor. When they reached the cabin door, there was a loud knock. Someone in the room answered, but Onodera had no idea who. The door opened and a sunburned young officer came in. He made a polite bow. His face was tense, and the paper he held in his hand shook slightly.

  “Just now a message came from Fleet Command in Yokosuka,” said the officer, looking at the paper, his voice unsteady. “A large-scale quake has occurred in the Kanto Region. The epicenter is twenty miles out to sea off Tokyo Bay. Its magnitude is 8.5. Tidal waves have struck the entire shoreline of Tokyo Bay and Sagami Bay. In Tokyo the force of from 6 to 7, together with the suddenness with which it hit, appears to have caused extensive damage. This vessel, on orders from the Sea Defense Force Headquarters, is changing its course and is proceeding to Tokyo Bay for rescue operations. . . .”

  IV

  The Home Islands

  1

  At a little before five, Yamazaki was about to leave Plan D headquarters, on the sixth floor of a building next to Harajuku Station. At six o’clock a high-speed helicopter of the Sea Self-Defense Force was to land at Harumi Pier to pick him up and fly him to the Yoshino, then approaching the Sea of Enshu.

  “Well, I think I’ll be going. Tonight I’ll be on the waves.”

  “Sorry to hear it, answered Yasugawa breezily as he punched the keys of a computer. “I’ve got a full night’s work ahead of me.

  “Don’t overdo it,” said Yamazaki, putting on his hat. “It wouldn’t do to ruin your health while you’re still young.” As he spoke, Yamazaki moved over to the window to see how bad was the rush-hour traffic in the streets below.

  Just as he came to the window a mass of dark specks, like a billowing cloud o
f pepper, rose up into the sky in the direction of Yoyogi Grove. Pigeons, sparrow, crows—birds of every kind were taking to flight as though seized with a sudden frenzy.

  A cry formed on the lips of the startled Yamazaki, though no sound came from his throat. At the same instant, bolts of lightning, one after another, flashed down from the lead-colored clouds gathered in the already darkened eastern sky and darted over the ground. The staccato flashes covered the horizon with glaring sheets of light.

  “Yasugawa!” Yamazaki, whose eyes had been fixed on the scene outside, turned and shouted to his friend in a shrill voice. “Come here! Look! Something’s happening.”

  There was no way of fixing their points of origin, but beginning somewhere in the east and extending into the city itself, pillars of light were boiling up from the earth as though to tear it asunder and climbing toward the clouds. The columns—two, three of them—keeping a fixed distance from one another, shimmered brilliantly. A crimson-tinged ball of light spurted up from one of them and, describing a flashing arc, fell back to earth.

  “What is it?” asked Yasugawa, rising from his desk.

  But at that instant a thunderous shock struck, and the floor seemed to billow up beneath them. Before they had time even to register alarm, the floor rose again, as if a giant hammer were striking from below, blow upon blow, as though to pound every thing to rubble. While the two men struggled to keep their feet, ink bottles, water glasses, and the like bounced up into the air with each shock. A box of thumbtacks turned over in mid-flight, the tacks spilling out over the floor.

  “An earthquake!” said Yamazaki. “It looks like it’s going to be a big one.”