IN this chapter we shall learn what we can as to the physical condition of the interior of our earth so far as it may be reasonably inferred from the facts of observation. We have already explained in the last chapter that a very high temperature must be found at the depth of even a small fraction of the earth’s radius11, and we have pointed12 out that the excessively high pressure characteristic of the earth’s interior must be borne in mind in any consideration as to the condition of the matter there found.
Let us take, for instance, that primary question in terrestrial physics, as to whether the interior of the earth is liquid or solid. If we were to judge merely 159from the temperatures reasonably believed to exist at a depth of some twenty miles, and if we might overlook the question of pressure, we should certainly say that the earth’s interior must be in a fluid state. It seems at least certain that the temperatures to be found at depths of two score miles, and still more at greater depths, must be so high that the most refractory14 solids, whether metals or minerals, would at once yield if we could subject them to such temperatures in our laboratories. At such temperatures every metal would become fluid, even if it were not transformed into a cloud of vapour. But none of our laboratory experiments can tell us whether, under the pressure of thousands of tons on the square inch, the application of any heat whatever would be adequate to transform solids into liquids. It may indeed be reasonably doubted whether the terms solids and liquids are applicable, in the sense in which we understand them, to the materials forming the interior of the earth.
It was my good fortune some years ago to enjoy a most interesting trip to Norway, in company with a distinguished15 geologist16. Under his guidance I there saw evidence which demonstrates conclusively17 that, when subjected to great pressure, solids, as we should call them, behave in a manner which, if not that of actual liquids, resembles at all events in some of its characteristics the behaviour of liquids. These rocks in some places are conglomerates18, of which the leading constituents20 are water-worn pebbles21 of granite23. These pebbles are of various sizes, from marbles to paving-stones. In some parts of the country these granite pebbles remain in the form which they acquired on the beach on which they were rolled by 160the prim13?val ocean; in other parts of the same interesting region the form of the pebbles has been greatly changed from what it was originally. For in the course of geological periods, and after the pebbles had become consolidated24 into the conglomerate19, the rock so formed had been in some cases submitted to enormous pressure. This may have been lateral25 pressure, such as is found to have occurred in many other places, where it has produced the well-known geological phenomenon of strata26 crumpled27 into folds. In the present case, however, it seemed more probable that it was the actual weight of the superincumbent rocks, which once lay over these beds of conglomerate, which produced the surprising transformation28. It seems to be not at all improbable that at one time these beds of conglomerate must have been covered with strata of which the thickness is so great that it may actually be estimated by miles. There has, however, been immense denudation29 of the superficial rocks in this part, at all events, of Norway, so that in the course of ages these strata, overlying the conglomerate for ages, have been so far worn away, and indeed removed, by the action of ice and the action of water that the conglomerate is now exposed to view. It offers for our examination striking indications of the enormous pressure to which it was subjected during the incalculable ages of geological time.
The effect of this long continuance of great pressure upon the pebbles of the conglomerate in certain parts of the country has been most astonishing. The granite in the pebbles still retains its characteristic crystalline structure; it has obviously not undergone anything that could be described as fusion30; yet under 161the influence of the two factors of that pressure, namely, its intensity31 and its long continuance, the granite pebbles have yielded. In some cases they are slightly elongated32, in others they are much elongated, while in yet others they are even rolled out flat. At different places along the valley the various phases of the transformation can be studied. We can find places where the pebbles seem little altered, and then we can trace each stage until the solid granite pebbles have, by the application of excessive pressure, been compressed into thin sheets whose character it would not have been easy to divine if it had not been possible to trace out their history. These sheets lie close and parallel, so that the material thus produced acquires some of the characteristics of slate33. It splits easily along the flattened34 sheets, and this rolled-out conglomerate is indeed actually used as a substitute for slate, and in some places there are houses roofed with the conglomerate which has been treated in this extraordinary fashion.
This fact will illustrate35 a principle, already well known in the arts, that many, if not all, solids may be made to flow like liquids if only adequate pressure be applied36. The making of lead tubes is a well-known practical illustration of the same principle, for these tubes are simply formed by forcing solid lead by the hydraulic37 press through a mould which imparts the desired form.
If then a solid can be made to behave like a liquid, even with such pressures as are within our control, how are we to suppose that the solids would behave with such pressures as those to which they are subjected in the interior of the earth? The fact is 162that the terms solid and liquid, at least as we understand them, appear to have no physical meaning with regard to bodies subjected to these stupendous pressures, and this must be carefully borne in mind when we are discussing the nature of the interior of the earth.
It must, however, be admitted that the interior of the earth in its actual physical state seems to possess at least one of the most important characteristics of a solid, for it seems to be intensely rigid1. We mean by this, that the material of the earth, or rather each particle of that material, is very little inclined to move from its position with reference to the adjacent particles by the application of force. Possibly a liquid, such as water, might not behave very differently in this respect from a solid such as cast iron, if each of them were exposed to a pressure of scores of thousands of tons per square inch, as are the materials which form the great bulk of the earth. But, without speculating on these points, we are able to demonstrate that the earth, as a whole, does exhibit extreme rigidity. This is one of the most remarkable38 discoveries which has ever been made with regard to the physics of our earth. The discovery that the earth is so rigid is mainly due to Lord Kelvin.
We shall now mention the line of evidence which appears to prove, in the simplest and most direct manner, the excessive rigidity of our earth. It is derived39 from the study of earthquake phenomena40, and we must endeavour to set it forth41 with the completeness its importance deserves.
As to the immediate42 cause of earthquakes, there is no doubt considerable difference of opinion. But I think 163it will not be doubted that an earthquake is one of the consequences, though perhaps a remote one, of the gradual loss of internal heat from the earth. As this terrestrial heat is gradually declining, it follows from the law that we have already so often had occasion to use that the bulk of the earth must be shrinking. No doubt the diminution43 in the earth’s diameter, due to the loss of heat must be excessively small, even in a long period of time. The cause, however, is continually in operation, and accordingly the crust of the earth has, from time to time, to be accommodated to the fact that the whole globe is lessening44. The circumference45 of our earth at the Equator must be gradually declining; a certain length in that circumference is lost each year. We may admit that loss to be a quantity far too small to be measured by any observations as yet obtainable, but, nevertheless, it is productive of phenomena so important that it cannot be overlooked.
It follows from these considerations that the rocks which form the earth’s crust over the surface of the continents and the islands, or beneath the beds of ocean, must have a lessening acreage year by year. These rocks must therefore submit to compression, either continuously or from time to time, and the necessary yielding of the rocks will in general take place in those regions where the materials of the earth’s crust happen to have comparatively small powers of resistance. The acts of compression will often, and perhaps generally, not proceed with uniformity, but rather with small successive shifts, and even though the displacements47 of the rocks in these shifts be actually very small, yet the pressures to 164which the rocks are subjected are so vast that a very small shift may correspond to a very great terrestrial disturbance48.
Suppose, for instance, that there is a slight shift in the rocks on each side of a crack, or fault, at a depth of ten miles. It must be remembered that the pressure ten miles down would be about thirty-five tons on the square inch. Even a slight displacement46 of one extensive surface over another, the sides being pressed together with a force of thirty-five tons on the square inch, would be an operation necessarily accompanied by violence greatly exceeding that which we might expect from so small a displacement if the forces concerned had been only of more ordinary magnitude. On account of this great multiplication49 of the intensity of the phenomenon, merely a small rearrangement of the rocks in the crust of the earth, in pursuance of the necessary work of accommodating its volume to the perpetual shrinkage, might produce an excessively violent shock extending far and wide. The effect of such a shock would be propagated in the form of waves through the globe, just as a violent blow given at one end of a bar of iron by a hammer is propagated through the bar in the form of waves. When the effect of this internal adjustment reaches the earth’s surface, it will sometimes be great enough to be perceptible in the shaking it gives that surface. The shaking may be so violent that buildings may not be able to withstand it. Such is the phenomenon of an earthquake.
Earthquakes have been made to yield testimony of the most striking character with regard to the rigidity of the earth. The researches we are now to describe 165are mainly due to Professor Milne, who, having enjoyed the advantage of studying earthquakes in their natural home in Japan, where are to be found some of the most earthquake-shaken regions of this earth, has now transferred his observations of these phenomena to the more peaceful regions of the Isle of Wight. But though the Isle of Wight is perhaps one of the last places in the world to which anyone who desired to experience violent earthquake shocks would be likely to go, yet by the help of a beautiful apparatus50 Professor Milne is actually able to witness important earthquakes that are happening all over the world. He has a demonstration51 of these earthquakes in the indications of an extremely sensitive instrument which he has erected52 in his home at Shide.
When our earth is shaken by one of those occasional adjustments of the crust which I have described, the wave that spreads like a pulsation53 from the centre of agitation54 extends all over our globe and, indeed I may say, is transmitted right through it. At the surface lying immediately over the centre of disturbance there will be a violent shock. In the surrounding country, and often over great distances, the earthquake may also be powerful enough to produce destructive effects. The convulsion may also be manifested over a far larger area of country in a way which makes the shock to be felt, though the damage wrought55 may not be appreciable56. But beyond a limited distance from the centre of the agitation the earthquake will produce no destructive effects upon buildings, and will not even cause vibrations that would be appreciable to ordinary observation.
This earth of ours may transmit from an earthquake 166pulses of a very distinct and definite character, which are too weak to be perceived by our unaided senses; but, just as the microscope will render objects visible which are too minute to be perceived without this aid to the ordinary vision, so these faint earth-pulses may be rendered perceptible by the delicate indications of an instrument which perceives and records tremors that would pass unnoticed by our ordinary observations. The ingenious instrument for studying earthquakes is called a seismometer. It marks on a revolving57 drum of paper the particulars of those infinitesimal tremors by which the earth is almost daily agitated58 in one place or another.
Let us suppose, for example, that an earthquake occurs in Japan, in which much agitated country it is, I believe, estimated that no fewer than one thousand earthquakes of varying degrees of intensity occur annually59 in one district or another. Let us suppose that this earthquake behaves as serious earthquakes usually do; that it knocks down buildings and monuments, causes landslips, raises great waves in the sea and hurls60 them as inundations on the land. We may also suppose that it issues tragically61 in the loss of many lives and that there is a destruction of much property, and that its energies in the acutely violent form extend over, let us say, an area of a hundred square miles. Beyond that area of greatest destruction such an earthquake would be felt over a great extent of country as a shaking more or less vehement62, and characteristic rumbling63 sounds would be heard. But the intensity declines with the distance, and we may feel confident that not even the faintest indications of the earthquake would be perceptible by the unaided senses at 167a thousand miles from its origin. A thousand miles is, however, less than a fifth of the distance between Tokio and Shide, in the Isle of Wight, measured in a great circle round the earth’s surface. The acutest sense could not perceive the slightest indication of the convulsion in Japan at even half the distance between these two places. But the earth transmits so faithfully the undulations committed to its care that though the intensity may have declined so as to be no longer perceptible to the unaided sense, it is still possible that they may be shown distinctly on the seismometer in Professor Milne’s laboratory, even after a journey of five thousand miles. This instrument not only announces that an earthquake has been in progress some little time previously64, but the recording65 pencil reproduces with marvellous fidelity66 some actual details of the vibration9. The movements of the line up and down on the revolving drum of paper show how the convulsions succeed each other, and their varying intensity. Thus Professor Milne is enabled to set down some features of the earthquake long before the post brings an account of the convulsion from the unhappy locality.
Professor Milne’s account of work in studying earthquakes has the charm of a romance, even while it faithfully sets out the facts of Nature. I have supposed the earthquake to take place in Japan; but we must observe that the seismometer at Shide will also take account of considerable earthquakes in whatever part of the world the disturbance may arise. There are, for example, localities in the West Indies in which earthquakes are by no means infrequent, though they may not be phenomena of almost 168daily occurrence, as they are in Japan. Every considerable earthquake, no matter where its centre may lie, produces in our whole globe a vibration or a tingle67 which is sufficient to be manifested by the delicate indications of the seismometer at Shide. Thus this instrument, which in the morning may record an earthquake from Japan, will in the afternoon of the same day delineate with equal fidelity an earthquake from the opposite hemisphere in the neighbourhood of the Caribbean Sea.
In each locality in which earthquakes are chronic68 it would seem as if there must be some particularly weak spot in the earth some miles below the surface. A shrinkage of the earth, in the course of the incessant69 adjustment between the interior and the exterior70, will take place by occasional little jumps at this particular centre. The fact that there is this weak spot at which small adjustments are possible may provide, as it were, a safety-valve for other places in the same part of the world. Instead of a general shrinking, the materials would be sufficiently71 elastic72 and flexible to allow the shrinking for a very large area to be done at this particular locality. In this way we may explain the fact that immense tracts73 on the earth are practically free from earthquakes of a serious character, while in the less fortunate regions the earthquakes are more or less perennial74.
The characteristics of an earthquake record, a seismogram, if we give it the correct designation, depend on the distance of the origin from the locality where the record is made. The length of the journey, as might be expected, tells on the character of the inscription75 which the earthquake waves make on the drum. 169If, for instance, the first intimation of a large earthquake received at Shide precedes the second by about thirty-five minutes, it may be concluded that the earthquake has come from Japan.
In like manner the shocks, with their origin in the West Indies, will proceed from their particular earthquake centre, and consequently all the earthquakes from this source will possess a characteristic resemblance. The Japan group of earthquakes will have, so to speak, a family resemblance; and the Trinidad group of earthquakes, though quite different from the Japan group, will also possess a family resemblance. These features are faithfully transmitted by undulations through the earth and round the earth; thus in due course they reach the Isle of Wight, and they are reproduced by the pencil of the seismometer. The different earthquakes of a family may differ in size, in intensity, and undulation, but they will have the features appropriate to the particular group from which they come. From long experience Professor Milne has become so familiar with the lineaments of these earthquake families, that in his study at Shide, as he looks at the indications of his instrument, he is able to say, for example, “Here is an earthquake, and it is a little earthquake from Japan;” then a little later, when a new earthquake begins, he will say, “And here is a big earthquake from Trinidad.”
Professor Milne’s apparatus has brought us remarkable information with regard to the interior of the earth. The story which we have to tell is really one of the most astonishing in physical science. Let us suppose that an earthquake originates in Japan. We shall assume that the earthquake is a vigorous one, 170capable of producing bold and definite indications on the seismometer even in the Isle of Wight. It is to be noted76 that this instrument is not content merely with a single version of the story of that earthquake; it will indeed repeat that story twice more. First of all, about a quarter of an hour after a shock has taken place in Japan, the pencil of the seismometer commences to record. But this record, though quite distinct, is not so boldly indicated as the subsequent records of the same event which will presently be received. It is to be regarded as a precursor7. After the first record is completed there is a pause of perhaps three-quarters of an hour, and then the pencil of the seismometer commences again. It commences to give an earthquake record, but it is obviously only a second version of the same earthquake. For the ups and downs traced by the pencil are just the same relatively77 as before. The picture given of the earthquake is, however, on a much larger scale than the one that is first sent. The extent of the shaking of the instrument in this second record is greater than in the first, and all the details are more boldly drawn78.
After the second diagram has been received, there is yet another pause, which may be perhaps for half an hour. Then, by the same pencil, a third and last version is conveyed to the seismometer. This diagram is not quite so strong as the last, though stronger than the first; in it again, however, the faithful pencil tells, with many a detail, what happened in this earthquake at Japan.
We have first to explain how it occurs that there are three versions of the event, for it need hardly 171be said that the same earthquake did not take place three different times over. The point is indeed a beautiful one. The explanation is so astonishing that we should hardly credit it were it not established upon evidence that does not admit of a moment’s question.
In the adjoining diagram we represent the position of Japan at one side of the earth, and the Isle of Wight at the other. When the earthquake takes place at Japan it originates, as we have said, a series of vibrations through our globe. We must here distinguish between the rocks—I might almost say the comparatively pliant80 rocks—which form the earth’s crust, and those which form the intensely rigid core of the interior of our globe. The vibrations which carry the tidings of the earthquake spread through 172the rocks on the surface, from the centre of the disturbance, in gradually enlarging circles. We may liken the spread of these vibrations to the ripples81 in a pool of water which diverge82 from the spot where a raindrop has fallen, or to the remarkable air-waves from Krakatoa, to which we shall presently refer. The vibrations transmitted by the rocks on the surface, or on the floor of the ocean, will carry the message all over the earth. As these rocks are flexible, at all events by comparison with the earth’s interior, the vibrations will be correspondingly large, and will travel with vigour83 over land and under sea. In due time they reach the Isle of Wight, where they set the pencil of the seismometer at work. But there are different ways round the earth from Japan to the Isle of Wight. There is the most direct route across Asia and Europe; there is also the route across the Pacific, America, and the Atlantic. The vibrations will travel by both routes, and the former is the shorter of the two. The vibrations which take the first route through the crust of the earth’s surface are travelling by the shorter distance; they consequently reach Shide first, and render their version of what has happened. But the vibrations which, starting from the centre of the disturbance, move through the earth’s crust in an opposite direction will also in their due course of expansion reach the Isle of Wight. They will have had a longer journey, and will consequently be somewhat enfeebled, though they will still retain the characteristics marking the particular earthquake centre from which they arose.
We thus account for both the second and the 173third of the different versions of the earthquake which are received at Shide. And now for the first of the three versions. This is the one which is of special interest to us at present. The original subterranean84 impulse was, as we have seen, propagated through the rocks forming the earth’s crust. Part of it, however, entered into the core forming the earth’s interior. The earthquake had the power not only of shaking the earth’s crust all over, but it produced the astonishing effect of setting the whole interior of our globe into a tremble. There was not a single particle of our earth, from centre to surface, which was not made to vibrate, in some degree, in consequence of the earthquake. Certain of these vibrations, spreading from the centre of disturbance, took a direct course to the Isle of Wight, right through the globe. They consequently had a shorter journey in travelling from Tokio to Shide than those which went round the earth’s crust. The former travelled near the chord, while the latter travelled on the arc. Even for this reason alone the internal vibrations might be expected to accomplish their journey more rapidly than the superficial movements. With the same velocity85 they would take a shorter time for the journey. There is, however, another reason for the lesser86 time taken by the internal vibrations. Not only is the journey shorter, but the speed with which these vibrations travel through the solid earth is much greater than the speed with which superficial vibrations travel through the crust. It has been shown that the average velocity of these vibrations when travelling through the centre of the earth is rather more than ten miles a second. The velocity 174varies with the square root of the depth, and near the surface it is scarcely two miles a second.
There are two points to be specially87 noticed. The vibrations, which, passing through the earth’s interior with a high velocity, arrive as precursors, make a faithful diagram, but only on a very small scale. We say that these vibrations have but small amplitude88. This shows that the particles in the earth’s interior are not much displaced by the earthquake, as compared with those on the earth’s crust, and this is one indication of the effective rigidity of the earth. It is also to be noted that the great speed with which the vibrations traverse the solid earth is a consequence of the extreme rigidity of our globe. These vibrations travel more rapidly through the earth than they would do through a bar of solid steel. In other words, we have here a proof that, under the influence of the tremendous pressures characteristic of the earth’s interior, the material of which that earth is composed, notwithstanding the high temperature to which it is raised, possesses a rigidity which is practically greater than that of steel itself.
SHOWING LOCALITIES OF EARTHQUAKES
This is perhaps the most striking testimony that can be borne to the rigidity of our globe; but we must not imagine that we are dependent solely89 upon the phenomena of earthquakes for the demonstration of this important point; there are other proofs. It can be shown that the ebb22 and flow of the tides on our coasts would be very different from that which they actually are were it not that the earth behaves as a rigid globe. It has also been demonstrated that certain astronomical90 phenomena connected with the way in which the earth turns round on its axis91 175would not be the same as we actually find them to be if the earth were not solid in its interior.
The result of these investigations92 is to show that, though this globe of ours must be excessively hot inside, so hot indeed that at ordinary pressures even the most refractory solids would be liquefied or vaporised, yet under the influence of the pressure to which its materials are subjected the behaviour of that globe is as that of the most rigidly93 solid body.
Happily in this country we do not often experience earthquakes other than delicate movements shown by the record of the seismometer. But though most of us live our lives without ever having felt an earthquake shock, yet earthquakes do sometimes make themselves felt in Great Britain. The map we here give, which was drawn by Professor J. P. O’Reilly, indicates the localities in England in which from time to time earthquake shocks have been experienced.
The internal heat of the earth, derived from the prim?val nebula94, is in no way more strikingly illustrated95 than by the phenomena of volcanoes. We have shown in this chapter that there is no longer any reason to believe that the earth is fluid in its interior. The evidence has proved that, under the extraordinary pressure which prevails in the earth, the materials in the central portions of our globe behave with the characteristics of solids rather than of liquids. But though this applies to the deep-seated regions of our globe, it need not universally apply at the surface or within a moderate depth from the surface. When the circumstances are such that the pressure is relaxed, then the heat is permitted to exercise its property of transforming the solids into liquids. Masses of matter 176near the earth’s crust are thus, in certain circumstances, and in certain localities, transformed into the fluid or viscid form. In that state they may issue from a volcano and flow in sluggish96 currents as lava97.
There has been much difference of opinion as to the immediate cause of volcanic98 action, but there can be little doubt that the energy which is manifested in a volcanic eruption99 has been originally derived in some way from the contraction100 of the prim?val nebula. The extraordinary vehemence101 that a volcanic eruption sometimes attains102 may be specially illustrated by the case of the great eruption of Krakatoa. It is, indeed, believed that in the annals of our earth there has been no record of a volcanic eruption so vast as that which bears the name of this little island in far Eastern seas, ten thousand miles from our shores.
Until the year 1883 few had ever heard of Krakatoa. It was unknown to fame, as are hundreds of other gems103 of glorious vegetation set in tropical waters. It was not inhabited, but the natives from the surrounding shores of Sumatra and Java used occasionally to draw their canoes up on its beach, while they roamed through the jungle in search of the wild fruits that there abounded104. Geographers105 in early days hardly condescended106 to notice Krakatoa; the name of the island on their maps would have been far longer than the island itself. It was known to the mariner107 who navigated108 the Straits of Sunda, for it was marked on his charts as one of the perils109 of the intricate navigation in those waters. It was no doubt recorded that the locality had been once, or more than once, the seat of an active volcano. In fact, the island seemed to owe its existence to some frightful110 eruption of bygone 177days; but for a couple of centuries there had been no fresh outbreak. It almost seemed as if Krakatoa might be regarded as a volcano that had become extinct. In this respect it would only be like many other similar objects all over the globe, or the countless111 extinct volcanoes all over the moon.
In 1883 Krakatoa suddenly sprang into notoriety. Insignificant112 though it had hitherto seemed, the little island was soon to compel by its tones of thunder the whole world to pay it instant attention. It was to become the scene of a volcanic outbreak so appalling113 that it is destined115 to be remembered throughout the ages. In the spring of that year there were symptoms that the volcanic powers in Krakatoa were once more about to awake from the slumber116 that had endured for many generations. Notable warnings were given. Earthquakes were felt, and deep rumblings proceeded from the earth, showing that some disturbance was in preparation, and that the old volcano was again to burst forth after its long period of rest. At first the eruption did not threaten to be of any serious type; in fact, the good people of Batavia, so far from being terrified at what was in progress in Krakatoa, thought the display was such an attraction that they chartered a steamer and went forth for a pleasant picnic to the island. Many of us, I am sure, would have been delighted to have been able to join the party who were to witness so interesting a spectacle. With cautious steps the more venturesome of the excursion party clambered up the sides of the volcano, guided by the sounds which were issuing from its summit. There they beheld117 a vast column of steam pouring forth with terrific noise from a profound opening about thirty yards in width.
178As the summer of this dread118 year advanced the vigour of Krakatoa steadily119 increased, the noises became more and more vehement; these were presently audible on shores ten miles distant, and then twenty miles distant; and still those noises waxed louder and louder, until the great thunders of the volcano, now so rapidly developing, astonished the inhabitants that dwelt over an area at least as large as Great Britain. And there were other symptoms of the approaching catastrophe120. With each successive convulsion a quantity of fine dust was projected aloft into the clouds. The wind could not carry this dust away as rapidly as it was hurled121 upwards122 by Krakatoa, and accordingly the atmosphere became heavily charged with suspended particles. A pall114 of darkness thus hung over the adjoining seas and islands. Such was the thickness and the density123 of these atmospheric124 volumes of Krakatoa dust that, for a hundred miles around, the darkness of midnight prevailed at midday. Then the awful tragedy of Krakatoa took place. Many thousands of the unfortunate inhabitants of the adjacent shores of Sumatra and Java were destined never to behold125 the sun again. They were presently swept away to destruction in an invasion of the shore by the tremendous waves with which the seas surrounding Krakatoa were agitated.
Gradually the development of the volcanic energy proceeded, and gradually the terror of the inhabitants of the surrounding coasts rose to a climax126. July had ended before the manifestations127 of Krakatoa had attained128 their full violence. As the days of August passed by the spasms129 of Krakatoa waxed more and more vehement. By the middle of that month the panic 180was widespread, for the supreme130 catastrophe was at hand.
Fig. 26.—Showing Coasts invaded by the Great Sea-waves from Krakatoa.
(From the Royal Society’s Reports.)
On the night of Sunday, August 26th, 1883, the blackness of the dust-clouds, now much thicker than ever in the Straits of Sunda and adjacent parts of Sumatra and Java, was only occasionally illumined by lurid131 flashes from the volcano. The Krakatoan thunders were on the point of attaining132 their complete development. At the town of Batavia, a hundred miles distant, there was no quiet that night. The houses trembled with the subterranean violence, and the windows rattled133 as if heavy artillery134 were being discharged in the streets. And still these efforts seemed to be only rehearsing for the supreme display. By ten o’clock on the morning of Monday, August 27th, 1883, the rehearsals135 were over and the performance began. An overture136, consisting of two or three introductory explosions, was succeeded by a frightful convulsion which tore away a large part of the island of Krakatoa and scattered137 it to the winds of heaven. In that final effort all records of previous explosions on this earth were completely broken.
This supreme effort it was which produced the mightiest138 noise that, so far as we can ascertain139, has ever been heard on this globe. It must have been indeed a loud noise which could travel from Krakatoa to Batavia and preserve its vehemence over so great a distance; but we should form a very inadequate140 conception of the energy of the eruption of Krakatoa if we thought that its sounds were heard by those merely a hundred miles off. This would be little indeed compared with what is recorded, on testimony which it is impossible to doubt.
THE EARLY STAGE OF THE ERUPTION OF KRAKATOA.
(From a Photograph taken on May 27th, 1883.)
181Westward from Krakatoa stretches the wide expanse of the Indian Ocean. On the opposite side from the Straits of Sunda lies the island of Rodriguez, the distance from Krakatoa being almost three thousand miles. It has been proved by evidence which cannot be doubted that the booming of the great volcano attracted the attention of an intelligent coastguard on Rodriguez, who carefully noted the character of the sounds and the time of their occurrence. He had heard them just four hours after the actual explosion, for this is the time the sound occupied on its journey.
We shall better realise the extraordinary vehemence of this tremendous noise if we imagine a similar event to take place in localities more known to most of us than are the far Eastern seas.
If Vesuvius were vigorous enough to thunder forth like Krakatoa, how great would be the consternation142 of the world! Such a report might be heard by King Edward at Windsor, and by the Czar of all the Russias at Moscow. It would astonish the German Emperor and all his subjects. It would penetrate143 to the seclusion144 of the Sultan at Constantinople. Nansen would still have been within its reach when he was furthest north, near the Pole. It would have extended to the sources of the Nile, near the Equator. It would have been heard by Mohammedan pilgrims at Mecca. It would have reached the ears of exiles in Siberia. No inhabitant of Persia would have been beyond its range, while passengers on half the liners crossing the Atlantic would also catch the mighty145 reverberation146.
The subject is of such exceptional interest that I may venture on another illustration. Let us suppose that a similar earth-shaking event took place in a central 182position in the United States. Let us say, for example, that an explosion occurred at Pike’s Peak as resonant147 as that from Krakatoa. It would certainly startle not a little the inhabitants of Colorado far and wide. The ears of dwellers148 in the neighbouring States would receive a considerable shock. With lessening intensity the sound would spread much further around—indeed, it might be heard all over the United States. The sonorous149 waves would roll over to the Atlantic coast, they would be heard on the shores of the Pacific. Florida would not be too far to the south, nor Alaska too remote to the north. If, indeed, we could believe that the sound would travel as freely over the great continent as it did across the Indian Ocean, then we may boldly assert that every ear in North America might listen to the thunder from Pike’s Peak, if it rivalled Krakatoa. The reverberation might even be audible by skin-clad Eskimos amid the snows of Greenland, and by naked Indians sweltering on the Orinoco. Can we doubt that Krakatoa made the greatest noise that has ever been recorded?
Fig. 27.—Spread of the Air-wave from Krakatoa to the Antipodes.
(From the Royal Society’s Reports.)
Among the many other incidents connected with this explosion, I may specially mention the wonderful system of divergent ripples that started in our atmosphere from the point at which the eruption took place. I have called them ripples, from the obvious resemblance which they bear to the circular expanding ripples produced by raindrops which fall upon the still surface of water. But it would be more correct to say that these objects were a series of great undulations which started from Krakatoa and spread forth in ever-enlarging circles through our atmosphere. The initial impetus150 was so tremendous that these waves spread for 184hundreds and thousands of miles. They diverged151, in fact, until they put a mighty girdle round the earth, on a great circle of which Krakatoa was the pole. The atmospheric waves, with the whole earth now well in their grasp, advanced into the opposite hemisphere. In their further progress they had necessarily to form gradually contracting circles, until at last they converged152 to a point in Central America, at the very opposite point of the diameter of our earth, eight thousand miles from Krakatoa. Thus the waves completely embraced the earth. Every part of our atmosphere had been set into a tingle by the great eruption. In Great Britain the waves passed over our heads, the air in our streets, the air in our houses, trembled from the volcanic impulse. The very oxygen supplying our lungs was responding also to the supreme convulsion which took place ten thousand miles away. It is needless to object that this could not have taken place because we did not feel it. Self-registering barometers153 have enabled these waves to be followed unmistakably all over the globe.
Such was the energy with which these vibrations were initiated154 at Krakatoa, that even when the waves thus arising had converged to the point diametrically opposite in South America their vigour was not yet exhausted155. The waves were then, strange to say, reflected back from their point of convergence to retrace156 their steps to Krakatoa. Starting from Central America, they again described a series of enlarging circles, until they embraced the whole earth. Then, advancing into the opposite hemisphere, they gradually contracted until they had regained157 the Straits of Sunda, from which they had set forth about thirty-six 185hours previously. Here was, indeed, a unique experience. The air-waves had twice gone from end to end of this globe of ours. Even then the atmosphere did not subside158 until, after some more oscillations of gradually fading intensity, at last they became evanescent.
But, besides these phenomenal undulations, this mighty incident at Krakatoa has taught us other lessons on the constitution of our atmosphere. We previously knew little, or I might almost say nothing, as to the conditions prevailing159 above the height of ten miles overhead. We were almost altogether ignorant of what the wind might be at an altitude of, let us say, twenty miles. It was Krakatoa which first gave us a little information which was greatly wanted. How could we learn what winds were blowing at a height four times as great as the loftiest mountain on the earth, and twice as great as the loftiest altitude to which a balloon has ever soared? We could neither see these winds nor feel them. How, then, could we learn whether they really existed? No doubt a straw will show the way the wind blows, but there are no straws up there. There was nothing to render the winds perceptible until Krakatoa came to our aid. Krakatoa drove into those winds prodigious160 quantities of dust. Hundreds of cubic miles of air were thus deprived of that invisibility which they had hitherto maintained. They were thus compelled to disclose those movements about which, neither before nor since, have we had any opportunity of learning.
With eyes full of astonishment161 men watched those vast volumes of Krakatoa dust start on a tremendous journey. Westward141 the dust of Krakatoa took its way. Of course, everyone knows the so-called tradewinds 186on our earth’s surface, which blow steadily in fixed162 directions, and which are of such service to the mariner. But there is yet another constant wind. We cannot call it a trade-wind, for it never has rendered, and never will render, any service to navigation. It was first disclosed by Krakatoa. Before the occurrence of that eruption no one had the slightest suspicion that far up aloft, twenty miles over our heads, a mighty tempest is incessantly163 hurrying with a speed much greater than that of the awful hurricane which once laid so large a part of Calcutta on the ground, and slew164 so many of its inhabitants. Fortunately for humanity, this new trade-wind does not come within less than twenty miles of the earth’s surface. We are thus preserved from the fearful destruction that its unintermittent blasts would produce, blasts against which no tree could stand, and which would, in ten minutes, do as much damage to a city as would the most violent earthquake. When this great wind had become charged with the dust of Krakatoa, then, for the first and, I may add, for the only time, it stood revealed to human vision. Then it was seen that this wind circled round the earth in the vicinity of the Equator, and completed its circuit in about thirteen days.
Please observe the contrast between this wind of which we are now speaking and the waves to which we have just referred. The waves were merely undulations or vibrations produced by the blow which our atmosphere received from the explosion of Krakatoa, and these waves were propagated through the atmosphere much in the same way as sound waves are propagated. Indeed, these waves moved with the 187same velocity as sound. But the current of air of which we are now speaking was not produced by Krakatoa; it existed from all time, before Krakatoa was ever heard of, and it exists at the present moment, and will doubtless exist as long as the earth’s meteorological arrangements remain as they are at present. All that Krakatoa did was simply to provide the charges of dust by which for one brief period this wind was made visible.
In the autumn of 1883 the newspapers were full of accounts of strange appearances in the heavens. The letters containing these accounts poured in upon us from residents in Ceylon; they came from residents in the West Indies, and from other tropical places. All had the same tale to tell. Sometimes experienced observers assured us that the sun looked blue; sometimes we were told of the amazement165 with which people beheld the moon draped in vivid green. Other accounts told of curious halos, and, in short, of the signs in the sun, the moon, and the stars, which were exceedingly unusual, even if we do not say that they were absolutely unprecedented166.
Those who wrote to tell of the strange hues167 that the sun manifested to travellers in Ceylon, or to planters in Jamaica, never dreamt of attributing the phenomena to Krakatoa, many thousands of miles away. In fact, these observers knew nothing at the time of the Krakatoa eruption, and probably few of them, if any, had ever heard that such a place existed. It was only gradually that the belief grew that these, phenomena were due to Krakatoa. But when the accounts were carefully compared, and when the dates were studied at which the phenomena were witnessed in 188the various localities, it was demonstrated that these phenomena, notwithstanding their worldwide distribution, had certainly arisen from the eruption in this little island in the Straits of Sunda. It was most assuredly Krakatoa that painted the sun and the moon, and produced the other strange and weird168 phenomena in the tropics.
After a little time we learned what had actually happened. The dust manufactured by the supreme convulsion was whirled round the earth in the mighty atmospheric current into which the volcano discharged it. As the dust-cloud was swept along by this incomparable hurricane, it showed its presence in the most glorious manner by decking the sun and the moon in hues of unaccustomed splendour and beauty. The blue colour in the sky under ordinary circumstances is due to particles in the air, and when the ordinary motes169 of the sunbeam were reinforced by the introduction of the myriads170 of motes produced by Krakatoa, even the sun itself sometimes showed a blue tint171. Thus the progress of the great dust-cloud was traced out by the extraordinary sky effects it produced, and from the progress of the dust-cloud we inferred the movements of the invisible air current which carried it along. Nor need it be thought that the quantity of material projected from Krakatoa should have been inadequate to produce effects of this worldwide description. Imagine that the material which was blown to the winds of heaven by the supreme convulsion of Krakatoa could be all recovered and swept into one vast heap. Imagine that the heap were to have its bulk measured by a vessel172 consisting of a cube one mile 189long, one mile broad, and one mile deep; it has been estimated that even this prodigious vessel would have to be filled to the brim at least ten times before all the products of Krakatoa had been measured.
It was in the late autumn of 1883 that the marvellous series of celestial173 phenomena connected with the great eruption began to be displayed in Great Britain. Then it was that the glory of the ordinary sunsets was enhanced by a splendour which has dwelt in the memory of all those who were permitted to see them. The frontispiece of this volume contains a view of the sunset as seen at Chelsea at 4.40 p.m. on November 26th, 1883. The picture was painted from nature by Mr. W. Ascroft, and is given in the great work on Krakatoa which was published by the Royal Society. There is not the least doubt that it was the dust from Krakatoa which produced the beauty of those sunsets, and so long as that dust remained suspended in our atmosphere, so long were strange signs to be witnessed in the heavenly bodies. But the dust which had been borne with unparalleled violence from the interior of the volcano, the dust which had been shot aloft by the vehemence of the eruption to an altitude of twenty miles, the dust which had thus been whirled round and round our earth for perhaps a dozen times or more in this air current, which carried it round in less than a fortnight, was endowed with no power to resist for ever the law of gravitation which bids it fall to the earth. It therefore gradually sank downwards174. Owing, however, to the great height to which it had been driven, owing to the impetuous nature of the current by which 190it was hurried along, and owing to the exceedingly minute particles of which it was composed, the act of sinking was greatly protracted175. Not until two years after the original explosion had all the particles with which the air was charged by the great eruption finally subsided176 on the earth.
At first there were some who refused to believe that the glory of the sunsets in London could possibly be due to a volcano in the Straits of Sunda, at a distance from England which was but little short of that of Australia. But the gorgeous phenomena in England were found to be simultaneous with like phenomena in other places all round the earth. Once again the comparison of dates and other circumstances proved that Krakatoa was the cause of these exceptional and most interesting appearances.
Nor was the incident without a historical parallel, for has not Tennyson told us of the call to St. Telemachus—
Been hurl’d so high they ranged about the globe?
For day by day, thro’ many a blood-red eve,
In that four-hundredth summer after Christ,
The wrathful sunset glared....”
点击
收听单词发音
收听单词发音 |
1
rigid
|
|
| adj.严格的，死板的；刚硬的，僵硬的 | |
参考例句： |
|
|
|
|
2
rigidity
|
|
| adj.钢性，坚硬 | |
参考例句： |
|
|
|
|
3
testimony
|
|
| n.证词；见证，证明 | |
参考例句： |
|
|
|
|
4
tremors
|
|
| 震颤( tremor的名词复数 )； 战栗； 震颤声； 大地的轻微震动 | |
参考例句： |
|
|
|
|
5
isle
|
|
| n.小岛，岛 | |
参考例句： |
|
|
|
|
6
precursors
|
|
| n.先驱( precursor的名词复数 )；先行者；先兆；初期形式 | |
参考例句： |
|
|
|
|
7
precursor
|
|
| n.先驱者；前辈；前任；预兆；先兆 | |
参考例句： |
|
|
|
|
8
vibrations
|
|
| n.摆动( vibration的名词复数 )；震动；感受；（偏离平衡位置的）一次性往复振动 | |
参考例句： |
|
|
|
|
9
vibration
|
|
| n.颤动，振动；摆动 | |
参考例句： |
|
|
|
|
10
diverging
|
|
| 分开( diverge的现在分词 )； 偏离； 分歧； 分道扬镳 | |
参考例句： |
|
|
|
|
11
radius
|
|
| n.半径，半径范围；有效航程，范围，界限 | |
参考例句： |
|
|
|
|
12
pointed
|
|
| adj.尖的，直截了当的 | |
参考例句： |
|
|
|
|
13
prim
|
|
| adj.拘泥形式的，一本正经的；n.循规蹈矩，整洁；adv.循规蹈矩地，整洁地 | |
参考例句： |
|
|
|
|
14
refractory
|
|
| adj.倔强的，难驾驭的 | |
参考例句： |
|
|
|
|
15
distinguished
|
|
| adj.卓越的，杰出的，著名的 | |
参考例句： |
|
|
|
|
16
geologist
|
|
| n.地质学家 | |
参考例句： |
|
|
|
|
17
conclusively
|
|
| adv.令人信服地，确凿地 | |
参考例句： |
|
|
|
|
18
conglomerates
|
|
| n.（多种经营的）联合大企业( conglomerate的名词复数 )；砾岩；合成物；组合物 | |
参考例句： |
|
|
|
|
19
conglomerate
|
|
| n.综合商社，多元化集团公司 | |
参考例句： |
|
|
|
|
20
constituents
|
|
| n.选民( constituent的名词复数 )；成分；构成部分；要素 | |
参考例句： |
|
|
|
|
21
pebbles
|
|
| [复数]鹅卵石； 沙砾； 卵石，小圆石( pebble的名词复数 ) | |
参考例句： |
|
|
|
|
22
ebb
|
|
| vi.衰退，减退；n.处于低潮，处于衰退状态 | |
参考例句： |
|
|
|
|
23
granite
|
|
| adj.花岗岩，花岗石 | |
参考例句： |
|
|
|
|
24
consolidated
|
|
| a.联合的 | |
参考例句： |
|
|
|
|
25
lateral
|
|
| adj.侧面的，旁边的 | |
参考例句： |
|
|
|
|
26
strata
|
|
| n.地层（复数）；社会阶层 | |
参考例句： |
|
|
|
|
27
crumpled
|
|
| adj. 弯扭的, 变皱的 动词crumple的过去式和过去分词形式 | |
参考例句： |
|
|
|
|
28
transformation
|
|
| n.变化；改造；转变 | |
参考例句： |
|
|
|
|
29
denudation
|
|
| n.剥下；裸露；滥伐；剥蚀 | |
参考例句： |
|
|
|
|
30
fusion
|
|
| n.溶化；熔解；熔化状态，熔和；熔接 | |
参考例句： |
|
|
|
|
31
intensity
|
|
| n.强烈，剧烈；强度；烈度 | |
参考例句： |
|
|
|
|
32
elongated
|
|
| v.延长，加长( elongate的过去式和过去分词 ) | |
参考例句： |
|
|
|
|
33
slate
|
|
| n.板岩，石板，石片，石板色，候选人名单；adj.暗蓝灰色的，含板岩的；vt.用石板覆盖，痛打，提名，预订 | |
参考例句： |
|
|
|
|
34
flattened
|
|
| [医]（水）平扁的，弄平的 | |
参考例句： |
|
|
|
|
35
illustrate
|
|
| v.举例说明，阐明；图解，加插图 | |
参考例句： |
|
|
|
|
36
applied
|
|
| adj.应用的；v.应用，适用 | |
参考例句： |
|
|
|
|
37
hydraulic
|
|
| adj.水力的；水压的，液压的；水力学的 | |
参考例句： |
|
|
|
|
38
remarkable
|
|
| adj.显著的，异常的，非凡的，值得注意的 | |
参考例句： |
|
|
|
|
39
derived
|
|
| vi.起源；由来；衍生；导出v.得到( derive的过去式和过去分词 )；（从…中）得到获得；源于；（从…中）提取 | |
参考例句： |
|
|
|
|
40
phenomena
|
|
| n.现象 | |
参考例句： |
|
|
|
|
41
forth
|
|
| adv.向前；向外，往外 | |
参考例句： |
|
|
|
|
42
immediate
|
|
| adj.立即的；直接的，最接近的；紧靠的 | |
参考例句： |
|
|
|
|
43
diminution
|
|
| n.减少；变小 | |
参考例句： |
|
|
|
|
44
lessening
|
|
| 减轻，减少，变小 | |
参考例句： |
|
|
|
|
45
circumference
|
|
| n.圆周，周长，圆周线 | |
参考例句： |
|
|
|
|
46
displacement
|
|
| n.移置，取代，位移，排水量 | |
参考例句： |
|
|
|
|
47
displacements
|
|
| n.取代( displacement的名词复数 )；替代；移位；免职 | |
参考例句： |
|
|
|
|
48
disturbance
|
|
| n.动乱，骚动；打扰，干扰；(身心)失调 | |
参考例句： |
|
|
|
|
49
multiplication
|
|
| n.增加，增多，倍增；增殖，繁殖；乘法 | |
参考例句： |
|
|
|
|
50
apparatus
|
|
| n.装置，器械；器具，设备 | |
参考例句： |
|
|
|
|
51
demonstration
|
|
| n.表明，示范，论证，示威 | |
参考例句： |
|
|
|
|
52
ERECTED
|
|
| adj. 直立的，竖立的，笔直的 vt. 使 ... 直立，建立 | |
参考例句： |
|
|
|
|
53
pulsation
|
|
| n.脉搏，悸动，脉动；搏动性 | |
参考例句： |
|
|
|
|
54
agitation
|
|
| n.搅动；搅拌；鼓动，煽动 | |
参考例句： |
|
|
|
|
55
wrought
|
|
| v.引起；以…原料制作；运转；adj.制造的 | |
参考例句： |
|
|
|
|
56
appreciable
|
|
| adj.明显的，可见的，可估量的，可觉察的 | |
参考例句： |
|
|
|
|
57
revolving
|
|
| adj.旋转的，轮转式的；循环的v.（使）旋转( revolve的现在分词 )；细想 | |
参考例句： |
|
|
|
|
58
agitated
|
|
| adj.被鼓动的，不安的 | |
参考例句： |
|
|
|
|
59
annually
|
|
| adv.一年一次，每年 | |
参考例句： |
|
|
|
|
60
hurls
|
|
| v.猛投，用力掷( hurl的第三人称单数 )；大声叫骂 | |
参考例句： |
|
|
|
|
61
tragically
|
|
| adv. 悲剧地，悲惨地 | |
参考例句： |
|
|
|
|
62
vehement
|
|
| adj.感情强烈的；热烈的；(人)有强烈感情的 | |
参考例句： |
|
|
|
|
63
rumbling
|
|
| n. 隆隆声, 辘辘声 adj. 隆隆响的 动词rumble的现在分词 | |
参考例句： |
|
|
|
|
64
previously
|
|
| adv.以前，先前（地） | |
参考例句： |
|
|
|
|
65
recording
|
|
| n.录音，记录 | |
参考例句： |
|
|
|
|
66
fidelity
|
|
| n.忠诚，忠实；精确 | |
参考例句： |
|
|
|
|
67
tingle
|
|
| vi.感到刺痛，感到激动；n.刺痛，激动 | |
参考例句： |
|
|
|
|
68
chronic
|
|
| adj.(疾病)长期未愈的，慢性的；极坏的 | |
参考例句： |
|
|
|
|
69
incessant
|
|
| adj.不停的，连续的 | |
参考例句： |
|
|
|
|
70
exterior
|
|
| adj.外部的，外在的；表面的 | |
参考例句： |
|
|
|
|
71
sufficiently
|
|
| adv.足够地，充分地 | |
参考例句： |
|
|
|
|
72
elastic
|
|
| n.橡皮圈，松紧带；adj.有弹性的；灵活的 | |
参考例句： |
|
|
|
|
73
tracts
|
|
| 大片土地( tract的名词复数 )； 地带； （体内的）道； （尤指宣扬宗教、伦理或政治的）短文 | |
参考例句： |
|
|
|
|
74
perennial
|
|
| adj.终年的；长久的 | |
参考例句： |
|
|
|
|
75
inscription
|
|
| n.（尤指石块上的）刻印文字，铭文，碑文 | |
参考例句： |
|
|
|
|
76
noted
|
|
| adj.著名的，知名的 | |
参考例句： |
|
|
|
|
77
relatively
|
|
| adv.比较...地，相对地 | |
参考例句： |
|
|
|
|
78
drawn
|
|
| v.拖，拉，拔出；adj.憔悴的，紧张的 | |
参考例句： |
|
|
|
|
79
fig
|
|
| n.无花果(树) | |
参考例句： |
|
|
|
|
80
pliant
|
|
| adj.顺从的；可弯曲的 | |
参考例句： |
|
|
|
|
81
ripples
|
|
| 逐渐扩散的感觉( ripple的名词复数 ) | |
参考例句： |
|
|
|
|
82
diverge
|
|
| v.分叉，分歧，离题，使...岔开，使转向 | |
参考例句： |
|
|
|
|
83
vigour
|
|
| （=vigor）n.智力，体力，精力 | |
参考例句： |
|
|
|
|
84
subterranean
|
|
| adj.地下的，地表下的 | |
参考例句： |
|
|
|
|
85
velocity
|
|
| n.速度，速率 | |
参考例句： |
|
|
|
|
86
lesser
|
|
| adj.次要的，较小的；adv.较小地，较少地 | |
参考例句： |
|
|
|
|
87
specially
|
|
| adv.特定地；特殊地；明确地 | |
参考例句： |
|
|
|
|
88
amplitude
|
|
| n.广大；充足；振幅 | |
参考例句： |
|
|
|
|
89
solely
|
|
| adv.仅仅，唯一地 | |
参考例句： |
|
|
|
|
90
astronomical
|
|
| adj.天文学的，（数字）极大的 | |
参考例句： |
|
|
|
|
91
axis
|
|
| n.轴，轴线，中心线；坐标轴，基准线 | |
参考例句： |
|
|
|
|
92
investigations
|
|
| （正式的）调查( investigation的名词复数 )； 侦查； 科学研究； 学术研究 | |
参考例句： |
|
|
|
|
93
rigidly
|
|
| adv.刻板地，僵化地 | |
参考例句： |
|
|
|
|
94
nebula
|
|
| n.星云，喷雾剂 | |
参考例句： |
|
|
|
|
95
illustrated
|
|
| adj. 有插图的，列举的 动词illustrate的过去式和过去分词 | |
参考例句： |
|
|
|
|
96
sluggish
|
|
| adj.懒惰的，迟钝的，无精打采的 | |
参考例句： |
|
|
|
|
97
lava
|
|
| n.熔岩，火山岩 | |
参考例句： |
|
|
|
|
98
volcanic
|
|
| adj.火山的；象火山的；由火山引起的 | |
参考例句： |
|
|
|
|
99
eruption
|
|
| n.火山爆发；（战争等）爆发；（疾病等）发作 | |
参考例句： |
|
|
|
|
100
contraction
|
|
| n.缩略词，缩写式，害病 | |
参考例句： |
|
|
|
|
101
vehemence
|
|
| n.热切；激烈；愤怒 | |
参考例句： |
|
|
|
|
102
attains
|
|
| （通常经过努力）实现( attain的第三人称单数 )； 达到； 获得； 达到（某年龄、水平、状况） | |
参考例句： |
|
|
|
|
103
gems
|
|
| growth； economy； management； and customer satisfaction 增长 | |
参考例句： |
|
|
|
|
104
abounded
|
|
| v.大量存在，充满，富于( abound的过去式和过去分词 ) | |
参考例句： |
|
|
|
|
105
geographers
|
|
| 地理学家( geographer的名词复数 ) | |
参考例句： |
|
|
|
|
106
condescended
|
|
| 屈尊，俯就( condescend的过去式和过去分词 )； 故意表示和蔼可亲 | |
参考例句： |
|
|
|
|
107
mariner
|
|
| n.水手号不载人航天探测器，海员，航海者 | |
参考例句： |
|
|
|
|
108
navigated
|
|
| v.给（船舶、飞机等）引航，导航( navigate的过去式和过去分词 )；（从海上、空中等）横越；横渡；飞跃 | |
参考例句： |
|
|
|
|
109
perils
|
|
| 极大危险( peril的名词复数 )； 危险的事（或环境） | |
参考例句： |
|
|
|
|
110
frightful
|
|
| adj.可怕的；讨厌的 | |
参考例句： |
|
|
|
|
111
countless
|
|
| adj.无数的，多得不计其数的 | |
参考例句： |
|
|
|
|
112
insignificant
|
|
| adj.无关紧要的，可忽略的，无意义的 | |
参考例句： |
|
|
|
|
113
appalling
|
|
| adj.骇人听闻的，令人震惊的，可怕的 | |
参考例句： |
|
|
|
|
114
pall
|
|
| v.覆盖，使平淡无味；n.柩衣，棺罩；棺材；帷幕 | |
参考例句： |
|
|
|
|
115
destined
|
|
| adj.命中注定的；(for)以…为目的地的 | |
参考例句： |
|
|
|
|
116
slumber
|
|
| n.睡眠，沉睡状态 | |
参考例句： |
|
|
|
|
117
beheld
|
|
| v.看，注视( behold的过去式和过去分词 )；瞧；看呀；（叙述中用于引出某人意外的出现）哎哟 | |
参考例句： |
|
|
|
|
118
dread
|
|
| vt.担忧，忧虑；惧怕，不敢；n.担忧，畏惧 | |
参考例句： |
|
|
|
|
119
steadily
|
|
| adv.稳定地；不变地；持续地 | |
参考例句： |
|
|
|
|
120
catastrophe
|
|
| n.大灾难，大祸 | |
参考例句： |
|
|
|
|
121
hurled
|
|
| v.猛投，用力掷( hurl的过去式和过去分词 )；大声叫骂 | |
参考例句： |
|
|
|
|
122
upwards
|
|
| adv.向上，在更高处...以上 | |
参考例句： |
|
|
|
|
123
density
|
|
| n.密集，密度，浓度 | |
参考例句： |
|
|
|
|
124
atmospheric
|
|
| adj.大气的，空气的；大气层的；大气所引起的 | |
参考例句： |
|
|
|
|
125
behold
|
|
| v.看，注视，看到 | |
参考例句： |
|
|
|
|
126
climax
|
|
| n.顶点；高潮；v.(使)达到顶点 | |
参考例句： |
|
|
|
|
127
manifestations
|
|
| n.表示，显示（manifestation的复数形式） | |
参考例句： |
|
|
|
|
128
attained
|
|
| （通常经过努力）实现( attain的过去式和过去分词 )； 达到； 获得； 达到（某年龄、水平、状况） | |
参考例句： |
|
|
|
|
129
spasms
|
|
| n.痉挛( spasm的名词复数 )；抽搐；（能量、行为等的）突发；发作 | |
参考例句： |
|
|
|
|
130
supreme
|
|
| adj.极度的，最重要的；至高的，最高的 | |
参考例句： |
|
|
|
|
131
lurid
|
|
| adj.可怕的；血红的；苍白的 | |
参考例句： |
|
|
|
|
132
attaining
|
|
| （通常经过努力）实现( attain的现在分词 )； 达到； 获得； 达到（某年龄、水平、状况） | |
参考例句： |
|
|
|
|
133
rattled
|
|
| 慌乱的，恼火的 | |
参考例句： |
|
|
|
|
134
artillery
|
|
| n.(军)火炮，大炮；炮兵(部队) | |
参考例句： |
|
|
|
|
135
rehearsals
|
|
| n.练习( rehearsal的名词复数 )；排练；复述；重复 | |
参考例句： |
|
|
|
|
136
overture
|
|
| n.前奏曲、序曲，提议，提案，初步交涉 | |
参考例句： |
|
|
|
|
137
scattered
|
|
| adj.分散的，稀疏的；散步的；疏疏落落的 | |
参考例句： |
|
|
|
|
138
mightiest
|
|
| adj.趾高气扬( mighty的最高级 )；巨大的；强有力的；浩瀚的 | |
参考例句： |
|
|
|
|
139
ascertain
|
|
| vt.发现，确定，查明，弄清 | |
参考例句： |
|
|
|
|
140
inadequate
|
|
| adj.(for,to)不充足的，不适当的 | |
参考例句： |
|
|
|
|
141
westward
|
|
| n.西方，西部；adj.西方的，向西的；adv.向西 | |
参考例句： |
|
|
|
|
142
consternation
|
|
| n.大为吃惊，惊骇 | |
参考例句： |
|
|
|
|
143
penetrate
|
|
| v.透(渗)入；刺入，刺穿；洞察，了解 | |
参考例句： |
|
|
|
|
144
seclusion
|
|
| n.隐遁，隔离 | |
参考例句： |
|
|
|
|
145
mighty
|
|
| adj.强有力的；巨大的 | |
参考例句： |
|
|
|
|
146
reverberation
|
|
| 反响； 回响； 反射； 反射物 | |
参考例句： |
|
|
|
|
147
resonant
|
|
| adj.(声音)洪亮的，共鸣的 | |
参考例句： |
|
|
|
|
148
dwellers
|
|
| n.居民，居住者( dweller的名词复数 ) | |
参考例句： |
|
|
|
|
149
sonorous
|
|
| adj.响亮的，回响的；adv.圆润低沉地；感人地；n.感人，堂皇 | |
参考例句： |
|
|
|
|
150
impetus
|
|
| n.推动，促进，刺激；推动力 | |
参考例句： |
|
|
|
|
151
diverged
|
|
| 分开( diverge的过去式和过去分词 )； 偏离； 分歧； 分道扬镳 | |
参考例句： |
|
|
|
|
152
converged
|
|
| v.（线条、运动的物体等）会于一点( converge的过去式 )；（趋于）相似或相同；人或车辆汇集；聚集 | |
参考例句： |
|
|
|
|
153
barometers
|
|
| 气压计，晴雨表( barometer的名词复数 ) | |
参考例句： |
|
|
|
|
154
initiated
|
|
| n. 创始人 adj. 新加入的 vt. 开始，创始，启蒙，介绍加入 | |
参考例句： |
|
|
|
|
155
exhausted
|
|
| adj.极其疲惫的，精疲力尽的 | |
参考例句： |
|
|
|
|
156
retrace
|
|
| v.折回；追溯，探源 | |
参考例句： |
|
|
|
|
157
regained
|
|
| 复得( regain的过去式和过去分词 )； 赢回； 重回； 复至某地 | |
参考例句： |
|
|
|
|
158
subside
|
|
| vi.平静，平息；下沉，塌陷，沉降 | |
参考例句： |
|
|
|
|
159
prevailing
|
|
| adj.盛行的；占优势的；主要的 | |
参考例句： |
|
|
|
|
160
prodigious
|
|
| adj.惊人的，奇妙的；异常的；巨大的；庞大的 | |
参考例句： |
|
|
|
|
161
astonishment
|
|
| n.惊奇，惊异 | |
参考例句： |
|
|
|
|
162
fixed
|
|
| adj.固定的，不变的，准备好的；(计算机)固定的 | |
参考例句： |
|
|
|
|
163
incessantly
|
|
| ad.不停地 | |
参考例句： |
|
|
|
|
164
slew
|
|
| v.（使）旋转；n.大量，许多 | |
参考例句： |
|
|
|
|
165
amazement
|
|
| n.惊奇，惊讶 | |
参考例句： |
|
|
|
|
166
unprecedented
|
|
| adj.无前例的，新奇的 | |
参考例句： |
|
|
|
|
167
hues
|
|
| 色彩( hue的名词复数 )； 色调； 信仰； 观点 | |
参考例句： |
|
|
|
|
168
weird
|
|
| adj.古怪的，离奇的；怪诞的，神秘而可怕的 | |
参考例句： |
|
|
|
|
169
motes
|
|
| n.尘埃( mote的名词复数 )；斑点 | |
参考例句： |
|
|
|
|
170
myriads
|
|
| n.无数，极大数量( myriad的名词复数 ) | |
参考例句： |
|
|
|
|
171
tint
|
|
| n.淡色，浅色；染发剂；vt.着以淡淡的颜色 | |
参考例句： |
|
|
|
|
172
vessel
|
|
| n.船舶；容器，器皿；管，导管，血管 | |
参考例句： |
|
|
|
|
173
celestial
|
|
| adj.天体的；天上的 | |
参考例句： |
|
|
|
|
174
downwards
|
|
| adj./adv.向下的（地），下行的（地） | |
参考例句： |
|
|
|
|
175
protracted
|
|
| adj.拖延的；延长的v.拖延“protract”的过去式和过去分词 | |
参考例句： |
|
|
|
|
176
subsided
|
|
| v.（土地）下陷（因在地下采矿）( subside的过去式和过去分词 )；减弱；下降至较低或正常水平；一下子坐在椅子等上 | |
参考例句： |
|
|
|
|
177
fiery
|
|
| adj.燃烧着的，火红的；暴躁的；激烈的 | |
参考例句： |
|
|
|
| 欢迎访问英文小说网 |