Romance of Modern Geology

<h2 class="nobreak" id="CHAPTER_XIV">CHAPTER XIV</h2> <h3>SOME FAMOUS EARTHQUAKES</h3></div> <p>Of all earthquakes perhaps the best known and remembered is that of Lisbon on November 1st, 1755, and volumes have been written about it. The first shocks of this earthquake came without other warning than a deep sound resembling thunder, which appeared to proceed from beneath the ground, and it was immediately followed by a quaking which threw down the entire city of Lisbon. In six minutes sixty thousand persons perished. The day was almost immediately turned into night, owing to the thickness of the dust from the ruined city. A few minutes afterwards fire sprang up among the ruins. The new Lisbon quay, which had been built entirely of marble, suddenly sank down into the bay with an immense crowd of people, who thronged to it for safety, and it is said that none of the bodies of the drowned were ever seen again. Following hard on the first shocks the sea retired from the land, carrying boats and other craft with it, only to return in a great wave, which completed the destruction in and about the city. This great sea wave, the mightiest that has ever been described in connection with an earthquake, <span class="pagenum" id="Page_149">-149-</span> is said to have washed not only the coasts of Portugal and Spain, but to have extended with destructive violence to other countries. At Kinsale, in Ireland, it was strong enough to whirl vessels about in the harbour and to pour into the market-place, and it was of great violence also at the island of Madeira. Portions of the sea-coast between Cape-da-Roca and Cape Carvociro fell away into the sea, and the damage was very great along the coast between Cape St. Vincent and the mouth of the Guadiana. The great Sierra da Estrella, on the west of the Tagus valley, was split and rent in a most remarkable manner, and threw down avalanches of rock into the valley.</p> <p>The great earthquake which shook Calabria and North-Eastern Sicily in the year 1783 stands out in rather striking contrast with other disturbances of history, because it was carefully studied by a great number of skilled observers. Among them were Vivenzio, the court physician of the King of Naples, who has supplied us with a narrative of the events; Grimaldi, the Minister of War, who at the King's command visited the region and has left accurate measurements of the greater and lesser fissures associated with the earthquake; Pignaturo, a physician, who kept a record of the long-continuing shocks, together with an estimate of their intensities; the French geologist Dolomieu; and Sir William Hamilton, who was the British Ambassador at Naples. The Academy of Naples sent a special commission to the scene of the earthquake's destruction, and prepared a bulky report of great scientific value. Calabria is a <span class="pagenum" id="Page_150">-150-</span> country which has many times been racked with earthquakes; the disturbances being almost as conspicuous for number as in Japan. The areas shaken have not usually been great in extent, but as regards the geological changes and the loss to life by which they have been accompanied, they rank among the greatest in history.</p> <p>The shocks of 1783, which cost thirty thousand lives, came without warning on February 5th, and in two minutes threw down the structures in hundreds of cities and villages scattered through Calabria and North-Eastern Sicily. The great central granite formation of Calabria, which was but slightly disturbed by the first shock, was more heavily shaken by those which followed; and it was noted by the early writers on this earthquake that the mountains had been a little raised in comparison with the neighbouring plains at their bases. The fact of the elevation of mountains by earthquakes or some other underground disturbance has been elsewhere noted. On November 19th, 1822, a great earthquake shook the Chilian coast for a distance of twelve hundred miles north and south. The greatest energy was shown about one hundred miles north of Valparaiso, where the coast was found to have risen suddenly from three to five feet for a distance which has never been accurately ascertained, but which is known to have exceeded thirty-five miles. In 1835 and in 1837 similar elevations of the coast were caused by earthquakes at Concepcion, about three hundred miles south of Valparaiso, and at Valdivia, about two hundred miles south of Concepcion. Charles Darwin, in the <i>Voyage of the "Beagle,"</i> says: "I have convincing <span class="pagenum" id="Page_151">-151-</span> proofs that this part of the continent of South America has been elevated near the coast at least from four to five hundred feet, and in some parts from one thousand to thirteen hundred feet, since the epoch of living shells." Darwin finds his evidence in the raised beaches near the coast on which these shells abound. That this uplift has been going on by small and sudden movements, from a foot to ten feet at each shock, for more than two centuries is attested by good evidence. The coast in many places is proven to be from twenty to thirty feet higher to-day than it was in the middle of the seventeenth century. Sir Charles Lyell, in his <i>Principles of Geology</i>, gives a most interesting account of the sudden upheaval of a portion of a mountain range, with the accompaniment of a great earthquake, near Wellington, in New Zealand, in January, 1855. Both the North and South Islands of that colony have been affected by upliftings during the nineteenth century, and these movements have been attended by powerful and far-reaching earthquakes. The changes wrought by these movements on the shores and farther inland as well have been remarkable during the last hundred years.</p> <p>Another example of the same kind of activity is seen in the occasional rise of islands from the sea; but to this we shall refer again, and for the present we may return to the Calabrian earthquake, which presented many curious and many characteristic features. During the earthquake the surface of the country heaved in great undulations, which were productive of a feeling of sea-sickness, and which, according to some observers, made the clouds appear to <span class="pagenum" id="Page_152">-152-</span> stand still, as they will sometimes seem to do from the deck of a tossing ship. The fissures which appeared in the ground were numbered by thousands, and sometimes the displacements of the earth amounted to as much as ten feet. Houses were lifted high up; in other places the land or the sea-floor sank several feet. Many of the fissures opened, spurted out sand or water, and then closed again; and some of the Calabrian plains after the earthquake were found to be dotted with circular hollows, on the average about the size of carriage wheels, which were like wells, but were sometimes filled with sand instead of water. These were afterwards found to be <b>V</b>-shaped. In addition to these hundreds of small cone-shaped hollows or wells there were other water basins more deserving the name of ponds or lakes. One of these in the neighbourhood of Seminara, to which the name of Lago di Tolfilo was given, was about a third of a mile in length, and was so copiously fed by the springs ranged in a fissure in its bottom that all attempts to drain it proved useless. Near Sitizam a valley was completely choked up by the landslip from opposite sides, and behind this new dam a lake was formed which was about two miles in length and one mile in breadth. Vivenzio states that fifty lakes arose at the time of the earthquake, and the Government surveyors, who included ponds, counted no fewer than 215. The first effect of the more violent shocks was generally to dry up the rivers. Immediately afterwards many of their beds were so blocked up over them that the rivers overflowed. From the rock of Scylla opposite to Charybdis, in the Straits of Messina, large <span class="pagenum" id="Page_153">-153-</span> sections of cliff were broken off, in one instance for a whole mile's length of coast. The sea and the neighbourhood was greatly disturbed; and soon after the fall of the cliffs of Scylla the sea rose to a height of twenty feet, and the wave rolling over the coast-line drowned 1500 people.</p> <p>Japan is perhaps as unstable an area as anywhere exists on the earth, and the records of its earthquakes are more complete than in any other country. The number of destructive earthquakes recorded there in the last fifteen hundred years is 223. Since the beginning of the seventeenth century the records are fairly perfect, and it is found that since then a destructive earthquake has occurred somewhere in the Japanese islands nearly every two and a half years. For the lighter shocks systematic observation has become necessary, and the Japanese, with that development of the scientific spirit which is so remarkable an accompaniment of their progress during the last generation, have organised an Earthquake Recording Service&mdash;a Seismological Bureau&mdash;at which such conspicuous meteorologists as Mr. John Milne and Dr. Knott have worked, and which has produced great seismologists among the Japanese themselves. As many of our readers are aware, the earth is hardly ever still; it trembles continually like a boiling kettle, though not for the same reasons; and the delicate instruments for measuring earthquakes, which are called seismometers, show continual earth tremors or earth shivers. Since 1888 the earthquakes of all intensities recorded in Japan give a yearly average of 1447 shocks, or a daily average <span class="pagenum" id="Page_154">-154-</span> of four. Until the great earthquake of 1891, the greatest shocks within the memory of living men were those of 1854-5.</p> <p>The earthquake of October 28th, 1891, shook an area of 243,000 square miles, or more than three-fifths of the entire area of Japan, though the greatest damage was done on the Mino-Owari Plain, a broad expanse of country occupied by rice fields and surrounded by mountains. Without the least warning the blow came, and in the first shock 20,000 buildings fell, 7000 people were killed and 17,000 were injured. Innumerable fissures great and small appeared all over the plain, and the houses in the thickly packed villages fell like packs of cards. The plain is one of Japan's great gardens, and supported almost 1000 people to the square mile. Villages were thereabout continuous, and a narrow lane of unusual destruction could be traced through them for twenty miles. After the first shock there were numerous smaller ones, and during the next five months no fewer than 256 shocks were recorded in all. Among the more remarkable effects of the earthquake was the actual shifting of the country. Along a crack many miles in length the plain after the earthquake was some feet lower on one side than on the other. Reservoirs and swamps were formed, as well as sand pits and mud craters. The most conspicuous effect, however, from a geological standpoint was the shifting and distortion of the strata.</p> <div class="figcenter"> <ANTIMG class="w100" src="images/fpage154.png" width-obs="451" height-obs="608" alt="" /> <div class="txtlf"><i>Photo, G. C. Niven</i></div> <div class="figcaption" style="clear: both;"> <p class="tdc"><span class="smcap">The Curious Eruption of Mount Asama, Japan</span></p> <p>Mount Asama is nearly 8000 feet high, and the crater is nearly a mile across, and has a depth of about 1000 feet. Steam is being continually discharged. The above display was photographed from about 8 miles distance. The discharge was about 1&frac12; miles high, and shot up to that height in some ninety seconds. The evident inference is either that water is being forced out of the rocks by volcanic action, or that the eruptions are of the nature of steam explosions caused by water which comes in contact with molten rock.</p> </div> </div> <p><span class="pagenum" id="Page_155">-155-</span></p> <p>A few years later, on the 26th and 27th August, 1896, occurred the remarkable Icelandic earthquake, which affected a triangular plateau, bordered by high mountains, including Mount Hecla and other well-known volcanoes, in the south-western portion of the island. During the shocks the earth's surface was thrown into waves, so that neither man nor cattle could stand. Persons who were lying on the ground near a cliff were by the shock thrown bodily over the edge. A high hill in the plain is described as shaken "like a dog coming out of the water," and a thick mantle of loose soil which had covered it was afterwards found distributed in heaps about its base. The surface of the plain was scarred by open fissures or by rock walls which had been caused by the earth's rising on one side of a fissure. One of the fissures was nine miles and another seven miles in length. The mountains round the plains were riven by clefts, and many landslips occurred. As we have mentioned elsewhere, a new geyser was formed, throwing up water to an enormous height, but soon spending its early force; and many geysers and springs were violently disturbed.</p> <p>An earthquake of a very different kind occurred the next year in the province of Assam, India (June 12th, 1897). Unlike the Icelandic earthquake, almost the whole damage was here the result of the first shock. Everything was destroyed within the first fifteen seconds of the earthquake, and the heavy shocks had all passed before two and a half minutes had elapsed. In this brief space of time an area of 1,750,000 square miles had been shaken and 150,000 square miles laid in ruins. A member of the Geological Survey of India, who was in the town of Shillong, says that a rumbling sound like near thunder <span class="pagenum" id="Page_156">-156-</span> preceded the shocks by a second or so and increased in loudness, so that when masonry began to fall the noise and rattle of the falling stones were hardly to be perceived. Unable to stand on his feet, this observer sat down on the ground, and not only felt but saw the ground thrown into violent waves as if "composed of soft jelly." These waves seemed to run along the ground. When the shocks had passed all the masonry houses in Shillong had been levelled to the ground, and over each hung a cloud of pink plaster particles and dust. Some of the shocks seem to have occurred with a kind of twist, and stone monuments were given the appearance of corkscrews. There were left many fissures and depressions in the ground, and the rivers and lakes and streams were greatly affected. Thirty new lakes were formed; along the great Brahmaputra River rolled a great wave ten feet high. One great rent in the geological strata at the earth's surface was twelve miles long. Important changes of level of great blocks of country were clearly shown by the alterations in the aspect of the landscape. Ranges of hills which before had not been visible from certain points now came into view for the first time, while others had disappeared. Though the most destructive shock was that felt during the first few seconds, there were others which followed, lasting for nearly a week afterwards. This earthquake is of special interest, because it was the first one which was registered on the earthquake instruments set up in Europe. Since that date these instruments have been set up all over the world, and, as we say elsewhere, a great earthquake is <span class="pagenum" id="Page_157">-157-</span> now usually recorded on the seismometers and seismographic instruments set up in observatories stationed thousands of miles away.</p> <p>All of our readers will recollect the Jamaica earthquake which occurred comparatively recently. Port Kingston, in Jamaica, has had its share of earthquake disasters. In the year 1692 Port Royal, the then chief city, was destroyed, and in rebuilding it the Jamaicans moved it across the harbour, because the old town site was largely submerged beneath the sea. It was a recurrence of the settlement of the ground which in part produced the earthquake of January 14th, 1907. There were slight shocks preceding the earthquake, and subterranean rumblings. The chief damage was done before thirty-five seconds had gone by, and of course the catastrophe was greater because the shocks were felt in the neighbourhood of a city. Considered by itself the earthquake was not of the order of "great" earthquakes, but many of the effects were most curious. A statue of Queen Victoria on a pedestal was partly turned round; a series of steep terraces was formed by the side of the harbour; a small spring was converted into a stream eight feet wide; and, as we all know, very great destruction was inflicted on life and property. Soundings which have since then been made in the harbour show that its depth has greatly increased in some parts, in one instance by not less than twenty-seven feet. The greatest depression occurred near Port Royal (the old city), where a hundred yards or more of the ground was submerged by water varying from eight to twenty-five feet in depth.</p> <p><span class="pagenum" id="Page_158">-158-</span></p> <p>Proceeding northwards from the Antilles to North America, we come to other famous areas of earthquake disturbance. In 1811 and 1812 there were earthquakes along the lower lands of the great Mississippi River, which were felt throughout the whole of the eastern portion of the United States and as far west as exploration had gone. At New Madrid, which appears to have been near the centre of the disturbance, "subterranean thunder" appears to have been heard frequently for many years preceding the earthquake, though it had ceased for nearly a year. About two o'clock in the morning of December 16th, 1811, there came a severe shock accompanied by a noise which was like near thunder, and a few minutes afterwards the air was filled with sulphurous vapour. People thought that the end of the world had come. Light shocks were felt till sunrise; and then one more violent than the first occurred. But this was not the end. For three months the shocks went on, and in that time no fewer than 1874 shocks were recorded, eight of them great ones. The shock of January 23rd, though as violent as any that preceded it, was surpassed by the so-called "hard shock," which came at about four o'clock in the afternoon of February 7th. It was accompanied by a discharge of sulphurous vapour in the atmosphere, and an unusual darkness which added greatly to the terror of the people.</p> <div class="figcenter"> <ANTIMG class="w100" src="images/fpage158.png" width-obs="422" height-obs="666" alt="" /> <div class="txtlf"><i>Stereo Copyright, Underwood &amp; U.</i></div> <div class="txtrt"><i>London and New York</i></div> <div class="figcaption" style="clear: both; padding-top:1em;"> <p class="tdc"><span class="smcap">A House destroyed by an Earthquake</span></p> <p>This was Senator Stanford's house at Palo Alto, about 25 miles from San Francisco, which is situated on a fault or ancient fracture of the earth's surface.</p> </div> </div> <p><span class="pagenum" id="Page_159">-159-</span></p> <p>The Mississippi seemed to recede from its banks, and its waters gathered up like mountains, leaving boats high up on the sands. "The waters then moved inwards with a front wall fifteen to twenty feet in height, tearing the boats from their moorings and carrying them closely packed up a creek for a quarter of a mile. The river fell as rapidly as it had risen, and receded from its banks with such violence that it took with it a grove of cotton-woods which hedged its borders. These trees were broken off with such regularity that it was hard to persuade people who had not witnessed the catastrophe that it had not been brought about by human agency." During all the greater shocks the earth's surface was reported to have been raised in great crumplings, the crests of which opened into fissures. Some of these were six hundred to seven hundred feet long and twenty to thirty feet wide, and water and sand and even coal<SPAN name="FNanchor_13" href="#Footnote_13" class="fnanchor">[13]</SPAN> were spouted out of them to a height of forty feet. Many craters and holes in the ground were formed, surrounded by rings of sand; and traces of them remain to this day, a century-old monument of the destruction wrought. Notable changes in the level of the country were effected; new lakes and new islands came into existence; some lakes disappeared; some of the lakes then formed remain to this day. On the eastern bank of the Mississippi a lake a hundred miles long, six miles wide, and ten to fifty feet in depth was formed; and another lake, known now as Reelfoot Lake, which came then into existence, is twenty miles long, seven miles broad&mdash;larger than Windermere, and deeper. The fishermen's boats to-day float over the top of eighteenth-century cypress trees. In addition to sections of country which were depressed and submerged, an area of some twenty miles in diameter was elevated into a low dune twenty to twenty-five<span class="pagenum" id="Page_160">-160-</span> feet above the level of the plain of the Mississippi. Many years after the great shocks, smaller ones were felt; and even now scarcely a year passes without slight tremors in this region, and small fissures are still formed in the ground.</p> <div class="footnote"> <p><SPAN name="Footnote_13" href="#FNanchor_13" class="label">[13]</SPAN> Or "lignite," a form of hard pitch.</p> </div> <p>It must be repeated that the great earthquakes are not those of which most is heard. The earthquake of San Francisco which did such widespread damage because it took place in the neighbourhood of a thickly populated city was, after all, less in magnitude than the Sonora earthquake of 1887, which took place in a great expanse of desert country in which few people lived and few towns had been built. But this earthquake was felt all over the countries of Mexico and the State of Arizona; and a range of mountains, the Sierra Teras, was uplifted between faults which opened upon either side. Millions of cubic feet of rock were thrown down from the slopes of the mountains into the deep ca&ntilde;ons and water-courses, and cliffs of hard rock were shattered and split as though by a charge of giant powder. The Yakutat Bay earthquake in Alaska changed the whole face of the country over thousands of square miles during September, 1899; and along the shore of the bay the shore showed that in some cases it had been lifted from five to thirty and in some cases even fifty feet. New reefs and islands were formed; and a study of the country and the coast-line seems to show that from time to time this neighbourhood, like the beaches south of Valparaiso, is being lifted by some agency, perhaps the gradual elevation of a continent, perhaps by continuous earthquake action.</p> <div class="figcenter"> <ANTIMG class="w100" src="images/fpage160.png" width-obs="420" height-obs="659" alt="" /> <div class="txtlf"><i>Stereo Copyright, Underwood &amp; U.</i></div> <div class="txtrt"><i>London and New York</i></div> <div class="figcaption" style="clear: both; padding-top:1em;"> <p class="tdc"><span class="smcap">The Ruins of the Magnificent City Hall of San Francisco</span></p> <p>The great earthquake of 1906 caused this destruction. Some of the distortive effects of an earthquake movement can be perceived.</p> </div> </div> <p><span class="pagenum" id="Page_161">-161-</span></p> <p>But if the San Francisco earthquake of April 18th, 1906, was not of itself a very great earthquake, it brought about an enormous amount of damage. The heavy shocks came without warning at about five o'clock in the morning of April 18th. They lasted about a minute, and then went off into lighter quakes, which were felt till evening, and for many days after, gradually growing smaller and smaller. The loss of life, though great, was but a tenth of what it would have been had the worst shocks come at a later hour when men were at their places of business and the children in school. As it was, the greatest loss was due to the fire which was started by the earthquake, and which was soon beyond control, because the water-main had been snapped by the earth movement. The cause of the earthquake has been generally assigned to the slipping of the strata of California. Athwart the whole state runs a straight furrow, like an ancient earthquake crack of primeval times, which is about four hundred miles long, and the rocks about which are still liable to slip. As we have said, however, the Californian earthquake, though accompanied by great destruction of property, and by the characteristic accompaniments of fissures in the ground, and slight elevations and depressions of the country over a line sixty miles long, was not a very profound earthquake.</p> <p>Rather a curious coincidence may be here noted. We have spoken of submarine earthquakes and volcanoes and of islands which are raised by something akin to volcanic action or earthquake action underneath the sea.</p> <p><span class="pagenum" id="Page_162">-162-</span></p> <p>Some weeks after the Californian earthquake the officers and crew of the U.S. Fish Commission steamer <i>Albatross</i>, while on their way to investigate, with Professor Charles H. Gilbert, the fisheries of Japan, passed the group of islands known as the Bogoslofs, and to their astonishment perceived that a third island had been added to the other two. Professor Gilbert, in a letter concerning the first sight of the island, on May 28th, wrote: "When I saw the Bogoslofs in 1890 there were really two small islands about 1&frac12; miles apart, one of them steaming and the other cooled off. This has been the condition for a number of years, so the hot one had received the name of Fire Island, the cold one, Castle Island. When they came in sight yesterday, we were astonished to find that Fire Island was no longer smoking, and that a very large third island had arisen half-way between the other two. It was made of jagged, rugged lava, and was giving off clouds of steam and smoke from any number of little craters scattered all over it. Around these craters the rocks were all crusted with yellow sulphur. The new cone, occupying much of the space between the two older ones, was somewhat higher than either, but was certainly far from 900 feet high&mdash;300 feet would be an extreme figure. There was no evidence of a central crater. The steam and fumes were given off most abundantly from cracks and fumaroles on the slopes. About these were heavy incrustations of sulphur. We saw no indications of boiling water, nor did we believe that landing would be impossible."</p> <p><span class="pagenum" id="Page_163">-163-</span></p> <p>All three of these Bogoslof islands, which are about 120 miles south of the Pribyloff Islands, belonging to Russia in the Behring Sea, have risen above the waters hot and steaming in the last 150 years. The oldest Bogoslof, now called Castle Island, rose from the sea in 1796; and Kotzebue describes the first glimpse of it, as seen by a trader, named Krinkof, who had been forced to seek refuge from a storm on a neighbouring island. The birth of the volcanic islet was accompanied by an earthquake which shook the island where the trader had taken refuge, and by an outburst of fire with thunderous explosions. The island was said to emit fire for months afterwards, and for eight years afterwards the water round it was warm and its ashes unbearably hot. The eruption of 1883, in which the second Bogoslof, called Fire Island, was born, had no witnesses; but in September of that year great volumes of steam and smoke, accompanied by showers of ashes, were thrown out from the summit and through fissures in the sides and base, the bright reflections from the heated interior being visible at night. At the time of this eruption a severe earthquake was felt in the sea off Cape Mendocino, apparently in the line of the Californian furrow or rift.</p> <p>The islands were visited in 1884 by the officers of the U.S. revenue cutter <i>Corwin</i>, and Lieutenant J. C. Cantwell and Surgeon H. W. Yemans made the ascent of New Bogoslof. Lieutenant Cantwell thus describes his experience in the <i>Cruise of the Corwin</i>:&mdash;</p> <p>"The sides of New Bogoslof rise with a gentle slope to the crater. The ascent at first appears easy, but a thin <span class="pagenum" id="Page_164">-164-</span> layer of ashes, formed into a crust by the action of rain and moisture, is not strong enough to sustain a man's weight. At every step my feet crushed through the outer covering and I sank at first ankle deep, and later on knee deep, into a soft, almost impalpable dust, which arose in clouds and nearly suffocated me. As the summit was reached the heat of the ashes became unbearable.... On all sides of the cone there are openings through which steam escaped with more or less energy."</p> <p>Seven years after that Drs. Merriam and Mendenhall, of the Behring Sea Seal Commission, found the newer island still smoking, steaming, and occasionally roaring like a giant steam escape. The older island had quite cooled, and had become a sheer cliff or hill of cold ashes, and was, and is, the home of countless sea birds, as well as of a small herd of sea lions. Captain Cook, in the eighteenth century, had passed by the neighbourhood of this island. This was eighteen years, however, before it was born, and he named a pillar of ash or rock which he found there Ship Rock. Ship Rock fell in ruins five years after the birth of Fire Island.</p> <p>Since that time the new island has again sunk beneath the waves. But it will probably rise again, or another island somewhere in its neighbourhood will take its place, for a great new submarine ridge of volcanic rocks is forming in this neighbourhood and has been forming for many hundreds of years. The Pribyloff Islands are known to be volcanic from the materials of which they are composed, and sprang up above the waves in the same way.</p> <hr class="chap x-ebookmaker-drop" /> <p><span class="pagenum" id="Page_165">-165-</span></p> <div style="break-after:column;"></div><br />