 Principles of Geology, Chapter 27, Part 1. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, visit LibriVox.org. Chapter 27. Earthquakes and Their Effects. In the sketch before given of the geographical boundaries of volcanic regions, I stated that although the points of eruption are but thinly scattered, constituting mere spots on the surface of those vast districts, yet the subterranean movements extend simultaneously over immense areas. We may now proceed to consider the changes which these movements produce on the surface and in the internal structure of the Earth's crust. Chapter 28. Deficiencies of Ancient Accounts. It is only within the last century and a half, since Hook first promulgated in 1688 his views respecting the connection between geological phenomena and earthquakes, that the permanent changes affected by these convulsions have excited attention. Before that time, the narrative of the historian was almost exclusively confined to the number of human beings who perished, the number of cities laid in ruins, the value of property destroyed, or certain atmospheric appearances which dazzled or terrified the observers. The creation of a new lake, the engulfing of a new city, or the raising of a new island are sometimes it is true, adverted to, as being too obvious or of too much geographical or political interest to be passed over in silence. But no researches were made expressly with a view of ascertaining the amount of depression or elevation of the ground, or any particular alterations in the relative position of sea and land, and very little distinction was made between the raising of soil by volcanic ejections and the upheaving of it by forces acting from below. The same remark applies to a very large proportion of modern accounts, and how much reason we have to regret this deficiency of information appears from this, that in every instance where a spirit of scientific inquiry has animated the eyewitnesses of these events, facts calculated to throw light on former modifications of the earth's structure are recorded. Phenomena Attending Earthquakes As I shall confine myself almost entirely in the following notice of earthquakes to the changes brought about by them in the configuration of the earth's crust, I may mention, generally, some accompaniments of these terrible events, which are almost uniformly commemorated in history, that it may be unnecessary to advert to them again. Irregularities in the seasons preceding or following the shots, sudden gusts of wind interrupted by dead calms, violent rains at unusual seasons or in countries where such phenomena are almost unknown, a reddening of the sun's disc and haziness in the air often continued for months, an evolution of electric matter or of inflammable gas from the soil with sulfurous and mephitic vapors, noises underground like the running of carriages or the discharge of artillery or distant thunder, animals uttering cries of distress and evincing extraordinary alarm being more sensitive than men of the slightest movement, a sensation like sea sickness and a dizziness in the head experienced by men, these and other phenomena less connected with our present subject as geologists have occurred again and again at distant ages and in all parts of the globe. I shall now begin the enumeration of earthquakes with the latest authentic narratives and so carry back the survey retrospectively that I may bring before the reader in the first place the minute and circumstantial details of modern times and thus enable him by observing the extraordinary amount of change within the last 150 years to perceive how great must be the deficiency in the meager and alls of earlier eras, earthquakes of the 19th century, Syria, January 1837. It has been remarked that earthquakes affect elongated areas. The violent shock which devastated Syria in 1837 was felt on a line 500 miles in length by 90 in breadth, more than 6,000 persons perished. Deep rents were caused in solid rocks and new hot springs burst out at Taboraya, Chile, Valdivia, 1837. One of the latest earthquakes by which the position of solid land is known to have been permanently altered is that which occurred in Chile on November 7th, 1837. On that day, Valdivia was destroyed by an earthquake and a whaler commanded by Captain Caste was violently shaken at sea and lost her masts in latitude 43 degrees, 38 minutes south inside of the land. The captain went on the 11th of December following to a spot near the island of Limas, one of the Chonas archipelago where he had anchored two years before and found that the bottom of the sea had been raised more than 8 feet. Some rocks formerly covered at all times by the sea were now constantly exposed and an enormous quantity of shells and fish in a decaying state which had been thrown there by the waves or suddenly laid dry during the earthquake attested the recent date of the occurrence. The whole coast was screwed with uprooted trees. Chile, Conception, 1835. Fortunately, we have a still more detailed account of the geographical changes produced in the same country on the 20th of February, 1835. An earthquake was then felt at all places besides Copiapo and Chiloé from north to south and from Mendoza to Juan Fernandez from east to west. Quote, Vessels, says Mr. Caldlú. Quote, navigating the Pacific within 100 miles of the coast, experienced the shock with considerable force, end quote. Conception, Talcahuano, Chilean, and other towns were thrown down from the account of Captain Fitzroy R.N., who was then employed in surveying the coast. We learned that after the shock, the sea retired in the Bay of Conception and the vessels grounded, even those which had been lying in seven fathoms water. All the shoals were visible and soon afterwards a wave rushed in and then retreated and was followed by two other waves. The vertical height of these waves does not appear to have been much greater than from 16 to 20 feet, although they rose to much greater heights when they broke upon a sloping beach. According to Mr. Caldlú and Mr. Darwin, the whole volcanic chain of the Chilean Andes, arranged 150 miles in length, was in a state of unusual activity, both during the shocks and for sometimes proceeding and after the convulsion, and lava was seen to flow from the crater at Osorno, seamap, figure 69. The island of Juan Fernández, distant 365 geographical miles from Chile, was violently shaken at the same time and devastated by a great wave. A submarine volcano broke out there, near Bacaleo Head, about a mile from the shore in 69 fathoms water and illumined the whole island during the night. At Conception, says Captain Fitzroy, quote, the earth opened and closed rapidly in numerous places. The direction of the cracks was not uniform, though generally from southeast to northwest. The earth was not quiet for three days after the great shock, and more than 300 shocks were counted between the 20th of February and the 4th of March. The loose earth of the valley of Biobío was everywhere parted from the solid rocks which bound the plane, there being an opening between them from an inch to a foot in width. For some days after the 20th of February, the sea at Talcajuanos, says Captain Fitzroy, quote, did not rise in the usual marks by four or five feet vertically. When walking on the shore, even at high water, beds of dead mussels, numerous chitans, and limpets, and withered seaweeds still adhering though lifeless to the rocks on which they had lived, everywhere met the eye, end quote. But this difference in the relative level of the land and sea gradually diminished, till in the middle of April, the water rose again to within two feet of the former high watermark. It might be supposed that these changes of level merely indicated a temporary disturbance in the set of the currents, or in the height of the tides at Talcajuanos. But on considering what occurred in the neighboring island of Santa Maria, Captain Fitzroy concluded that the land had been raised four or five feet in February, and that it had returned in April to within two or three feet of its former level. Santa Maria, the island just alluded to, is about seven miles long and too broad, and about 25 miles southwest of conception, see map figure 70. The phenomena observed there are most important. It appeared, says Captain Fitzroy, who visited Santa Maria twice, the first time at the end of March and afterwards in the beginning of April, quote, that the southern extremity of the island had been raised eight feet, the middle nine, and the northern end upwards of 10 feet. On steep rocks where vertical measures could be correctly taken, beds of dead muscles were found 10 feet above high watermark. One foot lower than the highest bed of muscles, a few limpets and chitons were seen adhering to the rock where they had grown. Two feet lower than the same, dead muscles, chitons, and limpets were abundant. An extended rocky flat lies around the northern parts of Santa Maria. Before the earthquake, this flat was covered by the sea, some projecting rocks only showing themselves. Now the whole flat is exposed and square acres of it are covered with dead shellfish. The stench arising from which is abominable. By this elevation of the land, the southern port of Santa Maria has been almost destroyed, little shelter remaining there, and very bad landing, end quote. The surrounding sea is also stated to have become shallower in exactly the same proportion as the land had risen. The surroundings having diminished a fathom and a half everywhere around the island. At two ball, also to the southeast of Santa Maria, the land was raised six feet at mocha two feet, but no elevation could be ascertained at Valdivia. Among other effects of the catastrophe, it is stated that cattle standing on the steep slope near the shore were rolled down into the sea, and many others were washed off by the great wave from low land and drowned. In November of the same year, 1835, conception was shaken by a severe earthquake, and on the same day Osorno, the distance of 400 miles, renewed its activity. These facts prove not only the connection of earthquakes with volcanic eruptions in this region, but also the vast extent of the subterranean areas over which the disturbing cause acts simultaneously. Ischia, 1828. On the 2nd of February, the whole island of Ischia was shaken by an earthquake, and in the October following, I found all the houses of Casimiccio still without their roofs. On the sides of Irvine between that town and Forreo, I saw masses of greenish turf which had been thrown down. The hot spring of Rita, which was nearest the center of the movement, was ascertained by Monsieur Covelli to have increased in temperature, showing as he observes that the explosion took place below the reservoirs, which heat the thermal waters. Bogota, 1827. On the 16th of November, 1827, the plain of Bogota in New Granada, or Colombia, was convulsed by an earthquake, and a great number of towns were thrown down. Torrents of rain swelled the Magdalena, sweeping along vast quantities of mud and other substances, which emitted a sulfurous vapor and destroyed the fish. Popayan, which is distant 200 geographical miles southwest of Bogota, suffered greatly. Wide crevices appeared in the road of Guanacas, leaving no doubt that the whole of the Cordilleras sustained a powerful shock. Other fissures opened near Costa in the plains of Bogota, into which the River Tunza immediately began to flow. It is worthy of remark that in all such cases the ancient graveled bed of a river is deserted and a new one formed at a lower level, so that a wand of relation in the position of alluvial beds of the existing watercourses may be no test of the high antiquity of such deposits, at least in countries habitually convulsed by earthquakes. Extraordinary rains accompanied the shocks before mentioned, and two volcanoes are said to have been in eruption in the mountain chain nearest to Bogota. Chile, 1822. On the 19th of November, 1822, the coast of Chile was visited by a most destructive earthquake. The shock was felt simultaneously throughout a space of 1200 miles from north to south. Santiago, Valparaiso, and some other places were greatly injured. When the district round Valparaiso was examined on the morning after the shock, it was found that the coast for a considerable distance was raised above its former level. At Valparaiso the elevation was three feet, and at Cuintero about four feet. Part of the bed of the sea says Mrs. Graham remained bare and dry at high water, quote, with beds of oysters, mussels, and other shells adhering to the rocks on which they grew, the fish being all dead, and exhaling most offensive effluvia. An old rack of a ship which before could not be approached became accessible from the land, although its distance from the original seashore had not altered. It was observed that the water course of a mill at the distance of about a mile from the sea gained a fall of 14 inches, a little more than 100 yards, and from this fact it is inferred that the rise in some parts of the inland country was far more considerable than at the borders of the ocean. Part of the coast thus elevated consisted of granite, in which parallel fissures were caused, some of which were traced for a mile and a half inland. Cones of earth about four feet high were thrown up in several districts by the forcing up of water mixed with sand through funnel-shaped hollows, a phenomenon very common in Calabria and the explanation of which will hereafter be considered. Those houses in Chile, of which the foundations were on rock, were less damaged than such as were built on alluvial soil. Mr. Crookshanks, an English botanist who resided in the country during the earthquake, has informed me that some rocks of greenstone at Quintero, a few hundred yards from the beach, which had always been underwater until the shock of 1822, have since been uncovered when the tide is at half ebb. And he states that after the earthquake, it was the general belief of the fishermen and inhabitants of the Chilean coast not that the land had risen, but that the ocean had permanently retreated. Dr. Mann, a Prussian traveler who visited Valparaiso in 1831, says that on examining the rocks both north and south of the town, nine years after the event, he found in corroboration of Mrs. Graham's account that remains of animals and seaweed, the lasonia of boride de solf et sol, de solf et sol, which has a firm, lignious stem, still adhered to those rocks, which in 1822 had been elevated above high watermark. According to the same author, the whole coast of central Chile was raised about four feet and banks of marine shells were laid dry on many parts of the coast. He observed similar banks elevated at unknown periods in several places, especially at Copiapo, where the species all agree with those now living in the ocean. Mr. Fryer also, who resided some years in South America, has confirmed these statements. And Mr. Darwin obtained evidence that the remains of an ancient wall, formally washed by the sea and now 11.5 feet above high watermark, acquired several feet of this additional elevation during the earthquake of 1822. The shocks continued up to the end of September 1823. Even then, 48 hours seldom passed without one, and sometimes two or three were felt during 24 hours. Mrs. Graham observed after the earthquake of 1822 that besides a beach newly raised above high watermark, there were several older, elevated lines of beach, one above the other, consisting of shingle mixed with shells, extending in a parallel direction to the shore to the height of 50 feet above the sea. Extent of country elevated. By some observers, it has been supposed that the whole country, from the foot of the Andes to a great distance under the sea, was upraised in 1822, the greatest rise being at the distance of about two miles from the shore. Quote, the rise upon the coast was from two to four feet at the distance of a mile inland. It must have been from five to six or seven feet. End quote. It has also been conjectured by the same eyewitnesses to the convulsion that the area over which this permanent alteration of level extended may have been equal to 100,000 square miles. Although the increased fall of certain water courses may have afforded some ground for this conjecture, it must be considered as very hypothetical, and the estimate may have exceeded or greatly fallen short of the truth. It may nevertheless be useful to reflect on the enormous amount of change, which this single convulsion occasioned, if the extent of country moved upward really amounted to 100,000 square miles, an extent just equal to half the area of France or about five six of the area of Great Britain and Ireland. If we suppose the elevation to have been only three feet on an average, it will be seen that the mass of rock added to the continent of America by the movement, or in other words, the mass previously below the level of the sea and after the shocks permanently above it must have contained 57 cubic miles in bulk, which would be sufficient to form a conical mountain two miles high or about as high as Etna with a circumference at the base of nearly 33 miles. We may take the mean specific gravity of the rock at 2.655, a fair average and a convenient one in such computations because at such a rate a cubic yard weighs two tons, then assuming the great pyramid of Egypt, if solid, to weigh in accordance with an estimate before given 6 million tons, we may state the rock added to the continent by the Chilean earthquake to have more than equaled 100,000 pyramids. But it must always be born in mind that the weight of rock here alluded to constituted but an insignificant part of the whole amount which the volcanic forces had to overcome. The whole thickness of rock between the surface of Chile and the subterranean foci of volcanic action may be many miles or leagues deep. Say that the thickness was only two miles, even then the mass which changed place and rose three feet being 200,000 cubic miles in volume must have exceeded in weight 363 million pyramids. It may be instructing to consider these results in connection with others already obtained from a different source and to compare the working of two antagonistic forces, the leveling power of running water and the expansive energy of subterranean heat. How long it may be asked would the Ganges require, according to data before explained, page 283, to transport to the sea a quantity of solid matter equal to that which may have been added to the land by the Chilean earthquake. The discharge of mud in one year by the Ganges was estimated at 20,000 million cubic feet. According to that estimate it would require about four centuries or 418 years before the river could bear down from the continent into the sea a mass equal to that gained by the Chilean earthquake. In about half that time perhaps the United Waters of the Ganges and Buran Puter might accomplish the operation. Kuch, 1819. A violent earthquake occurred at Kuch in the Delta of the Indus on the 16th of June 1819, CMAP, figure 71. The principal town, Buj, was converted into a heap of ruins and its stone buildings were thrown down. The movement was felt over an area having a radius of 1,000 miles from Buj and extending to Kabat Mandu, Calcutta and Pondicherry. The vibrations were felt in northwest India at a distance of 800 miles after an interval of about 15 minutes after the earthquake at Buj. At Ahmedabad the great mosque erected by Sultan Ahmed nearly 450 years before fell to the ground attesting how long a period had elapsed since a shock of similar violence had visited that point. At Anjar the fort with its tower and guns was hurled to the ground in one common mass of ruin. The shocks continued until the 20th when 30 miles northwest from Buj the volcano called Denodur is said by some to have sent forth flames, but Captain Grant was unable to authenticate this statement. Subsidence in the Delta of the Indus. Although the ruins of towns was great, the face of nature in the inland country says Captain McMurdo was not visibly altered. In the hills some large masses only of rock and soil were detached from the precipices, but the eastern and almost deserted channel of the Indus which bounds the province of Kuch was greatly changed. This estuary or inlet of the sea was before the earthquake formidable at Lukput being only about a foot deep when the tide was adept and at flood tide never more than six feet before it was deepened at the fort of Lukput after the shock to more than 18 feet at low water. On sounding other parts of the channel it was found that where previously the depth of the water at flood never exceeded one or two feet it had become from four to ten feet deep. By these and other remarkable changes of level a part of the inland navigation of that country which had been closed for centuries became again practicable. Fort and village submerged. The fort and village of Sindri on the eastern arm of the Indus above Lukput are stated by the same writer to have been overflowed and after the shock the tops of the houses and wall were alone to be seen above the water for the houses although submerged were not cast down. Had they been situated therefore in the interior where so many forts were leveled to the ground their site would perhaps have been regarded as having remained comparatively unmoved. Hence we may suspect that great permanent upheavings and depressions of soil may be the result of earthquakes without the inhabitants being in the least degree conscious of any change of level. A more recent survey of Kuch by Sir A Burns who was not in communication with Captain Mercurdo confirms the facts above enumerated and adds many important details that officer examined the Delta of the Indus in 1826 and 1828 and from his account it appears that when Sindri subsided in June 1819 the sea flowed in by the eastern mouth of the Indus and in a few hours converted a tract of land 2000 square miles in area into an inland sea or lagoon. Neither the rush of the sea into this new depression nor the movement of the earthquake threw down entirely the small fort of Sindri one of the four towers the northwestern still continuing to stand and the day after the earthquake the inhabitants who had ascended to the top of this tower saved themselves in boats end of chapter 27 part 1 principles of geology chapter 27 part 2 this is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer visit LibriVox.org the principles of geology by Charles Lyle chapter 27 part 2 elevation of the Ulabund immediately after the shock the inhabitants of Sindri saw at the distance of five miles and a half from their village a long elevated mound where previously there had been a low and perfectly level plain seamap figure 71 to this uplifted tract they gave the name of Ulabund or the mound of god to distinguish it from several artificial dams previously thrown across the eastern arm of the Indus extent of country raised it has been ascertained that this new raised country is upwards of 50 miles in length from east to west running parallel to that line of subsidence before mentioned which raised the grounds around Sindri to be flooded the range of this elevation extends from Puchum Island towards Gary its breath from north to south is conjectured to be in some parts 16 miles and its greatest ascertained height above the original level of the delta is 10 feet an elevation which appears to the eye to be very uniform throughout for several years after the convulsion of 1819 the course of the Indus was very unsettled and at length in 1826 the river through a vast body of water into its eastern arm that called the for on above Sindri and forcing its way in a more direct course to the sea burst through all the artificial dams which had been thrown across its channel and at length cut right through the Ulabund whereby a natural section was obtained in the perpendicular cliffs thus laid open sir abe burns found the upraised lands consistent of clay filled with shells the new channel of the river where it intersected the boond was 18 feet deep and 40 yards in width but in 1828 the channel was still farther enlarged the Indus when it first opened this new passage through such a body of water into the new mere or salt lagoon of Sindri that it became fresh for many months but it had recovered its saltness in 1828 when the supply of river water was less copious and finally it became more salt than the sea in consequence as the natives suggested to sir abe burns of the saline particles which the with which the run of kuch is impregnated in 1828 sir abe burns went in a boat to the ruins of Sindri where a single remaining tower was seen in the midst of a wide expanse of sea the tops of the ruined walls rose two or three feet above the level of the water and standing on one of these he could behold nothing in the horizon but water except in one direction where a blue streak of land to the north indicated the Ulabund this scene presents to the imagination a lively picture of the revolution's now in progress on the earth a waste of waters where a few years before all is land in the only land visible consisting of ground uplifted by a recent earthquake ten years after the visit of sir abe burns above alluded to my friend captain grant fgs of the bombe engineers had the kindness to send at my request a native surveyor to make a plan of Sindri and Ulabund in march 1838 from his description it appears that at that season the driest of the whole year he found the channel traversing the boond to be 100 yards wide without water and encrusted with salt he was told that it has now only four or five feet of water in it after rains the sides or banks were nearly perpendicular and nine feet in height the lagoon has diminished both in area and depth and part near the fort was dry land the annex drawing made by captain grant from the surveyors plan shows the appearance of the fort in the midst of the lake as seen in 1838 from the west or from the same point as that from which captain grin lays sketch see figure 72 was taken in 1808 before the earthquake the run of cooch is a flat region of a very peculiar character and no less than 7 000 square miles in area a greater superficial extent than yorkshire or about one fourth the area of ireland it is not a desert of moving sand nor a marsh but evidently the dried up bed of an inland sea which for a great part of every year has a hard and dry bottom uncovered by weeds or grass and only supporting here and there a few tamarisks but during the monsoons when the sea runs high the salt water driven up from the gulf of cooch and the creeks at look put overflows a large part of the run especially after rains when the soaked ground permits the seawater to spread rapidly the run is also liable to be overlooked occasionally in some parts by river water and it is remarkable that the only portion which was ever highly cultivated that anciently called sira is now permanently submerged the surface of the run is sometimes encrusted with salt above an inch in depth in consequence of the evaporation of the seawater islands rise up in some parts of the waste and the boundary lands form bays and promontories the natives have various traditions respecting the former separation of cooch and sinned by a bay of the sea and the drying up of the district called the run but these tales besides the usual uncertainty of oral tradition are farther obscured by mythological fictions the conversion of the run into land is chiefly ascribed to the miraculous powers of a hindu saint by name damarath or durunath who had previously done penance for 12 years on the summit of denodur hill captain grant infers on various grounds that this saint flourished about the 11th or 12th century of our era in proof of the drying up of the run some towns far inland are still pointed out as having once been ancient ports it has moreover been always said that ships were wrecked and engulfed by the great catastrophe and in the jets of black muddy water thrown out of fissures in that region in 1819 there were cast up numerous pieces of wrought iron and ship nails cones of sand six to eight feet in height or at the same time thrown up on these lands we must not conclude without alluding to a moral phenomenon connected with this tremendous catastrophe which we regard as highly deserving the attention of geologists it is stated by sir a burns that quote these wonderful events passed unheeded by the inhabitants of cooch for the region convulsed though once fertile had for a long period been reduced to sterility by want of irrigation so that the natives were indifferent as to its fate now it is to this profound apathy which all but highly civilized nations feel in regard to physical events not having an immediate influence on their worldly fortunes that we must describe the extraordinary dearth of historical information concerning changes of the earth's surface which modern observations show to be by no means of rare occurrence in the ordinary course of nature since the above account was written a description has been published of more recent geographical changes in the district of cooch near the mouth of the quarry or eastern branch of the indus which happened in june 1845 a large area seems to have subsided and the sin tree lake had become a salt marsh island of sumbara 1815 in april 1815 one of the most frightful eruptions recorded in history occurred in the province of tomboro in the island of sumbara seamap figure 39 page 351 about 200 miles from the eastern extremity of java in april of the year proceeding the volcano had been observed in a state of considerable activity ashes having fallen upon the decks of vessels which sailed past the coast the eruption of 1815 began on the fifth of april but was most violent on the 11th and 12th and did not entirely cease till july the sound of the explosions was heard in sumatra at the distance of 970 geographical miles in a direct line and at ternate in an opposite direction at the distance of 720 miles out of a population of 12 000 in the province of tomboro only 26 individuals survived violent whirlwinds carried up men horses cattle and whatever else came within their influence into the air tore up the largest trees by the roots and covered the whole sea with floating timber great tracks of land were covered by lava several streams of which issuing from the crater of the tomboro mountain reached the sea so heavy was the fall of ashes that they broke into the residence house at beema 40 miles east of the volcano and rendered it as well as many other dwellings in the town uninhabitable on the side of java the ashes were carried to the distance of 300 miles and 217 toward celibies in sufficient quantity to darken the air the floating cinders to the westward of sumatra formed on the 12th of april amassed two feet thick and several miles an extent through which ships with difficulty forced their way the darkness occasioned in the daytime by the ashes in java was so profound that nothing equal to it was ever witnessed in the darkest night although this volcanic dust when it fell was an impalpable powder it was of considerable weight when compressed a pint of it weighing 12 ounces and three quarters some of the finest particles says mr crofford were transported to the islands of aboyne and banda which last is about 800 miles east from the site of the volcano although the southeast monsoon was then at its height they must have been projected therefore into the upper regions of the atmosphere where a countercurrent prevailed along the seacoast of simbawa and the adjacent aisles the sea rose suddenly to the height of from two to 12 feet a great wave rushing up the estuaries and then suddenly subsiding although the wind at bima was still during the whole time the sea rolled in upon the shore and filled the lower parts of the houses with water a foot deep every prow and boat was forced from the anchorage and driven on shore the town called tom borough on the west side of simbawa was overflowed by the sea which encroached upon the shore so that the water remained permanently 18 feet deep in places where there was land before here we may observe that the amount of subsidence of land was apparent in spite of the ashes which would naturally have caused the limits of the coast to be extended the area over which tremulous noises and other volcanic effects extended was 1000 english miles in circumference including the whole of the meluca islands java a considerable portion of celibies to matra and borneo in the island of amboyna in the same month and year the ground opened throughout water and then closed again in conclusion i may remind the reader that but for the accidental presence of sir stamford raffles then governor of java we should scarcely have heard in europe of this tremendous catastrophe he required all the residents in the various districts under his authority to send in a statement of the circumstances which occurred within their own knowledge but valuable as were their communications they are often calculated to excite rather than to satisfy the curiosity of the geologists they mentioned that similar effects though in a less degree had about seven years before accompanied an eruption of karang asam a volcano in the island of bali west of sumatra but no particulars of that great catastrophe are recorded caracas 1812 on the 26th of march 1812 several violent shocks of an earthquake were felt in caracas the surface undulated like a boiling liquid and terrific sounds were heard underground the whole city with its splendid churches was in an instant a heap of ruins under which 10 000 of the inhabitants were buried on the 5th of april enormous rocks were detached from the mountains it was believed that the mountain silla lost from 300 to 360 feet of its height by subsidence but this was an opinion not founded on any measurement on the 27th of april a volcano in st. vincent's threw out ashes and on the 30th lava flowed from its crater into the sea while its explosions were heard at a distance equal to that between visuvius and switzerland the sound being transmitted as humboldt supposes through the ground during the earthquake which destroyed caracas an immense quantity of water was thrown out at valisillo near valencia as also at porto cabello through openings in the earth and in the lake maracaibo the water sank humboldt observed that the cordieras composed of guineas and mica slate and the country immediately at their feet were more violently shaken than the plains south carolina and new madrid missouri 1811 to 12 previous to the destruction at lagara and caracas in 1812 earth quakes were felt in south carolina and the shocks continued till those cities were destroyed the valley also of the mississippi from the village of new madrid to the mouth of the ohio in one direction and to the st francis and another was convulsed in such a degree as to create new lakes and islands it has been remarked by humboldt in his cosmos that the earthquake of new madrid presents one of the few examples on record of the incessant quaking of the ground for several successive months far from any volcano flint the geographer who visited the country seven years after the event informs us that a tract of many miles and extent near the little prairie became covered with water three or four feet deep and when the water disappeared a stratum of sand was left in its place large lakes of 20 miles and extent were formed in the course of an hour and others were drained the graveyard at new madrid was precipitated into the bed of the mississippi and it is stated that the ground where on the town is built and the river bank for 15 miles above sank eight feet below their former level the neighboring forest presented for some years afterwards quote a singular scene of confusion the trees standing inclined in every direction and many having their trunks and branches broken end quote the inhabitants relate that the earth rose in great undulations and when these reached a certain fearful height the soil burst and vast volumes of water sand and pit coal were discharged as high as the tops of the trees flint saw hundreds of these deep chasms remaining in an alluvial soil seven years after the people in the country although inexperienced in such convulsions had remarked that the chasms in the earth were in a direction from southwest to northeast and they accordingly fell the tallest trees and laying them at right angles to the chasms stationed themselves upon them by this invention when chasms opened more than once under these trees several persons were prevented from being swallowed up at one period during this earthquake the ground not far below new madrid swelled up so as to arrest the Mississippi in its course and to cause a temporary reflux of its waves the motion of some of the shocks is described as having been horizontal and of others perpendicular and the vertical movement is said to have been much less desolating than the horizontal the above account has been reprinted exactly as it appeared in former editions of this work compiled from the authorities which i've cited but having more recently march 1846 had an opportunity myself of visiting the disturbed region of the mississippi and conversing with many eyewitnesses of the catastrophe i'm able to confirm the truth of these statements and to add some remarks on the present face and features of the country i skirted as was before related page 270 part of the territory immediately west of new madrid called the sunk country which was for the first time permanently submerged during the earthquake of 1811 to 12 it is said to extend along the course of the white water and its tributaries for a distance of between 70 and 80 miles north and south and 30 miles east and west i saw on its borders many full-grown trees still standing leafless the bottoms of their trunks several feet underwater and a still greater number lying prostrate an active vegetation of aquatic plants is already beginning to fill up some of the shallows and the sediment washed in by occasional floods when the mississippi rises to an extraordinary height contributes to convert the sunk region into marsh and forest land even on the dry ground along the confines of the submerged area i observed in some places that all the trees of prior date to 1811 were dead and leafless though standing erect and entire they're supposed to have been killed by the loosening of their roots during the repeated undulations which passed through the ground for three months in succession mr brinje an experienced engineer of new orleans who was on horseback near new madrid when some of the severest shocks were experienced related to me in 1846 that quote as the waves advanced the trees bent down and the instant afterwards while recovering their position they often met those of other trees similarly inclined so that their branches becoming interlocked they were prevented from writing themselves again the transit of the wave through the woods was marked by a crashing noise of countless mouths first heard on one side and then on the other at the same time powerful jets of water mixed with sand mud and fragments of coal a matter were cast up endangering the lives of both horse and rider i was curious to ascertain whether any vestiges still remained of these fountains of mud and water and carefully examined between new madrid and the little prairie several sink holes as they are termed they consist of cavities from 10 to 30 yards in width and 20 feet or more in depth and are very conspicuous interrupting the level surface of a flat alluvial plane i saw abundance of sand which some of the present inhabitants saw spouting from these deep holes also fragments of decayed wood and black bi-tuminous shale probably drifted down at some former period in the main channel of the mississippi from the coal fields farther north i also found numerous rents in the soil left by the earthquake some of them still several feet wide and a yard or two in depth although the action of rains frost and occasional inundations and especially the leaves of trees blown into them and countless numbers every autumn have done much to fill them up i measured the direction of some of the fissures which usually varied from 10 to 45 degrees west of north and were often parallel to each other i found however a considerable diversity in their direction many of them are traceable for half a mile and upwards but they must easily be mistaken for artificial trenches if resident settlers were not there to assure us that within their recollection they were quote as deep as well as end quote fragments of coley shale were strewed along the edges of some of these open fissures together with white sand in the same manner as round the sinkholes among other monuments of the changes wrought in 1811 to 12 i explored the bed of the lake called yulele near new madrid 300 yards along by 100 yards in width which was suddenly drained during the earthquake the parallel fissures by which the waters escaped are not yet entirely closed and all the trees growing on its bottom were at the time of my visit less than 34 years old they consisted of cottonwood willows and honey locust and other species differing from those clothing the surrounding higher grounds which are more elevated by 12 or 15 feet on them the hickory the black and white oak the gum and other trees many of them of ancient date or flourishing elution islands 1806 in the year 1806 a new island in the form of a peak with some low conical hills upon it is said to have risen from the sea among the elution islands east of camchatka according to langsdorf it was four geographical miles in circumference and von buch infers from its magnitude and from its not having again subsided below the level of the sea that it did not consist merely of ejected matter but of a solid rock of trachite upheaved another extraordinary eruption happened in the spring of the year 1814 in the sea near unalashka in the same archipelago a new isle was then produced of considerable size and with a peak 3000 feet high which remained standing for a year afterwards though with somewhat diminished height although it is not improbable that earthquakes accompanying these tremendous eruptions may have heaved up part of the bed of the sea yet the circumference of the islands not having disappeared like sabrina c page 416 may have arisen from the emission of lava if jerula for example in 1759 had risen from a shallow sea to the height of 1600 feet instead of attaining that elevation above the mexican plateau the massive current of basaltic lava which poured out from its crater would have enabled it to withstand for a long period the action of a turbulent sea reflections on the earthquakes of the 19th century we are now about to pass on to the events of the 18th century but before we leave the consideration of those already enumerated let us pause for a moment and reflect how many remarkable facts of geological interest are afforded by the earthquakes above described though they constitute but a small part of the convulsions even of the last 40 years new rocks have risen from the waters new hot springs have burst out and the temperature of others has been raised the coast of chile has been thrice permanently elevated a considerable tract in the delta of the indus has sunk down and some of its shallow channels have become navigable and adjoining part of the same district upwards of 50 miles in length and 16 in breadth has been raised about 10 feet above its former level part of the great plane of the mississippi for a distance of 80 miles in length by a 30 in breadth has sunk down several feet the town of tamboro has been submerged and 12 000 of the inhabitants of sambala have been destroyed yet with the knowledge of these terrific catastrophes witnessed during so brief a period by the present generation will the geologists declare with perfect composure that the earth has at length settled into a state of repose will he continue to assert that the changes of relative level of land and sea so common in former ages of the world have now ceased if in the face of so many striking facts he persists in maintaining this favorite dogma it is in vain to hope that by accumulating the proofs of similar convulsions during a series of antecedent ages we shall shake his tenacity of purpose se fractus illibatur orbus impavidium ferrient ruinei earthquakes of the 18th century keto 1797 on the morning of february 4th 1797 the volcano of tongue ragua in keto and the surrounding district for 40 leagues from south to north and 20 leagues from west to east experienced an undulating movement which lasted four minutes the same shock was felt over a tract of 170 leagues from south to north from pura to papayan and 140 from west to east from the sea to the river napo in the smaller district first mentioned where the movement was more intense every town was leveled to the ground and real bomba caro and other places were buried under masses detached from the mountains at the foot of tongue ragua the earth was rent open in several places and streams of water and fetid mud called moya poured out overflowing and wasting everything in valleys 1000 feet broad the water of these floods reached to the height of 600 feet and the mud deposit barred up the course of the river so as to form lakes which in some places continued for more than 80 days flames and suffocating vapors escaped from the lake kilo toa and killed all the cattle on its shores the shocks continued all february and march and on the fifth of april they recurred with almost as much violence as at first we're told the form of the surface in the district most shaken was entirely altered but no exact measurements are given whereby we may estimate the degree of elevation or subsidence indeed it would be difficult except in the immediate neighborhood of the sea to obtain any certain standard of comparison if the levels were really as much altered as the narrations imply kumana 1797 in the same year on the 14th of december the small and tillies experienced subterranean movements and four fifths of the town of kumana was shaken down by a vertical shock the form of the shoal of morna roge at the mouth of the river bordones was changed by an upheaving of the ground canada kebek 1791 we learned from captain bayfield's memoirs that earthquakes are very frequent on the shore of the estuary of the saint lorence a force efficient at times to split walls and throw down chimneys such were the effects experienced in december 1721 in st paul's bay about 50 miles northeast from kebek and the inhabitants say that about every 25 years of violent earthquake returns which lasts 40 days in the history of canada it is stated that in 1663 a tremendous convulsion lasted six months extending from kebek to tatosak a distance of about 130 miles the ice on the river was broken up and many landslips caused caracas 1790 in the caracas near where the calra joins the orinoco between the town san pedro de alcantara and san francisco de haripayo an earthquake on saint matthew's day 1790 caused a sinking in of the granitic soil and left a lake 800 yards in diameter and from 80 to 100 in depth it was a portion of the forest of haripayo which subsided and the trees remained green for several months under water sicily 1790 on the 18th of march in the same year at santa maria de nisgami some miles from terra nova near the south coast of sicily the ground gradually sunk down for a circumference of three italian miles during seven shocks and in one place to the depths of 30 feet it continued to subside to the end of the month several fissures sent forth sulfur petroleum steam and hot water and a stream of mud which flowed for two hours and covered a space 60 feet long and 30 broad this happened far from both the ancient and modern volcanic district in a group of strata consisting chiefly of blue clay java 1786 about the year 1786 an earthquake was felt at intervals for the period of four months in the neighborhood of batur in java and in eruption followed various rents were formed which emitted a sulfurous vapor separate tracks sunk away and were swallowed by the earth into one of these the rivulet dohtog entered and afterwards continued to follow a subterraneous course the village of jam pang was buried in the ground with 38 of its inhabitants who had not time to escape we are indebted to dr. hoarsefield for having verified the above mentioned facts end of chapter 27 part 2 principles of geology chapter 28 part 1 this is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer please visit LibriVox.org recording by Jonathan Reed principles of geology by Charles Lyle chapter 28 part 1 chapter 28 earthquake in Calabria 1783 Calabria 1783 of the numerous earthquakes which have occurred in different parts of the globe during the last hundred years that of Calabria in 1783 is almost the only one of which the geologist can be said to have such a circumstantial account as to enable him fully to appreciate the changes which this cause is capable of producing in the lapse of ages the shocks began in February 1783 and lasted for nearly four years to the end of 1786 neither in duration nor in violence nor in the extent of territory moved was this convulsion remarkable when contrasted with many experienced in other countries both during the last and present century nor were the alterations which had occasioned in the relative level of hill and valley land and sea so great as those affected by some subterranean movements in South America in later times the importance of the earthquake in question arises from the circumstance that Calabria is the only spot hitherto visited both during and after the convulsions by men possessing sufficient leisure zeal and scientific information to enable them to collect and describe with accuracy the physical facts which throw light on geological questions authorities among the numerous authorities vivensio physician to the king of naples transmitted to the court a regular statement of his observations during the continuance of the shocks and his narrative is drawn up with care and clearness francesco antonio grimaldi then secretary of war visited the different provinces at the king's command and published the most detailed description of the permanent changes in the surface he measured the length breadth and depth of the different fissures and gulfs which opened and ascertained their number in many provinces his comments moreover on the reports of the inhabitants and his explanations of their relations are judicious and instructive piñetaro a physician residing at monteleone a town placed in the very center of the convulsions kept a register of the shocks distinguishing them into four classes according to their degree of violence from his work it appears that in the year 1783 the number was 949 of which 501 were shocks of the first degree of force and in the following year there were 151 of which 98 were of the first magnitude count apolito also and many others wrote descriptions of the earthquake and the royal academy of naples not satisfied with these and other observations sent a deputation from their own body into colabria before the shocks had ceased who were accompanied by artists instructed to illustrate by drawings the physical changes of the district and the state of ruined towns and edifices unfortunately these artists were not very successful in their representations of the condition of the country particularly when they attempted to express on a large scale the extraordinary revolutions which many of the great and minor river courses underwent but many of the plates published by the academy are valuable and as they are little known i shall frequently avail myself of them to illustrate the facts about to be described in addition to these neapolitan sources of information our countrymen sir william hamilton surveyed the district not without some personal risk before the shocks had ceased and his sketch published in the philosophical transactions supplies many facts that would otherwise have been lost he has explained in a rational manner many events which as related in the language of some eyewitnesses appeared marvelous and incredible dolomio also examined colabria during the catastrophe and wrote an account of the earthquake correcting a mistake into which hamilton had fallen who supposed that a part of the track shaken had consisted of volcanic tough it is indeed a circumstance which enhances the geological interest of the commotions which so often modify the surface of colabria that they are confined to a country where there are neither ancient nor modern rocks of volcanic or trapean origin so that at some future time when the era of disturbance shall have passed by the cause of former revolutions will be as latent as in parts of great britain now occupied exclusively by ancient marine formations extent of the area convulsed the convulsion of the earth sea and air extended over the whole of colabria ultra the southeast part of colabria citra and across the sea to mesina and its environs a district lying between the 38th and 39th degrees of latitude the concussion was perceptible over a great part of sicily and as far north as naples but the surface over which the shocks acted so forcibly as to excite intense alarm did not generally exceed 500 square miles an area the soil of that part of colabria is composed chiefly like the southern part of sicily of calcareo argillaceous strata of great thickness containing marine shells this clay is sometimes associated with beds of sand and limestone for the most part these formations resemble in appearance and consistency the sub apennine marbles with their accompanying sands and sandstones and the whole group bears considerable resemblance in the yielding nature of its materials to most of our tertiary deposits in france in england chronologically considered however the colabria formations are comparatively of modern date often abounding in fossil shells referable to species now living in the mediterranean we learned from vivencio that on the 20th and 26th of march 1783 earthquakes occurred in the islands of zante sephalonia and sent mara and in the last mention the island several public edifices and private houses were overthrown and many people destroyed if the city of opeto in colabria ultra be taken as a center and around that center a circle be described with a radius of 22 miles this space will comprehend the surface of the country which suffered the greatest alteration and where all the towns and villages were destroyed the first shock of february 5th 1783 threw down in two minutes the greater part of the houses in all the city's towns and villages from the western flanks of the apennines in colabria ultra to messina in sicily and convulsed the whole surface of the country another occurred on the 28th of march with almost equal violence the granitic chain which passes through colabria from north to south and attains the height of many thousand feet was shaken but slightly by the first shock but more rudely by some which followed some riders have asserted that the wave-like movements which were propagated through the recent strata from west to east became very violent when they reached the point of junction with the granite as if a reaction was produced where the undulatory movement of the soft strata was suddenly arrested by the more solid rocks but the statement of dolomio on this subject is most interesting and perhaps in a geological point of view the most important of all the observations which are recorded the apennines he says which consist in great part of hard and solid granite with some mycaceous and argyllaceous shrists form bare mountains with steep sides and exhibit marks of great degradation at their base newer strata are seen of sand and clay mingled with shells a marine deposit containing such ingredients as would result from the decomposition of granite the surface of this newer tertiary formation constitutes what is called the plane of colabria a platform which is flat and level except we're intersected by narrow valleys or ravines which rivers and torrents have excavated sometimes to the depth of 600 feet the sides of these ravines are almost perpendicular for the superior stratum being bound together by the roots of trees prevents the formation of a sloping bank the usual effect of the earthquake he continues was to disconnect all those masses which either had not sufficient bases for their bulk or which was supported only by lateral adherence hence it follows that throughout almost the whole length of the chain the soil which adhered to the granite at the base of the mountains calona esoph sagra and aspermonte slid over the solid and steeply inclined nucleus and descended somewhat lower leaving almost interruptedly from st george to be on st christina a distance of from nine to ten miles a chasm between the solid granitic nucleus and the sandy soil many lands slipping thus were carried to a considerable distance from their former position so as entirely to cover others and disputes arose as to whom the property which had thus shifted its place should belong from this account of dolomue we might anticipate as the result of a continuance of such earthquakes first a longitudinal valley following the line of junction of the older newer rocks secondly greater disturbance in the newer strata near the point of contact than at a greater distance from the mountains phenomena very common in other parts of italy at the junction of the apennine and sub-apennine formations mr mallet in his valuable essay on the dynamics of earthquakes offers the following explanation of the fact to which dolomue has called attention when a wave of elastic compression of which he considers the earth wave to consist passes abruptly from a body having an extremely low elasticity such as clay and gravel into another like granite whose elasticity is remarkably high it changes not only its velocity but in part also its course a portion being reflected and a portion refracted the wave being thus sent back again produces a shock in the opposite direction doing great damage to buildings on the surface by thus returning upon itself at the same time the shocks are at once eased when they get into the more elastic materials of the granitic mountains the surface of the country during the colabrian earthquakes often heaved like the billows of a swelling sea which produced a swimming in the head like seasickness it is particularly stated in almost all of the accounts that just before each shock the clouds appeared motionless and although no explanation is offered of this phenomenon it is obviously the same as that observed in a ship at sea when it pitches violently the clouds seem arrested in their career as often as the vessel rises in a direction contrary to their course so that the colabrians must have experienced precisely the same motion on the land trees supported by their trunks sometimes bent during the shocks to the earth and touched it with their tops this is mentioned as a well-known fact by dolomue and he assures us that he was always on his guard against the spirit of exaggeration in which the vulgar are ever ready to indulge when relating these wonderful occurrences it is impossible to suppose that these waves which are described in ataly and other regions of earthquakes as passing along the solid surface of the earth in a given direction like a billow on the sea have any strict analogy with the undulations of a fluid they are doubtless the effects of vibrations radiating from some deep-seated point each of which on reaching the surface lifts up the ground and then allows it again to subside as the distance between the source of the subterranean movement and the surface must vary according to the outline of the country so the vibratory jar will reach different points in succession the academicians relate that in some of the cities of calabria effects were produced seeming to indicate a whirling or vorticos movement thus for example two obelisks placed at the extremities of a magnificent façade in the convent of san Bruno in a small town called Stefano del Bosco were observed to have undergone a movement of a singular kind the shock which agitated the building is described as having been horizontal and vorticos the pedestal of each obelisk remained in its original place but the separate stones above were turned partially round and removed sometimes nine inches from their position without falling it has been suggested by mr darwin that this kind of displacement may be due to a vibratory rather than a whirling motion and more lately mr mallet in the paper already cited has offered a very ingenious solution of the problem he refers the twisting simply to an elastic wave which has moved the pedestal forwards and back again by an alternate horizontal motion within narrow limits and he has succeeded in showing that a rectilinear movement in the ground may have suffice to cause an incumbent body to turn partially round upon its bed provided a certain relation exists between the position of the center of gravity of the body and its center of adherence i should now consider in the first place that class of physical changes produced by the earthquake which are connected with alterations in the relative level of the different parts of the land and afterwards describe those which are more immediately connected with the derangement of the regular drainage of the country and where the force of running water cooperated with that of the earthquake difficulty of ascertaining changes of level in regard to alterations of relative level none of the accounts established that they were on a considerable scale but it must always be remembered that in proportion to the area moved is the difficulty of proving that the general level has undergone any change unless the sea coast happens to have participated in the principal movement even then it is often impossible to determine whether an elevation or depression even if several feet has occurred because there is nothing to attract notice in a band of shingle and sand of unequal breadth above the level of the sea running parallel to a coast such bands generally marking the point reached by the waves during spring tides or the most violent tempests the scientific investigator has not sufficient topographical knowledge to discover whether the extent of beach has diminished or increased and he who has the necessary local information scarcely ever feels any interest in ascertaining the amount of the rise or fall of the ground add to this the great difficulty of making correct observations in consequence of the enormous waves which roll in upon a coast during an earthquake and a face every landmark near the shore subsidence of the key at messana it is evidently in seaports alone that we can look for very accurate indications of slight changes of level and when we find them we may presume that they would not be rare at other points if equal facilities of comparing relative altitudes were afforded gremaldi states and his account is confirmed by hamilton and others that at messana in sicily the shore was rent and the soil along the port which before the shock was perfectly level was found afterwards to be inclined towards the sea the sea itself near the bunchina becoming deeper and its bottom in several places disordered the key also sunk down about 14 inches below the level of the sea and the houses in its vicinity were much fishered among various proofs of partial elevation and depression in the interior the academicians mentioned in their survey that the ground was sometimes on the same level on both sides of new ravines and fishers but sometimes there had been a considerable shifting either by the upheaving of one side or the subsidence of the other thus on the sides of long rents in the territory of soriano the stratified masses had altered their relative position to the extent of from 8 to 14 palms 6 to 10 and a half feet polystena similar shifts in the strata are alluded to in the territory of polystena where there appeared innumerable fishers in the earth one of these was of great length and depth and in parts the level of the corresponding sides was greatly changed terra nova in the town of terra nova some houses were seen uplifted above the common level and others adjoining sunk down into the earth in several streets the soil appeared thrust up and abutted against the walls of houses a large circular tower of solid masonry part of which had withstood the general destruction was divided by a vertical rent and one side was upraised and the foundations heaved out of the ground it was compared by the academicians to a great tooth half extracted from the alveolus with the upper part of the fangs exposed along the line of this shift or fault as it would be termed technically by miners the walls were found to adhere firmly to each other and to fit so well that the only signs of there having been disunited was the want of correspondence in the courses of stone on either side of the rent dole amuse saw a stone well in the convent of the augustins at terra nova which had the appearance of having been driven out of the earth it resembled a small tower eight or nine feet in height and a little inclined this effect he says was produced by the consolidation and consequence sinking of the sandy soil in which the well was dug in some walls which had been thrown down or violently shaken in montelioni the separate stones were parted from the mortar so as to leave an exact mold where they had rested whereas in other cases the mortar was ground to dust between the stones it appears that the wave like motions often produced effects of the most capricious kind thus in some streets of montelioni every house was thrown down but one in others all but two and the buildings which were spared were often scarcely in the least degree injured in many cities of colabria all the most solid buildings were thrown down while those which were slightly built escaped but at risar no as also at messina in sicily it was precisely the reverse the massive edifices being the only ones that stood fishers it appears evident that a great part of the rending and fishing of the ground was the effect of a violent motion from below upwards and in a multitude of cases where the rents and chasms opened and closed alternately we must suppose that the earth was by turns heaved up and then let fall again we may conceive the same effect to be produced on a small scale if by some mechanical force a pavement composed of large flags of stone should be raised up and then allowed to fall suddenly so as to resume its original position if any small pebbles happen to be lying on the line of contact of two flags they would fall into the opening when the pavement rose and be swallowed up so that no trace of them would appear after the subsidence of the stones in the same manner when the earth was up heaved large houses trees cattle and men were engulfed in an instant in chasms and fishers and when the ground sank down again the earth closed upon them so that no vestige of them was discoverable on the surface in many instances individuals were swallowed up by one shock and then thrown out again alive together with large jets of water by the shock which immediately succeeded at jero carne a country which according to the academicians was lacerated in the most extraordinary manner the fishers ran in every direction like cracks on a broken plane of glass and as a great portion of them remained open after the shocks it is very possible that this country was permanently upraised it was usual as we learn from dule me you for the chasms and fishers throughout colabria to run parallel to the course of some pre-existing gorges in their neighborhood houses engulfed in the vicinity of opedo the central point from which the earthquake diffused its violent movements many houses were swallowed up by the yawning earth which closed immediately over them in the adjacent district also of cana maria four farm houses several oil stores and some spacious dwelling houses were so completely engulfed in one chasm that not a vestige of them was afterwards discernible the same phenomena occurred at terra nova santa christina and synovoli the academician state particularly that when deep abysses had opened in the argyllaceous strata of terra nova and houses had sunk into them the sides of the chasms closed with such violence that on excavating afterwards to recover articles of value the workmen found the contents and detached parts of the buildings jammed together so as to become one compact mass it is unnecessary to accumulate examples of similar occurrences but so many are well authenticated during this earthquake in colabria that we may without hesitation yield ascent to the accounts of catastrophes of the same kind repeated again and again in history where whole towns are declared to have been engulfed and nothing but a pool of water or tract of sand left in their place chasm formed near opedo on the sloping side of a hill near opedo a great chasm opened and although a large quantity of soil was precipitated into the abyss together with a considerable number of olive trees and part of a vineyard a great gulf remained after the shock in the form of an amphitheater 500 feet long and 200 feet deep dimensions of new fishers and chasms according to grimaldi many fishers and chasms formed by the first shock of february 5th were greatly widened lengthened and deepened by the violent convulsions of march 28th in the territory of san fili this observer found a new ravine half a mile in length two feet and a half broad and 25 feet deep and another of similar dimensions in the territory of rosarno a ravine nearly a mile long 105 feet broad and 30 feet deep opened in the district of plaisano where also two gulfs were caused one in a place called churchouli three quarters of a mile long 150 feet broad and above 100 feet deep and another at la fortuna nearly a quarter of a mile long above 30 feet in breadth and no less than 225 feet deep in the district of fosalano three gulfs opened one of these measured 300 feet square and above 30 feet deep another was nearly half a mile long 15 feet broad and above 30 feet deep the third was 750 feet square lastly a calcareous mountain called zephyrio at the southern extremity of the italian peninsula was cleft in two for the length of nearly half a mile and an irregular breadth of many feet some of these chasms were in the form of a crescent the annexed cut represents one by no means remarkable for its dimensions which remained open by the side of a small pass over the hill of sentangelo near soriano the small river mesima is seen in the foreground formation of circular hollows and new lakes in the report of the academy we find that some planes were covered with circular hollows for the most part about the size of carriage wheels but often somewhat larger or smaller when filled with water to within a foot or two of the surface they appeared like wells but in general they were filled with dry sand sometimes with a concave surface and at other times convex on digging down they found them to be funnel shaped and the moist loose sand in the center marked the tube up which the water spouted the annexed cut represents a section of one of these inverted cones when the water had disappeared and nothing but dry mycaceous sand remained a small circular pond of similar character was formed not far from palestina and in the vicinity of seminara a lake was suddenly caused by the opening of a great chasm from the bottom of which water issued this lake was called lago del tofilo it extended 1,785 feet in length by 937 in breadth and 52 in depth the inhabitants dreading the miasma of this stagnant pool endeavored at great cost to drain it by canals but without success as it was fed by springs issuing from the bottom of the deep chasm vivenzio states that near citizano a valley was nearly filled up to a level with the high grounds on each side by the enormous masses detached from the boundary hills and cast down into the course of two streams by this barrier a lake was formed of great depth about two miles long and a mile broad the same author mentions that upon the hole there were 50 lakes occasioned during the convulsions and he assigns localities to all of these the government surveyors enumerated 215 lakes but they included in this number many small ponds cones of sand thrown up many of the appearances exhibited in the alluvial planes such as springs spouting out their water like fountains at the moment of the shock have been supposed to indicate the alternate rising and sinking of the ground the first effect of the more violent shocks was usually to dry up the rivers but they immediately afterwards overflowed their banks in marshy places an immense number of cones of sand were thrown up these appearances hamilton explains by supposing that the first movement raised the fissured plane from below upwards so that the rivers and stagnant waters and bogs sank down or at least were not upraised with the soil but when the ground returned with violence to its former position the water was thrown up in jets through fissures the phenomenon according to mr mallet may be simply an accident contingent on the principal cause of disturbance the rapid transit of the earth wave the sources he says of copious springs usually lie in flat plates or fissures filled with water whether issuing from solid rock or from loose materials now if a vein or thin flat cavity filled with water be in such a position that the plane of the plate of water or fissure be transverse to the line of transit in the earth wave the effect of the arrival of the earth wave at the watery fissure will be at the instant to compress its walls more or less together and so squeeze out the water which will for a moment gush up at the spring head like a fountain and again remain and repose after the transit of the wave gradual closing in of fissures sir w hamilton was shown several deep fissures in the vicinity of melito which although not one of them was above a foot in breadth had opened so wide during the earthquake as to swallow an ox and nearly 100 goats the academicians also found on their return through districts which they had passed at the commencement of their tour that many rents had in that short interval gradually closed in so that their width had diminished several feet and the opposite walls had sometimes nearly met it is natural that this should happen in argyllaceous strata while in more solid rocks we may expect that fissures will remain open for ages should this be ascertained to be a general fact in countries convulsed by earthquakes it may afford a satisfactory explanation of a common phenomenon in mineral veins such veins often retain their full size so long as the rocks consist of limestone granite or other ingerated materials but they contract their dimensions become mere threads or are even entirely cut off where masses of an argyllaceous nature are interposed if we suppose the filling up of fissures with metallic and other ingredients to be a process requiring ages for its completion it is obvious that the opposite walls of rents where strata consists of yielding materials must collapse or approach very near to each other before sufficient time is allowed for the accretion of a large quantity of vein stone end of chapter 28 part 1 recording by jonathan reid