The Wonder Book of Volcanoes and Earthquakes

by Edwin J. Houston

Jamaica, one of the West Indian Islands, about ninety miles south of Cuba, suffered a very destructive earthquake in 1692. During this earthquake the ground was agitated like the waves of the sea. These movements were so violent that numerous fissures were made in the ground, as many as 300 being formed at the same time, rapidly opening and closing. Many of the inhabitants were swallowed up in these fissures. In some cases, however, their bodies were afterward thrown out of the fissures, along with quantities of water.

The Jamaican earthquake was characterized by marked sinkings of the ground. At the city of Port Royal, which was then the capital, many houses on the harbor side sank in from twenty-four to forty-eight feet of water. As in the case of the earthquake at Cutch, many of these houses were left standing, the chimney tops of some being seen above the water, with their foundations and other parts apparently uninjured, and some of them were standing at a date as late as 1780. At a little later date, 1793, they were mostly ruins.

During the Jamaican quake a tract of land containing at least 1,000 acres near the town was sunk, and a wave of the sea rolled over it. This wave is said by Lyell to have carried a frigate over the roofs of the houses and left it stranded on one roof. When the wave rolled back to the sea, the weight of the frigate made it fall through the roof.

Perhaps one of the most remarkable things about the Jamaican earthquake was the swallowing up of several plantations, which disappeared, together with all their inhabitants, their former place becoming a lake. But the lake soon disappeared, leaving a mass of sand and gravel which obliterated any least sign that dwellings and trees had once adorned the spot.

The forces developed during this earthquake were sufficiently powerful to make several rents in the Blue Mountains, and the shock of blows on the waters of the sea killed fish by the hundred thousands so that the silver shine of their dead bodies stretched for miles and was beheld for days "on the face of the deep."

Portions of the world that have been frequently visited by mighty earthquakes, are the coasts of Chile. On the 24th of May, 1751, a part of the Chilian coast near the ancient town of Concepcion, sometimes called Penco, was destroyed by an earthquake, and the powerful earthquake waves that afterwards rushed in from the sea. So complete was this destruction that the ancient harbor was rendered useless and the people had to build another town about ten miles from the coast, so as to be beyond the reach of earthquake waves from the sea.

Another great earthquake occurred on the coast of Chile on the 19th of November, 1822. This shock was felt simultaneously over a distance of 1,200 miles from north to south. It reached its greatest intensity about 100 miles north of Valparaiso. This earthquake caused a rising of the coast to a height of from three to five feet. From careful examinations it appears that the area over which a permanent elevation of the country took place must have been equal to 100,000 square miles, an area equal to about half of the area of France, and five-sixths that of Great Britain and Ireland.

"If we suppose," says Dana, "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 shock, permanently above it, must have contained fifty-seven 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 thirty-three miles.... Assuming the Great Pyramid of Egypt, if solid, to weigh in accordance with the estimate before given 6,000,000 tons, we may state that the rock added to the continent by the Chilian earthquake would have equalled more than 100,000 pyramids.

"But it must always be borne 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 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 363,000,000 pyramids."

The shocks of this earthquake continued from the time of its occurrence, on November 19th, 1822, to the end of September, 1823, and even then there were scarcely two days that passed without a shock.