Great Disasters and Horrors in the World's History

by Allen Howard Godbey

Much speculation has been spent upon the fact of an earthquake being very severe in two or three different localities, but being imperceptible or very mild in intervening places. In South America it has become so common a peculiarity that the natives speak of such localities as “bridging” the earthquakes. Not improbably the reason is the same that produces calm when two waves interfere, crest to trough; the motions destroy each other. It may be also that the character of the underlying rocks has much to do with such cases. Experiments with explosions in mines show that vibrations of the soil travel over three hundred yards per second through sand beds, or about as rapidly as in the air; over five hundred yards in granite; while through iron they travel over three thousand eight hundred and fifty yards per second. So a vibration extremely destructive to a region underlaid by massive rocks might be comparatively harmless to a town on a sand-bed or mud-bank. Observations on earthquakes themselves have shown great variation in the rate of speed. The earthquake of Germany of 1846 moved four hundred and ninety-two yards per second; while the earthquake of Viege in 1855 traveled nine hundred and sixty yards a second toward Strasburg, but only half that speed towards Turin. So, also, the Lisbon earthquake traveled three times as rapidly around the coast as down the Rhine valley. So it must be that certain regions owe their comparative immunity from earthquakes to the nature of the ground beneath.

One or two ingenious savants have suggested that the earth is a vast thermo-electric pile, and that disturbances in the electrical equilibrium of the earth are the cause of earthquakes and volcanic eruptions. But as already seen, the electrical phenomena of volcanic eruptions are fairly considered an effect, and not a cause, of the eruptions, as the hydro-electric machine illustrates. In the theory of these men, the molten veins of the interior represent conductors which are too small or imperfect to allow the electricity to pass freely, and are fused in consequence. One of these men, Steffens, alleges that such phenomena can only occur where large veins of coal exist, because large masses of carbon would be necessary to keep up a strong electric tension in the interior. Herr Steffens must account for the fact that the great coal regions of the world have been peculiarly favored in their comparative immunity from shocks.

Still others have advocated the idea that atmospheric whirlwinds and cyclones produce earthquakes. While not a few shocks have been accompanied by violent storms, the exception seems to be the rule. And in the case of storms, we have seen that the outpour of heat and vapor in a volcanic eruption would necessarily produce one. As concerns the winds that have accompanied earthquakes, they have as often come after the shock as before.

But these bring up certain phenomena that must be noticed. It is not easy to say how great is the connection between electrical and atmospheric disturbances, and the shiverings of the earth; but that there is some peculiar bond between them has been thought indisputable. It is only in the present century that scientists have carefully conned this matter, and generally rejected the belief. But the opinion is very ancient, and has a strong hold upon the people. It is generally adhered to by South Americans, Italians, West Indians, Japanese, and the inhabitants of Central Asia. Kamtschatkans, Kurile Islanders and Japanese, assert shocks are most frequent at the equinoxes. In equatorial America, the natives say an earthquake is preceded by drought, and is the precursor of rain. In the Dauphiny Alps, the people regard earthquakes as the result of avalanches; and the latter are readily started by the slightest atmospheric disturbances. In Central America the equinoctial idea prevails.

These things set the wise men to investigating. Much to their surprise, they began to discover that the idea of connection between the seasons and shocks seemed well-grounded. In 1834 Professor Merian announced that of one hundred and eighteen earthquakes at Basle, the majority had occurred in the winter. Volger made a list of twelve hundred and thirty shocks in the Alps; seven hundred and seventy-four occurred in autumn and winter. December showed one hundred and sixty-eight; July forty. Of ninety-eight quite severe shocks, but one had occurred in the summer. Of five hundred and thirty-nine earthquakes in the Rhine basin, one hundred and three occurred in the spring, one hundred and one in the summer, one hundred and sixty-five in the autumn, one hundred and seventy in winter. Observations in the Antilles show a slight predominance of autumn and winter.

Another peculiar fact is that most shocks seem to occur at night. Out of four hundred and seventy-two earthquakes in 1855-56, whose time was exactly noted, but one hundred and seventy-two happened in the day. Of those at night, three-fifths were during the latter half, forty-four being between one and two o’clock. Squier has told us that during several years residence in Central America, nearly all shocks occurred at night; also, that he experienced none save at the change of seasons. Hence, one is almost compelled to conclude that, while the primal cause of earthquakes must exist in the depths of the earth, yet external and climatic influences are strong modifiers.

Some other peculiarities are adduced to show the connection between atmospheric disturbances and earthquakes. In Central and Tropical America the temperature is said to fall after any shock. After the earthquake at Lechsand, Sweden, in 1856, the temperature fell eighty-six degrees. The same shock was violent as far as Smyrna in Asia Minor, where the thermometer fell at once twenty-nine degrees, the night being the coldest of the winter. Many similar cases are mentioned. But in view of the fact that one hundred times as many sudden and marked changes of temperature occur every year in various localities without the intervention of an earthquake, it seems difficult to regard the above instances as more than mere coincidences. The greatest fall in temperature the writer ever experienced occurred within three hours of a transit of Venus; but one swallow—nor a flock of them—cannot make a summer.

Barometric observations have been dragged into the combat. The great Lisbon earthquake, and the convulsion in Calabria, were preceded by low barometer. Similar observations have been made in this century. The constantly recurring shocks of 1855-56 were in each case preceded by fall of barometers. But Humboldt, in South America, and Ehrmann, in Central America, were unable to find such order; though the shocks were so invariably followed by such changes that unusual earthquakes were believed by the natives (as is also believed in India) to advance the rainy season. The resultant electric phenomena might produce this expedition.

But in this field all at present is mere guess work. The exceptions to any association of earthquake and storm are so far the rule; except in case of a volcanic eruption also occurring. In the latter case a storm invariably follows, so far as present observations go; but then the storm is not co-extensive with the earthquake, but is usually confined to the neighborhood of the volcano.

It should be noticed that certain scientists have endeavored to prove these convulsions are due to planetary influence. It does not appear that they have been able to find the least trace of any connection between the earth’s convulsions and the planets; but some affirm the existence of an earthquake cycle coincident with the Saros of the moon. Effort is also made to connect earthquakes and volcanoes with the gigantic convulsions of the sun, known as “sun spots.” It is argued by certain advocates of the molten interior that the attraction of the sun and moon produces an interior tidal wave, like that of the sea; and any irregularities in this produce the phenomena of earthquakes and volcanic eruptions. Objections to the molten interior have been already noted; and in regard to the other suggestions, so long as the great convulsions are peculiarly prevalent in certain regions, so long it will be necessary to seek their chief cause or most powerful modifiers in entirely local influences.