The term temblor is applied to any trepidation or shaking of the ground. Many earthquakes argon so depressed as to pass almost unrecognised, others are sufficiently enounce to excite general alarm, while some spread awful destruction. Destructive earth-quakes are mutually confined to limited regions.
The usual phe-nomena recorded in well-known earthquakes are first a frisson, next one or more severe shocks, and thus a trembling which gradually dies away. In most cases, for each one shock lasts only a few seconds, but the trembling that follow may continue for days, weeks, or even months.
Noises of various(a) kinds usually accom-pany an earthquake. They pass water been likened to the howling of storm, the growling of thunder, the clanking and impinge on of iron chains, or the rumbling of heavy wagons along a road.
Such noises are conducted through the ground, or they may choke through the sea or air, and are often comprehend at great distances from the place where the shock is felt.
Some earthquakes, how-ever, are not go with by these noises. At the time of the austere shock which destroyed Riobamba in Ecuador on February 4, 1797, a pad silence reigned.
Many changes are produced on the earths surface by earth-quakes.
They cause landslips and cracks in the earth, which will sometimes alter the drainage system of a country. They are fre-quently accompanied by great sea waves, which will often haul rocks and sand great distances inland.
Permanent elevations and depressions of land are sometimes caused. After the great earth-quakes of 1750, the coast of Chili was found to have been durablely raised from three to four feet.
Well-known examples of permanent depressions are those of the Run of Kutch and the coastlands near Chittagong, which suddenly sank during the Bengal earthquake of 1762.
Earthquakes are most common in volcanic and hilly regions, and many of them are no doubt due to volcanic action. These appear to originate in the...If you want to get a full essay, order it on our website: Orderessay
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