The area disturbed by an earthquake is generally proportionate to the intensity of the shock. The great earthquake of Lisbon disturbed an area four times as great as the whole of Europe. In the form of tremors and pulsations, Mr. Milne remarks, it may have shaken the whole globe.
In a violent submarine earthquake the ordinary earth-wave and sound-wave are accompanied by sea-waves. These waves may be twenty, sixty or even eighty feet higher than the highest tide, and are usually more dreaded than the earthquake shock itself in such regions as the maritime districts of South America. The greatest sea-wave on record is that which in 1737, is said to have broken near Cape Lopatka, at the south end of Kamchatka, two hundred and ten feet in height.
NOTABLY DESTRUCTIVE EARTHQUAKES
79. One accompanied by the eruption of Vesuvius; the cities of Pompeii and Herculaneum buried.
742. Awful one in Syria, Palestine, and Asia; more than 500 towns were destroyed and the loss of life surpassed all calculations.
936. Constantinople overturned; all Greece shaken.
1137. Catania, in Sicily, overturned, and 15,000 persons buried in the ruins.
1186. At Calabria; one of its cities and all its inhabitants overwhelmed in the Adriatic Sea.
1456. At Naples, 40,000 persons perished.
1537. At Lisbon; 1,500 houses and 30,000 persons buried in the ruins; several neighboring towns ingulfed with their inhabitants.