The ancient Greeks knew everything. Earthquakes, they maintained, were caused by the restless struggles of a mean and spiteful monster called Typhon, who was buried underneath the ground.
Typhon, it seems, had not always been thus confined. At one stage he had become ambitious, to the extent of challenging the sovereignty of the supreme god Zeus, and after a pitched battle between the two, Zeus emerged the victor by striking down his opponent with a thunderbolt. As punishment for his rebellion, Zeus had Typhon confined in an underground prison beneath Mount Etna; earthquakes and volcanoes were Typhon's periodic struggles to escape.
Aristotle, however, surmised earthquakes were caused by subterranean winds, a theory taken up by Hotspur in Shakespeare's Henry IV:
"Diseased Nature oftentimes breaks forth
In strange eruptions; oft the teeming earth
Is with a kind of colic pinchd and vex'd
By the imprisoning of unruly wind
Within her womb; which, for enlargement striving,
Shakes the old beldam earth, and topples down
Steeples and moss-grown towers."
In Norse mythology it is Loki, former god of strife, who is confined underground. He is chained to a rock with a snake above his head as punishment for all the troubles he has caused the other gods and goddesses. Every now and then a drop of venom falls from the serpent's fangs on Loki's head, and the resulting pain causes him to writhe in agony and create an earthquake.
In Japan the writhing organism is a catfish or namazu. The fish produces an earthquake by thrashing its body, but it is usually restrained by a local god who keeps a rock pressed down upon its head; sometimes, however, the attention of the deity may wander and the namazu gives a massive jerk. The people of Siberia, on the other hand, associate earthly tremors with the dogs of Tuil. They were believed to be infested with fleas and when their master took them for a walk they would occasionally stop to scratch - and, of course, the Earth would shake.
But in ancient India it was believed earthquakes were caused by the occasional stirrings of a giant mole which, for most of the time, slept quietly in its burrow deep below the surface of the Earth. Every so often, however, the giant mole would move - and it stirred in its sleep near the Rann of Kutch in Gujarat last Friday, with catastrophic consequences for thousands of defenceless human beings up above.