Eight causes of earthquakes:
1. This great earth, is established upon liquid, the liquid upon the atmosphere, and the atmosphere upon space. And when, mighty atmospheric disturbances take place, the liquid is agitated. And with the agitation of the liquid, tremors of the earth arise.
2. When an ascetic or holy man of great power, one who has gained mastery of his mind, or a deity who is mighty and potent, develops intense concentration on the delimited aspect of the earth element, and to a boundless degree on the liquid element, he, too, causes the earth to tremble, quiver, and shake.
3. When the Bodhisatta (Buddha-to-be) departs from the Tusita realm and descends into his mother’s womb, mindfully and clearly comprehending.
4. When the Bodhisatta comes out from his mother’s womb, mindfully and clearly comprehending.
5. When the Tathagata becomes fully enlightened in unsurpassed, supreme Enlightenment.
6. When the Tathagata sets rolling the excellent Wheel of the Dhamma.
7. When the Tathagata renounces his will to live on.
(from Digha Nikaya 16)