An earthquake in a dream tends to shake something foundational -- a belief, relationship, or sense of security you assumed was solid ground. The dream rarely warns of literal disaster; it more often names a fear that something structural in your life is less stable than you've been letting yourself admit.
Three manner of wayes the Planets are varied or changed, by reason of their first qualities, of their Houses, and significations. - William Lilly (1602.-1681.)