Based on the context and the answer, generate a question. 

Context: I experienced my first earthquake today . At first my chair was kind of wobbling and I thought one of the cats was trying to climb up the back of it . But I turned around and there was no cat and the shaking had stopped . So I turned back to my desk and the wobbling began again and I seriously wondered if I was having a seizure or something .

Answer:

They just moved to an earthquake prone area .



What may be the reason why they have n't experienced an earthquake ?