The severity of the earthquake will determine the amount of damage done to a panel. There is a chance that minor earthquakes will not do any damage, much as your home does not always sustain damage. Earthquakes will pose a risk for micro-fractures within the cells if it is a significant earthquake that may cause a loss in production. If the earthquake is severe enough to damage your home substantially, then the chances are that your panels will also be severely damaged. It is recommended to add your solar system to your current homeowners insurance policy or your earthquake insurance policy if this is a concern to you.