This is the second one we have had this year. They are minor aftershocks from the epicentre in Iran, where the fault line really is.
All it did to some parts of the city was shut down the power for an hour or so. The last one was so minor that many people (myself included) didn't even notice it until the building was being evacuated!
When the crytal palaces start crumbling around our ears, then we should worry.
Knight