A cluster of earthquakes that began Tuesday night continued Wednesday in northern Orange County, keeping residents on edge but causing little significant damage. Photos emerged of bottles falling off a supermarket shelf in Anaheim Hills, but fire officials said they didn't get reports of anything more serious. At a news conference Wednesday morning, Kate Hutton of the U.S. Geological Survey at Caltech said there had been at least 30 quakes since last night, but only three could be felt by residents.