There, soil had been pumped in to fill the bay, but had not been compacted. Naturally, that soil was shaken loose more easily, he said. So, residents should know where they stand in relation to the mapping, but should not be alarmed about potential damage, or declining property values as a result of the study, Tolles said. That report studied areas from Irvine to Los Angeles, and found that softer soil content and flatter land would lead to more damage. That research began after the Northridge quake, which killed 57 people and caused millions in damage.
Maps are also available on the department's Web site.