Areas Damaged by Historic Earthquakes (1800-1998)
The shaded areas indicate regions that have experienced at least Modified Mercalli Intensity VII in historic earthquakes. Modified Mercalli Intensity VII is defined as slight to moderate damage in older (masonry) structures, damage considerable in poorly built or badly designed structures. Click on the image to obtain a more detailed version of the map.
Example of MMI VII damage. This level of damage includes fall of brick facing, as observed in the 1987 Whittier Narrows earthquake. Photo by C. Wills, CGS.