The earthquake data shown on this map and listed in table 1 are a list of earthquakes that were originally used in preparing the Seismic Risk Studies in the United States in the United States (Algermissen, 1969) which have been recompiled and updated through 1979. These data have been reexamined which resulted in some revisions of epicenters and intensities as well as assignment of intensities to earthquakes that previously had none assigned. Only earthquakes located within the boundary of the State are listed in table 1 even though earthquakes in bordering states or countries may be felt or cause damage in this state. Intensity values were updated from new and additional data sources that were not available at the time of original compilation. Some epicenters were relocated on the basis of new information. The data shown in table 1 are estimates of the most accurate epicenter, magnitude, and intensity of each earthquake, on the basis of historical and current information. Some of the aftershocks from large epicenters are listed but are incomplete in many instances, especially for ones that occurred before seismic instruments were in universal usage.