Earthquake

The EASI Earthquake Index is based on a seismic measure called "effective peak acceleration." This measure relates to the specific site ground motions with an assumed 90 percent probability of ground motion not being exceeded in 50 years. This seismic measure is the degree of protection provided for in public and occupant buildings against the potential of earthquakes.

The factors which are related to federal building requirements are not the likelihood of an earthquake but a measure of how building requirements are changed according to possible structural damage that could be caused by an earthquake. The factors from low to high are 0; .05; .10; .15; .20; .25; .30; .and .40. These factors are based on a county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. designation.