EarthWorks Geospatial Catalog

Seismic Hazard Map for the United States

This polygon shapefile represents seismic hazards in the United States. The data represent a model showing the probability that ground motion will reach a certain level. This map layer shows peak horizontal ground acceleration (the fastest measured change in speed, for a particle at ground level that is moving horizontally due to an earthquake) with a 10% probability of exceedance in 50 years. Values are given in %g, where g is acceleration due to gravity, or 9.8 meters/second^2. The lines of equal hazard, which are the lines between the polygons, were determined by interpolating from a grid of equally spaced points in latitude and longitude. Each point was weighted based on the seismic hazard at that location. The grid spacing is 0.1 degrees for Alaska, 0.05 degrees for the conterminous United States, and 0.02 degrees for Hawaii. This layer is part of the 1997-2014 edition National Atlas of the United States.This map summarizes the quantitative information, available from geologic and geophysical sources, about seismic ground motion hazard in the United States. The data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:2,000,000-scale data. No responsibility is assumed by the U.S. Geological Survey or the National Atlas of the United States in the use of these data.
National Atlas of the United States
United States, Alaska, Alabama, Arizona, Arkansas, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York (State), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington (D.C.), Washington (State), West Virginia, Wisconsin, and Wyoming
Earthquake zones, Earthquake hazard analysis, Earthquakes, Geoscientific Information, and Economy
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