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For designing buildings and other structures to safely resist earthquakes, the 2009 NEHRP Recommended Seismic Provisions and the 2010 ASCE/SEI 7 Standard contain maps of Maximum Considered Earthquake Geometric Mean (MCEG) peak ground accelerations.
These peak ground accelerations are each for the geometric mean of two horizontal components and a site average shear wave velocity within 30 m of the surface (VS30) of 760 m/s. For more information, see Chapters 11, 21, and 22 of the 2009 NEHRP Recommended Seismic Provisions and the 2010 ASCE/SEI 7 Standard.
Maps for the U.S. territories of Guam and American Samoa are not included because geometric mean peak ground motion parameters have not yet been developed for those islands. Therefore, the mapped maximum considered earthquake geometric mean peak ground accelerations shall be 0.6 for Guam and 0.4 for American Samoa and no maps or shapefiles are provided in this data release.
