2002 USGS National Seismic Hazard Maps

This page contains probabilistic seismic hazard maps for the Western United States. Six maps are presented for three different regions (Western US, California/Nevada, and the Pacific Northwest): peak ground acceleration (pga), 5-Hz spectral acceleration, and 1-Hz spectral acceleration (5% damping), each for 10%- and 2%-in-fifty-years probability of exceedance.

Explanation of April 2003 Revision

To view and print the postscript (ps) files from your browser, download, (free), the GSview utility. To view and print the PDF files from your browser, download, (free), the Adobe Acrobat Reader.

Hazard Maps
Spectral Acceleration (%g)	Probability of Exceedance in 50 Years
Western U.S. Region (Revised April 2003)	2%	10%
Peak Ground Acceleration	[GIF | PDF | PS]	[GIF | PDF | PS]
0.2 Second	[GIF | PDF | PS]	[GIF | PDF | PS]
1.0 Second	[GIF | PDF | PS]	[GIF | PDF | PS]
California/Nevada Region	2%	10%
Peak Ground Acceleration	[GIF | PDF | PS]	[GIF | PDF | PS]
0.2 Second	[GIF | PDF | PS]	[GIF | PDF | PS]
1.0 Second	[GIF | PDF | PS]	[GIF | PDF | PS]
Pacific Northwest Region	2%	10%
Peak Ground Acceleration	[GIF | PDF | PS]	[GIF | PDF | PS]
0.2 Second	[GIF | PDF | PS]	[GIF | PDF | PS]
1.0 Second	[GIF | PDF | PS]	[GIF | PDF | PS]

Although these maps have been used by the U.S. Geological Survey, no warranty, expressed or implied is made by the USGS as to the accuracy of the maps and related material nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith.