Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
ShakeMap of 1906 San Francisco Earthquake constructed using historical macroseismic data. Compare with one without Macroseismic data version.
Public Domain.
