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.
Exposure of the San Andreas Fault in a trench. The horizontal colored lines highlight different layers of sediment. The red line is traced on a fault that offsets the layers. (Kate Scharer, USGS)
Public Domain.
