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.
Thumbnail image for Image of the Week: Von Karman Vortices in the Atlantic by the USGS Earth Resources Observation and Science (EROS) Center.
Public Domain.
