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.
If Mount St. Helens (Washington) were to have an eruption today the same size as that of May 18, 1980, this model simulation shows the ash cloud reach.
Public Domain.