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.
USGS scientist Peter Kelly collects a gas sample from Mount St. Helens. The sample for helium isotopes is collected in a copper tube that is clamped in a tray and then taken to the laboratory for analysis.
Public Domain.
