Fotograf:
Austin Post, USGS
Licens:
PD USGS
Källa
http://commons.wikimedia.org/wiki/File:MSH80%20eruption%20mount%20st%20helens%2005-18-80.jpg
Huge tif converted to jpeg and caption from USGS Mount St. Helens, Washington May 18, 1980 Eruption Images