Over 20 years ago, Mt. St Helens--thought to be dormant--shocked America when it exploded. It is an acidic volcano--the magma beneath is full of volatiles making it highly explosive. Find out more in Season 2, Episode 10, "Mount Saint Helens." #HowtheEarthWasMade

Subscribe for more from How the Earth Was Made and other great HISTORY shows:
https://histv.co/SubscribeToHistory

Find out more about the show and watch full episodes on our site:
http://www.history.com/shows/

Check out exclusive HISTORY content:
History Newsletter: www.history.com/newsletter
Website - http://www.history.com
Facebook -   / history  
Twitter -   / history  

HISTORY® is the leading destination for award-winning original series and specials that connect viewers with history in an informative, immersive, and entertaining manner across all platforms. The network's all-original programming slate features a roster of hit series, premium documentaries, and scripted event programming.