Mount St. Helens Map (IMAGE) Penn State Caption This is a simulation of the May 18, 1980 blast at Mount St. Helens (USA) at 380 seconds. Credit Istituto Nazionale di Geofisica e Vulcanologia, Italy. Usage Restrictions non commercial adverstising use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.