The ash in this capsule was violently ejected from Mount St. Helens during the most disastrous volcanic activity in US history. On the morning of May 18 1980, after weeks of small tremors, a magnitude 5.1 earthquake shook the state of Washington. The quake caused the largest landslide ever recorded according to the USGS, and simultaneously, a lateral explosion from the side of the mountain. The explosion was rated a 5 on the Volcanic Explosivity Index making it one of the largest eruptions in the 20th century. The sound of the eruption was heard up to 700 miles away. Some areas were covered in debris, avalanches, and mudflows, and forests were scorched and scoured with hot gases.