On what date did the 1980 eruption of Mount St. Helens, in which "Crater Glacier" was formed, occur?
1980 eruption of Mount St. Helens On May 18, 1980, a major volcanic eruption occurred at Mount St. Helens, a volcano located in Skamania County, in the state of Washington, United States. The eruption (a VEI 5 event) was the only significant volcanic eruption to occur in the contiguous 48 U.S. states since the 1915 eruption of Lassen Peak in California. However, it has often been declared as the most disastrous volcanic eruption in United States history. The eruption was preceded by a two-month series of earthquakes and steam-venting episodes, caused by an injection of magma at shallow depth below the volcano that created a large bulge and a fracture system on the mountain's north slope.
Symphony No. 50 (Hovhaness) Symphony No. 50, Op. 360, Mount St. Helens is a three-movement orchestral composition by the American composer Alan Hovhaness. The symphony was commissioned by former Hovhaness publisher C.F. Peters and was completed January 24, 1982. It premiered March 2, 1984, and was performed by the San Jose Symphony under conductor George Cleve. The piece commemorates the volcano Mount St. Helens, culminating in the events of its 1980 eruption, which Hovhaness had witnessed from his Seattle home.