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.
Mount Callaghan Mount Callaghan is a volcanic peak located east of the headwaters of the Squamish River, just northeast of the Powder Mountain Icefield and just south of the Pemberton Icefield in the Sea to Sky Country of southwestern British Columbia, Canada, about 20 km directly west of the Resort Municipality of Whistler. A crack was observed across Callaghan's summit in the spring of 1999. In 2000, a section of the summit collapsed. Callaghan Lake lies below the south face of the mountain.