West Crater is a small lava dome , made up of andesitic lava with two large lava flows . It is not highly prominent . The volcanic edifice has a ridge of Tertiary volcanic and intrusive rock , which lies on the southern edge of West Crater . West Crater 's dome reaches an elevation of , with a diameter of . It has a summit crater with a width of and a depth of . The dome still possesses a lobe of lava at the bottom of this summit crater . West Crater 's lava dome formed on the floor of a glacial cirque , and has a similar size to the lava dome formed after the 1980 eruption of Mount St. Helens
1980 eruption of Mount St. Helens
1980 eruption of Mount St. Helens
West Crater