Global Volcanism Program | Image GVP-02835
East Dome, the small lava dome at the center, is seen in this 1978 aerial photograph. An explosive eruption preceded emplacement of the dome on the lower E flank of Mount St. Helens about 1,800 years ago. Both the tephra deposit and the lava dome are of a hypersthene dacite composition unique to Mount St. Helens products. This eruption was part of the Sugar Bowl Eruptive Period.
Photo by Rick Hoblitt, 1978 (U.S. Geological Survey).